JP2016081153A - Electrostatic detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic detection apparatus configured to prevent false detection of an unintended tap operation.SOLUTION: An electrostatic detection apparatus includes: a capacitance detection section 10 having a detection electrode (first detection electrode 101 and second detection electrode 102) for detecting a finger or the like approaching or touching an object, with touch sensitivity based on the change in capacitance value; and a control section 20 comprising a touch detection section 210 which detects a touch on the detection electrode, on the basis of touch sensitivity read from the detection electrode, and sets sensitivity flag when the current touch sensitivity is a predetermined multiple of an initial sensitivity value set at the time of touch-on detection, after detecting the touch-on, and a tap detection section which detects a tap, on the basis of the change in touch sensitivity of the detection electrode, after detecting the touch-on. The tap detection section 220 is configured to determine tap-on when the touch detection section 210 detects touch-off with the sensitivity flag on.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrostatic detection device.

  Conventionally, an electrostatic detection device that performs touch detection based on a change in capacitance of an electrostatic touch electrode has been proposed (for example, Patent Document 1).

  Specifically, the calculation is performed from the detection maximum value at the detection point of the capacitance type input means and the detection values at the positions before and after the detection value, and when this calculation value is equal to or less than the first threshold value, the coordinate data is generated. Cancel. Further, when the calculated value is between the first threshold value and the second threshold value, the correction value at the time of generation with the coordinate data is switched to a smaller value. With such a configuration, when the variation amount of the electrostatic capacitance on the input unit is small, by preventing generation of coordinate data, for example, erroneous detection when the palm of the input unit is touched can be prevented. . In addition, it is said that the touch of the cursor display or the like when the finger or the like is stopped can be suppressed by changing the correction value depending on whether the variation in the amount of change in capacitance is sharp or not.

JP 2002-82765 A

  In the configuration of Patent Document 1, touch detection is performed by calculating from the detection maximum value at the detection point and the detection values at positions before and after the detection value. Since such touch detection methods are not based on time-series information, for example, when the operator is wearing gloves or when the finger is held slightly off the touch surface, the operator's unintentional There is a case where the touch-on determination is made for a moment due to a finger moving or a vehicle vibration. As a result, it may be erroneously determined that a tap operation has been performed with a finger.

  Therefore, an object of the present invention is to provide an electrostatic detection device that can suppress erroneous determination of an unintended tap operation.

[1] In order to achieve the above object, a capacitance detection unit including a detection electrode that detects proximity or contact of an object with touch sensitivity based on a change in capacitance value, and touch sensitivity read from the detection electrode. A touch detection unit that performs touch detection on the detection electrode, detects a touch-on, and then sets a sensitivity flag when the current touch sensitivity is equal to or greater than a predetermined magnification of a sensitivity initial value at the time of touch-on detection; and A tap detection unit that performs tap detection based on a change in touch sensitivity of the detection electrode after detection, and the tap detection unit detects the touch detection in a state where the sensitivity flag is set. Provided is an electrostatic detection device that performs tap-on determination when a unit detects touch-off.

[2] The electrostatic detection device according to [1], wherein the predetermined magnification is 2.

[3] The control unit performs the double tap on determination when the tap on is determined within a predetermined time after the tap on is determined. [1] or [2] ] May be used.

  According to the electrostatic detection device of the present invention, erroneous determination of an unintended tap operation can be suppressed.

FIG. 1 is an overall block diagram of the electrostatic detection device of the present invention. FIG. 2 is a flowchart showing an operation flow of the electrostatic detection device according to the embodiment of the present invention. FIG. 3 is a graph showing a relationship between touch sensitivity and time indicating a change in touch sensitivity in the tap operation. FIG. 4A is an overall perspective view showing a configuration when the electrostatic detection device according to the embodiment of the present invention is applied to a remote operation of a vehicle navigation device or the like, and FIG. It is a top view which shows a part. FIG. 5A is a graph showing a change in touch sensitivity during a normal double tap operation, and FIG. 5B is a graph showing a change in touch sensitivity when an erroneous double tap occurs.

(Embodiment of the present invention)
The electrostatic detection device 1 according to the embodiment of the present invention can detect touch-on and can detect tap-on. Touch-on (touch operation) is detected when the touch sensitivity detected by the detection electrode exceeds a predetermined touch-on threshold when an object such as a finger approaches or touches the detection electrode. Further, tap-on (tap operation) is detected based on a change in touch sensitivity of the detection electrode after detection of touch-on. Furthermore, when the tap-on is further determined within a predetermined time after the tap-on is determined, the double-tap can be determined to be on.

  The electrostatic detection device 1 according to the embodiment of the present invention uses an unintended tap operation or non-tap at the time of non-touch by using the time-series change of the touch sensitivity in a capacitive touch pad or the like. The operation is suppressed or prevented. By using the time-series change of the touch sensitivity, it is possible to suppress or prevent an erroneous tap operation such as a case where the tap operation is not intended from a state where the finger or the like is slightly lifted from the detection surface such as the touch surface. In particular, when applied to a touchpad or the like for remotely operating a vehicle navigation device or the like, an unintended tap operation or double tap operation may be assumed due to vehicle vibration or the like. According to this, such an erroneous operation can be suppressed or prevented.

(Configuration of electrostatic detection device 1)
FIG. 1 is an overall block diagram of the electrostatic detection device of the present invention.

  The electrostatic detection device 1 according to the embodiment of the present invention includes detection electrodes (first detection electrode 101, second detection electrode) that detect proximity or contact of an object such as a finger based on touch sensitivity based on a change in capacitance value. The capacitance detection unit 10 including the detection electrode 102) and the detection electrode (first detection electrode 101, second detection electrode 102) based on the touch sensitivity read from the detection electrode (first detection electrode 101, second detection electrode 102). A touch detection unit 210 that performs a touch detection on the second detection electrode 102) and detects a touch-on, and then sets a sensitivity flag when the current touch sensitivity is equal to or greater than a predetermined magnification of a sensitivity initial value at the time of touch-on detection; A control unit 20 including a tap detection unit that performs tap detection based on a change in touch sensitivity of the detection electrodes (first detection electrode 101, second detection electrode 102) after detection of touch-on. Tap detection unit 220, the touch detection unit 210 in a state where the sensitivity flag is raised is configured to perform the determination of Tappuon when detecting the touch-off.

  As will be described later, the detection electrode includes a first detection electrode 101 that intersects the x-axis and a second detection electrode 102 that intersects the y-axis, so that touch-on and tap at positions defined by x and y , Double tap etc. can be detected.

(Configuration of capacitance detection unit 10)
The capacitance detection unit 10 is, for example, a touch pad that detects a position (detection point) on the operation area 100 touched by an operation finger. For example, the operator can operate the connected electronic device by operating the operation area 100. As the capacitance detection unit 10, for example, a capacitance type touch pad capable of detecting a plurality of detection fingers can be used.

  The capacitance detection unit 10 is, for example, a touch pad that detects a change in the capacitance value formed by the detection electrode and the finger when the finger approaches the operation region 100. As shown in FIG. 1, a plurality of detection electrodes are provided below the operation area 100.

  The detection electrodes are arranged so that a plurality of first detection electrodes 101 and a plurality of second detection electrodes 102 formed in an elongated shape cross each other with a dielectric therebetween. The first detection electrodes 101 are arranged at equal intervals so as to intersect the x-axis defined along the horizontal direction of the sheet of FIG. Further, the second detection electrodes 102 are arranged at equal intervals so as to intersect the y-axis determined along the vertical direction of the sheet of FIG. The origin of the x-axis and y-axis is the upper left of the operation area 100 shown in FIG.

  As shown in FIG. 1, the capacitance detection unit 10 includes a drive unit 11 that drives the second detection electrode 102 and a reading unit 12 that reads the capacitance from the first detection electrode 101. .

The drive unit 11 is configured to sequentially supply a periodic drive signal based on the drive signal S ₁ acquired from the control unit 20 to the second detection electrode 102.

The readout unit 12 is configured to read out the electrostatic capacitance by sequentially switching the connection with the first detection electrode 101 while one second detection electrode 102 is being driven. The reading unit 12 is configured to output detection point information S ₂ including information on the coordinates of the detection points to the control unit 20. The calculation of the coordinates of the detection points is performed by a weighted average as an example.

(Configuration of control unit 20)
The control unit 20 includes a touch detection unit 210, a tap detection unit 220, a storage unit 230, and the like. The control unit 20 is a microcomputer that includes a CPU that performs operations, processing, and the like on acquired data according to a stored program, and a RAM and ROM that are semiconductor memories as the storage unit 230. In this ROM, for example, a program for operating the control unit 20 is stored. For example, the RAM is used as a storage area for temporarily storing calculation results and the like.

The touch detection unit 210 detects whether the touch sensitivity Z based on the capacitance value read from the detection electrodes (the first detection electrode 101 and the second detection electrode 102) exceeds the touch-on threshold Zth. Touch detection is performed on the first detection electrode 101 and the second detection electrode 102). When the touch sensitivity Z exceeds the touch-on threshold value Zth, it is determined that the detected point in the x and y coordinates is touched with a finger or the like (touch-on determination). Incidentally, the touch sensitivity at the electrode for detecting (x, y), the capacitance reading charges which are charged at a predetermined frequency by the drive signals S ₁ of the drive unit 11 as a detection point information S ₂ at the reading unit 12 A / This is a touch sensitivity value obtained by D conversion.

When the current touch sensitivity Z exceeds the sensitivity initial value Z ₀ at the time of touch-on detection × the magnification α, the above-described sensitivity flag is set to 1 (True). Here, the magnification α can be set to α = 2, for example, as a value that can be discriminated between touch and non-touch even when a touch operation is performed while wearing gloves. Note that the magnification α can be changed as appropriate, and is set to an optimal value while being calibrated and stored in the storage unit 230, particularly with parameters and the like of the entire apparatus determined.

  The tap detection unit 220 determines a tap operation or a double tap operation by using a time series change of the touch sensitivity (capacitance) based on the value of the touch sensitivity and the state of the sensitivity flag according to a predetermined algorithm. To do.

(Operation of the embodiment of the present invention)
FIG. 2 is a flowchart showing an operation flow of the electrostatic detection device according to the embodiment of the present invention. FIG. 3 is a graph showing a relationship between touch sensitivity and time indicating a change in touch sensitivity in the tap operation.

When the operation of the electrostatic detection device 1 starts, first, the control unit 20 detects a touch-on by the touch detection unit 210. As shown in FIG. 3, it is detected whether or not the touch-off P _{0 is changed} to the touch-on P ₁ . When the current touch sensitivity Z exceeds the touch-on threshold value Zth, the touch detection unit 210 determines that the detected point in the x and y coordinates is touched with a finger or the like (touch-on determination) (step S01). If it is determined that the touch-on has been made from touch-off, the process proceeds to step S02. If it is not determined that the touch-on has been made from touch-off, the process proceeds to step S04.

As the sensitivity initial value _{Z 0,} substituting touch sensitivity Zpre just before became touch in step S01 the sensitivity initial value _{Z 0} (step S02).

  As the previous touch sensitivity Zpre, the current touch sensitivity Z is substituted into the touch sensitivity Zpre (step S03).

In FIG. 3, P ₀ is a touch-off state. Becomes touch a touch-off in P _1, the _{P 1} is in the state of step S01~ step S03.

  In the control unit 20, the touch detection unit 210 detects touch-on. When the current touch sensitivity Z exceeds the touch-on threshold value Zth, the touch detection unit 210 determines that the detected point at the x and y coordinates is in the touch-on state (touch-on determination) (step S04). If it is determined that the touch is on, the process proceeds to step S05. If it is determined that the touch is not on, the process proceeds to step S07.

The touch detection unit 210 determines whether or not the current touch sensitivity Z satisfies the following condition.
Current touch sensitivity Z> initial sensitivity value Z ₀ × magnification α
Sensitivity initial value Z ₀ is the value assigned in step S02, the magnification alpha, is a predetermined value set as a touch or non-touch or cut can values. If the above condition is satisfied, the process proceeds to step S06. If the above condition is not satisfied, the process proceeds to step S03 (step S05).

  The control unit 20 sets the sensitivity flag to 1 (True) (step S06).

As shown in FIG. 3, the sensitivity initial value Z ₀ × the magnification α is set to a predetermined value, and the sensitivity flag is set when the touch sensitivity is larger than the predetermined value. That is, the sensitivity flag is set to 1 (True). The sensitivity flag being 1 (True) is a precondition for tap determination (tap-on determination). Therefore, by appropriately setting the magnification α, it is possible to determine that a tap operation with a glove or a finger slightly floating from the touch surface is an erroneous operation.

After step S06 ends, the process returns to step S01 via step S03. In the touched state, the process returns to step S04, and steps S04 to S06 to S01 to S04 are repeated. This, in FIG. 3, in the state of step S04~ step S06 that the touch-on state is maintained as indicated by _{P 2.}

The control unit 20 detects the touch-off using the touch detection unit 210. As shown in FIG. 3, to detect whether consisted touch P ₂ in the touch-off P _3. When the current touch sensitivity Z is equal to or less than the touch-on threshold Zth, the touch detection unit 210 determines that the detected point at the x and y coordinates is touched off (touch-off determination) (step S07). If it is determined that the touch-off has occurred, the process proceeds to step S08. If it is not determined that the touch-on has changed from touch-on, the process proceeds to step S03.

  The control unit 20 determines whether the sensitivity flag is 1 (True) by the tap detection unit 220 (step S08). If the sensitivity flag is 1 (True), the process proceeds to step S09. If the sensitivity flag is not 1 (True), the process proceeds to step S10.

The tap detection unit 220 of the control unit 20 performs tap-on determination on the assumption that tap-on has been performed, and proceeds to step S11 (step S09). Incidentally, the tap determination is touch P ₂ is a predetermined time period (e.g., 180 ms, etc.) can be determined by adding other conditions such that the condition that is within.

  If the sensitivity flag is not 1 (True) in step S08, the control unit 20 determines that the tap is erroneous, cancels the tap, and proceeds to step S11 (step S10).

  After the tap determination, the control unit 20 sets the sensitivity flag to 0 (False), and proceeds to step S03.

In FIG. 3, P ₃ becomes the touch-off state from touch-on state of P _2, and a Tappuon state satisfying the condition of sensitivity flags.

  The process returns to step S01 via step S03, and the series of touch determination and tap determination described above are repeated. The above flow is continued until an interrupt signal such as a stop / interrupt signal is input.

  FIG. 4A is an overall perspective view showing a configuration when the electrostatic detection device according to the embodiment of the present invention is applied to a remote operation of a vehicle navigation device or the like, and FIG. It is a top view which shows a part.

  As an example, the electrostatic detection device 1 can be applied to a car navigation device 7 mounted on a vehicle 5 as shown in FIG. 4A, but is not limited thereto. Moreover, the electrostatic capacitance detection part 10 of the electrostatic detection apparatus 1 is arrange | positioned at the center console 50 between the driver's seat of the vehicle 5, and a passenger seat, for example. The operator can operate the capacitance detection unit 10 of the electrostatic detection device 1.

  As shown in FIG. 4A, for example, a map display of car navigation is displayed on the display screen 60 of the display device 6 arranged on the instrument panel 52, and the position is selected by touching the cursor 68. Various operations such as performing a position determination by a tap operation or shifting to a menu screen by a double tap operation can be performed.

  FIG. 5A is a graph showing a change in touch sensitivity during a normal double tap operation, and FIG. 5B is a graph showing a change in touch sensitivity when an erroneous double tap occurs.

FIG. 5A is a graph showing changes in touch sensitivity when a tap operation is performed with a finger in contact with the capacitance detection unit 10. Touch sensitivity of the vertical axis is set to a value reading unit 12 is normalized (standardized) at 200 the value of the read capacitance A / D converted as detection point information S ₂ shown in FIG. Z _{01 for the} first time or Z _{02 for the} second time satisfies the sensitivity flag ON condition (sensitivity initial value Z ₀ × magnification α or more) shown in step S05, and determination of double tap ON is made. That is, it is usually a double tap operation.

The control unit 20 can perform the double tap on determination when the tap on determination is made within a predetermined time after the tap on determination is made. That is, the double tap determination can be made on condition that the period T1 from the _first tap determination to the start of the second tap determination is within a predetermined period (for example, 280 ms).

FIG. 5B shows, for example, a touch when a tap operation is performed while wearing a glove, a state where the finger is slightly lifted from the touch surface, or a state where the finger is lifted from the touch surface due to vehicle vibration or the like. It is a graph which shows the change of a sensitivity. Both the first time Z ₀₃ and the second time Z ₀₄ do not satisfy the sensitivity flag ON condition (sensitivity initial value Z ₀ × magnification α or more) shown in step S 05. As a result, since the sensitivity flag is not raised in step S06, it is not determined that the double tap is on. That is, an erroneous double tap operation is performed.

(Effect of the embodiment of the present invention)
The electrostatic detection device according to the embodiment of the present invention uses a time-series change in touch sensitivity (capacitance) based on the value of touch sensitivity and the state of the sensitivity flag, thereby performing tap operation and double tap. Determine the operation. That is, when the current touch sensitivity Z exceeds the sensitivity initial value Z ₀ at the time of touch-on detection × the magnification α, the sensitivity flag is set to 1 (True), and the tap determination is performed on the condition that this sensitivity flag is set. Do. Thereby, it is possible to determine a tap operation with a glove or a finger slightly lifted from the touch surface as an erroneous operation. Further, by appropriately setting the magnification α, it is possible to discriminate between touch and non-touch, and it is possible to determine a tap operation with a glove or a finger slightly lifted from the touch surface as an erroneous operation. Therefore, it is possible to provide an electrostatic detection device that can suppress unintended tap operations and erroneous double tap determination.

  As mentioned above, although embodiment of this invention was described, these embodiment is only an example and does not limit the invention which concerns on a claim. These novel embodiments and modifications thereof can be implemented in various other forms, and various omissions, replacements, changes, and the like can be made without departing from the scope of the present invention. . In addition, not all the combinations of features described in these embodiments are essential to the means for solving the problems of the invention. Furthermore, these embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Electrostatic detection apparatus, 5 ... Vehicle, 6 ... Display apparatus 10 ... Capacitance detection part, 11 ... Drive part, 12 ... Reading part 20 ... Control part 50 ... Center console, 52 ... Instrument panel 60 ... Display screen , 68 ... Cursor 100 ... Operation area, 101 ... First detection electrode, 102 ... Second detection electrode 210 ... Touch detection unit, 220 ... Tap detection unit, 230 ... Storage unit Z ... Current touch sensitivity Z ₀ ... Sensitivity Initial value Zth ... Touch-on threshold Zpre ... Previous touch sensitivity α ... Magnification

Claims (3)

A capacitance detection unit including a detection electrode that detects proximity or contact of an object by touch sensitivity based on a change in capacitance value;
After performing touch detection on the detection electrode based on the touch sensitivity read from the detection electrode and detecting touch-on, the sensitivity flag is set when the current touch sensitivity is equal to or higher than a predetermined magnification of the initial sensitivity value at the time of touch-on detection. A control unit including a touch detection unit that stands up, and a tap detection unit that performs tap detection based on a change in touch sensitivity of the detection electrode after detection of the touch-on,
The tap detection unit is an electrostatic detection device that performs tap-on determination when the touch detection unit detects a touch-off in a state where the sensitivity flag is set.   The electrostatic detection apparatus according to claim 1, wherein the predetermined magnification is two.   The electrostatic detection device according to claim 1, wherein the control unit performs a double tap on determination when the tap on is determined within a predetermined time after the tap on is determined. .

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