JPH07182105A - Matrix type display driving device and digitizer integrated display device - Google Patents

Abstract

(57) [Summary] [Purpose] To realize high position detection speed in a digitizer-integrated display device. A voltage superposition signal detection circuit 33 outputs a scanning signal from an output terminal 33 to a display electrode based on an electrode drive signal from a driver 31. Voltage superimposed signal detection circuit 33
Outputs a position data signal in the row direction from the scanning signal and the voltage signal from the output terminal 33. Shift register 35
Performs parallel-serial conversion of position data signals in the row direction from all the voltage superposition signal detection circuits 33 with a shift clock and sends them to the coordinate position detection circuit. Thus
Since the position data signal in the row direction induced in the display electrodes can be separated regardless of the level of the scanning signal, position detection can be performed independently at the same time as image display, and high position detection speed can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type display driving device and a digitizer body type display device using the matrix type display driving device.

[0002]

2. Description of the Related Art Conventionally, a digitizer integrated type display device in which a display device such as a liquid crystal display device having a display electrode and a digitizer are integrally formed can be roughly classified into the following two types.

(1) A display device and a digitizer sense board are laminated and mechanically integrated to form a digitizer integrated display device. At that time, there are cases where the digitizer sense board is arranged above the display device and cases where it is arranged below the display device. Which case is taken depends on the digitizing method of the digitizer sense board used and the type of display device. FIG. 6 shows an example in which the digitizer sense board is arranged above the liquid crystal display device.

In FIG. 6, the tip coordinates of the position detecting pen 2 on the digitizer sense board are detected, and the display device 3 corresponding to the tip coordinates is detected based on the detection result.
Display at the upper coordinate position.

However, in the digitizer-integrated type display device in which the display device and the digitizer sense board are laminated and mechanically integrated, there is a drawback that the formed device becomes thick. In particular, when a liquid crystal display device is used as the display device, one of the features of the liquid crystal display device, that is, the feature of thinning, is not exhibited at all.

Further, a position error in stacking the display device and the digitizer sense board appears as an error in display coordinates with respect to the detected coordinates.

Further, as shown in FIG. 6, when the digitizer sense board 1 is arranged above the display device 3, the display screen is viewed through the digitizer sense board 1. Therefore, the transmittance of the digitizer sense board 1 causes a reduction in the brightness of the display screen, and the reflection of external light on the surface of the digitizer sense board 1 causes a reduction in the display quality.

On the other hand, when the digitizer sense board is arranged below the display device, noise from the display device to the position detection signal and interruption of the position detection signal by the display device occur.

Therefore, in order to solve the above-mentioned drawback (1), a digitizer integrated display device as shown in (2) has been proposed.

(2) By using the position detecting electrode also as the display electrode of the display device, the display device and the digitizer sense board are functionally integrated to form a digitizer integrated display device. Then, as shown in FIG. 7, a display period and a position detection period are provided for each frame by time division.

FIG. 8 is a block diagram of a digitizer-integrated display device using a liquid crystal display device as the display device. During the position detection period, the switching circuit 9 supplies the position detection control signal from the position detection control circuit 11 to the gate driver 7 and the source driver 8, and the row electrodes and columns of the liquid crystal panel 5 are based on the position detection control signal. The electrodes are scanned. Then, based on the position detection signal from the position detection pen 6 and the timing signal from the position detection control circuit 11, the coordinate position detection circuit 12 detects the tip coordinates of the position detection pen. Further, display data representing the position coordinates thus detected is generated and supplied to the display control circuit 10.

On the other hand, during the above display period, the switching circuit 9
The display control signal from the display control circuit 10 is supplied to the gate driver 7 and the source driver 8, and a point is displayed at the detected coordinate on the liquid crystal panel 5 based on the display data representing the detected position coordinate.

[0013]

[Problems to be Solved by the Invention]
The digitizer integrated display device shown in (2) has the following problems.

That is, in this digitizer-integrated display device, one frame period is time-divided into a position detection period and a display period for position detection and image display.
The position coordinate detection is performed once per frame, and its speed
(Position detection speed: times / second) is restricted by the display timing (frames / second). That is, since the frame frequency is usually about 60 Hz, the position detection speed is determined to be 60 times / second. Therefore, it is not possible to easily improve the position detection speed.

Further, the above-mentioned display device tends to have higher resolution, and it is expected that the number of position detection electrodes will increase in the future. Therefore, position detection is performed once per frame.
Even when it is carried out once, a matrix type display driving device which operates at high speed is required.

Therefore, an object of the present invention is to provide a matrix type display driving device which can obtain a high position detecting speed and can output detected position information with a smaller number of output than the number of detection electrodes, and its matrix type display. An object is to provide a digitizer-integrated display device using a drive device.

[0017]

In order to achieve the above object, a matrix type display driving device according to claim 1 drives a display having pixels arranged in a matrix to display an image. In the device, a driver that outputs an electrode driving signal applied to each display electrode of the display from an output terminal associated with the display electrode, an output terminal of the driver associated with each other, and a display electrode of the display The electrode drive signal provided from the output terminal of the driver is interposed between the display electrodes, and based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode, An electrode superposition signal detection circuit for detecting and outputting an electrode superposition signal superposed on the display electrode; Is characterized by having a position data processing circuit and outputting the time series converting said electrode superimposed signal from the superimposed signal detecting circuit.

According to a second aspect of the present invention, there is provided the matrix type display driving device according to the first aspect, wherein the electrode type superimposition signal from the position data processing circuit is time-sequentially converted and the electrodes are received. It is characterized in that it has a peak position detection circuit for detecting the position where the superimposed signal shows a peak value with higher accuracy than the distance between the electrodes.

According to a third aspect of the present invention, in the matrix type display driving device for driving a display having pixels arranged in a matrix form to display an image, the voltage is applied to each display electrode of the display. A driver that outputs an electrode drive signal from an output terminal associated with the display electrode, and an output terminal of the driver that is provided between the output terminal of the driver associated with each other and the display electrode of the display. The supplied electrode drive signal is supplied to the display electrode, and the electrode superposition signal superposed on the display electrode is detected based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode. Electrode superposition signal detection circuit that outputs the signal and the electrode superposition signal from the electrode superposition signal detection circuit It is characterized by having a position data processing circuit for detecting the position of the display electrode shown a maximum value of the item.

Further, in the digitizer integrated display device according to the present invention, when a display having pixels arranged in a matrix is driven to display an image, the display device is electrostatically coupled to each display electrode of the display. A position detection signal having a tip having an electrode is supplied to the display electrode, and a position data signal induced in each display electrode of the display due to the position detection signal is detected,
In the digitizer integrated display device for detecting the tip coordinates of the position detecting pen, the tip coordinate of the position detecting pen is detected by using the matrix type display driving device according to any one of claims 1 to 3. It is characterized by outputting as.

[0021]

According to the matrix type display driving device of the present invention, the driver drives the display by applying an electrode driving signal to each display electrode of the display from the output terminal associated with the display electrode. . Then, the electrode superposition signal detection circuit provided between the output terminal of the driver and the display electrode of the display associated with each other supplies the electrode drive signal supplied from the output terminal of the driver to the display electrode, Based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode,
The electrode superimposition signal superimposed on the display electrode is detected and output. That is, when the voltage signal of the display electrode includes, for example, a signal indicating the tip position of the position detecting pen, the signal indicating the tip position is separated from the voltage signal as an electrode superposition signal. Then, the position data processing circuit time-series converts the electrode superposition signal from the electrode superposition signal detection circuit and outputs it.

Therefore, by performing the position detection independently at the same time as the image display, a high position detection speed is obtained, and the position data signal induced in each display electrode of the above display is output with a smaller number of terminals than the number of display electrodes. it can.

According to the matrix type display driving device of the second aspect, in the matrix type display driving device of the first aspect, the electrode superposition signal from the position data processing circuit is received in time series, The peak position detection circuit detects the position indicating the peak value of the electrode superposition signal with higher accuracy than the distance between the electrodes.

Therefore, since the position detection is performed with a higher accuracy than the distance of the display electrodes, the external position is compared with the case where the same process is performed by receiving the signal obtained by converting the electrode superposition signal in time series. The detection circuit can be simplified.

Further, according to the matrix type display driving device of the third aspect, the driver applies an electrode driving signal to each display electrode of the display from the output terminal associated with the display electrode to drive the display. To drive. Then, the electrode superposition signal detection circuit provided between the output terminal of the driver and the display electrode of the display associated with each other supplies the electrode drive signal supplied from the output terminal of the driver to the display electrode, The electrode superposition signal superposed on the display electrode is detected and output based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode. Then, the position data processing circuit detects the position of the display electrode showing the maximum value of the electrode superposition signal from the electrode superposition signal detection circuit.

Therefore, by performing the position detection independently at the same time as the image display, a high position detection speed can be obtained, and the position data signal induced in each display electrode of the display is smaller than the number of display electrodes. Can be output with the number of terminals. Further, by configuring the position data processing circuit with, for example, a comparator and an encoder,
The position data of the electrode for which the electrode superposition signal shows the maximum value can be constantly output in real time.

Further, according to the digitizer integrated type display device of claim 4, by the electrode drive signal supplied to each display electrode of the display from the matrix type display drive device according to any one of claims 1 to 3, Each display electrode of the display is driven to display an image. On the other hand, a position data signal is induced in each display electrode of the display due to the position detection signal supplied to the electrode at the tip of the position detection pen. In this state,
The position data signal from the position detection pen superimposed on the display electrode is detected by the electrode superposition signal detection circuit in the matrix type display driving device on each display electrode in the display.

As described above, the tip coordinates of the position detecting pen can be detected by the position data processing circuit based on the position data signal separated from the voltage signal formed by superposing the position data signal of each display electrode. . Therefore,
A high position detection speed can be obtained, and the position data signal induced in each display electrode of the display can be output with a smaller number of terminals than the number of display electrodes.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The matrix type display driving device and the digitizer integrated type display device of the present invention will be described in detail below with reference to embodiments.

(First Embodiment) FIG. 1 is a block diagram of a matrix type display driving device of the first embodiment. This matrix type display driving device is a gate driver 22 or a source driver 23 (both drivers are generically referred to) for driving an active matrix type liquid crystal panel (hereinafter referred to as a liquid crystal panel) 21 in the digitizer integrated type display device shown in FIG. LCD driver).

Prior to the description of the matrix type display driving device, a digitizer integrated display device using the matrix type display driving device as the gate driver 22 and the source driver 23 will be described with reference to FIG.

FIG. 2 is a block diagram of a digitizer-integrated display device for driving the liquid crystal panel 21 by the gate driver 22 and the source driver 23 to display an image and detecting the tip coordinates of the position detecting pen 26. Pixels (not shown) are arranged in a matrix on the liquid crystal panel 21, and a thin film transistor (hereinafter abbreviated as TFT) is provided in each pixel. A plurality of row electrodes G for applying a voltage to the gate of the TFT are arranged in parallel in the row direction, and a column electrode S for applying a voltage according to a display signal to the source of the TFT is arranged in parallel in the column direction. Are
(Both electrodes are collectively called display electrodes).

The gate driver 22 generates a scanning signal based on the display control signal from the display control circuit 24,
This scanning signal is sequentially applied to each row electrode G of the liquid crystal panel 21 to scan each row electrode G. On the other hand, the source driver 23 generates a display signal according to the display data based on the display control signal from the display control circuit 24, and applies the display signal to all the column electrodes S of the liquid crystal panel all at once. In this way, the scanning signal is applied to the gate, and the voltage corresponding to the display data is applied to the liquid crystal of the pixel connected to the "ON" TFT to display an image.

Further, the position detection signal generating circuit 25 is
A position detection signal for detecting the tip coordinates of the position detection pen 26 is generated, and the position detection signal is used as the position detection signal.
Supply to. The position detecting pen 26 has a tip electrode at its tip that is electrostatically coupled to the row electrode G and the column electrode S of the liquid crystal panel 21, and the position detection signal from the position detection signal generating circuit 25 is applied to this tip electrode. Supplied.

The coordinate position detecting circuit 27 detects and outputs the tip coordinates of the position detecting pen 26 based on the position data signals from the gate driver 22 in the row direction and from the source driver 23 in the column direction. To do.

Next, a matrix type display driving device which constitutes the liquid crystal driver (gate driver 22 or source driver 23) will be described in detail with reference to FIG. Note that, for simplicity of explanation, the matrix type display drive device shown in FIG. 1 is assumed to constitute the gate driver 22.

The gate driver 22 outputs the electrode drive signal corresponding to each row electrode G based on the display control signal from the display control circuit 24 shown in FIG.
In response to the electrode drive signal from the driver 31, a scanning signal is output to the output terminals 33, 33, ... Corresponding to each row electrode G, and the signal from the electrode drive signal and the row electrode G is superimposed on the row electrode G. , Which outputs the generated electrode superposition signal, and the electrode superposition signal from the electrode superposition signal detection circuits 32, 32, ..., And the electrode superposition signal is used as a shift clock from the outside. Based on the parallel-serial conversion, that is, time series conversion, a shift register 35 as a position data processing circuit that outputs a time series position data signal is provided.

The gate driver 22 having the above-mentioned configuration is based on the display control signal from the display control circuit 24 and the driver 3
The electrode drive signal corresponding to each row electrode G is output from 1.
The electrode superposition signal detection circuits 32, 32, ... Receive electrode drive signals from the driver 31, and output scanning signals to the output terminals 33, 33 ,.
At this time, if the position detection signal is supplied from the position detection signal generation circuit 25 to the tip electrode of the position detection pen 26 of FIG.
Positional data in the row direction at a level corresponding to the distance from the position detection pen 26 is induced in each row electrode G of the liquid crystal panel 21. That is, a signal in which the position data in the row direction is superimposed on the scanning signal is generated at each row electrode G.

Then, the electrode superposition signal detection circuit 32,
32, ... Detects the electrode superposition signal superposed on the row electrode G from the voltage signal in which the position data is superposed on the electrode drive signal from the driver 31 and the scanning signal of the row electrode G. Receiving the electrode superimposition signals from the electrode superimposition signal detection circuits 32, 32, ..., The shift register 35 performs parallel-serial conversion of the electrode superimposition signals based on a shift clock from the outside, and a time series in the row direction. Output position data signal.

Also in the source driver 23, the electrode superimposed signal detection circuit 32 and the shift register 35 are used in the liquid crystal panel 2 as in the gate driver 22.
The electrode superimposition signal superposed on one column electrode S is detected, and a time-series position data signal in the column direction is output. And the position data signal in the row direction from the gate driver 22,
In response to the position data signal in the column direction from the source driver 23, the coordinate position detection circuit 27 shown in FIG. 2 detects the coordinate position of the tip of the position detection pen 26.

As described above, the position data signal can be detected simultaneously with the image display independently of the display period in which the image is displayed on the liquid crystal panel 21. Therefore, the position can be detected any number of times in one frame without being restricted by the timing of the electrode driving signal output from the driver 31 once in one frame, and the matrix type display driving device can be used as a digitizer integrated display device. When used as a liquid crystal driver, high position detection speed can be realized.

Further, as the resolution of the liquid crystal panel is increased,
Even if the position detection electrodes (the number of display electrodes) increase and it is necessary to shorten the coordinate detection period and increase the coordinate detection speed,
According to the matrix type display drive device of the first embodiment, the display period and the position detection period can be overlapped, and a high resolution display device can be easily realized.

Further, the shift register 35 time-sequentially converts the electrode superposition signals from the electrode superposition signal detection circuits 32, 32, ... And outputs as position data signals, so that each display electrode G of the liquid crystal panel 21 is output. The position data signal induced in S can be output with a smaller number of terminals than the number of display electrodes.

(Second Embodiment) FIG. 3 is a block diagram of a matrix type display driving device of the second embodiment. This matrix type display drive device has the same configuration as that of the first embodiment except the peak position detection circuit 36.
The same components are given the same reference numerals. The matrix type display driving device includes the shift register 3
The peak position detection circuit 3 which receives the time-series position data signal 5 and detects the position indicating the peak position with higher accuracy than the interval of the display electrodes from the electrode superposition signal converted in time series.
6 is provided. It should be noted that this matrix type display driving device constitutes the gate driver 22.

The gate driver 22 receives the electrode superposition signals detected by the electrode superposition signal detection circuits 32, 32, ... And the shift register 35 outputs a parallel-serial converted time series position data signal. Then, receiving the time-series position data signal from the shift register 35, the peak position detection circuit 36 detects the position indicating the peak position with higher accuracy than the interval between the display electrodes.

As an example of detection of the peak position in the peak position detection circuit 36, there is a method of approximating the maximum value of the electrode superposition signal and the values from the row electrodes G before and after the maximum value. A method for detecting the peak position approximately will be described below with reference to FIGS. The maximum value of the electrode superposition signal is the value of the Nth row electrode G.
b, the N−1th and N + 1th values of the row electrodes G before and after that are a and c, and the interval between the row electrodes G is L.

When a = b in FIG. 4 (a), the peak position is N-
It can be inferred that it is the midpoint between the 1st and Nth. That is, N-1
1 / (2 in the direction from the nth row electrode G to the Nth row electrode G
L) position.

In the case of a> c in FIG. 4 (b), the position of the intersection of the straight line P1 connecting the points B and C and the straight line P2 passing through the point A and having the opposite sign and the same absolute value as the straight line P1 has the same absolute value. It is close to the peak position. In this case, the peak position is from the Nth row electrode G to N-
Assuming that the position is X1 in the direction of the first row electrode G, X1 = (a−c) / {2 (b−c)} × L.

When a = c in FIG. 4C, it can be inferred that the peak position is on the Nth row electrode G.

In the case of a <c in FIG. 4D, the intersection of the straight line P3 connecting the points A and B, the straight line P3 connecting the points A and B passing through the point C, and the straight line P4 having the opposite sign. The position is approximated to the peak position. In this case, the peak position is from the Nth row electrode G to N +
Assuming that the position is X2 in the direction of the first row electrode G, X2 = (a−c) / {2 (b−c)} × L.

When b = c in FIG. 4 (e), the peak position can be estimated to be the midpoint between the Nth and N + 1th peaks. That is, in the direction from the Nth row electrode G to the (N + 1) th row electrode G, 1 / (2
L) position.

As described above, N-1, N, N + of the row electrode G is
The peak position can be approximately calculated from the values a, b, and c of the first three points. As described above, the peak position can be obtained by size comparison and simple addition, subtraction, multiplication and division, so that the peak position detection circuit can be configured by the comparator and the operational amplifier.

Although the peak position is linearly approximated in the second embodiment, three points of the row electrodes G at the (N-1, N, N + 1) th values a, b, c are secondary paraboloids. As three points on the curve, it is possible to determine the peak of the quadratic parabolic curve as the peak position.

In this way, the gate driver 22 is used in the digitizer-integrated type display device shown in FIG. The position data signal in the row direction is output with higher accuracy. On the other hand, also in the source driver 23, similarly to the gate driver 22, the electrode superposition signal detection circuit 32 and the shift register 3 are arranged.
5 and the peak position detection circuit 36, the liquid crystal panel 2
The electrode superposition signal superposed on one column electrode S is detected and a position data signal in the column direction is output. Then, receiving the position data signal in the row direction from the gate driver 22 and the position data signal in the column direction from the source driver 23,
The coordinate position detection circuit 27 shown in FIG.
The coordinate position of the tip of is detected.

Therefore, the position data signal can be detected independently of the display period in which an image is displayed on the liquid crystal panel 21. Further, even if the position detection electrodes (the number of display electrodes) are increased with the increase in the resolution of the liquid crystal panel and the coordinate detection period is required to be shortened and the coordinate detection speed is increased, the second embodiment described above is used. According to this, the display period and the coordinate detection period can be overlapped, and a high-resolution display device can be easily realized.

Further, the shift register 35 performs time series conversion of the electrode superposition signals from the electrode superposition signal detection circuits 32, 32, ..., And the peak position detection circuit 36 determines the peak position based on the time series position data signal. Is detected and output, the position data signal induced in each display electrode G, S of the liquid crystal panel 21 can be output with a smaller number of terminals than the number of display electrodes.

Further, since the position detection is performed with higher accuracy than the electrode spacing of the display electrodes G and S, the circuit for position detection by the external circuit can be simplified.

(Third Embodiment) FIG. 5 is a block diagram of a matrix type display driving apparatus of the third embodiment. This matrix type display driving device has the same structure except the shift register 35 of the first embodiment, and the same components are designated by the same reference numerals. It should be noted that this matrix type display driving device constitutes the gate driver 22. The gate driver 22
Instead of the shift register 35, comparators 37, 37, which compare the magnitudes of the electrode superposition signals from two adjacent electrode superposition signal detection circuits 32, 32, and binarize and output the result.
, And an encoder 38 that binary-codes the binarized signals from the respective comparators 37, 37, ... And outputs the binary-coded position data signal. , And the encoder 38.
And constitute a position data detection circuit.

In the gate driver 22 having the above-described structure, the electrode superposition signal detection circuits 32, 32, ... Receive the electrode drive signal from the driver 31 and output the scanning signal to the row electrode G, and at the same time, the electrode drive signal and the row electrode. The electrode superposition signal superposed on the row electrode G is detected based on the G electrode signal. And
The comparator 37, 37, ... Receives the electrode superimposition signals from the two adjacent electrode superimposition signal detection circuits 32, 32, respectively, compares the magnitudes of the electrode superimposition signals, and outputs the binarized signals. The encoder 38 binary-codes the binarized signal and outputs a position data signal.
That is, the position data signal binary-coded by the encoder 38 indicates the position data of the row electrode G showing the maximum value of the electrode superposition signals detected by the electrode superposition signal detection circuits 32, 32, .... .

In this way, the position of the tip electrode of the position detecting pen 26, that is, the position of the row electrode G indicating the peak value of the electrode superposition signal is detected by using the gate driver 22 in the digitizer integrated display device shown in FIG. Then, the position data signal in the row direction is output. On the other hand, also in the source driver 23, similarly to the gate driver 22, the electrode superposition signal superposed on the column electrode S of the liquid crystal panel 21 by using the electrode superposition signal detection circuit 32, the comparators 37, 37 ... And the encoder 38. Is detected and a binary-coded position data signal in the column direction is output. Upon receiving the row-direction position data signal from the gate driver 22 and the column-direction position data signal from the source driver 23, the coordinate position detection circuit 27 shown in FIG. Detect the position.

Therefore, the position data signal induced by the position detecting pen 26 can be output to each display electrode G, S of the liquid crystal panel 21 with a smaller number of terminals than the number of display electrodes. In addition, the position data detection circuit is provided with a comparator 3
.. and the encoder 38, it is possible to constantly output the position data of the electrode at which the electrode superposition signal shows the maximum value in real time.

In the first to third embodiments, the active matrix type display driving device has been described as an example, but the present invention is not limited to this, and the present invention may be applied to a duty type display driving device. The display device used at that time is not limited to the liquid crystal display device.

Although the position detection signal generating circuit 25 for supplying a position detection signal to the position detection pen 26 shown in FIG. 2 is provided independently of the position detection pen 26, the invention is not limited to this. The wireless pen may be configured by incorporating the position detection signal generation circuit inside the position detection pen 26.

Further, the position detection signal generating circuit 2 shown in FIG.
If a signal having a frequency at least several times as high as the scanning frequency of the row electrode G and the column electrode S is used as the position detection signal generated from 5, the position data signal can be accurately separated from the display drive signal.

Further, in the second embodiment, the peak position detection circuit 36 uses a method of approximating the peak position from the three values of the maximum value of the electrode superposition signal and the values from the display electrodes before and after it. However, it goes without saying that the method of detecting the position where the electrode superposition signal shows the peak value with higher accuracy than the distance between the electrodes is not limited to this.

Further, in the third embodiment, the position data detection circuit is composed of the comparators 37, 37, ... And the encoder 38, but the position data detection circuit is not limited to this, and shows the maximum value of the electrode superposition signal. Any device that detects the position of the display electrode may be used.

[0067]

As is apparent from the above, the matrix type display driving device according to the first aspect of the present invention is a matrix type display driving device for driving a display having pixels arranged in a matrix to display an image, The driver outputs an electrode drive signal to be applied to each display electrode of the display from an output terminal associated with the display electrode, and between the output terminal of the driver associated with each other and the display electrode of the display. An electrode superposition signal detection circuit is provided, and the electrode superposition signal detection circuit supplies the electrode drive signal supplied from the output terminal of the driver to the display electrode, and the electrode drive signal from the output terminal of the driver. Detects and outputs the electrode superposition signal superposed on the display electrode based on the voltage signal of the display electrode , The position data processing circuit is to output the time series converting said electrode superimposed signal from the electrode superimposed signal detecting circuit.

Therefore, according to the matrix type display driving device of the first aspect of the invention, the electrodes superimposed on the respective display electrodes are based on the electrode driving signal output from the driver and the voltage signal of the display electrode signal of the display. Since the superposition signal is detected and the electrode superposition signal is converted into a time series, the position detection can be performed independently of the image display, and the position detection can be performed simultaneously with the image display. Therefore, a high position detection speed can be realized, and position detection information can be output with a smaller number of terminals than the number of detection electrodes.

According to a second aspect of the present invention, there is provided a matrix type display driving device, wherein the matrix type display driving device according to the first aspect receives a signal obtained by time-sequentially converting the electrode superposition signal from the position data processing circuit. The peak position detection circuit detects the position indicating the peak value of the electrode superposition signal with higher accuracy than the distance between the electrodes.

Therefore, since the position detection can be performed with a higher accuracy than the distance between the electrodes from the time-series converted signal, the position detection circuit in the external circuit can be simplified.

The matrix type display driving device of the invention of claim 3 is a matrix type display driving device for driving a display having pixels arranged in a matrix to display an image, each display of the matrix type display. From the electrode drive signal output to the electrode and the voltage signal of each display electrode, the electrode superposition signal detection circuit detects the electrode superposition signal superposed on each display electrode, and the position data processing circuit detects the electrode superposition signal detection circuit. The position of the display electrode showing the maximum value of the electrode superposition signal from is detected.

Therefore, it is possible to output the position data of the display electrode at which the electrode superposition signal shows the maximum value with a smaller number of outputs than the number of detection electrodes. Further, by configuring the position data processing circuit by, for example, a comparator and an encoder, instead of the number of seconds of the conventional position detection speed,
The position data can always be output.

In the digitizer-integrated display device according to a fourth aspect of the present invention, when displaying an image on a display having pixels arranged in a matrix, electrodes that are electrostatically coupled to the respective display electrodes of the display are provided. A position detection signal having a tip at the position is supplied to the display electrode, and a position data signal induced in each display electrode of the display due to the position detection signal is detected to detect the tip coordinate of the position detection pen. In the digitizer integrated display device for detecting the position, the matrix type display driving device according to any one of claims 1 to 3 is used to detect and output the tip coordinates of the position detecting pen.

Therefore, according to the digitizer-integrated display device of the fourth aspect of the invention, the display is driven by the driver of the display drive device of any one of the first to third aspects, and the position overlapped with the display electrode is achieved. By detecting the position data signal from the detection pen, the tip coordinates of the position detection pen can be detected. Therefore, the position detection can be performed simultaneously with the image display and independently of the image display, the position detection speed can be increased without being restricted by the display timing, and the position detection can be performed with the number of terminals smaller than the number of detection electrodes. Information can be output.

[Brief description of drawings]

FIG. 1 is a block diagram of a matrix type display driving device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a digitizer-integrated display device using the matrix-type display driving device of the first embodiment.

FIG. 3 is a block diagram of a matrix type display driving device according to a second embodiment of the present invention.

4 (a) to 4 (e) are diagrams showing peak position detection in the second embodiment.

FIG. 5 is a block diagram of a matrix type display driving device according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a digitizer-integrated display device in which a conventional digitizer sense board is laminated on an upper side of a liquid crystal panel.

FIG. 7 is a diagram showing timings of a display period and a position detection period in a conventional digitizer-integrated display device in which a digitizer sense board and a display device are functionally integrated.

8 is a block diagram of a conventional digitizer-integrated display device that performs image display and position detection at the timing shown in FIG. 7.

[Explanation of symbols]

21 ... Liquid crystal panel, 22 ... Gate driver, 23 ... Source driver, 24 ... Display control circuit, 25 ... Position detection signal generating circuit, 26 ...
Position detection pen, 27 ... Coordinate position detection circuit, 3
1 ... Driver, 32 ... Electrode superimposed signal detection circuit, 3
5 ... shift register, 36 ... peak position detection circuit,
37 ... Comparator, 38 ... Encoder.

Claims (4)

[Claims] 1. A matrix type display driving device for driving a display having pixels arranged in a matrix to display an image, wherein an electrode driving signal applied to each display electrode of the display is associated with the display electrode. A driver for outputting from the output terminal, an electrode driving signal provided from the output terminal of the driver, which is provided between the output terminal of the driver and the display electrode of the display, which are associated with each other, to the display electrode. While supplying, based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode,
An electrode superposition signal detection circuit for detecting and outputting the electrode superposition signal superposed on the display electrode, and a position data processing circuit for time-sequentially converting and outputting the electrode superposition signal from the electrode superposition signal detection circuit are output. A matrix type display drive device characterized by the above. 2. The matrix type display driving device according to claim 1, wherein a position where the electrode superposition signal shows a peak value is received by receiving a signal obtained by time-series conversion of the electrode superposition signal from the position data processing circuit. A matrix type display drive device having a peak position detection circuit for detecting with a higher accuracy than the distance between the electrodes. 3. A matrix type display driving device for driving a display having pixels arranged in a matrix to display an image, wherein an electrode driving signal applied to each display electrode of the display is associated with the display electrode. A driver for outputting from the output terminal, an electrode driving signal provided from the output terminal of the driver, which is provided between the output terminal of the driver and the display electrode of the display, which are associated with each other, to the display electrode. While supplying, based on the electrode drive signal from the output terminal of the driver and the voltage signal of the display electrode,
An electrode superposition signal detection circuit for detecting and outputting the electrode superposition signal superposed on the display electrode, and position data for detecting the position of the display electrode showing the maximum value of the electrode superposition signal from the electrode superposition signal detection circuit. A matrix-type display driving device comprising: a processing circuit. 4. When a display having pixels arranged in a matrix is driven to display an image, the display is performed from a position detection pen having an electrode electrostatically coupled to each display electrode of the display. A digitizer integrated display device that supplies a position detection signal to the electrodes, detects the position data signal induced in each display electrode of the display due to the position detection signal, and detects the tip coordinates of the position detection pen. In the digitizer integrated display device, the matrix type display driving device according to any one of claims 1 to 3 is used to detect and output tip coordinates of the position detection pen.