JP2018063234A - Display device with touch detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device with a touch detection function capable of suppressing deterioration in detection accuracy of a force applied to an input surface of a touch panel.SOLUTION: A display device 1 with a touch detection function includes: an input surface to which a force is applied by an object to be detected; a touch detection electrode that is provided on a first substrate 31 and faces the input surface; a drive electrode (first electrode) that is provided on a second substrate 21 and faces the touch detection electrode; an electrode (second electrode) facing the first electrode with a dielectric layer sandwiched between them; a touch detection control part 40 for detecting contact or proximity of the object to be detected to the input surface on the basis of an electrostatic capacity between the drive electrode and the touch detection electrode; and a force detection control part 50 for detecting a force applied to the input surface by the object to be detected on the basis of an electrostatic capacity between the drive electrode and the second electrode. The force detection control part 50 corrects a force detection value on the basis of a reference capacity value at a reference temperature between the drive electrode and the second electrode when the object to be detected is not in contact with the input surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device with a touch detection function capable of detecting a pressing force at the time of touching, that is, a force (force).

  In recent years, a so-called touch panel called a touch detection device capable of detecting an external proximity object has attracted attention. The touch panel is mounted on a display device such as a liquid crystal display device or integrated with the display device and used as a display device with a touch detection function. The display device with a touch detection function displays various button images and the like on the display device, thereby enabling information input using the touch panel as a substitute for a normal mechanical button.

  In addition to touch detection, force detection devices that can detect force are also being used.

  As a related technique, Patent Document 1 described below describes an electrostatic touch panel control device that prevents erroneous determination of touch presence / absence due to a temperature difference between a touch panel and an external proximity object.

JP, 2006-058047, A

  There is a force detection device that detects a force based on a change in capacitance between a first conductor provided on the input surface side of the touch panel and a second conductor provided on the back surface side of the touch panel. When a force is applied to the input surface of the detection device, the touch panel is bent, the thickness of the air layer between the first conductor and the second conductor is reduced, and the space between the first conductor and the second conductor is reduced. , And the capacitance between the first conductor and the second conductor increases. The force detection device outputs a force signal value based on the change in capacitance.

  By the way, when the above-described force detection device is applied to a display device with a touch detection function, in addition to an air layer, for example, a film or light constituting a backlight is provided between the first conductor and the second conductor. There may be a laminate in which a diffusion sheet, a light guide, and the like are laminated. Generally, the laminate constituting the backlight is made of an acrylic resin. Such an acrylic resin expands or contracts due to a change in temperature, and the dielectric constant changes accordingly, so that the capacitance between the first conductor and the second conductor changes, and the touch panel The detection accuracy of the force applied to the input surface may be reduced.

  An object of this invention is to provide the display apparatus with a touch detection function which can suppress the fall of the detection accuracy of the force applied to the input surface of a touch panel.

  The display device with a touch detection function of one embodiment of the present invention includes an input surface to which a force is applied by an object to be detected, a touch detection electrode provided on the first substrate and facing the input surface, and a second substrate. A first electrode facing the touch detection electrode, a second electrode facing the first electrode across a dielectric layer, and a capacitance between the first electrode and the touch detection electrode Based on the touch detection control unit that detects contact or proximity of the detection object to the input surface, and based on the capacitance between the first electrode and the second electrode, the detection object A force detection control unit that detects a force applied to the input surface, wherein the force detection control unit includes the first electrode and the second electrode when the detected object is not in contact with the input surface. The force detection value is corrected based on the reference capacity value at the reference temperature during .

  The display device with a touch detection function of one embodiment of the present invention includes an input surface to which a force is applied by an object to be detected, a first electrode and a second electrode arranged to face each other with a dielectric layer interposed therebetween, The input by the detected object based on a touch detection control unit that detects contact or proximity of the detected object to the input surface and a capacitance generated between the first electrode and the second electrode. A force detection control unit that detects a force applied to the surface, wherein the force detection control unit is a reference capacitance value at a reference temperature of the capacitance when the detected object is not in contact with the input surface. And the force detection value is corrected based on the ratio of the detected object to the capacitance when not in contact with the input surface.

FIG. 1 is a block diagram illustrating a configuration of a display device with a touch detection function according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example of the touch detection unit and the display unit of the display device with a touch detection function according to the first embodiment. FIG. 3 is an explanatory diagram illustrating a state in which an object to be detected is in contact with or in proximity to each other for explaining the basic principle of mutual capacitance type touch detection. FIG. 4 is an explanatory diagram illustrating an example of an equivalent circuit for mutual capacitance type touch detection. FIG. 5 is a diagram illustrating an example of a drive signal and a detection signal waveform for mutual capacitance type touch detection. FIG. 6 is an explanatory diagram showing a state in which an object to be detected is not in contact with or in proximity to the basic principle of self-capacitance type touch detection. FIG. 7 is an explanatory diagram illustrating a state in which an object to be detected is in contact with or in proximity to the basic principle of the self-capacitance type touch detection. FIG. 8 is an explanatory diagram showing an example of an equivalent circuit for self-capacitance type touch detection. FIG. 9 is a diagram illustrating an example of a drive signal and a detection signal waveform of the self-capacitance type touch detection. FIG. 10 is a diagram illustrating an example of a module on which the display device with a touch detection function according to the first embodiment is mounted. FIG. 11 is a cross-sectional view illustrating a schematic cross-sectional structure of the display unit with a touch detection function. FIG. 12 is a circuit diagram illustrating a pixel arrangement of the display unit with a touch detection function. FIG. 13 is a perspective view illustrating a configuration example of drive electrodes and touch detection electrodes of a display unit with a touch detection function. FIG. 14 is an exploded perspective view illustrating a configuration example of the display device with a touch detection function according to the first embodiment. FIG. 15 is an exploded perspective view showing the backlight unit. FIG. 16 is a cross-sectional view illustrating a configuration example of the display device with a touch detection function according to the first embodiment. FIG. 17 is a perspective view illustrating electrodes of the display device with a touch detection function according to the first embodiment. FIG. 18 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the first embodiment. FIG. 19 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the first embodiment. FIG. 20 is a diagram illustrating an example of the temperature characteristic of the capacitance between the drive electrode and the electrode in a state where no force is applied to the input surface. FIG. 21 is a diagram illustrating the relationship between the force applied to the input surface and the force detection value when the temperatures are different. FIG. 22 is a diagram illustrating an error in the force detection value due to temperature when the force applied to the input surface is constant. FIG. 23 is a diagram illustrating the relationship between the capacitance between the drive electrode and the electrode according to a temperature change and the force detection value. FIG. 24 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the first embodiment. FIG. 25 is a diagram illustrating the relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the first embodiment. FIG. 26 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the first embodiment. FIG. 27 is a timing diagram illustrating an example of operation timing of the display device with a touch detection function according to the first embodiment. FIG. 28 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the first embodiment. FIG. 29 is a perspective view illustrating electrodes of the display device with a touch detection function according to the first modification of the first embodiment. 30 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the second modification of the first embodiment. FIG. 31 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the second modification of the first embodiment. FIG. 32 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the third modification of the first embodiment. FIG. 33 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the third modification of the first embodiment. FIG. 34 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the fourth modification of the first embodiment. FIG. 35 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fourth modification of the first embodiment. FIG. 36 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the fifth modification of the first embodiment. FIG. 37 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fifth modification of the first embodiment. FIG. 38 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the sixth modification of the first embodiment. FIG. 39 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the sixth modification of the first embodiment. FIG. 40 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of the display device with a touch detection function according to the second embodiment. FIG. 41 is a diagram illustrating an arrangement example 1 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 42 is a diagram illustrating an arrangement example 2 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 43 is a diagram illustrating an arrangement example 3 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 44 is a diagram illustrating an arrangement example 4 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 45 is a diagram illustrating an arrangement example 5 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 46 is a diagram illustrating an example of the relationship between the correction coefficient and the temperature of the display device with a touch detection function according to the second embodiment. FIG. 47 is a diagram illustrating an example of a first correction coefficient table of the display device with a touch detection function according to the second embodiment. FIG. 48 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the second embodiment. FIG. 49 is a diagram illustrating a relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the second embodiment. FIG. 50 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the second embodiment. FIG. 51 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the second embodiment. FIG. 52 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of the display device with a touch detection function according to the third embodiment. FIG. 53 is a plan view of the display device with a touch detection function according to the third embodiment. FIG. 54 is a graph showing the relationship between the touch detection position in the Y-axis direction and the force detection value at the center position in the X-axis direction of the region where the force is applied on the input surface of the display device with a touch detection function according to the third embodiment. It is. FIG. 55 is a graph showing the relationship between the touch detection position in the Y-axis direction and the correction coefficient at the center position in the X-axis direction of the region where the force is applied on the input surface of the display device with a touch detection function according to the third embodiment. is there. FIG. 56 is a diagram illustrating an example of division of the force detection region on the input surface of the display device with a touch detection function according to the third embodiment. FIG. 57 is a diagram illustrating an example of a second correction coefficient table of the display device with a touch detection function according to the third embodiment. FIG. 58 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the third embodiment. FIG. 59 is a diagram illustrating a relationship between a force applied to the input surface and a force detection correction value in the display device with a touch detection function according to the third embodiment. FIG. 60 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the third embodiment. FIG. 61 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the third embodiment. FIG. 62 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of a display device with a touch detection function according to a modification of the third embodiment. FIG. 63 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the modification of the third embodiment. FIG. 64 is a diagram illustrating the relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the modification of the third embodiment. FIG. 65 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to a modification of the third embodiment. FIG. 66 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the modification of the third embodiment. FIG. 67 is a diagram illustrating an example of a module in which the display device with a touch detection function according to the fourth embodiment is mounted. FIG. 68 is a perspective view illustrating electrodes of the display device with a touch detection function according to the fourth embodiment. FIG. 69 is a cross-sectional view and an equivalent circuit diagram of a display device with a touch detection function according to the fourth embodiment. FIG. 70 is a cross-sectional view and an equivalent circuit diagram when an object to be detected is in contact with or close to the input surface of the display device with a touch detection function according to the fourth embodiment. FIG. 71 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fourth embodiment. FIG. 72 is a graph showing the capacitance value C in the Y-axis direction in a state where the detection object is not in contact with or close to the input surface. FIG. 73 is a graph showing a capacitance value C in the Y-axis direction in a state where an object to be detected is in contact with or close to the input surface. FIG. 74 is a graph showing the capacitance value C in the Y-axis direction when a force is applied to the input surface. FIG. 75 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the fourth embodiment. FIG. 76 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the fourth embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

(Embodiment 1)
FIG. 1 is a block diagram illustrating a configuration of a display device with a touch detection function according to the first embodiment.

  The display device with a touch detection function 1 according to the present embodiment includes a touch detection unit SE1, a display unit DP, a force detection unit SE2, and a control unit CTRL. In the present embodiment, the force detection unit SE2 and the control unit CTRL in the display device with a touch detection function 1 correspond to a “force detection device”.

  The touch detection unit SE1 detects contact or proximity of the object OBJ to the input surface IS of the cover member CG. Specifically, the touch detection unit SE1 outputs to the control unit CTRL a signal value corresponding to the contact or proximity of the area where the object OBJ overlaps in the direction perpendicular to the input surface IS.

  The detected object OBJ may be a first type of object that deforms in contact with the input surface IS, or does not deform even if it contacts the input surface IS, or is relative to the first type of object. It may be a second type of object with little deformation. The first type is exemplified by a finger, but is not limited thereto. Examples of the second type include, but are not limited to, resin or metal stylus pens.

  The number of detected objects OBJ that can be detected by the touch detection unit SE1 is not limited to one. The touch detection unit SE1 may be capable of detecting two or more detected objects OBJ.

  The touch detection unit SE1 is exemplified by a capacitive sensor or a resistive film sensor, but is not limited thereto. Examples of the capacitance method include a mutual capacitance method and a self-capacitance method.

  The display unit DP displays an image toward the input surface IS side. As for display part DP, although a liquid crystal display device or an organic electroluminescence (Electro-Luminescence) display device is illustrated, it is not limited to these.

  The touch detection unit SE1 and the display unit DP may be an integrated so-called in-cell type or hybrid type. The touch detection unit SE1 and the display unit DP may be a so-called on-cell type in which the touch detection unit SE1 is mounted on the display unit DP.

  The force detection unit SE2 detects the force applied by the detected object OBJ to the input surface IS. Specifically, the force detection unit SE2 outputs a signal corresponding to the force applied by the detected object OBJ to the input surface IS to the control unit CTRL.

  The force detection unit SE2 is exemplified by a capacitance type sensor.

  The control unit CTRL calculates a force signal value representing a force based on the signal output from the force detection unit SE2.

  The control unit CTRL includes a display control unit 11, a detection control unit 200, and a host HST. The detection control unit 200 includes a touch detection control unit 40 and a force detection control unit 50.

  The display control unit 11 is exemplified by an IC chip mounted on the glass substrate of the display unit DP. The detection control unit 200 is exemplified by an IC chip mounted on a printed circuit board (for example, a flexible printed circuit board) connected to the glass substrate of the display unit DP. The host HST is exemplified by a CPU (Central Processing Unit). The display control unit 11, the detection control unit 200, and the host HST cooperate to control the touch detection unit SE1, the display unit DP, and the force detection unit SE2.

  The process for calculating the force signal value executed by the control unit CTRL may be executed by the display control unit 11, the detection control unit 200, or the host HST. . Two or more of the display control unit 11, the detection control unit 200, and the host HST may be executed in cooperation.

  Hereinafter, specific configuration examples of the touch detection unit SE1, the display unit DP, and the force detection unit SE2 will be described. However, these configuration examples are examples, and are not limited to these configuration examples.

<Configuration example of touch detection unit and display unit>
FIG. 2 is a block diagram illustrating a configuration example of the touch detection unit and the display unit of the display device with a touch detection function according to the first embodiment. The display device 1 with a touch detection function shown in FIG. 2 is a device that detects the coordinates and contact area of the detection object OBJ by a so-called mutual capacitance method and self-capacitance method. The display device 1 with a touch detection function shown in FIG. 2 is a device that detects a force applied to the input surface IS when the detected object OBJ comes into contact with the input surface IS by a so-called mutual capacitance method. is there.

  The display device 1 with a touch detection function includes a display unit 10 with a touch detection function, a display control unit 11, a gate driver 12, a source driver 13, a source selector unit 13S, a drive electrode driver 14, and a force detection device 100. And a detection control unit 200.

  The display unit 10 with a touch detection function is a so-called in-cell type or hybrid type device in which a capacitive touch detection device 30 is integrated in a liquid crystal display device 20 using a liquid crystal display element as a display element. is there. The integration of the capacitive touch detection device 30 into the liquid crystal display device 20 means that, for example, some members such as a substrate and electrodes used as the liquid crystal display device 20 and the touch detection device 30 are integrated. And also serving as a part of a member such as a substrate or an electrode.

  The liquid crystal display device 20 corresponds to the display unit DP of FIG. The touch detection device 30 corresponds to the touch detection unit SE1 in FIG. The force detection device 100 corresponds to the force detection unit SE2 of FIG.

  The display unit with a touch detection function 10 is a so-called on-cell type device in which a capacitive touch detection device 30 is mounted above a liquid crystal display device 20 using a liquid crystal display element as a display element. May be. In the case of an on-cell type device, the touch detection device 30 may be provided immediately above the liquid crystal display device 20, or the touch detection device 30 is provided above another layer rather than directly above the liquid crystal display device 20. It may be done.

  As will be described later, the liquid crystal display device 20 is a device that performs scanning by sequentially scanning one horizontal line at a time in accordance with a scanning signal Vscan supplied from the gate driver 12.

  The display control unit 11 supplies control signals to the gate driver 12, the source driver 13, the drive electrode driver 14, and the detection control unit 200 based on the video signal Vdisp supplied from the host HST. It is a circuit that controls to operate in synchronization. Further, the display control unit 11 generates a pixel signal Vsig obtained by time-division multiplexing the pixel signals Vpix of the plurality of subpixels SPix of the liquid crystal display device 20 from the video signal Vdisp for one horizontal line, and supplies the pixel signal Vsig to the source driver 13. To do.

  The control unit CTRL includes a display control unit 11, a gate driver 12, a source driver 13, and a drive electrode driver 14. In the present embodiment, the display control unit 11 and the drive electrode driver 14 correspond to a “drive unit”, but the drive electrode driver 14 may correspond to a drive unit.

  The gate driver 12 has a function of sequentially selecting one horizontal line as a display driving target of the display unit 10 with a touch detection function based on a control signal supplied from the display control unit 11.

  The source driver 13 is a circuit that supplies a pixel signal Vpix to each pixel Pix (subpixel SPix) of the display unit 10 with a touch detection function based on a control signal supplied from the display control unit 11. For example, 6-bit R (red), G (green), and B (blue) image signals Vsig are supplied to the source driver 13.

  The source driver 13 receives the image signal Vsig from the display control unit 11 and supplies it to the source selector unit 13S. Further, the source driver 13 generates a switch control signal Vsel necessary for separating the pixel signal Vpix multiplexed on the image signal Vsig, and supplies the switch control signal Vsel to the source selector unit 13S together with the pixel signal Vpix. The source selector unit 13S can reduce the number of wires between the source driver 13 and the display control unit 11. The source selector unit 13S may not be provided. Further, the display control unit 11 may perform part of the control of the source driver 13, or only the source selector unit 13S may be arranged.

  Based on the control signal supplied from the display control unit 11, the drive electrode driver 14 applies a drive signal Vcom (a drive for mutual electrostatic capacitance type touch detection) to a drive electrode COML described later of the display unit 10 with a touch detection function. This is a circuit for supplying a signal (touch detection drive signal, hereinafter referred to as drive signal) Vcomtm, a self-capacitance touch detection drive signal Vcomts2, and a display drive voltage VcomDC which is a display voltage.

  The detection control unit 200 includes a drive driver 47 for supplying a drive signal Vcomts1 to a touch detection electrode TDL, which will be described later, when the touch detection control unit 40 performs a touch detection operation by a self-capacitance method.

  The touch detection device 30 operates based on the basic principle of mutual capacitive touch detection, and the touch detection electrode TDL outputs a detection signal Vdet1. The touch detection device 30 operates based on the basic principle of self-capacitance type touch detection, and the touch detection electrode TDL outputs a detection signal Vdet2. The touch detection device 30 operates based on the basic principle of self-capacitance type touch detection, and the drive electrode COML outputs a detection signal Vdet3.

  The touch detection device 30 can perform touch detection only by the mutual capacitance method. However, in order to suitably suppress the influence of water droplets and the like attached to the input surface IS and to detect stylus pens and the like, in the present configuration example, the touch detection device 30 is configured to detect mutual capacitance type touch detection and self Perform both capacitive touch detection. However, the present invention is not limited to the case where both the mutual capacitive touch detection and the self-capacitive touch detection are performed.

  The force detection device 100 operates based on the basic principle of mutual capacitance type force detection, and an electrode SUS described later outputs a detection signal Vdet4.

  With reference to FIG. 3 to FIG. 5, the basic principle of mutual capacitance type touch detection of the display device with a touch detection function 1 of this configuration example will be described.

  FIG. 3 is an explanatory diagram illustrating a state in which an object to be detected is in contact with or in proximity to each other for explaining the basic principle of mutual capacitance type touch detection. FIG. 4 is an explanatory diagram illustrating an example of an equivalent circuit for mutual capacitance type touch detection. FIG. 5 is a diagram illustrating an example of a drive signal and a detection signal waveform for mutual capacitance type touch detection. FIG. 4 also shows the detection circuit.

  For example, as illustrated in FIG. 3, the capacitive element C11 includes a drive electrode E1 and a touch detection electrode E2 that are a pair of electrodes disposed to face each other with the dielectric D interposed therebetween. As shown in FIG. 4, one end of the capacitive element C11 is connected to an AC signal source (drive signal source) S, and the other end is connected to a voltage detector (touch detection unit) DET. The voltage detector DET is an integration circuit included in the first detection signal amplifier 41 shown in FIG. 2, for example.

  When an AC rectangular wave Sg having a predetermined frequency (for example, about several kHz to several hundred kHz) is applied from the AC signal source S to the drive electrode E1 (one end of the capacitive element C11), the touch detection electrode E2 (the other end of the capacitive element C11) An output waveform (detection signal Vdet1) appears via the voltage detector DET connected to the side. The AC rectangular wave Sg corresponds to a drive signal Vcomtm described later.

In the state in which the detected object OBJ is not in contact (or proximity) (non-contact state), with the charging and discharging of the capacitive element C11, a current flows I ₀ corresponding to the capacitance value of the capacitor C11. As shown in FIG. 5, the voltage detector DET converts the fluctuation of the current I ₀ according to the AC rectangular wave Sg into the fluctuation of the voltage (solid line waveform V ₀ ).

On the other hand, when the object OBJ is in contact (or in proximity) (contact state), as shown in FIG. 3, the capacitance C12 formed by the finger is in contact with or in the vicinity of the touch detection electrode E2. As a result, the electrostatic capacity corresponding to the fringe between the drive electrode E1 and the touch detection electrode E2 is blocked, and acts as a capacitive element C11 ′ having a capacitance value smaller than the capacitance value of the capacitive element C11. When seen in the equivalent circuit shown in FIG. 4, the current I ₁ flows in the capacitor C11 '.

As shown in FIG. 5, the voltage detector DET converts the fluctuation of the current I ₁ according to the AC rectangular wave Sg into the fluctuation of the voltage (dotted line waveform V ₁ ). In this case, the waveform V ₁ has a smaller amplitude than the waveform V ₀ described above. As a result, the absolute value | ΔV | of the voltage difference between the waveform V ₀ and the waveform V ₁ changes according to the influence of the detected object OBJ. Since the voltage detector DET accurately detects the absolute value | ΔV | of the voltage difference between the waveform V ₀ and the waveform V ₁ , the voltage of the capacitor is adjusted according to the frequency of the AC rectangular wave Sg by switching in the circuit. More preferably, the operation is provided with a period Res for resetting charging and discharging.

  Referring to FIG. 2 again, the touch detection device 30 sequentially scans each drive electrode COML according to the drive signal Vcomtm supplied from the drive electrode driver 14 and outputs the detection signal Vdet1.

  Next, with reference to FIGS. 6 to 9, the basic principle of the self-capacitance type touch detection of the display device with a touch detection function 1 of this configuration example will be described.

  FIG. 6 is an explanatory diagram showing a state in which an object to be detected is not in contact with or in proximity to the basic principle of self-capacitance type touch detection. FIG. 7 is an explanatory diagram illustrating a state in which an object to be detected is in contact with or in proximity to the basic principle of the self-capacitance type touch detection. FIG. 8 is an explanatory diagram showing an example of an equivalent circuit for self-capacitance type touch detection. FIG. 9 is a diagram illustrating an example of a drive signal and a detection signal waveform of the self-capacitance type touch detection.

  6 shows a state in which the power source Vdd and the detection electrode E1 are connected by the switch SW11 and the detection electrode E1 is not connected to the capacitor Ccr by the switch SW12 in a state where the object to be detected OBJ is not in contact with or close to the object. Show. In this state, the capacitor Cx1 included in the detection electrode E1 is charged. The right side of FIG. 6 shows a state in which the connection between the power source Vdd and the detection electrode E1 is turned off by the switch SW11, and the detection electrode E1 and the capacitor Ccr are connected by the switch SW12. In this state, the charge of the capacitor Cx1 is discharged through the capacitor Ccr.

  The left diagram in FIG. 7 shows a state in which the power source Vdd and the detection electrode E1 are connected by the switch SW11 and the detection electrode E1 is not connected to the capacitor Ccr by the switch SW12 in a state where the object to be detected OBJ is in contact with or close to the object. Yes. In this state, in addition to the capacitance Cx1 that the detection electrode E1 has, the capacitance Cx2 that is generated by the object OBJ that is close to the detection electrode E1 is also charged. The right diagram in FIG. 7 shows a state in which the power source Vdd and the detection electrode E1 are turned off by the switch SW11, and the detection electrode E1 and the capacitor Ccr are connected by the switch SW12. In this state, the charge in the capacitor Cx1 and the charge in the capacitor Cx2 are discharged through the capacitor Ccr.

  Here, with respect to the voltage change characteristic of the capacitor Ccr at the time of discharging shown in the right diagram of FIG. 6 (in a state where the object to be detected OBJ is not in contact with or close to the object), at the time of discharging shown in the right diagram of FIG. The voltage change characteristics of the capacitor Ccr in the state of contact or proximity are clearly different due to the presence of the capacitance Cx2. Therefore, in the self-capacitance method, the presence or absence of contact or proximity of the detection object OBJ is determined using the fact that the voltage change characteristic of the capacitor Ccr varies depending on the presence or absence of the capacitance Cx2.

Specifically, an AC rectangular wave Sg (see FIG. 9) having a predetermined frequency (for example, about several kHz to several hundred kHz) is applied to the detection electrode E1. The voltage detector DET shown in FIG. 8 converts a current fluctuation according to the AC rectangular wave Sg into a voltage fluctuation (waveforms V ₃ and V ₄ ). The voltage detector DET is an integration circuit included in the first detection signal amplifier 41 shown in FIG. 2, for example.

As described above, the detection electrode E1 can be separated by the switch SW11 and the switch SW12. 9, at time _{T 01,} the AC rectangular wave Sg rises to a voltage level corresponding to the voltage _{V 0.} At this time, the switch SW11 is on and the switch SW12 is off. Therefore, the voltage of the detection electrodes E1 also rises to the voltage _{V 0.}

Then prior to the timing of time _{T 11,} and turns off the switch SW11. At this time, although the detection electrode E1 is in a floating state, the capacitance Cx1 (see FIG. 6) of the detection electrode E1 or the capacitance (Cx1 + Cx2) of the capacitance Cx1 of the detection electrode E1 plus the capacitance Cx2 due to contact or proximity of the object OBJ. , by reference to FIG. 7), the potential of the detection electrodes E1 are _{V 0} is maintained. Further, to turn on the switch SW13 in front of the timing of time T _11, is turned off after a predetermined time period, to reset the voltage detector DET. By this reset operation, the output voltage (detection signal) Vdet of the voltage detector DET becomes substantially equal to the reference voltage Vref.

Subsequently, when turning on the switch SW12 at time _{T 11,} the inverting input of the voltage detector DET is voltage _{V 0} which detection electrodes E1. Thereafter, according to the time constant of the capacitance Cx1 (or Cx1 + Cx2) of the detection electrode E1 and the capacitance C5 in the voltage detector DET, the inverting input portion of the voltage detector DET is lowered to the reference voltage Vref. At this time, since the electric charge accumulated in the capacitance Cx1 (or Cx1 + Cx2) of the detection electrode E1 moves to the capacitance C5 in the voltage detector DET, the output voltages (detection signals) Vdet2 and Vdet3 of the voltage detector DET rise. .

Output voltage Vdet2 of the voltage detector DET, when the detected object OBJ to the detection electrodes E1 are not in close proximity, next waveform _{V 3} shown by a solid line, and Vdet2 = Cx1 × V0 / C5. Similarly, the output voltage Vdet3 of the voltage detector DET, when the detected object OBJ to the detection electrodes E1 are not in close proximity, next waveform _{V 3} shown by a solid line, the Vdet3 = Cx1 × V0 / C5.

Output voltage Vdet2 of the voltage detector DET, when the capacity due to the influence of the detected object OBJ is added, becomes a waveform _{V 4} shown by a dotted line, the Vdet2 = (Cx1 + Cx2) × V0 / C5. Similarly, the output voltage Vdet3 of the voltage detector DET, when the capacity due to the influence of the detected object OBJ is added, becomes a waveform _{V 4} shown by a dotted line, the Vdet3 = (Cx1 + Cx2) × V0 / C5.

Then, turn off the switch SW12 at time _{T 31} after a charge of the capacitance Cx1 detection electrodes E1 (or Cx1 + Cx2) is sufficiently moved to the capacitor C5, by turning on the switch SW11 and the switch SW13, the detection electrodes E1 The potential is set to a low level that is the same potential as the AC rectangular wave Sg, and the voltage detector DET is reset. At this time, the timing for turning on the switch SW11 is, after turning off the switch SW12, may be any timing as long as the time T ₀₂ is previously. The timing for resetting the voltage detector DET is, after turning off the switch SW12, may be any timing as long as the time T ₁₂ before.

The above operation is repeated at a predetermined frequency (for example, about several kHz to several hundred kHz). Based on the absolute value | ΔV | of the difference between the waveform V ₃ and the waveform V ₄ , the presence / absence of the object OBJ (the presence / absence of touch) can be detected. The potential of the detecting electrode E1, as shown in FIG. 9, when no proximity detected object OBJ has a waveform of V _1, when the capacitance Cx2 due to the influence of the detected object OBJ is added is V ₂ It becomes the waveform. It is also possible to measure the presence / absence of an external proximity object (presence / absence of touch) by measuring the time during which the waveform V ₁ and the waveform V ₂ fall to a predetermined threshold voltage V _TH .

  In this configuration example, the touch detection device 30 is supplied with charges to the touch detection electrodes TDL according to the drive signal Vcomts1 supplied from the drive driver 47 shown in FIG. The detection electrode TDL outputs a touch detection signal Vdet2. Further, the touch detection device 30 is supplied with electric charges to the drive electrodes COML according to the drive signal Vcomts2 supplied from the drive electrode driver 14 shown in FIG. 2, performs touch detection by a self-capacitance method, and the drive electrodes COML The touch detection signal Vdet3 is output.

  Referring to FIG. 2 again, the detection control unit 200 includes a control signal supplied from the display control unit 11 and touch detection signals Vdet1, Vdet2, and Vdet3 supplied from the touch detection device 30 of the display unit with a touch detection function 10. , The presence or absence of a touch on the input surface IS (the contact state described above) is detected, the force applied to the input surface IS is detected based on the force detection signal Vdet4 supplied from the force detection device 100, This is a circuit for obtaining the coordinates and contact area in the touch detection area when there is a touch.

  The detection control unit 200 includes a first detection signal amplification unit 41, a second detection signal amplification unit 42, a first A / D conversion unit 43-1, a second A / D conversion unit 43-2, and a signal processing unit 44. And a coordinate extraction unit 45 and a detection timing control unit 46. The signal processing unit 44 includes a touch detection processing unit 441 and a force detection processing unit 442. The first detection signal amplification unit 41, the first A / D conversion unit 43-1, the coordinate extraction unit 45, and the touch detection processing unit 441 constitute a touch detection control unit 40. The first detection signal amplification unit 41, the second detection signal amplification unit 42, the first A / D conversion unit 43-1, the second A / D conversion unit 43-2, and the force detection processing unit 442 Configure.

  The touch detection control unit 40 is a component that detects the contact or proximity of the object OBJ to the input surface IS.

  The force detection control unit 50 is a component that detects the force applied to the input surface IS by the object OBJ.

  At the time of mutual capacitive touch detection, the touch detection device 30 outputs a touch detection signal Vdet1 from a plurality of touch detection electrodes TDL described later via the voltage detector DET shown in FIG. The first detection signal amplification unit 41 of the unit 200 is supplied.

  At the time of self-capacitive touch detection, the touch detection device 30 outputs a touch detection signal Vdet2 from a plurality of touch detection electrodes TDL, which will be described later, via the voltage detector DET shown in FIG. The first detection signal amplification unit 41 of the unit 200 is supplied. Further, during the touch detection of the self-capacitance method, the touch detection device 30 outputs a touch detection signal Vdet3 from a plurality of drive electrodes COML described later via the voltage detector DET shown in FIG. The first detection signal amplification unit 41 of the control unit 200 is supplied.

  At the time of mutual capacitance type force detection, the force detection device 100 outputs a force detection signal Vdet4 from a plurality of electrodes SUS described later, and supplies the force detection signal Vdet4 to the second detection signal amplification unit 42 of the detection control unit 200. It has become.

  The first detection signal amplifier 41 amplifies the touch detection signals Vdet1, Vdet2, and Vdet3 supplied from the touch detection device 30. The touch detection signals Vdet1, Vdet2, and Vdet3 amplified by the first detection signal amplification unit 41 are supplied to the first A / D conversion unit 43-1. The first detection signal amplification unit 41 may include a low-pass analog filter that removes high frequency components (noise components) included in the touch detection signals Vdet1, Vdet2, and Vdet3, extracts the touch detection components, and outputs them. good. The detection control unit 200 may not have the first detection signal amplification unit 41. That is, the touch detection signals Vdet1, Vdet2, and Vdet3 from the touch detection device 30 may be supplied to the first A / D conversion unit 43-1.

  The second detection signal amplifier 42 amplifies the force detection signal Vdet4 supplied from the force detection device 100. The force detection signal Vdet4 amplified by the second detection signal amplifier 42 is supplied to the second A / D converter 43-2. The second detection signal amplification unit 42 may include a low-pass analog filter that removes a high frequency component (noise component) included in the force detection signal Vdet4, extracts the force detection component, and outputs the component. The detection control unit 200 may not have the second detection signal amplification unit 42. That is, the force detection signal Vdet4 from the force detection device 100 may be supplied to the second A / D conversion unit 43-2.

  The first A / D conversion unit 43-1 is a circuit that samples each analog signal output from the first detection signal amplification unit 41 and converts it into a digital signal at a timing synchronized with the drive signals Vcomtm, Vcomts1, and Vcomts2. .

  The second A / D conversion unit 43-2 is a circuit that samples each analog signal output from the second detection signal amplification unit 42 and converts it into a digital signal at a timing synchronized with the drive signal Vcomtm.

  The signal processing unit 44 includes frequency components (noise components) other than the frequencies obtained by sampling the drive signals Vcomtm, Vcomts1, and Vcomts2 included in the output signals of the first A / D conversion unit 43-1 and the second A / D conversion unit 43-2. ) Is provided.

  The signal processing unit 44 is based on the output signal of the first A / D conversion unit 43-1 and detects the presence or absence of a touch on the input surface IS, and the force that detects the force applied to the input surface IS. It is a logic circuit that performs detection processing.

The signal processing unit 44 performs processing for extracting only a difference signal from the finger. The difference signal by the finger is the absolute value | ΔV | of the difference between the waveform V ₀ and the waveform V ₁ described above.

The signal processing unit 44 may perform an operation of averaging the absolute value | ΔV | of the difference between the waveform V ₀ and the waveform V ₁ to obtain an average value of the absolute value | ΔV |. Thereby, the signal processing unit 44 can reduce the influence of noise.

The signal processing unit 44 compares the detected difference signal by the finger with a predetermined threshold voltage _VTH, and determines that the external proximity object is in a non-contact state if the detected difference signal is equal to or higher than the threshold voltage _VTH .

On the other hand, the signal processing unit 44 compares the detected difference signal with a predetermined threshold voltage _VTH , and determines that the contact state of the external proximity object is present if the detected difference signal is less than the threshold voltage _VTH . In this way, the touch detection control unit 40 of the detection control unit 200 can perform touch detection.

  Further, in the display device with a touch detection function 1 according to the first embodiment, mutual capacitive touch detection and force detection are simultaneously performed. That is, the signal processing unit 44 performs a force detection process described later at the same time as the mutual capacitive touch detection described above.

  The coordinate extraction unit 45 obtains the coordinates of the touch detection position on the input surface IS when the signal processing unit 44 detects a touch on the input surface IS and when a force applied to the input surface IS is detected. It is a logic circuit. The detection timing control unit 46 controls the first A / D conversion unit 43-1, the second A / D conversion unit 43-2, the signal processing unit 44, and the coordinate extraction unit 45 to operate in synchronization. . The coordinate extraction unit 45 outputs the coordinates of the touch detection position as the touch detection position Vout.

  FIG. 10 is a diagram illustrating an example of a module on which the display device with a touch detection function according to the first embodiment is mounted. The display device with a touch detection function 1 includes a first substrate (for example, the pixel substrate 2) and a printed circuit board (for example, a flexible printed circuit board) T.

  The pixel substrate 2 has a second substrate 21. Note that the second substrate 21 is, for example, a glass substrate or a film substrate. A driving IC chip (for example, COG (Chip On Glass) 19) is mounted on the second substrate 21. Further, the display area Ad of the liquid crystal display device 20 and the frame Gd are formed on the pixel substrate 2 (second substrate 21).

  The COG 19 is an IC chip that is a driver mounted on the second substrate 21, and is a control device that incorporates each circuit necessary for display operation, such as the display control unit 11 shown in FIG.

  In this configuration example, the source driver 13 and the source selector unit 13 </ b> S are formed on the second substrate 21. The source driver 13 and the source selector unit 13S may be built in the COG 19.

  The drive electrode scanning units 14 </ b> A and 14 </ b> B, which are part of the drive electrode driver 14, are formed on the second substrate 21.

  The gate driver 12 is formed on the second substrate 21 as the gate drivers 12A and 12B.

  The display device with a touch detection function 1 may incorporate circuits such as the drive electrode scanning units 14A and 14B and the gate driver 12 in the COG 19. The COG 19 is merely a form of mounting and is not limited to this. For example, a configuration having the same function as the COG 19 may be mounted on the flexible printed circuit board T as COF (Chip On Film or Chip On Flexible).

  As shown in FIG. 10, the drive electrode COML and the touch detection electrode TDL are formed so as to cross three-dimensionally in a direction perpendicular to the surface of the second substrate 21.

  The drive electrode COML is divided into a plurality of striped electrode patterns extending in one direction. When performing the mutual capacitance type touch detection operation, the drive signal Vcomtm is sequentially supplied to each electrode pattern by the drive electrode driver 14. Further, when performing the self-capacitance type touch detection operation, the drive signal Vcomts2 is sequentially supplied to each electrode pattern by the drive electrode driver 14.

  In the example shown in FIG. 10, the drive electrode COML is formed in a direction parallel to the short side of the display unit 10 with a touch detection function. The touch detection electrode TDL, which will be described later, is formed in a direction intersecting with the extending direction of the drive electrode COML. For example, the touch detection electrode TDL is formed in a direction parallel to the long side of the display unit 10 with a touch detection function. The drive electrode COML may be formed in a direction parallel to the long side of the display unit 10 with a touch detection function. Further, the touch detection electrode TDL may be formed in a direction intersecting with the extending direction of the drive electrode COML, for example, in a direction parallel to the short side of the display unit 10 with a touch detection function. In FIG. 10, the side parallel to the X-axis direction is the short side and the side parallel to the Y-axis direction is the long side, but the side parallel to the X-axis direction is the long side and the side parallel to the Y-axis direction is It may be a short side.

  The touch detection electrode TDL is connected to a touch IC 49 mounted on the flexible printed circuit board T connected to the short side of the display unit 10 with a touch detection function. The touch IC 49 is an IC chip that is a driver mounted on the flexible printed circuit board T, and is a control device that incorporates circuits necessary for touch detection operation and force detection operation, such as the detection control unit 200 shown in FIG. . As described above, the touch IC 49 is mounted on the flexible printed board T and connected to each of the plurality of touch detection electrodes TDL arranged in parallel. The flexible printed board T may be a terminal and is not limited to a board. In this case, the touch IC 49 is provided outside the module. Note that the touch IC 49 is not limited to being disposed on the flexible printed circuit board T, and may be disposed on the second substrate 21 or the first substrate 31.

  In this configuration example, the touch IC 49 is a control device that functions as the detection control unit 200, but some functions of the detection control unit 200, for example, some functions of the touch detection control unit 40 or the force detection control unit 50 are It may be provided as a function of another MPU.

  Specifically, some functions (for example, noise removal) among various functions such as A / D conversion and noise removal that can be provided as functions of an IC chip that is a touch driver are the same as those of an IC chip that is a touch driver. You may implement by circuits, such as MPU provided separately. Further, when one IC chip as a driver (one chip configuration) is used, for example, a detection signal is transmitted to an IC chip as a touch driver on the array substrate via a wiring such as a flexible printed circuit board T. May be.

  The source selector section 13S is formed using a TFT element in the vicinity of the display area Ad on the second substrate 21. A large number of pixels Pix, which will be described later, are arranged in a matrix (matrix) in the display area Ad. The frame Gd is an area where the pixel Pix is not arranged when the surface of the second substrate 21 is viewed from the vertical direction. The gate electrode 12 and the drive electrode scanning units 14A and 14B of the drive electrode driver 14 are arranged in the frame Gd.

  The gate driver 12 includes, for example, gate drivers 12A and 12B, and is formed on the second substrate 21 using a TFT element. The gate drivers 12A and 12B can be driven from both sides across a display area Ad in which subpixels SPix (pixels) described later are arranged in a matrix. The scanning line is arranged between the gate driver 12A and the gate driver 12B. For this reason, the scanning lines are provided so as to extend in a direction parallel to the extending direction of the drive electrodes COML in the direction perpendicular to the surface of the second substrate 21.

  In this configuration example, two circuits of the gate drivers 12A and 12B are provided as the gate driver 12, but this is an example of a specific configuration of the gate driver 12, and is not limited thereto. For example, the gate driver 12 may be a single circuit provided only at one end of the scanning line.

  The drive electrode driver 14 includes, for example, drive electrode scanning units 14A and 14B, and is formed on the second substrate 21 using a TFT element. The drive electrode scanning units 14A and 14B receive the display drive voltage VcomDC from the COG 19 and the drive signals Vcomtm and Vcomts2. The drive electrode scanning units 14A and 14B can drive each of the plurality of drive electrodes COML arranged in parallel from both sides.

  In this configuration example, two circuits of the drive electrode scanning units 14A and 14B are provided as the drive electrode driver 14, but this is an example of a specific configuration of the drive electrode driver 14 and is not limited thereto. . For example, the drive electrode driver 14 may be a single circuit provided only at one end of the drive electrode COML.

  The display device 1 with a touch detection function outputs the touch detection signals Vdet1, Vdet2, and Vdet3 described above from the short side of the display unit 10 with a touch detection function. Thereby, the display device with a touch detection function 1 can easily route the wiring when connecting to the detection control unit 200 via the flexible printed circuit board T which is a terminal unit.

  FIG. 11 is a cross-sectional view illustrating a schematic cross-sectional structure of the display unit with a touch detection function. FIG. 12 is a circuit diagram illustrating a pixel arrangement of the display unit with a touch detection function. The display unit 10 with a touch detection function includes a pixel substrate 2, a second substrate (for example, a counter substrate 3) disposed in a direction perpendicular to the surface of the pixel substrate 2, the pixel substrate 2, and the counter substrate 3. And a display function layer (for example, a liquid crystal layer 6) inserted between the two.

  The pixel substrate 2 is formed between a second substrate 21 as a circuit substrate, a plurality of pixel electrodes 22 arranged in a matrix on the second substrate 21, and the second substrate 21 and the pixel electrode 22. A plurality of drive electrodes COML and an insulating layer 24 that insulates the pixel electrodes 22 and the drive electrodes COML are included.

  The second substrate 21 includes a thin film transistor (TFT) element Tr of each subpixel SPix shown in FIG. 12, a pixel signal line SGL for supplying a pixel signal Vpix to each pixel electrode 22 shown in FIG. Wirings such as scanning signal lines GCL for driving each TFT element Tr shown in FIG. 12 are formed. The pixel signal line SGL extends in a plane parallel to the surface of the second substrate 21 and supplies a pixel signal Vpix for displaying an image to the sub-pixel SPix. The subpixel SPix indicates a structural unit controlled by the pixel signal Vpix. The subpixel SPix is a region surrounded by the pixel signal line SGL and the scanning signal line GCL, and indicates a structural unit controlled by the TFT element Tr.

  As shown in FIG. 12, the liquid crystal display device 20 has a plurality of subpixels SPix arranged in a matrix. The subpixel SPix includes a TFT element Tr and a liquid crystal element LC. The TFT element Tr is composed of a thin film transistor. In this example, the TFT element Tr is composed of an n-channel MOS (Metal Oxide Semiconductor) TFT.

  One of the source and drain of the TFT element Tr is coupled to the pixel signal line SGL, the gate is coupled to the scanning signal line GCL, and the other of the source and drain is coupled to one end of the liquid crystal element LC. For example, the liquid crystal element LC has one end coupled to the drain of the TFT element Tr and the other end coupled to the drive electrode COML. In FIG. 11, the pixel electrode 22, the insulating layer 24, and the drive electrode COML are stacked in this order on the second substrate 21, but the present invention is not limited to this. The drive electrode COML, the insulating layer 24, and the pixel electrode 22 may be stacked in this order on the second substrate 21, or the drive electrode COML and the pixel electrode 22 may be formed in the same layer with the insulating layer 24 interposed therebetween. May be.

  The subpixel SPix is coupled to another subpixel SPix belonging to the same row of the liquid crystal display device 20 by the scanning signal line GCL. The scanning signal line GCL is coupled to the gate driver 12, and the scanning signal Vscan is supplied from the gate driver 12.

  The subpixel SPix is coupled to another subpixel SPix belonging to the same column of the liquid crystal display device 20 by the pixel signal line SGL. The pixel signal line SGL is coupled to the source driver 13, and the pixel signal Vpix is supplied from the source driver 13.

  Further, the subpixel SPix is coupled to another subpixel SPix belonging to the same row of the liquid crystal display device 20 by the drive electrode COML. The drive electrode COML is coupled to the drive electrode driver 14, and a drive signal Vcom is supplied from the drive electrode driver 14. That is, in this example, a plurality of subpixels SPix belonging to the same row share one drive electrode COML.

  The direction in which the drive electrode COML in this configuration example extends is parallel to the direction in which the scanning signal line GCL extends. The direction in which the drive electrode COML extends is not limited to this. For example, the direction in which the drive electrode COML extends may be a direction parallel to the direction in which the pixel signal line SGL extends. Further, the direction in which the touch detection electrode TDL extends is not limited to the direction in which the pixel signal line SGL extends. The direction in which the touch detection electrode TDL extends may be a direction parallel to the direction in which the scanning signal line GCL extends.

  The gate driver 12 shown in FIG. 2 is formed in a matrix form on the liquid crystal display device 20 by applying the scanning signal Vscan to the gate of the TFT element Tr of the pixel Pix via the scanning signal line GCL shown in FIG. One row (one horizontal line) among the sub-pixels SPix is sequentially selected as a display drive target.

  The source driver 13 shown in FIG. 2 supplies the pixel signal Vpix to each subpixel SPix constituting one horizontal line sequentially selected by the gate driver 12 via the pixel signal line SGL shown in FIG. In these sub-pixels SPix, one horizontal line is displayed in accordance with the supplied pixel signal Vpix.

  The drive electrode driver 14 shown in FIG. 2 applies the drive signal Vcom, and drives the drive electrode COML for each block including a predetermined number of drive electrodes COML.

  As described above, in the liquid crystal display device 20, one horizontal line is sequentially selected by driving the gate driver 12 so as to sequentially scan the scanning signal lines GCL in a time division manner. In the liquid crystal display device 20, the source driver 13 supplies the pixel signal Vpix to the subpixels SPix belonging to one horizontal line, so that display is performed for each horizontal line. When performing this display operation, the drive electrode driver 14 applies the drive signal Vcom to the block including the drive electrode COML corresponding to the one horizontal line.

  The liquid crystal layer 6 modulates light passing therethrough according to the state of the electric field. When the drive electrode COML is driven, a voltage corresponding to the pixel signal Vpix supplied to the pixel electrode 22 is applied to the liquid crystal layer 6 and an electric field is generated, so that the liquid crystal constituting the liquid crystal layer 6 exhibits orientation corresponding to the electric field. Thus, the light passing through the liquid crystal layer 6 is modulated.

  Thus, the pixel electrode 22 and the drive electrode COML function as a pair of electrodes that generate an electric field in the liquid crystal layer 6. That is, the liquid crystal display device 20 functions as a display unit DP whose display output content changes according to the electric charge applied to the pair of electrodes. Here, the pixel electrode 22 is disposed at least for each pixel Pix or subpixel SPix, and the drive electrode COML is disposed for at least each of the plurality of pixels Pix or subpixel SPix.

  In the present configuration example, as the liquid crystal display device 20, for example, a liquid crystal display device using a liquid crystal in a transverse electric field mode such as IPS (in-plane switching) including FFS (fringe field switching) is used. Note that alignment films may be provided between the liquid crystal layer 6 and the pixel substrate 2 and between the liquid crystal layer 6 and the counter substrate 3 shown in FIG.

  The liquid crystal display device 20 has a configuration corresponding to the horizontal electric field mode, but may have a configuration corresponding to another display mode. For example, the liquid crystal display device 20 has a configuration corresponding to a mode that mainly uses a vertical electric field generated between the main surfaces of the substrate, such as a TN (Twisted Nematic) mode, an OCB (Optically Compensated Bend) mode, and a VA (Vertical Aligned) mode. You may do it. In the display mode using the vertical electric field, for example, a configuration in which the pixel electrode 22 is provided on the pixel substrate 2 and the drive electrode COML is provided on the counter substrate 3 is applicable.

  The counter substrate 3 includes a first substrate 31 and a color filter 32 formed on one surface of the first substrate 31. A touch detection electrode TDL, which is a detection electrode of the touch detection device 30, is formed on the other surface of the first substrate 31, and a polarizing plate 35 is disposed on the touch detection electrode TDL.

  The mounting method of the color filter 32 may be a so-called color filter on array (COA) method in which the color filter 32 is formed on the pixel substrate 2 which is an array substrate.

  The color filter 32 shown in FIG. 11 periodically arranges color regions of color filters colored, for example, red (R), green (G), and blue (B), and each subpixel SPix has an R. , G, and B color areas 32R, 32G, and 32B are associated with each other, and the color areas 32R, 32G, and 32B constitute a set to constitute a pixel Pix.

  The pixels Pix are arranged in a matrix along a direction parallel to the scanning signal line GCL and a direction parallel to the pixel signal line SGL, and forms a display area Ad described later. The color filter 32 faces the liquid crystal layer 6 in a direction perpendicular to the second substrate 21. In this way, the sub-pixel SPix can perform single color display.

  The color filter 32 may be a combination of other colors as long as it is colored in a different color. Further, the color filter 32 may be omitted. As described above, there may be a region where the color filter 32 does not exist, that is, a sub-pixel SPix that is not colored. Further, the number of sub-pixels SPix included in the pixel Pix may be four or more.

  FIG. 13 is a perspective view illustrating a configuration example of drive electrodes and touch detection electrodes of a display unit with a touch detection function. The drive electrode COML according to this configuration example functions as a drive electrode of the liquid crystal display device 20 and also functions as a drive electrode of the touch detection device 30.

  The drive electrode COML faces the pixel electrode 22 in the direction perpendicular to the surface of the second substrate 21. The touch detection device 30 includes a drive electrode COML provided on the pixel substrate 2 and a touch detection electrode TDL provided on the counter substrate 3.

  The touch detection electrode TDL includes a striped electrode pattern extending in a direction intersecting with the extending direction of the electrode pattern of the drive electrode COML. The touch detection electrode TDL faces the drive electrode COML in a direction perpendicular to the surface of the second substrate 21. Each electrode pattern of the touch detection electrode TDL is connected to an input of the first detection signal amplification unit 41 of the detection control unit 200, respectively.

  The electrode pattern in which the drive electrode COML and the touch detection electrode TDL intersect with each other generates capacitance at the intersection. In the touch detection device 30, the drive electrode driver 14 applies the drive signal Vcomtm to the drive electrode COML, thereby outputting the touch detection signal Vdet1 from the touch detection electrode TDL and performing touch detection.

  That is, the drive electrode COML corresponds to the drive electrode E1 in the basic principle of the mutual capacitance type touch detection shown in FIGS. 3 to 5, and the touch detection electrode TDL corresponds to the touch detection electrode E2. The touch detection device 30 detects a touch according to this basic principle.

  As described above, the touch detection device 30 includes the touch detection electrode TDL that forms a mutual capacitance with one of the pixel electrode 22 and the drive electrode COML (for example, the drive electrode COML), and the mutual capacitance. The touch detection is performed based on the change in.

  The electrode pattern in which the drive electrode COML and the touch detection electrode TDL intersect each other constitutes a mutual capacitive touch sensor in a matrix. Therefore, the touch detection control unit 40 can detect the position and the contact area where the contact or proximity of the detection object OBJ occurs by scanning over the entire input surface IS of the touch detection device 30.

  That is, in the touch detection device 30, when performing the touch detection operation, the drive electrode driver 14 drives the drive electrodes COML shown in FIG. 10 so as to sequentially scan in a time division manner. Accordingly, the drive electrodes COML are sequentially selected in the scan direction Scan. Then, the touch detection device 30 outputs a touch detection signal Vdet1 from the touch detection electrode TDL. In this way, the touch detection device 30 is configured to perform touch detection for each drive electrode COML.

  Although the relationship between the detection block and the number of lines in the display output is arbitrary, in this embodiment, the touch detection area corresponding to the display area Ad for two lines is one detection block. In other words, the relationship between the detection block and the opposing pixel electrode, scanning signal line, or pixel signal line is arbitrary, but in the present embodiment, two pixel electrodes or two scanning signal lines, One drive electrode COML is opposed.

  Note that the touch detection electrode TDL or the drive electrode COML is not limited to a shape divided into a plurality of stripes. For example, the touch detection electrode TDL or the drive electrode COML may have a comb shape. Alternatively, the touch detection electrode TDL or the drive electrode COML may be divided into a plurality of parts, and the shape of the slit dividing the drive electrode COML may be a straight line or a curved line.

  As an example of the operation method of the display device 1 with a touch detection function, the display device 1 with a touch detection function performs a touch detection operation (touch detection period) and a display operation (display operation period) in a time-sharing manner. The touch detection operation and the display operation may be performed in any manner.

<Configuration example of force detection unit>
FIG. 14 is an exploded perspective view illustrating a configuration example of the display device with a touch detection function according to the first embodiment. As illustrated in FIG. 14, the display device 1 with a touch detection function includes a display unit 10 with a touch detection function and an illumination unit (for example, a backlight unit BL) that illuminates the input surface IS of the display unit 10 with a touch detection function from the back. ), A host HST that controls the display unit with a touch detection function 10 and the backlight unit BL, a housing CA, and a cover member CG.

  The display unit with a touch detection function 10 has a plane parallel to an XY plane defined by an X direction that is a first direction orthogonal to each other and a Y direction that is a second direction. In this configuration example, the X direction as the first direction and the Y direction as the second direction are orthogonal to each other, but may intersect at an angle other than 90 °. The Z direction that is the third direction is orthogonal to each of the X direction that is the first direction and the Y direction that is the second direction. The Z direction that is the third direction is the thickness direction of the display unit 10 with a touch detection function.

  The casing CA has a box shape with an opening at the top, and houses the display unit 10 with a touch detection function, the backlight unit BL, and the host HST. The case CA may be formed of a conductor such as metal, or may be formed of a resin and its surface layer may be a conductor such as a metal material.

  The cover member CG closes the opening of the casing CA and covers the display unit 10 with a touch detection function, the backlight unit BL, and the host HST.

  In the XY plan view, the size of the cover member CG is larger than the size of the second substrate 21 and the size of the first substrate 31. The cover member CG is exemplified by a light transmissive substrate such as a glass substrate or a resin substrate. When the cover member CG is a glass substrate, the cover member CG may be referred to as a cover glass.

  In the Z direction, which is the third direction, the display unit with a touch detection function 10 and the backlight unit BL are positioned between the bottom surface of the casing CA and the cover member CG, and the backlight unit BL touches the casing CA. It is located between the display unit with detection function 10. The backlight unit BL can be arranged at a distance from the display unit 10 with a touch detection function. Further, the backlight unit BL can be arranged with a space in the casing CA.

  The force detection area in which the force detection unit SE2 detects force may be the same as the display area Ad.

  FIG. 15 is an exploded perspective view showing the backlight unit. The backlight unit BL has a reflective polarizing film DBEF, a brightness enhancement film BEF, a light diffusion sheet DI, a light guide LG, a light reflection in the Z direction from the display unit 10 with a touch detection function toward the cover member CG. The body RS and the electrode SUS are stacked in this order. A light source LS is disposed opposite to one side of the light guide LG. The backlight unit BL has a shape and a size corresponding to the display unit 10 with a touch detection function.

  The electrode SUS is included in the force detection device 100 shown in FIG. 2, and corresponds to the force detection unit SE2 shown in FIG.

  In this configuration example, the light guide LG is formed in a flat rectangular shape. The light source LS emits light to the light guide LG. In this configuration example, the light source LS uses a light emitting diode (LED).

  The light reflector RS reflects light emitted from the light guide LG in the opposite direction to the display unit 10 with a touch detection function, and emits the light toward the display unit 10 with a touch detection function. The light reflector RS can improve the luminance level of the display image by reducing the loss of light. In this configuration example, the light reflector RS is formed in a rectangular sheet shape. In the XY plane, the area of the light reflector RS is substantially the same as the area of the light guide LG. For example, the light reflector RS may have a multilayer film structure using a polyester-based resin.

  The light diffusion sheet DI diffuses light incident from the light guide LG side and emits it to the display unit 10 with a touch detection function. That is, since the light transmitted through the light diffusion sheet DI is diffused, the light diffusion sheet DI can suppress luminance unevenness in the XY plane of the light emitted from the backlight unit BL. In this configuration example, the light diffusion sheet DI is formed in a rectangular sheet shape. In the XY plane, the area of the light diffusion sheet DI is substantially the same as the area of the light guide LG.

  The brightness enhancement film BEF has an effect of improving the brightness level of the emitted light from the backlight unit BL. In this configuration example, the brightness enhancement film BEF is formed in a rectangular film shape. In the XY plane, the area of the brightness enhancement film BEF is substantially the same as the area of the light guide LG.

  The reflective polarizing film DBEF has an effect of improving the utilization efficiency of the emitted light from the backlight unit BL. In this configuration example, the reflective polarizing film DBEF is formed in a rectangular film shape. In the XY plane, the area of the reflective polarizing film DBEF is substantially the same as the area of the light guide LG.

  The front frame FFR and the rear frame RFR are used for modularization of the backlight unit BL. The reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, the light guide LG, the light reflector RS, the electrode SUS, and the light source LS are housed inside the rear frame RFR. Thereby, the reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, the light guide LG, the light reflector RS, the relative position of the electrode SUS, and the light guide LG and the light source LS. The relative position is fixed.

  In this configuration example, the front frame FFR and the rear frame RFR are formed in a rectangular frame shape. The front frame FFR has an opening at the top so as not to interfere with illumination of the display unit 10 with a touch detection function. In the XY plane, the rear frame RFR entirely surrounds the aggregate of the light guide LG and the light source LS. A path FRP through which the flexible printed circuit board T connected to the light source LS passes is formed in the rear frame RFR. A predetermined clearance is provided in the Z direction between the front frame FFR and the reflective polarizing film DBEF. The front frame FFR and the rear frame RFR may be made of a conductive material such as metal.

  In addition, the shape of the front frame FFR and the rear frame RFR in the XY plane can be variously modified and may be any shape that does not hinder the illumination of the display unit 10 with a touch detection function. For example, the shape of the front frame FFR and the rear frame RFR in the XY plane is an L shape facing two adjacent sides of the light guide LG, a saddle shape facing the three adjacent sides of the light guide LG, or Illustrated is an II shape facing two opposing sides of the light guide LG.

  Here, the backlight unit BL is exemplarily shown in FIG. 15, but various forms can be applied as the backlight unit BL. For example, the backlight unit BL may be formed except at least a part of the reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, and the light reflector RS. Alternatively, the backlight unit BL may be formed by adding an optical member not shown in FIG. The backlight unit BL only needs to be configured to emit light to the display unit 10 with a touch detection function.

  FIG. 16 is a cross-sectional view illustrating a configuration example of the display device with a touch detection function according to the first embodiment. As shown in FIG. 16, the display device 1 with a touch detection function includes a display unit 10 with a touch detection function, a COG 19, a cover member CG, a first optical element OD1, a second optical element OD2, and a touch IC 49. , A backlight unit BL, and a first printed board, a second printed board, and a third printed board (for example, flexible printed boards T, T2, and T3).

  The COG 19 is mounted on the pixel substrate 2 of the display unit 10 with a touch detection function. The flexible printed board T2 is connected to the pixel board 2. The connector CO1 and the connector CO2 are mounted on the flexible printed circuit board T2. The flexible printed board T2 is connected to the host HST via the connector CO1.

  The flexible printed circuit board T connects between the touch detection electrode TDL and the connector CO2. The COG 19 is connected to the touch IC 49 via the flexible printed board T2, the connector CO2, and the flexible printed board T. For example, the touch IC 49 may be mounted on any one of the flexible printed circuit boards T, T2, T3, and the counter substrate 3, or any two or more of the touch ICs 49 may be disposed. It can be divided and mounted on a substrate.

  The flexible printed circuit board T3 connects between the electrode SUS and the flexible printed circuit board T2. The host HST is connected to the electrode SUS via the connector CO1 and the flexible printed board T3. The electrode SUS may be connected to the touch IC 49 via the flexible printed circuit board T3, the flexible printed circuit board T2, and the flexible printed circuit board T.

  The means for connecting the host HST, the display unit with a touch detection function 10, the touch detection electrode TDL, the light source LS, and the electrode SUS can be variously modified.

  For example, instead of the three independent flexible printed boards T, T2, and T3 and the connectors CO1 and CO2, one flexible printed board may be used. In this case, one flexible printed board is connected to the host HST, the first branch portion of the flexible printed board is connected to the display unit 10 with a touch detection function, and the second branch portion of the flexible printed board is connected to the touch detection electrode TDL. The third branch portion of the flexible printed circuit board can be connected to the light source LS. The flexible printed circuit boards or between the flexible printed circuit board and the host HST or the printed circuit board may be connected via connectors such as the connector CO1 and the connector CO2, or connected by soldering or the like instead of the connector. May be.

  The host HST, COG 19, and touch IC 49 function as a control unit CTRL that controls the touch detection unit SE1 including the drive electrode COML and the touch detection electrode TDL of the display unit 10 with a touch detection function.

  In addition, the host HST, the COG 19, and the touch IC 49 function as a control unit CTRL that controls the force detection unit SE2 including the drive electrode COML and the electrode SUS of the display unit 10 with a touch detection function.

  The host HST can be rephrased as an application processor. The touch IC 49 can provide the COG 19 with a timing signal that informs the drive timing of the touch detection unit SE1 and the force detection unit SE2. Alternatively, the COG 19 can provide a timing signal that informs the drive timing of the drive electrode COML to the touch IC 49. Alternatively, the host HST can provide a timing signal to each of the COG 19 and the touch IC 49. By this timing signal, the driving of the COG 19 and the driving of the touch IC 49 can be synchronized.

  The cover member CG is located outside the display unit 10 with a touch detection function and faces the counter substrate 3. In this configuration example, the input surface IS of the display device with a touch detection function 1 is the surface of the cover member CG. The display device with a touch detection function 1 can detect the position and the contact area of the detected object OBJ when the detected object OBJ comes into contact with the input surface IS.

  The force detection unit SE2 of the display device with a touch detection function 1 can output a signal corresponding to the force to the control unit CTRL when a force is applied to the input surface IS by the detection object OBJ. The signal corresponding to the force is a signal corresponding to the force with which the detected object OBJ presses down the input surface IS, and is a signal that varies depending on the magnitude of the force.

  A spacer SP is provided between the display unit 10 with a touch detection function and the front frame FFR of the backlight unit BL, and an air layer (air) is provided between the display unit 10 with a touch detection function and the reflective polarizing film DBEF. Gap) AG is formed. The spacer SP is a nonconductor, and polyurethane is exemplified.

  When a force is applied to the input surface IS, the spacer SP is elastically deformed according to the force, and the force applied to the input surface IS can be detected.

  The first optical element OD1 is disposed between the pixel substrate 2 and the backlight unit BL. The first optical element OD1 is attached to the pixel substrate 2.

  The second optical element OD2 is disposed between the display unit with a touch detection function 10 and the cover member CG. The second optical element OD2 is attached to the counter substrate 3 and the touch detection electrode TDL.

  Each of the first optical element OD1 and the second optical element OD2 includes at least a polarizing plate, and may include a retardation plate as necessary. The absorption axis of the polarizing plate included in the first optical element OD1 intersects the absorption axis of the polarizing plate included in the second optical element OD2. For example, the absorption axis of the polarizing plate included in the first optical element OD1 and the absorption axis of the polarizing plate included in the second optical element OD2 are orthogonal to each other.

  The cover member CG is attached to the second optical element OD2 with the adhesive layer AL. The adhesive layer AL is exemplified by an optical transparent resin (OCR: Optically Clear Resin). Since the display unit 10 with a touch detection function detects a force, the adhesive layer AL may be elastically deformed, but it is only necessary to transmit the force applied from the cover member CG to the second optical element OD2.

  The touch detection electrode TDL is disposed between the drive electrode COML and the cover member CG. In this configuration example, the touch detection electrode TDL is provided above the surface of the counter substrate 3 on the side facing the second optical element OD2. The touch detection electrode TDL may be in contact with the counter substrate 3 or may be separated from the counter substrate 3. When the touch detection electrode TDL is separated from the counter substrate 3, a member such as an insulating film (not shown) is interposed between the counter substrate 3 and the touch detection electrode TDL. The touch detection electrode TDL extends in the Y direction that is the second direction.

  The drive electrode COML and the touch detection electrode TDL constitute a mutual capacitance type and self capacitance type touch detection unit SE1. The drive electrode COML functions as a display electrode and also functions as a sensor drive electrode. The touch detection unit SE1 is used to detect the position and contact area of the object to be detected OBJ.

  In this configuration example, the electrode SUS is made of a conductor (for example, aluminum). The touch IC 49 and the electrode SUS are electrically connected, and the force detection signal Vdet4 from the electrode SUS is output to the touch IC 49.

  The electrode SUS is disposed at a distance from the display unit 10 with a touch detection function. In this configuration example, an air layer AG is provided between the display unit with a touch detection function 10 and the electrode SUS. That is, an air layer AG is provided between the electrode SUS and the drive electrode COML. Due to the presence of the air layer AG, the distance between the electrode SUS and the drive electrode COML can be changed according to the magnitude of the force applied to the input surface IS. Further, when the force applied to the input surface IS is removed, the interval between the electrode SUS and the drive electrode COML returns to the original interval as time passes.

  In the present embodiment, between the electrode SUS and the drive electrode COML, the reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, the light guide LG, and the light reflection that constitute the backlight unit BL are provided. A stacked body LB in which the bodies RS are stacked is provided. That is, the electrode SUS is provided on the surface opposite to the surface on the incident surface IS side of the stacked body LB.

  In the present embodiment, the drive electrode COML corresponds to the “first electrode”. The electrode SUS corresponds to the “second electrode”. The air layer AG and the stacked body LB correspond to the “dielectric layer”.

  In this configuration example, the air layer AG is provided between the display unit with a touch detection function 10 and the backlight unit BL, but the present invention is not limited to this. Instead of the air layer AG, a resin layer having a high transmittance of light emitted from the backlight unit BL may be provided between the display unit with a touch detection function 10 and the backlight unit BL.

  The distance d from the electrode SUS to the drive electrode COML is a distance in the Z direction, which is the third direction, from the surface of the electrode SUS facing the drive electrode COML to the surface of the drive electrode COML facing the electrode SUS. It is the distance to. The distance d changes according to the magnitude of the force applied to the cover member CG and the position where the force is applied.

  A capacitance C exists between the drive electrode COML and the electrode SUS. That is, the drive electrode COML is capacitively coupled with the electrode SUS. The capacity C changes corresponding to the distance d. Therefore, the COG 19 can detect force information by detecting a change in the capacitance C. The principle of force detection will be described in detail later.

  The display control unit 11 and the detection control unit 200 drive the drive electrode COML and extract force information based on the change in the capacitance C from the electrode SUS. For example, the display control unit 11 and the detection control unit 200 are included in the COG 19 and the touch IC 49. The COG 19 outputs a signal to the drive electrode COML, and the touch IC 49 reads a signal based on the change in the capacitance value C from the electrode SUS as the force detection signal Vdet4. The display control unit 11 may be included in the COG 19 or the host HST. In addition, the detection control unit 200 may be included in the touch IC 49 or the host HST. The display control unit 11, the detection control unit 200, and the host HST may cooperate to control the touch detection unit SE1, the display unit DP, and the force detection unit SE2.

  In this configuration example, the drive electrode COML is shared by the touch detection unit SE1, the display unit DP, and the force detection unit SE2.

  FIG. 17 is a perspective view illustrating electrodes of the display device with a touch detection function according to the first embodiment. The plurality of touch detection electrodes TDL and the plurality of drive electrodes COML constitute the touch detection unit SE1 in FIG. Further, the plurality of drive electrodes COML and the electrode SUS constitute the force detection unit SE2 of FIG.

  In the present embodiment, the drive electrode COML that is driven by the touch detection unit SE1 and the force detection unit SE2 is shared, and the mutual capacitance type touch detection and force detection are simultaneously performed as described above.

  In the example illustrated in FIG. 17, the electrode SUS includes a striped electrode pattern extending in a direction intersecting with the extending direction of the electrode pattern of the drive electrode COML. The electrode SUS faces the drive electrode COML in the Z direction.

  The electrode pattern in which the drive electrode COML and the electrode SUS intersect with each other generates capacitance at the intersection. In the force detection unit SE2, when the drive electrode driver 14 applies the drive signal Vcomtm to the drive electrode COML, the detection signal Vdet4 is output from the electrode SUS, and force detection is performed.

<Principle of force detection>
[Basic principle]
FIG. 18 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the first embodiment. The display device with a touch detection function 1 according to the first embodiment performs force detection by detecting the mutual capacitance between the drive electrode COML and the electrode SUS.

As shown in FIG. 18, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS is C _G , which is the capacitance formed by the second substrate 21. The capacitance formed by the element OD1 is C _OD1 , the capacitance formed by the air layer AG is C _AG , the capacitance formed by the reflective polarizing film DBEF is C _DBEF , and the capacitance formed by the brightness enhancement film BEF is C _BEF. When the capacitance formed by the light diffusion sheet DI is C _DI , the capacitance formed by the light guide LG is C _LG , and the capacitance formed by the light reflector RS is C _RS , it is expressed by the following formula (1). be able to.

_{C = C G × C OD1 ×} C AG × C DBEF × C BEF × C DI × C LG × C RS / (C G + C OD1 + C AG + C DBEF + C BEF + C DI + C LG + C RS) ··· (1)

FIG. 19 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the first embodiment. As shown in FIG. 19, when the object OBJ applies a force to the input surface IS, the display unit 10 with a touch detection function bends. When the display unit with a touch detection function 10 bends, the thickness of the air layer AG is reduced. At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS. It is represented by (2).

C _AG '= C _AG + ΔC _AG (2)

  Further, the capacitance value C ′ between the drive electrode COML and the electrode SUS at this time can be expressed by the following formula (3).

_{C '= C G × C OD1} × C AG' × C DBEF × C BEF × C DI × C LG × C RS / (C G + C OD1 + C AG '+ C DBEF + C BEF + C DI + C LG + C RS) ··· (3)

  In the present embodiment, the display device with a touch detection function 1 detects the amount of change in capacitance (C′−C) generated between the drive electrode COML and the electrode SUS as a force detection value.

  Here, the influence which the temperature characteristic of the dielectric material which comprises the display apparatus 1 with a touch detection function which concerns on Embodiment 1 has in a force detection process is demonstrated.

  The cover member CG, the adhesive layer AL, the second optical element OD2, the first substrate 31, the second substrate 21, the first optical element OD1, the air layer AG, and the reflection that constitute the display device with a touch detection function 1 according to the first embodiment. The dielectrics constituting the members such as the type polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, the light guide LG, and the light reflector RS have temperature characteristics for each dielectric. Among these, in the present embodiment, the second substrate 21, the first optical element OD1, the air layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion provided between the drive electrode COML and the electrode SUS. The capacitance C between the drive electrode COML and the electrode SUS varies depending on the temperature characteristics of the dielectrics that form the sheet DI, the light guide LG, and the light reflector RS. Further, the change in the capacitance C between the drive electrode COML and the electrode SUS is also caused by the change in the thickness of each layer due to the thermal expansion of each dielectric. A change in the capacitance C between the drive electrode COML and the electrode SUS due to a change in the thickness of each layer due to the temperature characteristics of the dielectric or thermal expansion can affect the force detection process.

  FIG. 20 is a diagram illustrating an example of the temperature characteristic of the capacitance between the drive electrode and the electrode in a state where no force is applied to the input surface. In FIG. 20, the horizontal axis indicates the temperature, and the vertical axis indicates the capacitance value between the drive electrode COML and the electrode SUS.

  In the example shown in FIG. 20, the capacitance value between the drive electrode COML and the electrode SUS is Ca at the temperature a, the capacitance value between the drive electrode COML and the electrode SUS is Cb at the temperature b, and the drive electrode at the temperature c. In the example, the capacitance value between COML and the electrode SUS is Cc.

  As shown in FIG. 20, the capacitance value between the drive electrode COML and the electrode SUS varies depending on the temperature even when no force is applied to the input surface IS.

  The example shown in FIG. 20 shows an example in which the capacitance value between the drive electrode COML and the electrode SUS increases as the temperature rises, that is, the graph has a positive slope. Varies depending on the dielectric material and the combination of each dielectric, and the slope of the graph can be negative. In the example shown in FIG. 20, the capacitance value between the drive electrode COML and the electrode SUS changes linearly according to the temperature. However, the capacitance value may change to a quadratic curve.

  FIG. 21 is a diagram illustrating the relationship between the force applied to the input surface and the force detection value when the temperatures are different. In FIG. 21, the horizontal axis indicates the force applied to the input surface, and the vertical axis indicates the force detection value F. FIG. 22 is a diagram illustrating an error in the force detection value due to temperature when the force applied to the input surface is constant. In FIG. 22, the horizontal axis indicates the temperature, and the vertical axis indicates the force detection value F.

  As shown in FIGS. 21 and 22, when the force f applied to the input surface IS is constant, the force detection value F depends on the temperature characteristics of each dielectric provided between the drive electrode COML and the electrode SUS. An error will occur in the value of. Specifically, even if the force f applied to the input surface IS is constant, the value of the force detection value F is Fa at the temperature a, the value of the force detection value F is Fb at the temperature b, and at the temperature c. The value of the force detection value F is Fc.

  FIG. 23 is a diagram illustrating the relationship between the capacitance between the drive electrode and the electrode according to a temperature change and the force detection value. As shown in FIG. 23, the capacitance value between the drive electrode COML and the electrode SUS corresponding to the temperature change and the force detection value F are in a proportional relationship. That is, the following expressions (4) and (5) are established.

  Fb / Fa = Cb / Ca (4)

  Fb / Fc = Cb / Cc (5)

  Here, in a state where the object OBJ is not in contact with the input surface IS (hereinafter also referred to as “non-contact”), the reference temperature between the drive electrode COML and the electrode SUS (for example, at room temperature of 25 ° C.) ) The reference capacitance value in Tref is Cref, the capacitance value (first capacitance value) between the drive electrode COML and the electrode SUS at the time of non-contact is Ccur1, and the force is applied to the input surface IS (hereinafter referred to as “contact”) The capacitance value (second capacitance value) between the drive electrode COML and the electrode SUS is Ccur2, and the force detection value that is the amount of change in the capacitance between the drive electrode COML and the electrode SUS is When Fcur and the force detection correction value to be calculated are Fcor, the following equations (6) and (7) are obtained.

  Fcur = Ccur2-Ccur1 (6)

  Fcor = (Cref / Ccur1) * Fcur (7)

  As shown in the above equations (6) and (7), the force detection control unit 50 determines the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and the value at the time of non-contact. By multiplying the force detection value Fcur (= Ccur2-Ccur1) by the ratio (Cref / Ccur1) of the capacitance value Ccur1 between the drive electrode COML and the electrode SUS, a force detection correction value Fcor obtained by correcting the force detection value Fcur is obtained. Can be obtained.

  FIG. 24 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the first embodiment. In FIG. 24, the horizontal axis indicates the temperature, and the vertical axis indicates the force detection value F. In FIG. 24, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  FIG. 25 is a diagram illustrating the relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the first embodiment. In FIG. 25, the horizontal axis indicates the force applied to the input surface, and the vertical axis indicates the force detection value F. In FIG. 25, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  In the example shown in FIGS. 24 and 25, the temperature b is set to the reference temperature Tref.

  For example, as shown in FIG. 24, the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact with respect to the force detection value Fa at the temperature a using the above formulas (6) and (7). Is multiplied by the ratio (Cref / Cacur1) of the reference capacitance value Cref at the time of contact and the capacitance value Cacur1 between the drive electrode COML and the electrode SUS at the time of non-contact, to obtain a force detection correction value Facor obtained by correcting the force detection value Fa Can be obtained.

  Further, for example, as shown in FIG. 24, the reference between the drive electrode COML and the electrode SUS at the time of non-contact with respect to the force detection value Fc at the temperature c using the above formulas (6) and (7). A force detection correction value obtained by correcting the force detection value Fc by multiplying the reference capacitance value Cref at the temperature Tref by the ratio (Cref / Cccur1) of the capacitance value Cccur1 between the drive electrode COML and the electrode SUS when not in contact. Fccor can be obtained.

  Thus, as shown in FIG. 25, the second substrate 21, the first optical element OD1, the air layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF, which are provided between the drive electrode COML and the electrode SUS, The force detection value that is the amount of change in capacitance between the drive electrode COML and the electrode SUS caused by the temperature characteristics of the dielectrics constituting the light diffusion sheet DI, the light guide LG, and the light reflector RS is corrected. .

<Configuration and operation of force detection control unit>
In the present embodiment, the force detection process described above is performed by the force detection control unit 50 shown in FIG. More specifically, for example, this is performed by the force detection processing unit 442 of the signal processing unit 44 in the force detection control unit 50 shown in FIG.

  FIG. 26 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the first embodiment. In the present embodiment, the force detection processing unit 442 of the force detection control unit 50 is exemplified as being included in the signal processing unit 44 of the detection control unit 200.

  The force detection control unit 50 is a component that detects the force applied to the input surface IS by the detection object OBJ based on the capacitance generated between the drive electrode COML and the electrode SUS.

  The force detection processing unit 442 of the force detection control unit 50 includes a contact determination unit 51, a non-contact capacity calculation unit 52, a contact capacity calculation unit 53, a force detection value calculation unit 54, and a capacitance value ratio calculation unit 55. And a force detection value correction unit 56 and a reference capacitance value storage unit 57. The reference capacitance value storage unit 57 stores a reference temperature Tref (for example, between the drive electrode COML and the electrode SUS at the time of non-contact, which is individually set at the time of shipment of the display device 1 with a touch detection function according to the first embodiment. It is assumed that a reference capacitance value Cref in a room temperature 25 ° C. environment) is stored. The reference capacitance value storage unit 57 is configured by a register, for example.

  The contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, and the force detection value correction unit 56 are configured by, for example, a circuit. Further, the touch determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, and the force detection value correction unit 56 are programmed by the touch IC 49, for example. It may be realized by executing. In this case, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, and the force detection value correction unit 56 are, for example, the COG 19 or the host. The HST may be realized by executing a program, or may be realized by, for example, two or more of the COG 19, the touch IC 49, and the host HST executing the program in cooperation. .

The contact determination unit 51 determines whether or not the detected object OBJ is in contact with or close to the input surface IS based on a signal output from the first A / D conversion unit 43-1 (see FIG. 2). As a method for determining whether or not the detected object OBJ is in contact with or close to the input surface IS, for example, the absolute value | ΔV | of the difference between the waveform V ₀ and the waveform V ₁ shown in FIG. 5 is detected. Alternatively, a change in the capacitance value of the capacitive element C11 shown in FIGS. 3 and 4 may be detected. The present invention is not limited by the method for determining whether or not the object OBJ is in contact with or close to the input surface IS.

  When the drive signal Vcomtm is applied to the drive electrode COML, the non-contact-time capacity calculation unit 52 determines that the object to be detected OBJ is not in contact with or close to the input surface IS when the drive signal Vcomtm is applied to the drive electrode COML. Based on a signal output from the second A / D conversion unit 43-2 (see FIG. 2), a capacitance value Ccur1 between the drive electrode COML and the electrode SUS when not in contact is calculated, and a force detection value calculation unit is calculated. 54 and the capacitance value ratio calculation unit 55.

  When the drive signal Vcomtm is applied to the drive electrode COML, the contact-time capacity calculation unit 53 determines whether the detected object OBJ is in contact with or close to the input surface IS. Based on the signal output from the 2A / D conversion unit 43-2 (see FIG. 2), the capacitance value Ccur2 between the drive electrode COML and the electrode SUS at the time of contact is calculated, and the force detection value calculation unit 54 Output.

  The force detection value calculation unit 54 calculates a change amount (Ccur2-Ccur1) of the capacitance value Ccur2 at the time of contact with respect to the capacitance value Ccur1 at the time of non-contact as a force detection value Fcur, and outputs the force detection value Fcur to the force detection value correction unit 56.

  The capacitance value ratio calculation unit 55 calculates a ratio (Cref / Ccur1) between the reference capacitance value Cref at the time of non-contact at the reference temperature Tref and the capacitance value Ccur1 detected at the time of non-contact, and the force detection value correction unit 56 Output to.

  The force detection value correction unit 56 is not in contact with the reference capacitance value Cref at the time of non-contact at the reference temperature Tref input from the capacitance value ratio calculation unit 55 with respect to the force detection value Fcur input from the force detection value calculation unit 54. The force detection correction value Fcor (= (Cref / Ccur1) * Fcur) is calculated and output by multiplying the ratio (Cref / Ccur1) with the capacitance value Ccur1 detected at times.

  FIG. 27 is a timing diagram illustrating an example of operation timing of the display device with a touch detection function according to the first embodiment.

  In the display device 1 with a touch detection function according to the first embodiment, one display frame that displays one image (one frame) includes two one touch frames that perform touch detection and force detection on the input surface IS. One display frame may include one touch frame or three or more.

  In the present embodiment, the mutual static between the drive electrode COML and the touch detection electrode TDL during the blanking period other than the display period 138 in which the pixel signal Vpix is applied to the display unit DP and the display unit DP performs display writing of the image. A mutual capacitance detection period 139 for detecting the capacitance and the mutual capacitance between the drive electrode COML and the electrode SUS, and a self-capacitance detection period 140 for detecting the self-capacitance of the touch detection electrode TDL. And a self-capacitance detection period 141 for detecting the self-capacitance of the drive electrode COML.

  In the mutual capacitance detection period 139, the drive signal Vcomtm is applied to the plurality of drive electrodes COML. The mutual capacitance between the drive electrode COML and the touch detection electrode TDL detected in the mutual capacitance detection period 139 is used for touch detection in the touch detection control unit 40. Further, the mutual capacitance between the drive electrode COML and the electrode SUS detected in the mutual capacitance detection period 139 is used for force detection in the force detection control unit 50.

  In the self-capacitance detection period 140, the drive signal Vcomts1 is sequentially applied to the plurality of touch detection electrodes TDL, and the self-capacitance of the touch detection electrodes TDL is detected. The self-capacitance of the touch detection electrode TDL detected in the self-capacitance detection period 140 is used for touch detection in the touch detection control unit 40.

  In the self-capacitance detection period 141, the drive signal Vcomts2 is applied to the plurality of drive electrodes COML, and the self-capacitance of the drive electrodes COML is detected. The self-capacitance of the drive electrode COML detected in the self-capacitance detection period 141 is used for touch detection in the touch detection control unit 40.

  The touch detection control unit 40 detects the mutual capacitance between the drive electrode COML and the touch detection electrode TDL detected in the mutual capacitance detection period 139, and the touch detection detected in the self-capacitance detection period 140. Touch detection is performed based on the self-capacitance of the electrode TDL and the self-capacitance of the drive electrode COML detected in the self-capacitance detection period 141. The touch detection control unit 40 adds the self-capacitance of the touch detection electrode TDL and the self-capacitance of the drive electrode COML in addition to the mutual capacitance between the drive electrode COML and the touch detection electrode TDL. In addition, the influence of water droplets or the like can be suitably suppressed, and a stylus pen or the like can be suitably detected.

  In the present embodiment, the force detection control unit 50 performs force detection based on the capacitance value detected by the electrode SUS in the mutual capacitance detection period 139.

  FIG. 28 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the first embodiment. The process shown in FIG. 28 is performed in the mutual capacitance detection period 139 described above.

  The non-contact-time capacity calculation unit 52 calculates a capacitance value Ccur1 between the drive electrode COML and the electrode SUS at the non-contact time based on a signal output from the second A / D conversion unit 43-2 (see FIG. 2). Calculate (step S101).

The contact determination unit 51 determines whether or not the detected object OBJ is in contact with or close to the input surface IS (step S102). When the contact determination unit 51 determines that the object OBJ is not in contact with or close to the input surface IS, that is, no force is applied to the input surface IS (step S102; No), the process returns to step S101. The processes in steps S101 and S102 are repeatedly performed until it is determined in step S102 that the object OBJ is in contact with or close to the input surface IS. The contact in the determination unit 51, as a method of determining whether the detected object OBJ is in contact with or in proximity to the input surface IS, for example, the absolute of the difference between the waveform V ₀ and the waveform V ₁ shown in FIG. 5 The value | ΔV | may be detected, or a change in the capacitance value of the capacitive element C11 shown in FIGS. 3 and 4 may be detected.

  When the contact determination unit 51 determines that the detected object OBJ is in contact with or close to the input surface IS (step S102; Yes), the contact-time capacity calculation unit 53 includes the second A / D conversion unit 43- Based on the signal output from 2 (see FIG. 2), the capacitance value Ccur2 between the drive electrode COML and the electrode SUS at the time of contact is calculated (step S103).

  The force detection value calculation unit 54 calculates a change amount (Ccur2-Ccur1) of the capacitance value Ccur2 at the time of contact with respect to the capacitance value Ccur1 at the time of non-contact as a force detection value Fcur, and outputs it to the force detection value correction unit 56 (step). S104).

  The capacitance value ratio calculation unit 55 calculates a ratio (Cref / Ccur1) between the reference capacitance value Cref at the time of non-contact at the reference temperature Tref and the capacitance value Ccur1 detected at the time of non-contact, and the force detection value correction unit 56 (Step S105).

  The force detection value correction unit 56 is not in contact with the reference capacitance value Cref at the time of non-contact at the reference temperature Tref input from the capacitance value ratio calculation unit 55 with respect to the force detection value Fcur input from the force detection value calculation unit 54. The force detection correction value Fcor (= (Cref / Ccur1) * Fcur) is calculated by multiplying the ratio (Cref / Ccur1) with the capacitance value Ccur1 detected at times (step S106), and the process of step S101 is performed. Return.

  By performing the above-described processing, it is possible to suppress the influence on the force detection processing due to the temperature characteristics of the air layer AG provided between the drive electrode COML and the electrode SUS and the dielectric material constituting the stacked body LB. , It is possible to suppress a decrease in detection accuracy in the force detection process.

<Modification 1>
FIG. 29 is a perspective view illustrating a touch detection electrode, a drive electrode, and an electrode of the display device with a touch detection function according to the first modification of the first embodiment. As shown in FIG. 29, the electrode SUS may be composed of a single electrode. The electrode SUS may have a configuration in which the number of electrode patterns is larger than that in the example shown in FIG. 17 or may be configured by an electrode pattern in which a plurality of electrodes are arranged in a matrix.

<Modification 2>
30 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the second modification of the first embodiment. FIG. 31 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the second modification of the first embodiment. As illustrated in FIGS. 30 and 31, in the second modification of the first embodiment, the electrode SUS is provided between the light guide LG and the light reflector RS. In this case, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS can be expressed by the following formula (8).

_{C = C G × C OD1 ×} C AG × C DBEF × C BEF × C DI × C LG / (C G + C OD1 + C AG + C DBEF + C BEF + C DI + C LG) ··· (8)

  In the second modification of the first embodiment, the capacitance value C ′ between the drive electrode COML and the electrode SUS when a force is applied to the input surface IS can be expressed by the following equation (9). .

_{C '= C G × C OD1} × C AG' × C DBEF × C BEF × C DI × C LG / (C G + C OD1 + C AG '+ C DBEF + C BEF + C DI + C LG) ··· (9)

At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS, and the above-described equation It is represented by (2).

<Modification 3>
FIG. 32 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the third modification of the first embodiment. FIG. 33 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the third modification of the first embodiment. As shown in FIGS. 32 and 33, in the third modification of the first embodiment, the electrode SUS is provided between the light diffusion sheet DI and the light guide LG. In this case, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS can be expressed by the following equation (10).

_{C = C G × C OD1 ×} C AG × C DBEF × C BEF × C DI / (C G + C OD1 + C AG + C DBEF + C BEF + C DI) ··· (10)

  In the third modification of the first embodiment, the capacitance value C ′ between the drive electrode COML and the electrode SUS when a force is applied to the input surface IS can be expressed by the following equation (11). .

_{C '= C G × C OD1} × C AG' × C DBEF × C BEF × C DI / (C G + C OD1 + C AG '+ C DBEF + C BEF + C DI) ··· (11)

At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS, and the above-described equation It is represented by (2).

<Modification 4>
FIG. 34 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the fourth modification of the first embodiment. FIG. 35 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fourth modification of the first embodiment. As shown in FIGS. 34 and 35, in Modification 4 of Embodiment 1, the electrode SUS is provided between the brightness enhancement film BEF and the light diffusion sheet DI. In this case, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS can be expressed by the following equation (12).

_{C = C G × C OD1 ×} C AG × C DBEF × C BEF / (C G + C OD1 + C AG + C DBEF + C BEF) ··· (12)

  In the fourth modification of the first embodiment, the capacitance value C ′ between the drive electrode COML and the electrode SUS when a force is applied to the input surface IS can be expressed by the following equation (13). .

_{C '= C G × C OD1} × C AG' × C DBEF × C BEF / (C G + C OD1 + C AG '+ C DBEF + C BEF) ··· (13)

At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS, and the above-described equation It is represented by (2).

<Modification 5>
FIG. 36 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the fifth modification of the first embodiment. FIG. 37 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fifth modification of the first embodiment. As shown in FIGS. 36 and 37, in Modification 5 of Embodiment 1, the electrode SUS is provided between the reflective polarizing film DBEF and the brightness enhancement film BEF. In this case, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS can be expressed by the following equation (14).

_{C = C G × C OD1 ×} C AG × C DBEF / (C G + C OD1 + C AG + C DBEF) ··· (14)

  In the fifth modification of the first embodiment, the capacitance value C ′ between the drive electrode COML and the electrode SUS when a force is applied to the input surface IS can be expressed by the following equation (15). .

_{C '= C G × C OD1} × C AG' × C DBEF / (C G + C OD1 + C AG '+ C DBEF) ··· (15)

At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS, and the above-described equation It is represented by (2).

<Modification 6>
FIG. 38 is a cross-sectional view and an equivalent circuit diagram when no force is applied to the input surface of the display device with a touch detection function according to the sixth modification of the first embodiment. FIG. 39 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the sixth modification of the first embodiment. As shown in FIGS. 38 and 39, in the sixth modification of the first embodiment, the electrode SUS is provided on the surface on the incident surface IS side of the stacked body LB constituting the backlight unit BL. In this case, the capacitance value C between the drive electrode COML and the electrode SUS when no force is applied to the input surface IS can be expressed by the following equation (16).

_{C = C G × C OD1 ×} C AG / (C G + C OD1 + C AG) ··· (16)

  In the sixth modification of the first embodiment, the capacitance value C ′ between the drive electrode COML and the electrode SUS when a force is applied to the input surface IS can be expressed by the following equation (17). .

_{C '= C G × C OD1} × C AG' / (C G + C OD1 + C AG ') ··· (17)

At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS, and the above-described equation It is represented by (2).

  The configurations according to Modification 2 to Modification 6 of Embodiment 1 described above can be realized by configuring the electrode SUS using a light-transmitting conductive film such as ITO (Indium Tin Oxide). it can.

  As shown in Modification 2 to Modification 6 of Embodiment 1, in the display device with a touch detection function 1 according to Embodiment 1, the object to be detected OBJ is placed on the input surface IS between the electrode SUS and the drive electrode COML. If a structure is provided in which an air layer AG (dielectric layer) whose thickness is changed by bending the display unit 10 with a touch detection function when a force is applied, the distance d from the electrode SUS to the drive electrode COML changes. The force information can be detected by detecting a change in capacitance between the drive electrode COML and the electrode SUS.

  Further, in the above-described first embodiment, the example in which the touch detection of both the mutual capacitance method and the self-capacitance method is performed has been described. However, the display device 1 with a touch detection function according to the first embodiment is described. It is also possible to apply to a configuration in which only the mutual capacitance type touch detection is performed without performing the self capacitance type touch detection.

  As described above, the display device with a touch detection function 1 according to the embodiment includes the input surface IS to which a force is applied by the detected object OBJ and the touch that is provided on the first substrate 31 and faces the input surface IS. The detection electrode TDL, the drive electrode COML (first electrode) provided on the second substrate 21 and facing the touch detection electrode TDL, and the electrode SUS facing the drive electrode COML (first electrode) across the dielectric layer (Second electrode), a touch detection control unit that detects contact or proximity of the object OBJ to the input surface IS based on the capacitance between the drive electrode COML (first electrode) and the touch detection electrode TDL. 40, and a force detection control unit 50 that detects the force applied to the input surface IS by the detected object OBJ based on the capacitance between the drive electrode COML (first electrode) and the electrode SUS (second electrode). And equipped with . The force detection control unit 50 corrects the force detection value Fcur based on the reference capacitance value Cref at the reference temperature T between the drive electrode COML and the force detection electrode SUS when the object OBJ is not in contact with the input surface IS. Then, the force detection correction value Fcor is output.

  In addition, the display device 1 with a touch detection function according to the first embodiment includes an input surface IS to which a force is applied by the detection object OBJ, and drive electrodes COML (first electrodes) arranged to face each other across a dielectric layer. And an electrode SUS (second electrode), a touch detection control unit 40 that detects contact or proximity of the object OBJ to the input surface IS, a drive electrode COML (first electrode), and an electrode SUS (second electrode) And a force detection control unit 50 that detects the force applied to the input surface IS by the object to be detected OBJ. The force detection control unit 50 determines the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS. Force detection based on the ratio (Cref / Ccur) of the capacitance value Ccur1 between the drive electrode COML (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS The value Fcur is corrected.

  More specifically, the force detection control unit 50 determines the reference temperature Tref between the drive electrode COML (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS. Of the reference capacitance value Cref at the time of non-contact with the input surface IS of the detected object OBJ and the capacitance value Ccur1 between the drive electrode COML (first electrode) and the electrode SUS (second electrode) (Cref / The force detection value Fcur is multiplied by Ccur) to correct the force detection value Fcur.

  With the above configuration, the influence of the temperature characteristics of the dielectric that constitutes the air layer AG and the stacked body LB provided between the drive electrode COML (first electrode) and the electrode SUS (second electrode) on the force detection process. It can suppress, and the fall of the detection accuracy in a force detection process can be suppressed.

  By this embodiment, the display apparatus with a touch detection function which can suppress the fall of the detection accuracy of the force applied to the input surface of a touch panel is obtained.

(Embodiment 2)
FIG. 40 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of the display device with a touch detection function according to the second embodiment. In addition, the overlapping description is abbreviate | omitted about the structure part equivalent or the same as Embodiment 1. FIG.

  As described in the first embodiment, the cover member CG, the adhesive layer AL, the second optical element OD2, the first substrate 31, the second substrate 21, the first optical element OD1, and the air that constitute the display device with a touch detection function 1a. The dielectrics constituting each member such as the layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF, the light diffusion sheet DI, the light guide LG, and the light reflector RS have temperature characteristics for each dielectric. The capacitance C between the drive electrode COML and the electrode SUS varies depending on the temperature characteristics of each dielectric provided between the drive electrode COML and the electrode SUS. Further, the change in the capacitance C between the drive electrode COML and the electrode SUS is also caused by the change in the thickness of each layer due to the thermal expansion of each dielectric. A change in the capacitance C between the drive electrode COML and the electrode SUS due to a change in the thickness of each layer due to the temperature characteristics of the dielectric or thermal expansion can affect the force detection process.

  In the present embodiment, as shown in FIG. 40, a temperature sensor 60 is provided in addition to the configuration of the first embodiment. The force detection control unit 50a corrects the force detection value by multiplying the force detection value by a predetermined correction coefficient (first correction coefficient) corresponding to the temperature detected by the temperature sensor 60.

  FIG. 41 is a diagram illustrating an arrangement example 1 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 42 is a diagram illustrating an arrangement example 2 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 43 is a diagram illustrating an arrangement example 3 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 44 is a diagram illustrating an arrangement example 4 of the temperature sensor of the display device with a touch detection function according to the second embodiment. FIG. 45 is a diagram illustrating an arrangement example 5 of the temperature sensor of the display device with a touch detection function according to the second embodiment.

  In this embodiment, it is set as the structure which detects the temperature inside the housing | casing of the display apparatus 1a with a touch detection function replaceable with the temperature of each dielectric material which comprises the display apparatus 1a with a touch detection function. As shown in FIG. 41, the temperature sensor 60 can be mounted on a flexible printed circuit board T on which a touch IC 49 is mounted, for example. For example, as shown in FIG. 42, the host HST may have a temperature sensor 60. Further, for example, as shown in FIG. 43, the temperature sensor 60 may be mounted on the second substrate 21 together with the COG 19, and for example, as shown in FIG. The sensor 60 may be configured, or the temperature sensor 60 may be configured inside the COG 19 as shown in FIG.

  FIG. 46 is a diagram illustrating an example of the relationship between the correction coefficient and the temperature of the display device with a touch detection function according to the second embodiment. FIG. 47 is a diagram illustrating an example of a first correction coefficient table of the display device with a touch detection function according to the second embodiment. In FIG. 46, the horizontal axis indicates the temperature, and the vertical axis indicates the correction coefficient by which the force detection value is multiplied. In the example shown in FIGS. 46 and 47, the temperature b is the reference temperature Tref, and the correction coefficient k at this time is 1 (k = 1).

  Depending on the location where the temperature sensor 60 is mounted, a temperature different from the temperature of each dielectric material constituting the display device with a touch detection function 1a may be detected. For example, as shown in FIG. 42, in the configuration in which the host HST has the temperature sensor 60, when it is configured in the package of the CPU, or as shown in FIG. 44 and FIG. When 60 is configured, the temperature due to heat generated by the IC chip such as the CPU, the touch IC 49, and the COG 19 may be added. Accordingly, the reference temperature Tref (that is, the temperature at which the correction coefficient k is 1 (k = 1)) varies depending on the location where the temperature sensor 60 is mounted. For this reason, for example, it is preferable to set the temperature detected by the temperature sensor 60 as the reference temperature Tref at the recommended use temperature assumed in the display device with a touch detection function 1a (for example, in a room temperature of 25 ° C. environment).

  In addition, the example shown in FIG. 46 shows an example in which the value of the correction coefficient k decreases as the temperature rises, that is, the slope of the graph becomes negative. Depending on the combination of dielectrics, the slope of the graph can be positive. In the example shown in FIG. 46, the correction coefficient k is linearly changed according to the temperature. However, the correction coefficient k may be changed to a quadratic curve.

  Here, the correction coefficient k of the display device with a touch detection function 1a according to the second embodiment will be described.

  As described with reference to FIG. 23 in the first embodiment, the capacitance value and the force detection value F between the drive electrode COML and the electrode SUS according to the temperature change are expressed by equations (4) and (5). There is a proportional relationship. When these equations (4) and (5) are transformed with respect to the force detection value Fb at the temperature b, the following equations (18) and (19) are obtained.

  Fb = (Cb / Ca) Fa (18)

  Fb = (Cb / Cc) Fc (19)

  Here, the reference capacitance value at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact (for example, at room temperature of 25 ° C.) is Cref, and between the drive electrode COML and the electrode SUS at the time of non-contact. The capacitance value (first capacitance value) is Ccur1, the capacitance value (second capacitance value) between the drive electrode COML and the electrode SUS at the time of contact is Ccur2, and the change in capacitance between the drive electrode COML and the electrode SUS. When the force detection value that is a quantity is Fcur and the force detection correction value to be obtained is Fcor, the following equations (20) and (21) are obtained.

  Fcur = Ccur2-Ccur1 (20)

  Fcor = (Cref / Ccur1) * Fcur (21)

  In the above equation (21), (Cref / Ccur1) is the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact, and the drive electrode COML and electrode SUS at the time of non-contact. It is a fixed value determined by the ratio with the capacitance value (first capacitance value) Ccur1. Therefore, by setting (Cref / Ccur1) as the correction coefficient k ((Cref / Ccur1) = k), the following equation (22) is obtained.

  Fcor = k * Fcur (22)

  The force detection control unit 50a includes a reference capacitance value Cref at a reference temperature Tref of a capacitance value between the drive electrode COML and the electrode SUS at the time of non-contact and a capacitance value between the drive electrode COML and the electrode SUS at a time of non-contact. A ratio (Cref / Ccur1) with Ccur1 is set in advance as a correction coefficient k. The force detection control unit 50a can obtain a force detection correction value Fcor obtained by correcting the force detection value Fcur by multiplying the force detection value Fcur (= Ccur2-Ccur1) by the correction coefficient k.

  FIG. 48 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the second embodiment. In FIG. 48, the horizontal axis indicates the temperature, and the vertical axis indicates the force detection value F. In FIG. 48, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  FIG. 49 is a diagram illustrating a relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the second embodiment. In FIG. 49, the horizontal axis represents the force applied to the input surface, and the vertical axis represents the force detection value F. In FIG. 49, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  In the example shown in FIGS. 48 and 49, the temperature b is set to the reference temperature Tref.

  For example, as shown in FIG. 48, the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact with respect to the force detection value Fa at the temperature a using the above formulas (20) and (22). The force detection correction value Facor obtained by correcting the force detection value Fa is obtained by multiplying the correction coefficient ka determined by the ratio between the reference capacitance value Cref and the capacitance value Cacur1 between the drive electrode COML and the electrode SUS at the time of non-contact. Can be obtained.

  For example, as shown in FIG. 48, the reference between the drive electrode COML and the electrode SUS at the time of non-contact with respect to the force detection value Fc at the temperature c using the above formulas (20) and (22). A force detection correction value obtained by correcting the force detection value Fc by multiplying a correction coefficient kc determined by the ratio between the reference capacitance value Cref at the temperature Tref and the capacitance value Cccur1 between the drive electrode COML and the electrode SUS when not in contact. Fccor can be obtained.

  Thereby, as shown in FIG. 49, the second substrate 21, the first optical element OD1, the air layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF provided between the drive electrode COML and the electrode SUS, The force detection value due to the change in the capacitance value between the drive electrode COML and the electrode SUS caused by the temperature characteristics of the dielectrics constituting the light diffusion sheet DI, the light guide LG, and the light reflector RS is corrected.

<Configuration and operation of force detection control unit>
In the present embodiment, the above-described force detection process is performed by, for example, the force detection processing unit 442a of the signal processing unit 44a in the force detection control unit 50a illustrated in FIG.

  FIG. 50 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the second embodiment.

  The force detection processing unit 442a of the force detection control unit 50a includes a contact determination unit 51, a non-contact capacity calculation unit 52, a contact capacity calculation unit 53, a force detection value calculation unit 54, and a force detection value correction unit 56a. And a first correction coefficient derivation unit 61 and a first correction coefficient table storage unit 62. It is assumed that the first correction coefficient table storage unit 62 stores a first correction coefficient table individually set in advance at the time of shipment of the display device with a touch detection function 1a according to the second embodiment. The first correction coefficient table storage unit 62 is configured by a register, for example.

  The contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56a, and the first correction coefficient derivation unit 61 are configured by a circuit, for example. . In addition, the touch determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56a, and the first correction coefficient derivation unit 61 are configured by, for example, the touch IC 49. It may be realized by executing a program. In this case, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56a, and the first correction coefficient derivation unit 61 are, for example, the COG 19 or The host HST may be realized by executing a program, or may be realized by, for example, two or more of the COG 19, the touch IC 49, and the host HST executing the program in cooperation. good.

  The operations of the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, and the force detection value calculation unit 54 are the same as those in the first embodiment.

  The first correction coefficient derivation unit 61 refers to the first correction coefficient table stored in the first correction coefficient table storage unit 62, derives a correction coefficient k corresponding to the temperature Tcur detected by the temperature sensor 60, and It outputs to the force detection value correction | amendment part 56a.

  The force detection value correction unit 56a multiplies the force detection value Fcur input from the force detection value calculation unit 54 by the correction coefficient k input from the first correction coefficient deriving unit 61, thereby detecting the force detection correction value Fcor (= k * Fcur) is output.

  In the present embodiment, the force detection control unit 50a performs force detection based on the capacitance value detected by the electrode SUS in the mutual capacitance detection period 139 (see FIG. 27) described in the first embodiment.

  FIG. 51 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the second embodiment. The process shown in FIG. 51 is performed in the mutual capacitance detection period 139 described above.

  In the flowchart shown in FIG. 51, the processing from step S201 to step S204 is substantially the same as the processing from step S101 to step S104 in the flowchart of the first embodiment shown in FIG. .

  The first correction coefficient derivation unit 61 refers to the first correction coefficient table stored in the first correction coefficient table storage unit 62, derives a correction coefficient k corresponding to the temperature Tcur detected by the temperature sensor 60, and It outputs to the force detection value correction | amendment part 56a (step S205).

  The force detection value correction unit 56a multiplies the force detection value Fcur input from the force detection value calculation unit 54 by the correction coefficient k input from the first correction coefficient derivation unit 61 to obtain a force detection correction value Fcor (= k * Fcur) is calculated and output (step S206), and the process returns to step S201.

  By performing the above-described processing, it is possible to suppress the influence on the force detection processing due to the temperature characteristics of the air layer AG provided between the drive electrode COML and the electrode SUS and the dielectric material constituting the stacked body LB. , It is possible to suppress a decrease in detection accuracy in the force detection process.

  As described above, the display device with a touch detection function 1a according to the second embodiment includes the temperature sensor 60 that detects the temperature inside the housing. The force detection control unit 50a corrects the force detection value Fcur according to the temperature Tcur detected by the temperature sensor 60.

  More specifically, the force detection control unit 50a determines the reference temperature Tref between the drive electrode COML (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS. Of the reference capacitance value Cref at the time of non-contact with the input surface IS of the detected object OBJ and the capacitance value Ccur1 between the drive electrode COML (first electrode) and the electrode SUS (second electrode) (Cref / Ccur1) is preset as the correction coefficient k. The force detection control unit 50a corrects the force detection value Fcur by multiplying the force detection value Fcur by a correction coefficient (first correction coefficient) k.

  Further, the force detection control unit 50a, based on the first correction coefficient table in which the temperature and the correction coefficient (first correction coefficient) k are associated with each other, according to the temperature detected by the temperature sensor 60, the force detection value Fcur. Correct.

  With the above configuration, the influence of the temperature characteristics of the dielectric that constitutes the air layer AG and the stacked body LB provided between the drive electrode COML (first electrode) and the electrode SUS (second electrode) on the force detection process. It can suppress, and the fall of the detection accuracy in a force detection process can be suppressed.

  By this embodiment, the display apparatus with a touch detection function which can suppress the fall of the detection accuracy of the force applied to the input surface of a touch panel is obtained.

(Embodiment 3)
FIG. 52 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of the display device with a touch detection function according to the third embodiment. In addition, the overlapping description is abbreviate | omitted about the structure part equivalent or the same as Embodiment 1. FIG.

  In the present embodiment, as shown in FIG. 52, the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40 is input to the force detection control unit 50b. The force detection control unit 50b multiplies the force detection value by a predetermined correction coefficient (second correction coefficient) corresponding to the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40, thereby detecting the force. Correct the value.

  FIG. 53 is a plan view of the display device with a touch detection function according to the third embodiment. In the force detection region Af, a straight line 130 that is parallel to the Y-axis direction and passes through the center of the force detection region Af in the X-axis direction is assumed.

  The coordinate s is located on the straight line 130 and in the center of the force detection area Af. The coordinate u is located on the straight line 130 and at the edge of the force detection area Af. The coordinate t is a coordinate located on the straight line 130 and in the middle between the coordinate s and the coordinate u.

  The vicinity of the central portion of the input surface IS, that is, the vicinity of the coordinate s shown in FIG. In other words, when a certain force is applied near the center of the input surface IS, the deflection amount (deformation amount) of the display unit 10 with a touch detection function is the same force applied near the edge of the input surface IS. This is larger than the amount of deflection of the display unit 10 with a touch detection function.

  That is, the amount of deflection of the display unit 10 with a touch detection function when a certain force is applied near the coordinate s is greater than the amount of deflection of the display unit 10 with a touch detection function when the same force is applied near the coordinate t. Is also big. Further, the deflection amount of the display unit 10 with a touch detection function when the same force is applied near the coordinate t is larger than the deflection amount of the display unit 10 with a touch detection function when the same force is applied near the coordinate s. It is smaller and larger than the deflection amount of the display unit with a touch detection function 10 when the same force is applied in the vicinity of the coordinate u.

  FIG. 54 is a graph showing the relationship between the touch detection position in the Y-axis direction and the force detection value at the center position in the X-axis direction of the region where the force is applied on the input surface of the display device with a touch detection function according to the third embodiment. It is. In FIG. 54, the horizontal axis represents the Y coordinate, and the vertical axis represents the force detection value F.

  As described above, it is most likely to bend near the center of the input surface IS, that is, near the coordinate s shown in FIG. Therefore, the force detection value F is maximum at the Y coordinate Ys. The force detection value at this Y coordinate Ys is defined as Fs. Similarly, the force detection value at the Y coordinate Yt is Ft, and the force detection value at the Y coordinate Yu is Fu.

  FIG. 55 is a graph showing the relationship between the touch detection position in the Y-axis direction and the correction coefficient at the center position in the X-axis direction of the region where the force is applied on the input surface of the display device with a touch detection function according to the third embodiment. is there. The example shown in FIG. 55 shows an example in which the center position of the input surface IS in the X-axis direction and the Y-axis direction, that is, the coordinate s is the reference position, and the correction coefficient kp at this reference position is 1 (kp = 1). ing.

  The reference position where the correction coefficient kp is 1 (kp = 1) is not limited to the center position of the input surface IS in the X-axis direction and the Y-axis direction, and an arbitrary position of the force detection region Af on the input surface IS. It can be a reference position.

  Here, the correction coefficient kp of the display device with a touch detection function 1b according to the third embodiment will be described.

  When the same force is applied to the coordinates s, t, u shown in FIG. 53 and the same force detection correction value Fcor is obtained at the coordinates s, t, u, the following equation (23) is established.

  Fcor = kps * Fs = kpt * Ft = kpu * Fu (23)

  When the above equation (23) is modified with respect to the correction coefficients kps, kpt, kpu, the following equations (24), (25), (26) are obtained.

  kps = Fcor / Fs (24)

  kpt = Fcor / Ft (25)

  kpu = Fcor / Fu (26)

  When the above equations (24), (25), and (26) are generalized as Fcur and a correction coefficient kp as a force detection value at an arbitrary position in the force detection region Af on the input surface IS, the following equation (27) is obtained. .

  kp = Fcor / Fcur (27)

  In the above equation (27), if an arbitrary position of the force detection area Af on the input surface IS is a reference position and the correction coefficient kp at this reference position is 1 (kp = 1), the force detection value Fcur at the reference position is The force detection correction value Fcor becomes equal (Fcor = Fcur). At this time, the above equations (24), (25), (26) can be transformed into the following equations (28), (29), (30).

  kps = Fcur / Fs (28)

  kpt = Fcur / Ft (29)

  kpu = Fcur / Fu (30)

  In the above formulas (28), (29), and (30), Fcur / Fs, Fcur / Ft, and Fcur / Fu are force detection at the reference position of the force detection region Af on the input surface IS under the same temperature condition. The value Fcur and the force detection value (for example, the force detection value Fs at the coordinate s, the force detection value Ft at the coordinate t, the force detection value at the coordinate u) at an arbitrary position (for example, coordinates s, t, u) of the force detection area Af It is a fixed value determined by the ratio to Fu). Therefore, by setting these Fcur / Fs, Fcur / Ft, and Fcur / Fu as correction coefficients kp, the following equation (31) is obtained from equation (7) described in the first embodiment.

  Fcor = kp * (Cref / Ccur1) * Fcur (31)

  The force detection correction unit 50b is configured so that the ratio between the force detection value Fcur at the reference position of the force detection area Af of the input surface IS and the force detection value at an arbitrary position of the force detection area Af under the same temperature condition is a correction coefficient kp in advance. Is set as The force detection correction unit 50b includes a reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and a capacitance value Ccur1 between the drive electrode COML and the electrode SUS at the time of non-contact. By multiplying the force detection value Fcur by the ratio (Cref / Ccur1) and further multiplying by the correction coefficient kp described above, a force detection correction value Fcor in which the force detection value Fcur is corrected according to the touch detection position can be obtained.

  In the above description, the case where the coordinates s, t, u are on the straight line 130 (see FIG. 53) is illustrated. However, in reality, the force detection area Af is two-dimensional as shown in FIG. Therefore, the display device with a touch detection function 1b uses a different correction coefficient kp for each two-dimensional position to which a force is applied. More specifically, the force detection area Af on the input surface IS is divided into a plurality of areas, and the correction coefficient kp corresponding to the touch detection position is used using the second correction coefficient table in which the correction coefficient kp is set for each area. Apply.

  FIG. 56 is a diagram illustrating an example of division of the force detection region on the input surface of the display device with a touch detection function according to the third embodiment. FIG. 57 is a diagram illustrating an example of a second correction coefficient table of the display device with a touch detection function according to the third embodiment. In the example shown in FIGS. 56 and 57, the correction coefficient kp in the region (Xp, Yq) including the center position of the input surface IS in the X-axis direction and the Y-axis direction is set to 1 (kp (p, q) = 1). An example is shown.

  FIG. 58 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the third embodiment. In FIG. 58, the horizontal axis indicates the temperature, and the vertical axis indicates the force detection value F. In FIG. 58, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  FIG. 59 is a diagram illustrating a relationship between a force applied to the input surface and a force detection correction value in the display device with a touch detection function according to the third embodiment. In FIG. 59, the horizontal axis indicates the force applied to the input surface, and the vertical axis indicates the force detection value F. In FIG. 59, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  In the example shown in FIGS. 58 and 59, the temperature b is set as the reference temperature Tref, and a constant force is applied to the coordinate t of the force detection region Af shown in FIG.

  The force detection control unit 50b has a ratio (Fcur / Ft) between the force detection value Fcur at the reference position of the force detection region Af of the input surface IS and the force detection value Fat at the coordinate t of the force detection region Af under the same temperature condition. ) Is previously set as the correction coefficient kpt.

  The force detection control unit 50b generates a capacitance value Cacur1 between the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS when not in contact with the drive electrode COML and the electrode SUS at the temperature a. The force detection correction value Fatcor obtained by correcting the force detection value Fat by multiplying the force detection value Fat by the ratio (Cref / Cacur1) to the force detection value (two-dot chain line) and further multiplying by the correction coefficient kpt at the coordinate t (one-dot chain line). Can be obtained.

  Further, the force detection control unit 50b generates a capacitance between the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS when not in contact and the drive electrode COML and the electrode SUS at non-contact at the temperature c. The force detection correction value Fctcor obtained by correcting the force detection value Fct is obtained by multiplying the force detection value Fct by the ratio (Cref / Cccur1) to the value Cccur1 (two-dot chain line) and further multiplying by the correction coefficient kpt at the coordinate t. be able to.

  Thereby, as shown in FIG. 59, the second substrate 21, the first optical element OD1, the air layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF provided between the drive electrode COML and the electrode SUS, The force detection value due to the change in the capacitance value between the drive electrode COML and the electrode SUS caused by the temperature characteristics of the dielectrics constituting the light diffusion sheet DI, the light guide LG, and the light reflector RS is corrected.

<Configuration and operation of force detection control unit>
In the present embodiment, the above-described force detection process is performed by, for example, the force detection processing unit 442b of the signal processing unit 44b in the force detection control unit 50b illustrated in FIG.

  FIG. 60 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the third embodiment.

  The force detection processing unit 442b of the force detection control unit 50b includes a contact determination unit 51, a non-contact capacity calculation unit 52, a contact capacity calculation unit 53, a force detection value calculation unit 54, and a capacitance value ratio calculation unit 55. A force detection value correction unit 56b, a reference capacitance value storage unit 57, a second correction coefficient derivation unit 63, and a second correction coefficient table storage unit 64. It is assumed that the second correction coefficient table storage unit 64 stores a second correction coefficient table individually set in advance at the time of shipment of the display device with a touch detection function 1b according to the third embodiment. The second correction coefficient table storage unit 64 is composed of, for example, a register.

  The contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, the force detection value correction unit 56b, and the second correction coefficient derivation unit 63 are: For example, it is composed of a circuit. Further, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, the force detection value correction unit 56b, and the second correction coefficient derivation unit 63. For example, the touch IC 49 may be realized by executing a program. In this case, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the capacitance value ratio calculation unit 55, the force detection value correction unit 56b, and the second correction coefficient derivation unit. 63 may be realized, for example, by the COG 19 or the host HST executing the program, and for example, two or more of the COG 19, the touch IC 49, and the host HST execute the program in cooperation. You may make it implement | achieve.

  The operations of the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, and the capacitance value ratio calculation unit 55 are the same as those in the first embodiment.

  The second correction coefficient deriving unit 63 refers to the second correction coefficient table stored in the second correction coefficient table storage unit 64, and detects the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40, that is, The correction coefficient kp corresponding to the coordinates of the touch detection position is derived and output to the force detection value correction unit 56b.

  The force detection value correction unit 56b is provided between the drive electrode COML and the electrode SUS at the time of non-contact input from the capacitance value ratio calculation unit 55 with respect to the force detection value Fcur input from the force detection value calculation unit 54. Multiplyed by the ratio (Cref / Ccur1) of the reference capacitance value Cref at the reference temperature Tref and the capacitance value Ccur1 between the drive electrode COML and the electrode SUS at the time of non-contact, and further inputted from the second correction coefficient derivation unit 63. The force detection correction value Fcor (= kp * (Cref / Ccur1) * Fcur) multiplied by the correction coefficient kp is output.

  In the present embodiment, the force detection control unit 50b performs force detection based on the capacitance value detected by the electrode SUS in the mutual capacitance detection period 139 (see FIG. 27) described in the first embodiment.

  FIG. 61 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the third embodiment. The process shown in FIG. 61 is performed in the mutual capacitance detection period 139 described above.

  In the flowchart shown in FIG. 61, the processing from step S301 to step S304 is substantially the same as the processing from step S101 to step S104 in the flowchart of the first embodiment shown in FIG. .

  The capacitance value ratio calculation unit 55 calculates a ratio (Cref / Ccur1) between the reference capacitance value Cref at the time of non-contact at the reference temperature Tref and the capacitance value Ccur1 detected at the time of non-contact, and a force detection value correction unit 56b. Output to. Further, the second correction coefficient deriving unit 63 refers to the second correction coefficient table stored in the second correction coefficient table storage unit 64, and the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40. That is, the correction coefficient k corresponding to the coordinates of the touch detection position is derived and output to the force detection value correction unit 56b (step S305).

  The force detection value correction unit 56b is configured to detect a non-contact reference capacitance value Cref at the reference temperature Tref input from the capacitance value ratio calculation unit 55 with respect to the force detection value Fcur input from the force detection value calculation unit 54, and non-contact. The force detection correction value Fcor (= kp * (Cref) is multiplied by the ratio (Cref / Ccur1) with the capacitance value Ccur1 detected at the time of contact, and further multiplied by the correction coefficient kp input from the second correction coefficient derivation unit 63. / Ccur1) * Fcur) is calculated and output (step S306), and the process returns to step S301.

  By executing the above-described processing, the force detection processing is given by the temperature characteristics of the air layer AG provided between the drive electrode COML and the electrode SUS and the dielectrics constituting the stacked body LB according to the touch detection position. The influence can be suppressed, and a decrease in detection accuracy in the force detection process can be suppressed.

<Modification>
FIG. 62 is a block diagram illustrating a configuration example of a touch detection unit and a display unit of a display device with a touch detection function according to a modification of the third embodiment.

  The example shown in FIG. 62 includes the temperature sensor 60 described in the second embodiment in addition to the configuration of the third embodiment described above. The force detection control unit 50c corrects the force detection value by multiplying the force detection value by a predetermined correction coefficient (first correction coefficient) corresponding to the temperature detected by the temperature sensor 60. That is, in the modification of the third embodiment, the force detection control unit 50c calculates the force detection value Fcur using the following equation (32) in which (Cref / Ccur1) of the above equation (31) is the correction coefficient k. to correct.

  Fcor = kp * k * Fcur (32)

  FIG. 63 is a diagram illustrating an example of a force detection correction value when the force applied to the input surface is constant in the display device with a touch detection function according to the modification of the third embodiment. In FIG. 63, the horizontal axis indicates the temperature, and the vertical axis indicates the force detection value F. In FIG. 63, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  FIG. 64 is a diagram illustrating the relationship between the force applied to the input surface and the force detection correction value in the display device with a touch detection function according to the modification of the third embodiment. In FIG. 64, the horizontal axis indicates the force applied to the input surface, and the vertical axis indicates the force detection value F. In FIG. 64, the broken line indicates the force detection value before correction, and the alternate long and short dash line indicates the force detection value after correction.

  In the example shown in FIGS. 63 and 64, the temperature b is set as the reference temperature Tref, and a constant force is applied to the coordinate t of the force detection region Af shown in FIG.

  The force detection control unit 50c compares the force detection value Fcur at the reference position of the force detection area Af of the input surface IS and the force detection value Fat at the coordinate t of the force detection area Af under the same temperature condition (Fcur / Ft ) Is previously set as the correction coefficient kpt.

  Further, the force detection control unit 50c is configured such that the capacitance between the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and the drive electrode COML and electrode SUS at the time of the non-contact at the temperature a. A ratio (Cref / Cacur1) with the value Cacur1 is set in advance as the correction coefficient ka. The force detection control unit 50c corrects the force detection value Fat by multiplying the force detection value Fat by the correction coefficient ka at the temperature a (two-dot chain line) and further by multiplying the correction coefficient kpt at the coordinate t (one-dot chain line). A force detection correction value Fatcor can be obtained.

  Further, the force detection control unit 50c is configured such that the capacitance between the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and the drive electrode COML and electrode SUS at the time of the non-contact at the temperature c. The ratio (Cref / Cccur1) to the value Cccur1 is set in advance as the correction coefficient kc. The force detection control unit 50c multiplies the force detection value Fct by the correction coefficient kc (two-dot chain line), and further multiplies the correction coefficient kpt at the coordinate t (one-dot chain line) to correct the force detection value Fct. The value Fctcor can be obtained.

  Thereby, as shown in FIG. 64, the second substrate 21, the first optical element OD1, the air layer AG, the reflective polarizing film DBEF, the brightness enhancement film BEF provided between the drive electrode COML and the electrode SUS, The force detection value due to the change in the capacitance value between the drive electrode COML and the electrode SUS caused by the temperature characteristics of the dielectrics constituting the light diffusion sheet DI, the light guide LG, and the light reflector RS is corrected.

<Configuration and operation of force detection control unit>
In the modification of the present embodiment, the above-described force detection processing is performed by, for example, the force detection processing unit 442c of the signal processing unit 44c in the force detection control unit 50c illustrated in FIG.

  FIG. 65 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to a modification of the third embodiment.

  The force detection processing unit 442c of the force detection control unit 50c includes a contact determination unit 51, a non-contact capacity calculation unit 52, a contact capacity calculation unit 53, a force detection value calculation unit 54, and a force detection value correction unit 56c. A first correction coefficient derivation unit 61, a first correction coefficient table storage unit 62, a second correction coefficient derivation unit 63, and a second correction coefficient table storage unit 64.

  The contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56c, the first correction coefficient derivation unit 61, and the second correction coefficient derivation unit 63 For example, it is composed of a circuit. Also, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56c, the first correction coefficient derivation unit 61, and the second correction coefficient derivation unit. For example, 63 may be realized by the touch IC 49 executing a program. In this case, the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, the force detection value calculation unit 54, the force detection value correction unit 56c, the first correction coefficient derivation unit 61, and the second correction coefficient derivation. The unit 63 may be realized, for example, by executing a program by the COG 19 or the host HST. For example, two or more of the COG 19, the touch IC 49, and the host HST execute the program in cooperation. This may be realized.

  The operations of the contact determination unit 51, the non-contact capacity calculation unit 52, the contact capacity calculation unit 53, and the force detection value calculation unit 54 are the same as those in the first embodiment, and the operation of the first correction coefficient derivation unit 61 is as follows. The operation of the second correction coefficient deriving unit 63 is the same as that of the third embodiment.

  The force detection value correction unit 56c multiplies the force detection value Fcur input from the force detection value calculation unit 54 by the correction coefficient k input from the first correction coefficient derivation unit 61, and further, a second correction coefficient derivation unit. The force detection correction value Fcor (= kp * k * Fcur) multiplied by the correction coefficient kp input from 63 is output.

  In the modification of the present embodiment, the force detection control unit 50c performs force detection based on the capacitance value detected by the electrode SUS in the mutual capacitance detection period 139 (see FIG. 27) described in the first embodiment. .

  FIG. 66 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the modification of the third embodiment. The process shown in FIG. 66 is performed in the mutual capacitance detection period 139 described above.

  In the flowchart shown in FIG. 66, the process from step S401 to step S404 is substantially the same as the process from step S101 to step S104 in the flowchart of the first embodiment shown in FIG. .

  The first correction coefficient derivation unit 61 refers to the first correction coefficient table stored in the first correction coefficient table storage unit 62, derives a correction coefficient k corresponding to the temperature Tcur detected by the temperature sensor 60, and This is output to the force detection value correction unit 56c. Further, the second correction coefficient deriving unit 63 refers to the second correction coefficient table stored in the second correction coefficient table storage unit 64, and the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40. That is, the correction coefficient kp corresponding to the coordinates of the touch detection position is derived and output to the force detection value correction unit 56b (step S405).

  The force detection value correction unit 56c multiplies the force detection value Fcur input from the force detection value calculation unit 54 by the correction coefficient k input from the first correction coefficient derivation unit 61, and further, a second correction coefficient derivation unit. The force detection correction value Fcor (= kp * k * Fcur) is calculated by multiplying by the correction coefficient kp input from 63 (step S406), and the process returns to step S401.

  By executing the above-described processing, the force detection processing is given by the temperature characteristics of the air layer AG provided between the drive electrode COML and the electrode SUS and the dielectrics constituting the stacked body LB according to the touch detection position. The influence can be suppressed, and a decrease in detection accuracy in the force detection process can be suppressed.

  As described above, the display devices with a touch detection function 1b and 1c according to the third embodiment provide the touch detection position Vout output from the coordinate extraction unit 45 of the touch detection control unit 40 to the force detection control units 50b and 50c. Is entered. The force detection control units 50b and 50c correct the force detection value Fcur according to the coordinates of the touch detection position.

  More specifically, the force detection control unit 50b calculates the force detection value Fcur at the reference position of the force detection area Af of the input surface IS and the force detection value at an arbitrary position of the force detection area Af under the same temperature condition. The ratio is set in advance as a correction coefficient (second correction coefficient) kp. The force detection control unit 50b calculates the ratio between the reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and the capacitance value Ccur1 between the drive electrode COML and the electrode SUS at the time of non-contact. The force detection value Fcur is multiplied by (Cref / Ccur1), and further multiplied by a correction coefficient (second correction coefficient) kp to correct the force detection value Fcur.

  Further, the force detection control unit 50c corrects in advance the ratio between the force detection value Fcur at the reference position of the force detection area Af of the input surface IS and the force detection value at an arbitrary position of the force detection area Af under the same temperature condition. It is set as a coefficient (second correction coefficient) kp. In addition, the force detection control unit 50c generates a reference capacitance value Cref at the reference temperature Tref between the drive electrode COML and the electrode SUS at the time of non-contact and a capacitance value Ccur1 between the drive electrode COML and the electrode SUS at the time of non-contact. Ratio (Cref / Ccur1) is preset as a correction coefficient k (first correction coefficient). The force detection control unit 50b corrects the force detection value Fcur by multiplying the force detection value Fcur by the correction coefficient k and further by a correction coefficient (second correction coefficient) kp.

  Furthermore, the force detection control units 50b and 50c are detected by the touch detection control unit 40 based on the second correction coefficient table in which the position on the force detection region Af and the correction coefficient (second correction coefficient) kp are associated with each other. The force detection value Fcur is corrected according to the touch detection position.

  With the above configuration, depending on the touch detection position, depending on the temperature characteristics of the air layer AG provided between the drive electrode COML (first electrode) and the electrode SUS (second electrode) and the dielectric constituting the stacked body LB. The influence on the force detection process can be suppressed, and a decrease in detection accuracy in the force detection process can be suppressed regardless of the touch detection position.

  By this embodiment, the display apparatus with a touch detection function which can suppress the fall of the detection accuracy of the force applied to the input surface of a touch panel is obtained.

(Embodiment 4)
FIG. 67 is a diagram illustrating an example of a module in which the display device with a touch detection function according to the fourth embodiment is mounted. FIG. 68 is a perspective view illustrating electrodes of the display device with a touch detection function according to the fourth embodiment. In addition, the overlapping description is abbreviate | omitted about the structure part equivalent or the same as Embodiment 1. FIG.

  The display device with a touch detection function 1d according to the fourth embodiment performs touch detection based on the basic principle of the self-capacitance method. In the case of the self-capacitance method, a plurality of electrodes EL provided in a matrix may be used as electrodes that have the functions of the touch detection electrode TDL and the drive electrode COML. In this case, each of the plurality of electrodes EL is connected to a drive electrode control unit 48 provided in the touch IC 49 via a connection unit such as a wiring L. In FIG. 67, only the wirings L of some of the electrodes EL are shown, but actually, all the electrodes EL are individually provided with the wirings L or similar connection portions. Note that the drive electrode control unit 48 may be provided on the array substrate (pixel substrate 2).

  The shape and size of the electrode EL are arbitrary, but the size of the electrode EL may correspond to, for example, the size of the pixel. In this case, one of the electrodes constituting the pixel (for example, the pixel electrode 22 in the pixel of the liquid crystal display device or the drive electrode COML as the counter electrode) may be used as the electrode EL. That is, the electrode EL may be used also as an electrode provided in each pixel of a display device having a plurality of pixels.

  As shown in FIG. 68, in the fourth embodiment, the plurality of electrodes EL constitute the touch detection unit SE1 of FIG. The plurality of electrodes EL and the electrodes SUS constitute the force detection unit SE2 in FIG.

  In this configuration example, the electrode SUS is formed of a conductor (for example, aluminum). The potential of the electrode SUS is a reference potential. The reference potential is exemplified by the ground potential GND. Note that any one of the touch IC 49, the COG 19, and the host HST may be electrically connected to the electrode SUS by a connection wiring or the like, and the reference potential may be supplied from any one of the touch IC 49, the COG 19, and the host HST. Further, the electrode SUS may be constituted by, for example, a rear frame RFR made of a conductive material.

  In the present embodiment, the electrode EL corresponds to a “first electrode”. The electrode SUS corresponds to the “second electrode”.

  In addition, when the electrode SUS is configured by an independent conductive component, the electrode SUS is connected to the force detection control units 50, 50a, 50b, 50c of the detection control units 200, 200a, 200b, 200c or a reference potential. It can be set as the structure similar to Embodiment 1- Embodiment 3 by setting it as the structure which can be selected. That is, the display device with a touch detection function 1d according to the fourth embodiment can be realized with the same configuration as the display devices with a touch detection function 1, 1a, 1b, and 1c according to the first to third embodiments.

<Principle of force detection>
[Basic principle]
FIG. 69 is a cross-sectional view and an equivalent circuit diagram of a display device with a touch detection function according to the fourth embodiment. As shown in FIG. 69, between the electrode EL and the electrode SUS, a capacitor formed by the second substrate 21 is formed by C _G , a capacitor formed by the first optical element OD1 is formed by C _OD1 , and an air layer AG. the capacitance _{C AG,} reflective polarizing film DBEF the capacitance formed by the _{C DBEF,} the capacitance formed by the brightness enhancement film BEF _{C BEF,} the capacitance formed by the light diffusion sheet DI _{C DI,} light capacity _{C LG} formed by the body LG, when the capacitance formed by the light reflector RS was _{C RS,} there is a capacitance value C1 as shown in formula (33).

_{C1 = C G × C OD1 ×} C AG × C DBEF × C BEF × C DI × C LG × C RS / (C G + C OD1 + C AG + C DBEF + C BEF + C DI + C LG + C RS) ··· (33)

  In a state where the object to be detected OBJ is not in contact with or close to the input surface IS, the capacitance value C detected by the electrode EL can be expressed by the following equation (34).

  C = C1 (34)

  FIG. 70 is a cross-sectional view and an equivalent circuit diagram when an object to be detected is in contact with or close to the input surface of the display device with a touch detection function according to the fourth embodiment. As shown in FIG. 70, when the object to be detected (here, a finger) OBJ contacts or approaches the input surface IS, a capacitance C2 is generated between the electrode EL and the object to be detected OBJ. At this time, the capacitance value C detected by the electrode EL can be expressed by the following equation (35).

  C = C2 + C1 (35)

FIG. 71 is a cross-sectional view and an equivalent circuit diagram when a force is applied to the input surface of the display device with a touch detection function according to the fourth embodiment. As shown in FIG. 71, when the object OBJ applies a force to the input surface IS, the display unit 10 with a touch detection function bends. When the display unit with a touch detection function 10 bends, the thickness of the air layer AG is reduced. At this time, the capacitance C _AG ′ formed by the air layer AG increases by ΔC _{AG with} respect to the capacitance C _AG formed by the air layer AG when no force is applied to the input surface IS. (36)

C _AG '= C _AG + ΔC _AG (36)

  Further, the capacitance value C1 'between the electrode EL and the electrode SUS at this time can be expressed by the following equation (37).

_{C1 '= C G × C OD1} × C AG' × C DBEF × C BEF × C DI × C LG × C RS / (C G + C OD1 + C AG '+ C DBEF + C BEF + C DI + C LG) ··· (37 )

At this time, the capacitance value C detected by the electrode EL can be expressed by the following equation (38).
C = C2 + C1 ′ (38)

  In the display device with a touch detection function 1d according to the fourth embodiment, the self-capacitance type touch detection and the force detection by the electrode EL are simultaneously performed. That is, the capacitance value C1 when the detected object OBJ is not in contact with or close to the input surface IS, the capacitance value C2 when the detected object OBJ is in contact with or close to the input surface IS, and the detected object OBJ is the input surface IS. By detecting the capacitance value C3 in a state where a force is applied to the touch, touch detection and force detection can be performed.

  FIG. 72 is a graph showing the capacitance value C in the Y-axis direction in a state where the detection object is not in contact with or close to the input surface. FIG. 73 is a graph showing a capacitance value C in the Y-axis direction in a state where an object to be detected is in contact with or close to the input surface. FIG. 74 is a graph showing the capacitance value C in the Y-axis direction when a force is applied to the input surface. 72 to 74, the horizontal axis represents the Y coordinate, and the vertical axis represents the capacitance value C detected by the electrode EL. In the example shown in FIGS. 72 to 74, the coordinate in the X-axis direction is the contact or proximity position of the detected object OBJ on the input surface IS. In addition, here, the Y-axis direction of the force detection region Af on the input surface IS is illustrated, but the same applies to the X-axis direction.

In the present embodiment, as shown in FIGS. 72 to 74, a predetermined threshold value _Cth is set for the capacitance value C detected by the electrode EL.

  In a state where the object to be detected OBJ is not in contact with or close to the input surface IS, as shown in FIG. 72, the capacitance value C1 between the electrode EL and the electrode SUS in the entire region of the force detection region Af on the input surface IS. Is detected uniformly (C = C1).

In the state where the object OBJ is in contact with or close to the input surface IS, as shown in FIG. 73, in the region Yab from the coordinate Ya to the coordinate Yb where the object OBJ is in contact or close, the electrode EL and the electrode SUS The capacitance C2 generated between the electrode EL and the detected object OBJ is added to the capacitance value C1 between and detected (C = C1 + C2). In the present embodiment determines, when a region where capacitance value C that is detected by the electrodes EL exceeds the threshold value C _th is present, assuming that the detected object OBJ to the input surface IS is in contact with or close proximity.

  Here, the capacitance value C (= C1 + C2) detected when the detected object OBJ is in contact with or close to the input surface IS and detected when the detected object OBJ is not in contact with or close to the input surface IS. By obtaining the difference from the capacitance value C (= C1), the capacitance C2 generated between the electrode EL and the object OBJ can be obtained (C2 = (C1 + C2) −C1).

  Further, in a state where a force is applied to the input surface IS, as shown in FIG. 74, the capacitance value C1 between the electrode EL and the electrode SUS increases in the entire region including the region Yab in contact with the object OBJ. (C1 <C1 ′). At this time, in the region Yab, the capacitance C2 generated between the electrode EL and the detected object OBJ obtained as described above is subtracted from the capacitance value C (= C1 ′ + C2) detected by the electrode EL. The capacitance value C in the entire area of the force detection area Af on the input surface IS can be obtained.

  Note that the calculation method of the capacitance value C in the area Yab in contact with the detected object OBJ is not limited to the above-described technique. For example, the coordinates Ya and the coordinates that are both ends of the area Yab in contact with the detected object OBJ are used. Yb may be detected, and the capacitance value C between the coordinates Ya and the coordinate Yb may be linearly interpolated, or curve interpolation may be performed using the capacitance values at a plurality of coordinates. The present invention is not limited by the method of calculating the capacitance value C in the region Yab in contact with the detected object OBJ.

<Configuration and operation of force detection control unit>
The force detection process in the present embodiment is performed by, for example, the force detection processing unit 442 of the signal processing unit 44 in the force detection control unit 50 illustrated in FIG. Moreover, the force detection process in this embodiment is performed by the force detection process part 442a of the signal processing part 44a in the force detection control part 50a shown in FIG. 40, for example. Moreover, the force detection process in this embodiment is performed by the force detection process part 442b of the signal processing part 44b in the force detection control part 50b shown in FIG. 52, for example. Moreover, the force detection process in this embodiment is performed by the force detection process part 442c of the signal processing part 44c in the force detection control part 50c shown in FIG. 62, for example. In the following description, a configuration example of the force detection processing unit 442d of the force detection control unit 50d that can be replaced with the force detection processing unit 442 in the force detection control unit 50 illustrated in FIG. 2 will be described.

  FIG. 75 is a diagram illustrating functional blocks of a force detection control unit of the display device with a touch detection function according to the fourth embodiment.

  The force detection processing unit 442d of the force detection control unit 50d includes a contact determination unit 51d, a non-contact capacity calculation unit 52d, a contact capacity calculation unit 53d, a force detection value calculation unit 54d, and a capacitance value ratio calculation unit 55d. And a force detection value correction unit 56d and a reference capacitance value storage unit 57d. In the reference capacitance value storage unit 57d, a reference temperature Tref (for example, between the electrode EL and the electrode SUS at the time of non-contact, which is individually set at the time of shipment of the display device with a touch detection function 1d according to the fourth embodiment). It is assumed that a reference capacitance value Cref in a room temperature (25 ° C. environment) is stored. The reference capacitance value storage unit 57d is configured with, for example, a register.

  The contact determination unit 51d, the non-contact capacity calculation unit 52d, the contact capacity calculation unit 53d, the force detection value calculation unit 54d, the capacitance value ratio calculation unit 55d, and the force detection value correction unit 56d are configured by a circuit, for example. The touch determination unit 51d, the non-contact capacitance calculation unit 52d, the contact capacitance calculation unit 53d, the force detection value calculation unit 54d, the capacitance value ratio calculation unit 55d, and the force detection value correction unit 56d are, for example, programmed by the touch IC 49. It may be realized by executing. In this case, the contact determination unit 51d, the non-contact capacity calculation unit 52d, the contact capacity calculation unit 53d, the force detection value calculation unit 54d, the capacitance value ratio calculation unit 55d, and the force detection value correction unit 56d are, for example, the COG 19 or the host The HST may be realized by executing a program, or may be realized by, for example, two or more of the COG 19, the touch IC 49, and the host HST executing the program in cooperation. .

The contact determination unit 51d determines whether or not the detected object OBJ is in contact with or close to the input surface IS based on a signal output from the first A / D conversion unit 43-1 (see FIG. 2). As a method for determining whether or not the object OBJ is in contact with or close to the input surface IS, for example, as described above, there is a region where the capacitance value C detected by the electrode EL exceeds the threshold value _Cth. In this case, it can be determined that the detected object OBJ is in contact with or close to the input surface IS. The present invention is not limited by the method for determining whether or not the object OBJ is in contact with or close to the input surface IS.

  When the drive signal Vcomts1 (or drive signal Vcomts2) is applied to the electrode EL, the non-contact-time capacity calculation unit 52d determines that the detected object OBJ is not in contact with or close to the input surface IS by the contact determination unit 51d. In this case, based on the signal output from the first A / D conversion unit 43-1 (see FIG. 2), the capacitance value Ccur1 at the time of non-contact is calculated, and the force detection value calculation unit 54d and the capacitance value ratio are calculated. It outputs to the calculation part 55d.

  When the drive signal Vcomts1 (or drive signal Vcomts2) is applied to the electrode EL, the contact-time capacity calculation unit 53d determines that the detected object OBJ is in contact with or close to the input surface IS by the contact determination unit 51d. In this case, based on the signal output from the first A / D converter 43-1 (see FIG. 2), the capacitance value Ccur2 at the time of contact is calculated and output to the force detection value calculator 54d.

  The force detection value calculation unit 54d calculates a change amount (Ccur2-Ccur1) of the capacitance value Ccur2 at the time of contact with respect to the capacitance value Ccur1 at the time of non-contact as a force detection value Fcur, and outputs the force detection value Fcur to the force detection value correction unit 56d.

  The capacitance value ratio calculation unit 55d calculates the ratio (Cref / Ccur1) between the reference capacitance value Cref at the time of non-contact and the capacitance value Ccur1 detected at the time of non-contact at the reference temperature Tref, and supplies it to the force detection value correction unit 56d. Output.

  The force detection value correction unit 56d is not in contact with the reference capacitance value Cref at the time of non-contact at the reference temperature Tref input from the capacitance value ratio calculation unit 55d with respect to the force detection value Fcur input from the force detection value calculation unit 54d. The force detection correction value Fcor (= (Cref / Ccur1) * Fcur) is calculated and output by multiplying the ratio (Cref / Ccur1) with the capacitance value Ccur1 detected at times.

  In the present embodiment, the force detection control unit 50d performs force detection based on the capacitance value detected by the electrode EL during the self-capacitance detection period 140 (or the self-capacitance detection period 141).

  FIG. 76 is a flowchart illustrating processing executed by the force detection control unit of the display device with a touch detection function according to the fourth embodiment. The process shown in FIG. 76 is performed in the self-capacitance detection period 140 (or self-capacitance detection period 141) described above.

  The non-contact capacity calculation unit 52d calculates a non-contact capacity value Ccur1 based on the signal output from the first A / D conversion unit 43-1 (see FIG. 2) (step S501).

The contact determination unit 51d determines whether or not the detected object OBJ is in contact with or close to the input surface IS (step S502). When the contact determination unit 51d determines that the detected object OBJ is not in contact with or close to the input surface IS, that is, no force is applied to the input surface IS (step S502; No), the process returns to step S501. The processes of steps S501 and S502 are repeatedly performed until it is determined in step S502 that the detected object OBJ is in contact with or close to the input surface IS. In the contact determination unit 51d, as a method for determining whether or not the detected object OBJ is in contact with or close to the input surface IS, for example, the capacitance value C detected by the electrode EL exceeds the threshold value _Cth . When the region exists, it can be determined that the detected object OBJ is in contact with or close to the input surface IS.

  When the contact determination unit 51d determines that the detected object OBJ is in contact with or close to the input surface IS (step S502; Yes), the contact-time capacity calculation unit 53d includes the first A / D conversion unit 43- Based on the signal output from 1 (see FIG. 2), the capacitance value Ccur2 at the time of contact is calculated (step S503).

  The force detection value calculation unit 54d calculates a change amount (Ccur2-Ccur1) of the capacitance value Ccur2 detected at the time of contact with respect to the capacitance value Ccur1 detected at the time of non-contact as a force detection value Fcur, and sends it to the force detection value correction unit 56d. Output (step S504).

  The capacitance value ratio calculation unit 55d calculates a ratio (Cref / Ccur1) between the reference capacitance value Cref at the time of non-contact at the reference temperature Tref and the capacitance value Ccur1 detected at the time of non-contact, and a force detection value correction unit 56d. (Step S505).

  The force detection value correction unit 56d is not in contact with the reference capacitance value Cref at the time of non-contact at the reference temperature Tref input from the capacitance value ratio calculation unit 55 with respect to the force detection value Fcur input from the force detection value calculation unit 54d. The force detection correction value Fcor (= (Cref / Ccur1) * Fcur) is calculated by multiplying the ratio (Cref / Ccur1) with the capacitance value Ccur1 detected at times (step S506), and the process of step S501 is performed. Return.

  By performing the above-described processing, it is possible to suppress the influence on the force detection processing due to the temperature characteristics of the dielectric that constitutes the air layer AG and the stacked body LB provided between the electrode EL and the electrode SUS, A decrease in detection accuracy in the force detection process can be suppressed.

  75 and 76 illustrate the configuration example and the processing example of the force detection processing unit 442d of the force detection control unit 50d that can be replaced with the force detection processing unit 442 in the force detection control unit 50 illustrated in FIG. The configuration and processing of the force detection control unit 50d of the display device with a touch detection function 1d according to the fourth embodiment are not limited thereto.

For example, the display device with a touch detection function 1d according to the fourth embodiment may be configured to be replaceable with the force detection processing unit 442a in the force detection control unit 50a illustrated in FIG. In this case, the predetermined threshold value _Cth for the capacitance value C detected by the electrode EL may be changed according to the temperature detected by the temperature sensor 60, for example. In this way, it becomes possible to detect with high accuracy that the object OBJ is in contact with or close to the input surface IS.

  Further, for example, it is possible to replace the force detection processing unit 442b in the force detection control unit 50b shown in FIG. 52, or to replace the force detection processing unit 442c in the force detection control unit 50c shown in FIG. A possible configuration is also possible. In this way, the force detection value Fcur can be corrected according to the coordinates of the touch detection position, and a reduction in detection accuracy in the force detection process can be suppressed regardless of the touch detection position.

  Further, in the above-described fourth embodiment, the example in which the touch detection of both the mutual capacitance method and the self-capacitance method is performed has been described. However, the display device with a touch detection function 1d according to the fourth embodiment is provided. It is also possible to apply to a configuration in which only the self-capacitance type touch detection is performed without performing the mutual capacitance type touch detection.

  As described above, the display device with a touch detection function 1d according to the fourth embodiment has the input surface IS to which a force is applied by the object to be detected OBJ and the electrodes EL (first electrodes) arranged opposite to each other across the dielectric layer. 1 electrode), an electrode SUS (second electrode), a touch detection control unit 40 that detects contact or proximity of the object OBJ to the input surface IS, an electrode EL (first electrode), and an electrode SUS (second electrode) ), And a force detection control unit 50d that detects the force applied to the input surface IS by the object to be detected OBJ. The force detection control unit 50d includes a reference capacitance value Cref at a reference temperature Tref between the electrode EL (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS. The force detection value Fcur based on the ratio (Cref / Ccur) between the capacitance value Ccur1 between the electrode EL (first electrode) and the electrode SUS (second electrode) when the object OBJ is not in contact with the input surface IS. Correct.

  With the above configuration, the influence on the force detection process is suppressed by the temperature characteristics of the air layer AG provided between the electrode EL (first electrode) and the electrode SUS (second electrode) and the dielectric constituting the stacked body LB. It is possible to suppress a decrease in detection accuracy in the force detection process.

  By this embodiment, the display apparatus with a touch detection function which can suppress the fall of the detection accuracy of the force applied to the input surface of a touch panel is obtained.

  In the embodiment described above, each component can be appropriately combined. In addition, other functions and effects brought about by the aspects described in the present embodiment, which are apparent from the description of the present specification, or can be appropriately conceived by those skilled in the art, are naturally understood to be brought about by the present invention. .

DESCRIPTION OF SYMBOLS 1 Display apparatus with a touch detection function 2 Pixel substrate 3 Counter substrate 6 Liquid crystal layer 10 Display part with a touch detection function 11 Display control part (drive part)
12 Gate Driver 13 Source Driver 14 Drive Electrode Driver (Driver)
19 COG
DESCRIPTION OF SYMBOLS 20 Liquid crystal display device 21 2nd board | substrate 22 Pixel electrode 30 Touch detection device 31 1st board | substrate 32 Color filter 40 Touch detection control part 41 1st detection signal amplification part 42 2nd detection signal amplification part 43-1 1st A / D conversion part 43-2 Second A / D Converter 44, 44a, 44b, 44c, 44d Signal Processor 45 Coordinate Extractor 46 Detection Timing Controller 47 Drive Driver 48 Drive Electrode Controller 49 Touch IC
50, 50a, 50b, 50c, 50d Force detection control unit 51, 51d Contact determination unit 52, 52d Non-contact capacity calculation unit 53, 53d Contact capacity calculation unit 54, 54d Force detection value calculation unit 55, 55d Capacity value ratio Calculation unit 56, 56a, 56b, 56c, 56d Force detection value correction unit 57, 57d Reference capacitance value storage unit 60 Temperature sensor 61 First correction coefficient derivation unit 62 First correction coefficient table storage unit 63 Second correction coefficient derivation unit 64 Second correction coefficient table storage unit 100 Force detection device 200, 200a, 200b, 200c Detection control unit 441 Touch detection processing unit 442, 442a, 442b, 442c, 442d Force detection processing unit BL Backlight unit CA Housing CG Cover member COML Drive electrode (first electrode)
CTRL control unit DET voltage detector DP display unit EL electrode GCL scanning signal line HST host IS input surface Pix pixel SE1 touch detection unit SE2 force detection unit SGL pixel signal line SPix subpixel SUS electrode (second electrode)
TDL touch detection electrode T flexible printed circuit board Tr TFT element

Claims (17)

An input surface to which a force is applied by an object to be detected;
A touch detection electrode provided on the first substrate and facing the input surface;
A first electrode provided on a second substrate and facing the touch detection electrode;
A second electrode facing the first electrode across a dielectric layer;
A touch detection control unit configured to detect contact or proximity of the detected object to the input surface based on a capacitance between the first electrode and the touch detection electrode;
A force detection control unit configured to detect a force applied to the input surface by the detected object based on a capacitance between the first electrode and the second electrode;
With
The force detection control unit
A display device with a touch detection function that corrects a force detection value based on a reference capacitance value at a reference temperature between the first electrode and the second electrode when the detection object is not in contact with the input surface. The force detection control unit
The first capacitance value between the first electrode and the second electrode when the detection object is not in contact with the input surface, and the first electrode when the detection object is in contact with the input surface. The touch detection function according to claim 1, wherein a second capacitance value between the first capacitance value and the second electrode is calculated, and a change amount of the second capacitance value with respect to the first capacitance value is detected as the force detection value. Display device. The force detection control unit
The display device with a touch detection function according to claim 1, wherein the force detection value is corrected by multiplying the force detection value by a ratio between the reference capacitance value and the first capacitance value. An input surface to which a force is applied by an object to be detected;
A first electrode and a second electrode disposed opposite to each other across a dielectric layer;
A touch detection control unit that detects contact or proximity of the detected object to the input surface; and
A force detection control unit configured to detect a force applied to the input surface by the detected object based on a capacitance generated between the first electrode and the second electrode;
With
The force detection control unit
Based on a ratio between a reference capacitance value at a reference temperature of the capacitance when the detection object is not in contact with the input surface and the capacitance when the detection object is not in contact with the input surface. A display device with a touch detection function that corrects force detection values. The force detection control unit
The display device with a touch detection function according to claim 4, wherein the force detection value is corrected by multiplying the force detection value by the ratio. The force detection control unit
The display device with a touch detection function according to claim 4, wherein the ratio is set in advance as a first correction coefficient, and the force detection value is corrected by multiplying the force detection value by the first correction coefficient. A temperature sensor,
The force detection control unit
The touch detection function according to claim 6, wherein the force detection value is corrected according to a temperature detected by the temperature sensor based on a first correction coefficient table in which a temperature is associated with the first correction coefficient. Display device. The force detection control unit
A ratio between the force detection value at the reference position of the force detection area of the input surface and the force detection value at an arbitrary position of the force detection area is set in advance as a second correction coefficient, and based on the second correction coefficient. The display device with a touch detection function according to claim 4, wherein the force detection value is corrected. The force detection control unit
The display device with a touch detection function according to claim 8, wherein the force detection value is corrected by multiplying the force detection value by the second correction coefficient. The force detection control unit
Based on the second correction coefficient table in which the position on the force detection region and the second correction coefficient are associated with each other, the force detection value is corrected according to the touch detection position detected by the touch detection control unit. The display device with a touch detection function according to claim 9. The force detection control unit
A first capacitance value of the capacitance when the detection object is not in contact with the input surface and a second capacitance value of the capacitance when the detection object is in contact with the input surface are calculated. 11. The display device with a touch detection function according to claim 4, wherein a change amount of the second capacitance value with respect to the first capacitance value is detected as the force detection value. The force detection control unit
The force applied to the input surface by the detected object is detected during a period in which the touch detection control unit detects a position of the detected object in contact with or close to the input surface. The display device with a touch detection function according to any one of 11. The display device with a touch detection function according to any one of claims 1 to 12, wherein the dielectric layer includes an air layer. The display device with a touch detection function according to any one of claims 1 to 13, wherein the dielectric layer includes a stacked body that constitutes a backlight unit that illuminates the input surface. The display device with a touch detection function according to claim 14, wherein the second electrode is provided on a surface opposite to the surface on the input surface side of the stacked body. The display device with a touch detection function according to claim 14, wherein the second electrode is provided on a surface on the input surface side of the stacked body. The display device with a touch detection function according to claim 14, wherein the second electrode is provided in an inner layer of the stacked body.

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