JPH11249813A - Display integrated type coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously execute an input by means of a pen and a manual input and to improve an operability by constituting the electrodes of a display panel and a driving circuit so as to be commonly used for a coordinate input by means of an indicating means and a coordinate input by means of fingers. SOLUTION: A display integrated type coordinate input device is provided with an input pen 15 which connects the capacitance of the first electrode to that of the second one 2 and indicates a position on the display panel, a first electrode driving means 4 for driving the first electrode 1 and the second electrode driving means 5 for driving the second electrode 2. Then, the electrodes 1 and 2 of the display panel and the driving means 4 and 5 are commonly used for a coordinate input by the pen 15 and that by the fingers 16. That is, a pen X and Y-coordinate detecting period for detecting a display period for displaying a picture during one frame period and the indication coordinate of the input pen 15 on the display panel 3 and also a finger X and Y-coordinate detecting period for detecting the indication coordinate by the fingers 16 on the display panel are provided so as to execute picture display and coordinate detection by time division.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display-integrated coordinate input device having an integrated display function used in personal computers, word processors, and the like.

[0002]

2. Description of the Related Art A coordinate input device capable of inputting a character, a figure, or a command by a pen, a finger or the like has been put into practical use as a means for performing a predetermined input to a computer or a word processor. As a coordinate input device used in such an application, a transparent coordinate input device such as a pressure-sensitive resistive film type or an electrostatic induction type is arranged on a front surface of an LCD or the like to enable input with a pen and a finger. There is.

FIG. 16 is a schematic perspective view for explaining a conventional pressure-sensitive resistive film type coordinate input device. In FIG. 16, reference numeral 501 denotes a pressure-sensitive resistive film type coordinate input device;
Is a finger, and 503 is an LCD. The coordinate input device 501 is
A plastic film having a transparent resistive film on the opposing surface and a glass substrate are arranged at a slight gap by a spacer, and the two are brought into contact with each other at a position indicated by pressing with a pen or a finger. The coordinates of the position are detected.

A coordinate input device of the electrostatic induction type is disclosed in Japanese Patent Application Laid-Open No. Hei 7-129321. As shown in FIG. 17, the high-frequency signal V ₀ having the frequency fo for detecting a finger input is supplied to the X-axis decoder 512 a and the Y-axis decoder 51.
The detection signal is applied to the coordinate input device 511 via 3a, and the detection signal is sent to the data output unit 514 from the X-axis decoder 512b and the Y-axis decoder 513b.

When a finger touches the surface of the coordinate input device 511, the X-axis electrode line 515 or the Y-axis electrode line 516 is electrostatically coupled and grounded to the human body, and the output value of the detection signal of the electrode line closest to the finger is output. Is the lowest voltage value, the position pointed by the finger is detected at the electrode line pitch. When the pen input high-frequency signal Vp of a frequency f _p from the pen 510 inside the high-frequency oscillator means, or X-axis electrode lines 515, are applied by electrostatic coupling to the Y-axis electrode line 516, the pen 510 Based on the detection signal with the highest output value from the nearest electrode line and the detection signals from both adjacent electrodes, the position pointed by the pen 510 is detected by calculation at a resolution finer than the electrode pitch.

Also, depending on the frequency of the detected signal,
By recognizing whether the input is with a finger or with a pen, and based on the recognition result, a coordinate detection process corresponding to each is performed, thereby enabling input with a pen and input with a finger.

Further, another electrostatic induction type coordinate input device is disclosed in Japanese Patent Application Laid-Open No. 8-137607. As shown in FIG. 18, a plurality of X electrodes 522 and a plurality of Y electrodes 523 are arranged on the upper and lower surfaces of a glass substrate in a matrix form via a tablet 521 and an analog switch 524.
An oscillating means 525 connected to each X electrode 522 and an input pen 526 incorporating the oscillating means are provided. Input pen 526
When the input is made by using the analog switch 524, the analog switch 524 is switched to the detection means side, and the voltage oscillated from the input pen 526 is applied to each of the electrodes 522 and 523 through a capacitor.
Utilizing that a voltage corresponding to the distance from the input pen 526 to the input pen 526 is output, a predetermined operation is performed based on these output voltages to determine the coordinates of the pointing position of the input pen 526.

When inputting with a finger, the analog switch 524 is switched to the oscillating means 525 side, and a voltage of a predetermined frequency is sequentially applied from the oscillating means 525 to each X electrode, and each X and Y electrode 522, 523 is applied. The pointing coordinates of the finger are determined by utilizing the fact that the voltage applied through the capacitor in between changes due to the decrease in the capacitance due to the contact of the finger.

[0009] Further, whether the input voltage is a finger input or a pen input is recognized depending on whether the output voltage of the detected signal has increased or decreased with respect to the reference value, and based on the recognition result, each of them is determined. The input by the pen and the input by the finger are made possible by selecting the corresponding coordinate detecting means by the switching means or by selecting the respective coordinate detecting means in a time sharing manner by the switching means.

[0010]

However, the above-mentioned conventional coordinate input device has the following problems. That is, the first problem is that the conventional example shown in FIG.
-129321 or JP-A-8-137667.
In the prior art disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, input with a pen and a finger is possible, but since all of them dispose a coordinate input device on a display device such as an LCD, the display quality is lowered. . In addition, since a coordinate input device is required in addition to a display device such as an LCD, there is a problem that the whole device becomes large and heavy, and causes a cost increase.

A second problem is that when a hand holding the pen contacts the coordinate input surface when performing an input operation with the pen,
This has the problem that the pen signal cannot be accurately input due to the influence of the detection signal. As a coordinate input device that solves the first problem, a display-integrated coordinate input device in which electrodes of a display device and a driving unit are also used for coordinate detection is disclosed in Japanese Patent Application Laid-Open No. 5-53726 as shown in FIG. It has been disclosed. In this prior art, since the input means is limited to only the pen, there is a problem that a simple input operation with a finger cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and allows a pen or a finger to input coordinates without deteriorating the display quality of a display device. An object of the present invention is to provide a coordinate input device capable of performing accurate coordinate input with a pen even when touching an input surface and improving operability by simultaneously performing input with a pen and finger input. Furthermore, since the electrodes and driving means of the display device are also used for coordinate detection, the size and
A lightweight and low-cost coordinate input device can be provided.

[0013]

In order to solve the above-mentioned problems, a display-integrated coordinate input device according to the present invention comprises a plurality of first electrodes arranged in parallel with each other and a plurality of first electrodes arranged in a direction orthogonal to the first electrodes. A plurality of second electrodes arranged in parallel with each other, a display panel having a pixel corresponding to a location where the first electrode and the second electrode intersect, and electrostatically coupling with the first electrode and the second electrode Indicating means for indicating a position on the display panel; first electrode driving means for driving the first electrode; second electrode driving means for driving the second electrode; and a display-integrated coordinate input device as a whole. DC power supply means for supplying a DC voltage, AC applying means for applying an AC voltage of a predetermined frequency to a predetermined DC power supply voltage and a predetermined control signal, and detecting an indication position of the indication means on the display panel. First coordinate detecting means for performing A second coordinate detecting means for detecting a pointing position of a finger on the panel; a control means for controlling the entire apparatus; a first electrode driving means and a second electrode driving means; A corresponding voltage is applied to the first electrode and the second electrode to control a display control means for setting a display period for displaying an image, and the first electrode driving means and the second electrode driving means, First detection control means for setting a first detection period for sequentially applying a scanning voltage for detecting the position of the indicating means to the first electrode and the second electrode;
The first electrode driving unit and the second electrode driving unit are controlled to apply an AC voltage to the display panel, and the first electrode driving unit and the second electrode driving unit are controlled to control the first electrode driving unit. A second detection control unit that sequentially scans a second electrode to set a second detection period connected to the second coordinate detection unit; the display control unit; the first detection control unit; Switching means for sequentially switching the detection control means, wherein the first coordinate detection means is induced by the indication means by electrostatic coupling between the indication means and the scanning voltage applied by the detection control means. Calculating means for calculating coordinates of the indicating means based on the induced voltage, wherein the second coordinate detecting means includes a first electrode associated with a finger touching the display panel to which the AC voltage has been applied; Detection obtained from two electrodes And a calculating means for calculating the coordinates of the finger based on the flow signal.

According to the above configuration, since the electrodes of the display panel and the driving means are used also for the coordinate input by the instruction means and the coordinate input by the finger, there is no need to separately provide a coordinate input panel, so that the visibility is improved. Thus, it is possible to input the coordinates of both the pointing means and the finger, and the operability is improved. In addition, it is possible to reduce the thickness and weight and reduce the cost.

Further, one of the coordinate detection by the first electrode and the coordinate detection by the second electrode of the indicating means is performed during the image display period. According to the above configuration, the time required for coordinate detection can be shortened, so that the use efficiency of the display panel can be improved.

Further, the AC application means applies an AC voltage having a predetermined frequency to the DC power supply and the control signal only during the second detection period for detecting the finger pointing position on the display panel. An AC signal of a predetermined frequency is given to the panel. This eliminates the need to apply an AC to the power supply and control signal and image data not related to the finger coordinate detection, so that the configuration of the AC applying unit can be simplified,
The scale can be reduced.

[0017] The first coordinate detecting means is configured to provide an instruction for detecting that the indicating means has approached the display panel based on an output signal induced by the indicating means by the AC voltage applied to the display panel. Means detecting means. With the above configuration, it is possible to detect that the indicating means has approached the display panel, so that it is possible to prevent malfunction due to noise mixed into the indicating means when the indicating means is separated from the display panel. Further, the second detection control means also has the function of the first detection control means. With the above configuration, it is possible to reduce the number of parts and to reduce the cost.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention are shown in FIGS.
It will be described based on. The display panel of the present embodiment will be described using a duty-type liquid crystal display. Therefore, the first electrode represents a segment electrode, the second electrode represents a common electrode, the first electrode drive means represents a segment drive means, and the second electrode drive means represents a common electrode drive means.

[Embodiment 1] FIG. 1 shows a block diagram of Embodiment 1 of a display-integrated coordinate input device according to the present invention. The display-integrated coordinate input device of the present invention includes a plurality of first electrodes 1 arranged in parallel with each other, a plurality of second electrodes 2 arranged in a direction orthogonal to the first electrodes, and a first electrode 1. A display panel 3 having pixels corresponding to locations where the second electrode 2 intersects; an input pen 15 capacitively coupled to the first electrode 1 and the second electrode 2 to indicate a position on the display panel; A first electrode driving means 4 for driving one electrode 1, a second electrode driving means 5 for driving the second electrode 2, a DC power supply means 14 for supplying a DC voltage to the entire device, and a predetermined DC power supply voltage And an AC applying means 6 for applying an AC voltage of a predetermined frequency to a predetermined control signal.

Further, a first coordinate detecting means 7 for detecting a pointing position of the input pen 15 on the display panel 3, a second coordinate detecting means 8 for detecting a pointing position of a finger on the display panel 3, Control means 9 for controlling the whole of the present apparatus;
The first electrode driving unit 4 and the second electrode driving unit 5 are controlled to apply a voltage corresponding to each pixel to the first electrode 1 and the second electrode 2 to set a display period for displaying an image. The display controller 10 controls the first electrode driver 4 and the second electrode driver 5 to sequentially apply a scanning voltage for detecting the position of the input pen 15 to the first electrode 1 and the second electrode 2. By controlling the first detection control means 11 for setting the first detection period, the first electrode driving means 4 and the second electrode driving means 5, an AC voltage is applied to the display panel 3 and the first electrode driving Means 4 and the second electrode driving means 5 to control
The second detection control means 12 for sequentially scanning the electrode 1 and the second electrode 2 to set a second detection period connected to the second coordinate detection means 8, the display control means 10, and the first detection control And a switching unit 13 for sequentially switching and controlling the second detection control unit 12.

This display-integrated coordinate input device also serves as a display electrode of a liquid crystal display and a coordinate detection electrode of an electrostatic induction type coordinate input device. Then, as shown in FIG. 2, a display period for displaying an image during one frame period, and
A pen XY coordinate detection period for detecting the indicated coordinates of the input pen 15 on the display panel 3 and a finger XY coordinate detection period for detecting the indicated coordinates by the finger 16 on the display panel 3 are provided to perform image display and coordinate detection. It is performed in a time-sharing manner.

In FIG. 1, a display panel 3 includes first electrodes X1 to Xm (hereinafter, an arbitrary first electrode is referred to as X) and second electrodes Y1 to Yn (hereinafter, referred to as X). A liquid crystal is interposed between the first electrode X and the second electrode Y, and each pixel is formed in a region where the first electrode X and the second electrode Y intersect. That is, the display panel 3 has pixels of m × n dots arranged in a matrix.

The DC power supply means 14 generates a predetermined DC voltage from AC 100 V and supplies it to predetermined components. The AC applying means 6 includes an oscillating means, and controls the control means 9, the display control means 10, the first detection control means 11, and the second detection means only during the finger XY coordinate detection period for detecting the position indicated by the finger 16 on the display panel 3. Various control signals from the control means 12 and a predetermined AC signal to a predetermined power supply voltage are applied.

The display-integrated coordinate input device operates as follows. That is, the first electrode driving means 4 for driving the first electrode 1 and the second electrode driving means 5 for driving the second electrode 2 are connected via the switching means 13 and the AC applying means 6. Connected to the display control means 10, the first detection control means 11, and the second detection control means 12.

The switching means 13 is controlled by the control means 9. In the display period, the switching unit 13 selects the display control unit 10, and in the first detection period in which the input by the input pen 15 is performed, the switching unit 13 switches the first detection control unit 11.
Is selected, and the switching unit 13 selects the second detection control unit 12 during the second detection period in which the input by the finger 16 is performed.
Thus, during the display period, the output signal from the display control unit 10 is transmitted to the second electrode driving unit 5 and the first electrode driving unit 4.
On the other hand, during the pen XY coordinate detection period, the output from the first detection control unit 11 is output to the first electrode driving unit 4 and the second electrode driving unit 5, and during the finger XY coordinate detection period,
The output from the second detection control means 12 is applied to the first electrode driving means 4
And it outputs to the 2nd electrode drive means 5.

In the display period, image data for displaying a desired image and a control signal are output from the display control means 10 via the switching means 13 and the AC applying means 6 and the first electrode driving means is provided. The pixel matrix of the display panel 3 is driven in accordance with the row order by the operation of the fourth electrode driving means 4 and the second electrode driving means 5, and the pixels corresponding to the display data are displayed on the display panel 3 by the same operation as the ordinary liquid crystal panel. You. At this time, each control signal, image data, and power supply voltage are sent via the AC applying means 6, but no AC is applied during this period as described above.

Next, the pen XY coordinate detection operation will be described. In the pen XY coordinate detection period, the first
A control signal for pen coordinate detection is output from the detection control unit 11 to the first electrode driving unit 4 and the second electrode driving unit 5 via the switching unit 13 and the AC applying unit 6. Also at this time, each control signal is sent via the AC applying means 6, but no AC is applied during this period as described above.

During the pen X coordinate detection period, a scanning pulse of the first electrode scanning signals x1 to xm (hereinafter, an arbitrary first electrode scanning signal is referred to as x) is output from the output terminal of the first electrode driving means 4. It is applied to the first electrodes X1 to Xm, and during the pen Y coordinate detection period, the second electrodes Y1 to Yn of the second electrode driving means are
Scanning pulses of the second electrode scanning signals y1 to yn (hereinafter, an arbitrary second electrode scanning signal is referred to as y) are sequentially applied to the first electrodes Y1 to Yn from the output terminal of the second electrode driving unit 5. . FIG. 3 is a timing chart of each scanning signal in the pen coordinate detection period of the display-integrated coordinate input device. The pen XY coordinate detection period is divided into an x coordinate detection period and a subsequent y coordinate detection period. In the x coordinate detection period, a first electrode scanning signal x which is a pulse voltage signal is sequentially applied to the first electrode 1. On the other hand, during the y coordinate detection period, the second electrode scanning signal y, which is a pulse voltage signal, is sequentially applied to the second electrode 2. Further, as shown in FIG. 4, the first coordinate detecting means includes amplifying means 71a, 71b, a comparator 72a,
72b, an operation means 73, and an instruction means detection means 74. By the application of the pulse voltage signal, a voltage is induced in the input pen 15 by the electrostatic coupling between the first electrode 1 or the second electrode 2 and the tip electrode of the input pen 15. The induced voltage changes according to the distance between the input pen 15 and each electrode, and reaches the highest value when the electrode closest to the input pen 15 is scanned. The induced voltage generated at the input pen 15 is input to the first coordinate detecting means 7 as an output signal. After the output signal is amplified to a predetermined voltage level by the amplifying means 71a or 71b, it is binarized by the comparator 72a or 72b, and the coordinate value is calculated by the calculating means 73 based on the timing signal from the control means 9. . By performing this operation for each scan of the first electrode 1 and the second electrode 2, the x coordinate or the y coordinate of the position indicated by the input pen 15 is detected.

At this time, when the finger 16 is on the display panel 3, the finger 1 electrostatically coupled to the first electrode 1 or the second electrode 2
6, since the impedance of the path from the human body to GND is sufficiently large, it does not affect the scanning pulse applied to the first electrode 1 or the second electrode 2, so that the detection of pen coordinates by the finger 16 It has no effect.

As will be described later, during the finger XY detection period, since the AC voltage is applied to the first electrode 1 and the second electrode 2 of the display panel 3, the input pen 15 is moved to the display panel 3. 3, the input pen has the first electrode 1
Further, a voltage is induced by the electrostatic coupling with the second electrode 2. Based on the induced voltage, the indicating means detecting means 7
4 detects that the input pen 15 has approached the display panel 3. When it is detected that the input pen 15 has approached the display panel 3, the calculated x coordinate and y coordinate are determined to be valid, and the input pen 15 has not approached the display panel 3. If it is the data at that time, it is invalidated as being caused by noise.

Next, the finger XY coordinate detection period will be described. In the finger XY coordinate detection period, a control signal for finger XY coordinate detection is output from the second detection control means 12. The first electrode driving means 4 and the second electrode driving means 5 are used as analog switches,
Further, the second electrode 2 is sequentially switched to an AC applying means 6 and a second coordinate detecting means 8.

When the finger 16 is placed on the display panel 3, as shown in FIG. 5, all the first electrodes 1 and the second electrodes 2
6 and electrostatically. However, the coupling capacitance increases as the distance between the electrode and the finger 16 decreases. Therefore, if the position of the electrode which is most strongly electrostatically coupled is known, the position of the finger is determined.
It can be seen that this is the position where As will be described later, when the finger 16 is placed on the display panel 3, a minute current flows through the first electrode 1, the second electrode 2, and the human body as a path.
An electrode having a stronger electrostatic coupling with the finger 16 allows more current to flow. Therefore, the first electrode 1 or the second electrode 2 is sequentially scanned from the end, the electrode through which the largest current flows is detected, and it can be determined that the finger 16 is placed near the electrode.

At this time, the input pen 15 is displayed on the display pulse 3.
However, the electrostatic coupling between the input pen 15 and the first electrode 1 and the second electrode 2 is sufficiently smaller than the electrostatic coupling with the finger 16, and the current flowing through the input pen is negligible. Therefore, the input pen 15 does not affect the finger coordinate detection.

FIG. 6 shows an equivalent circuit at the time of finger input. 6
0 indicates a power supply circuit whose impedance is Zc
Set as 61 is an excitation signal voltage Vsin generation source,
The power supply circuit 60 is connected in series. Cp1 is an electrostatic coupling capacitance between the finger 16 and the selection electrode, and Cp2 is an electrostatic coupling capacitance between the finger 16 and electrodes other than the selection electrode. Reference numeral 62 denotes a human body model electrostatically coupled to the ground, which is represented by a series connection of a resistance Rh and a capacitance Ch. In the present embodiment, the coordinate value is obtained by monitoring the value of the current flowing through Cp1 in this equivalent circuit.

FIG. 7 shows a block diagram of the second coordinate detecting means 8. As shown in FIG. 7, the second coordinate detecting means 8
Are amplifying means 81a and 81b and an AC canceling means 82
a, 82b, band-pass filters 83a, 83b, an analog switch 84, sample-and-hold means 85,
A / D conversion means 86, calculation means 87, and storage means 8
8. Using the first electrode 1 and the first electrode driving means 4, the above operation is performed and the X coordinate when the X coordinate is detected
FIG. 8 shows an example of a signal waveform and a timing chart.
In the finger XY coordinate detection, the X coordinate detection operation and the Y coordinate detection operation are performed in a time division manner, and the Y coordinate detection operation using the second electrode 2 and the second electrode driving means 5 is basically the same as the X coordinate detection operation. In the following description, only the X coordinate detection operation is performed, and the description of the Y coordinate detection operation is omitted.

The signal waveform shown in FIG. 9A is obtained by scanning the first electrode X. The cycle of this signal is the cycle of the excitation signal, and each peak value Vsx (i) (i = 1) ,
2, .., n) by performing sample hold and A / D conversion at timing T (i) (i = 1, 2,..., N),
A detection signal digital data sequence Dsx (i) (i = 1, 2,..., N) over the entire coordinate input panel is obtained.

Further, as described above, the first electrode 1 and the AC applying means 6 and the second coordinate detecting means 8 are connected via the first electrode driving means 4, and the electrodes in the first electrode group are connected. When switching from the AC applying means 6 to the second coordinate detecting means 8 and when switching from the second coordinate detecting means 8 to the AC applying means 6, switching noise occurs in the first electrode driving means. Therefore, the noise component Vnoise resulting from the switching noise is actually superimposed on the signal waveform shown in FIG. 8A (FIG. 9).
In the present invention, since the display panel is used to detect the coordinates, the voltage that can be applied to the first electrode 1 and the second electrode 2 is limited. This is due to the limitation by the electric characteristics of the first driving unit 4 and the second driving unit 5 or the limitation by the electric characteristics of each pixel in the display panel so as not to affect the display content.

As a result, since the detection signal is small, the detection signal at the position where the finger 16 is placed may not show the maximum value but show the maximum value at a different position. However, the above-mentioned noise component Vnois
e indicates a constant value depending on the panel. Therefore, in the present embodiment, the coordinate detection operation is performed in a state where the finger 16 is not placed on the display panel 3, and the digital data sequence Dnx () at each timing T (i) of the noise component Vnoise on the entire surface of the display panel 3. i) and the storage means 88
To memorize it. Then, when performing the coordinate input operation, Dnx (i) is subtracted from Dsx (i), the absolute value data Dax (i) of the subtraction result is calculated, and this detection signal digital data sequence Dax (i) is calculated. A predetermined calculation is performed on the basis of this to obtain a coordinate value x. As a result, even if the detection signal itself is smaller than the noise, good coordinate detection can be realized.

Further, in the above embodiment, the AC application to the display panel is performed only during the finger XY coordinate detection period, but the AC application may be performed constantly. In this case, the display operation and
An AC signal is also superimposed on a DC power supply voltage, a control signal, and image data related to the pen XY coordinate detection operation. However, an AC of the same homologous voltage is applied, and a potential difference due to the AC signal is applied between the electrodes. Does not affect the image display. Further, for pen XY coordinate detection, an alternating current is applied to the scan pulse of the first electrode scan signal x and the second electrode scan signal y in the pen coordinate detection operation as shown in FIG. In the configuration of the coordinate detecting means 7, as shown in the first coordinate detecting means 7 'of FIG. 11, there are provided AC canceling means 75a and 75b, and a pen detection signal is generated before binarization by the comparator 72a or 72b. By canceling the AC component from, the coordinates are obtained by the same calculation processing as the above-described pen coordinate detection. In this case, since the AC application is always performed, the control of the AC application unit 6 is simplified.

[Second Embodiment] FIG. 12 is a block diagram showing a display-integrated coordinate input device according to a second embodiment of the present invention. In the second embodiment, a TFT liquid crystal panel is used as a display panel. In this case, the first electrode 21 serves as the source electrode,
The electrode 22 represents a gate electrode, the first electrode driver 24 represents a source electrode driver, and the second electrode driver 25 represents a gate electrode driver. The application of the predetermined voltage to the counter electrode is performed by the first electrode driving unit 24 and the second electrode driving unit 2.
5 is performed. Further, in the following description, a case in which the AC application to the display panel 23 is performed only during the finger XY coordinate detection period will be described. However, the AC application may be performed at all times, and is similar to the description of another example in the first embodiment. The effect of the AC application is canceled by the method.

The display-integrated coordinate input device according to the second embodiment includes a plurality of first electrodes 21 arranged in parallel with each other and a plurality of second electrodes arranged in parallel with each other in a direction orthogonal to the first electrodes 21. Electrode 22, first electrode 21 and second electrode 22
Display panel 2 having pixels corresponding to the locations where
3, and the first electrode 21 and the second electrode 22 are electrostatically coupled,
Input pen 15 for indicating a position on the display panel 23
First electrode driving means 24 for driving the first electrode 21;
The apparatus includes a second electrode driving unit 25 that drives the second electrode 22 and a DC power supply unit that supplies a DC voltage to the entire device.

Further, an AC applying means 26 for applying an AC voltage having a predetermined frequency to a predetermined DC power supply voltage and a predetermined control signal, and a first coordinate for detecting a position indicated by the input pen 15 on the display panel 23. Detecting means 27, second coordinate detecting means 28 for detecting the position indicated by the finger 16 on the display panel 23, and control means 29 for controlling the entire apparatus.
And controlling the first electrode driving unit 24 and the second electrode driving unit 25 to apply a voltage corresponding to each pixel to the first electrode 21 and the second electrode 22 to display a desired image and A display for detecting the Y coordinate of the input pen 15 on the panel 23. A display control means 30 for setting a pen Y coordinate detection period.
A first detection control unit 31 for controlling a first electrode driving unit 24 to set a first detection period for sequentially applying a scanning voltage for detecting a position of an input pen to the first electrode 21;
By controlling the first electrode driving unit 24 and the second electrode driving unit 25 to apply an AC voltage to the display panel 23, the first electrode driving unit 24 and the second electrode driving unit 25 are controlled.
, And sequentially scans the first electrode 21 and the second electrode 22 to set a second detection period for connection to the second coordinate detection means 28; and the display control means Switching means 33 for sequentially switching and controlling the first detection control means 31 and the second detection control means 32;
It is composed of

This display-integrated coordinate input device serves as both a display electrode of a TFT type liquid crystal display and a coordinate detection electrode of an electrostatic induction type coordinate input device. As shown in FIG. 13, a display operation for displaying an image during one frame period, a display / pen Y coordinate detection period for performing a Y coordinate detection operation of the input pen 15 on the display panel 23, and a display operation on the display panel 23 are performed. A pen X coordinate detection period for detecting the X coordinate of the input pen 15 and a finger coordinate detection period for detecting the coordinate pointed by the finger 16 on the display panel 23 are provided, and the image display and the coordinate detection are performed in a time sharing manner. Like that.

The display-integrated coordinate input device operates as follows. That is, the first electrode driving unit 24 for driving the first electrode 21 and the second electrode driving unit 25 for driving the second electrode 22 are connected via the switching unit 33 and the AC applying unit 26. The display control means 30 and the first
It is connected to the detection control means 31 and the second detection control means 32. The switching unit 33 is controlled by the control unit 29. In the display / pen Y coordinate detection period, the switching unit 33 selects the display control unit 30, and in the first detection period in which the X coordinate input by the input pen 15 is performed, the switching unit 33 is selected.
Selects the first detection control means 31, and the switching means 33 selects the second detection control means 32 during the second detection period in which the input by the finger 16 is performed.

As a result, during the display / pen Y coordinate detection period, the output signal from the display control means 30 is output to the first electrode driving means 24 and the second electrode driving means 25, while during the pen X coordinate detection period. Outputs the output from the first detection control unit 31 to the first electrode driving unit 24 and the second electrode driving unit 25
And outputs the output from the second detection control unit 32 to the first electrode driving unit 24 and the second electrode driving unit 25 during the finger coordinate detection period.

During the display / pen Y coordinate detection period, the operation is performed based on the display control means 30.
The display is performed by the substantially same driving method as the T-type liquid crystal panel. However, in the present embodiment, since the Y coordinate is detected using the second electrode scanning in the conventional display period,
As will be described later, the waveform of the scanning voltage of the second electrode is different from the conventional one.

In the above display / pen Y coordinate detection period,
Image data for displaying a desired image and a control signal are output from the display control means 30 via a switching means 33 and an AC applying means 26, and the second electrode driving means 25
In addition, the pixel matrix of the liquid crystal panel 23 is driven in accordance with the row order by the operation of the first electrode driving means 24, and the pixels corresponding to the display data are formed by the same operation as that of the normal TFT type liquid crystal panel. 23 is displayed. However, although the display data and the control signal pass through the AC applying means 26, the AC is not applied during this period as described above.

At this time, the second electrode scanning signals V _{G1 to} V _Gn having the cutting pulse Pc near the center as shown in FIG. 14 are sequentially applied to the second electrode 22. The second
By the application of the electrode scanning signal, the second electrode 22 and the input pen 1
Of the input pen 15 due to the electrostatic coupling between the
And a voltage is induced in the first coordinate detecting means 27. Then, only the component Vps induced by the pulse Pc is extracted by the pulse extracting means 271 in the first coordinate detecting means 27. The induced voltage Vps changes according to the distance between the input pen 15 and each electrode, and reaches the maximum value when the electrode closest to the input pen 15 is scanned. This signal is amplified to a predetermined voltage by amplifying means 272, and LP
After the envelope processing is performed by the F processing means 273, it is binarized by the comparator 274, and the coordinate value is calculated by the calculation means 275 based on the timing signal from the control means 29. FIG. 15 shows the first coordinate detecting means at this time.

Next, the pen X coordinate detection is performed during the pen X coordinate detection period. In the pen X coordinate detection period, a control signal for pen coordinate detection is transmitted from the first detection control unit 31 via the switching unit 33 and the AC applying unit 26 to the first electrode driving unit 24 and the second electrode driving unit. Although output to the means 25, the point that the coordinate detection is performed only on the first electrode 21 is different from the first embodiment. And this pen X
Since the coordinate detection operation is performed in the same manner as the pen coordinate detection in the first embodiment, the description is omitted. Next, finger coordinate detection is performed during the finger coordinate detection period, but this is also performed by the same operation as in the first embodiment, and a description thereof will be omitted.

As described above, according to the present invention, when the pen coordinate detection operation is performed, a scanning pulse is applied to the electrodes of the display panel to detect a signal with the input pen. An AC signal is applied to all the electrodes of the display panel, and signal detection when a finger touches the display panel is performed by the electrodes of the display panel. The above two operations are performed in a time-division manner. That is, the pen coordinate detection operation and the finger coordinate detection operation are completely separated. Therefore, the finger input detection operation and the pen coordinate detection operation do not affect each other, so that the finger input and the pen input can be performed at the same time. Since the pen coordinate detection is not disturbed by the touch, the operability is improved. Also,
Since the input with the pen and the input with the finger can be performed independently and simultaneously, the two designated positions on the display panel can be handled at the same time. For example, an operation such as item selection → input that once required two actions is once performed. And the operability is improved.

Furthermore, the electrodes and the driving means of the display panel are also used for pen coordinate detection and finger coordinate detection, and the display operation, the pen coordinate detection operation, and the finger coordinate detection operation are performed in a time-sharing manner. There is no deterioration in quality. Further, since the electrodes and the driving means of the display device are also used for coordinate detection, a small, lightweight, low-cost coordinate input device can be provided. In the first and second embodiments, the first
Detection control means 11, 31 and second detection control means 12, 3
2 is provided separately, but the second detection control means 12 and 32 include:
The functions of the first detection control means 11 and 31 may be provided.
In this case, the cost can be reduced by reducing the number of parts.

The display panel is not limited to the above-mentioned duty type liquid crystal panel and TFT type liquid crystal panel, but may be any other type such as an EL panel, a plasma display, or a plasma addressed liquid crystal display. A second electrode, a first electrode driving unit,
The present invention is applicable as long as it has the second electrode driving means as a component.

[0053]

As described above, the electrodes of the display panel and
Since the drive circuit is also used for the coordinate input by the pointing means and the coordinate input by the finger, there is no need to separately provide a coordinate input panel, so that the visibility can be improved and accurate coordinate input of both the pointing means and the finger can be performed. Operability is improved. Also,
It is also possible to reduce the thickness, weight and cost. In addition, since either the coordinate detection by the first electrode of the pointing means or the coordinate detection by the second electrode is performed during the image display period, the time required for the coordinate detection can be reduced, and the use efficiency of the display panel can be improved. It becomes possible.

Also, a power source not related to finger coordinate detection, and
Since there is no need to apply an alternating current to the control signal and the image data, the configuration of the alternating current applying means can be simplified, and the scale can be reduced. Further, since it is possible to detect that the instruction means has approached the display panel, it is possible to prevent malfunction due to noise mixed in the instruction means when the instruction means is separated from the display panel. Further, since the second detection control means also has the function of the first detection control means, it is possible to reduce the number of parts and to reduce the cost.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a display-integrated coordinate input device of the present invention.
FIG. 2 is a block diagram showing the configuration of FIG.

FIG. 2 is a first embodiment of a display-integrated coordinate input device according to the present invention;
FIG. 4 is a diagram showing a relationship between a display operation and a coordinate detection operation in FIG.

FIG. 3 is a diagram illustrating an example of a scanning voltage during a pen coordinate detection period in FIG. 2;

FIG. 4 is a first embodiment of a display-integrated coordinate input device according to the present invention;
FIG. 2 is a block diagram showing an example of a configuration of a first coordinate detecting unit in FIG.

FIG. 5 is an explanatory diagram of electrostatic coupling between a finger and an electrode according to the display-integrated coordinate input device of the present invention.

FIG. 6 is an equivalent circuit diagram in a finger input detection operation according to the display-integrated coordinate input device of the present invention.

FIG. 7 is a block diagram showing an example of a configuration of a second coordinate detecting means according to the display-integrated coordinate input device of the present invention.

FIG. 8 is a signal waveform and timing chart at the time of X-coordinate detection of a finger input according to the display-integrated coordinate input device of the present invention.

FIG. 9 is a diagram showing a switching noise component according to the display-integrated coordinate input device of the present invention.

FIG. 10 is a diagram showing another example of the scanning voltage during the pen coordinate detection period in the display-integrated coordinate input device according to the first embodiment of the present invention.

FIG. 11 is a block diagram showing another example of the configuration of the first coordinate detecting means in the display-integrated coordinate input device according to the first embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a coordinate input device according to a second embodiment of the display-integrated coordinate input device of the present invention.

FIG. 13 is a diagram showing a relationship between a display / pen Y coordinate detection period and a coordinate detection period in the display-integrated coordinate input device according to the second embodiment of the present invention.

FIG. 14 is a diagram illustrating an example of a scanning voltage during the display / pen Y coordinate detection period in FIG. 12;

FIG. 15 is a block diagram showing a configuration of first coordinate detecting means in a display-integrated coordinate input device according to a second embodiment of the present invention.

FIG. 16 is a block diagram showing a configuration of a conventional resistive film type coordinate input device.

FIG. 17 is a block diagram showing a configuration of a conventional capacitive coordinate input device.

FIG. 18 is a block diagram showing a configuration of another conventional capacitive coordinate input device.

FIG. 19 is a block diagram showing a configuration of a conventional display-integrated coordinate input device.

[Description of Signs] 1,21 First electrode 2,22 Second electrode 3,23 Display panel 4,24 First electrode driving means 5,25 Second electrode driving means 6,26 AC applying means 7,27 First coordinates Detection means 8, 28 Second coordinate detection means 9, 29 Control means 10, 30 Display control means 11, 31 First detection control means 12, 32 Second detection control means 13, 33 Switching means 14, 34 DC power supply means 15 Instruction means (input pen) 16 fingers

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Iwahashi Sharp Corporation 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka

Claims (5)

[Claims] A plurality of first electrodes arranged in parallel with each other; a plurality of second electrodes arranged in parallel with each other in a direction perpendicular to the first electrodes; and a first electrode and a second electrode. A display panel having pixels corresponding to the intersections; an indicator that is electrostatically coupled with the first electrode and the second electrode to indicate a position on the display panel; a first electrode that drives the first electrode Driving means; second electrode driving means for driving the second electrode; DC power supply means for supplying a DC voltage to the entire display-integrated coordinate input device; and a predetermined DC power supply voltage and a predetermined control signal. AC applying means for applying an AC voltage having a frequency, first coordinate detecting means for detecting a position indicated by the indicating means on the display panel, and second coordinate detecting means for detecting a position indicated by a finger on the display panel. And the entire device And control means for said first electrode driving means and by controlling the second electrode driving means, the voltage of the first electrode and the second the corresponding to each pixel
A display control unit that applies a voltage to the electrodes to set a display period for displaying an image; and controls the first electrode driving unit and the second electrode driving unit to control the first electrode and the second electrode. A first detection control unit for setting a first detection period for sequentially applying a scanning voltage for detecting a position of the indicating unit; a first electrode driving unit and a second electrode driving unit; While applying an AC voltage to the first electrode driving means and the second electrode driving means,
The first electrode and the second electrode are sequentially scanned to obtain the second electrode.
A second detection control unit for setting a second detection period connected to the coordinate detection unit; and a switching unit for sequentially switching and controlling the display control unit, the first detection control unit, and the second detection control unit, The first coordinate detecting means calculates coordinates of the pointing means based on an induced voltage induced by the pointing means by electrostatic coupling between the pointing means and the scanning voltage applied by the detection control means. Computing means, wherein the second coordinate detecting means detects the finger based on a detected current signal obtained from a first electrode and a second electrode accompanying the contact of the finger with the display panel to which the AC voltage is applied. And a calculating means for calculating the coordinates of the display. 2. The display-integrated coordinate input device according to claim 1, wherein one of the coordinate detection by the first electrode and the coordinate detection by the second electrode of the indicating means is performed during an image display period. . 3. The AC applying means applies an AC voltage having a predetermined frequency to the DC power supply and the control signal only during the second detection period for detecting a pointing position of a finger on the display panel. 3. The display-integrated coordinate input device according to claim 1, wherein an AC signal having a predetermined frequency is supplied to the display panel. 4. An instruction for detecting that the indicating means has approached the display panel based on an output signal induced by the indicating means by the AC voltage applied to the display panel. 4. The display-integrated coordinate input device according to claim 1, further comprising means for detecting means. 5. The display-integrated coordinate input device according to claim 1, wherein the second detection control means has a function of the first detection control means.