JPH06314166A - Integrated type display tablet device and its driving method - Google Patents

Abstract

PURPOSE:To improve the detection precision of electronic pen tip coordinates when electrodes connected to the control terminal of the switching element of a display panel are scanned. CONSTITUTION:A shift register 21 which constitutes one unit of the row electrode scanning signal generation part of a row electrode driving circuit 2 shifts pulses of a shift data signal (s) in synchronism with a 1st clock signal ck1 to generate pulses for image display of row electrodes scanning signals ga1-ga4. Then AND gates 24, 25, 26, and 27 generate pulses for coordinate detection by holding the pulses for image display at a level 'L' for the period of pulses of a 2nd clock signal ck2 which is a delayed by time 'T0' from the 1st clock signal ck1. Then the pulses for coordinate detection are inserted into the pulses for image display at positions where there is not the effect of reference voltage variation of the column electrode driving signal to improve the detection precision of the electronic pen tip coordinates when the row electrodes connected to the control terminal of the switching element are scanned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display-integrated type tablet device having a display function used in a laptop computer, a word processor, etc., and a driving method thereof.

[0002]

2. Description of the Related Art Conventionally, there is a display-integrated type tablet device having both a display function and a tablet function by an active matrix system as shown in FIG.
This display-integrated type tablet device includes an active matrix type liquid crystal display panel (hereinafter, simply referred to as a display panel) 1, a row electrode drive circuit 2 and a column electrode drive circuit 3 for driving the display panel 1, and a row electrode drive. A display control circuit 4 that supplies a display control signal to the circuit 2 and the column electrode drive circuit 3, a detection control circuit 5 that supplies a detection control signal to the column electrode drive circuit 3, and a display panel that receives signals from the electronic pen 6. 1. A coordinate detection circuit 7 for detecting the tip coordinates of the electronic pen 6 on the device 1, a switching circuit 8 and a coordinate detection circuit 7
Is configured by a control circuit 9 for controlling the image display operation and the coordinate detection operation.

The display panel 1 is a transparent TFT substrate 1
, A plurality of row electrodes G1, G2, G3, ...
G6 (hereinafter, an arbitrary row electrode is referred to as G) and a plurality of column electrodes S1, which are arranged in parallel at right angles to the group of row electrodes G1,
, S6 (hereinafter, any column electrode is referred to as S). A TFT (thin film transistor) 11 is arranged at the intersection of each row electrode G and column electrode S, and each TFT 1
A row electrode G is connected to the first gate electrode, while a column electrode S is connected to the source electrode. The pixel electrode 12 is connected to the drain electrode of the TFT 11. The picture element electrodes 12 are arranged in a matrix in a region surrounded by the row electrodes G and the column electrodes S.

This TF is provided on the back side of the TFT substrate 10.
A counter substrate 13 is arranged to face the T substrate 10, and a counter electrode 14 having substantially the same area as the TFT substrate 10 is arranged on the inner surface of the counter substrate 13. Liquid crystal is sandwiched between each picture element electrode 12 and the counter electrode 13 to form a picture element matrix. A bias voltage is supplied to the counter electrode 14 by a power supply circuit 16 and a counter electrode drive circuit 15.

The row electrode drive circuit 2 has row electrode scanning signals g1 to g6 (hereinafter, an arbitrary row electrode scanning signal will be referred to as g).
The scanning pulse of 1 is sequentially applied to each row electrode G on the display panel 1 to scan the row electrode G. The column electrode drive circuit 3 synchronizes with the scanning of the row electrodes G and has a column electrode drive signal s having a voltage level according to the display content of the picture element of each row electrode G.
₁ 1 to s ₁ 6 (hereinafter, an arbitrary column electrode driving signals to as s ₁₎ is applied to the column electrode S. Furthermore, independently of the scanning of the row electrodes G, the column electrode scanning signal s ₂ 1 to s ₂ 6 (hereinafter, an arbitrary column electrode scanning signal s ₂ to as) the scanning pulse to each column electrode S The column electrodes S are scanned by sequentially applying. The scan pulse generated by the row electrode drive circuit 2 and the drive pulse and scan pulse generated by the column electrode drive circuit 3 are generated by the bias voltage from the power supply circuit 16.

The electronic pen 6 has at its tip a detection electrode (not shown) having a high input impedance, which is coupled to the row electrodes G and the column electrodes S on the display panel 1 by stray capacitance.
An induced voltage is induced in the detection electrodes due to the scanning pulse applied to the row electrode G or the scanning pulse applied to the column electrode S. The coordinate detection circuit 7 detects the generation timing of the induced voltage generated in the detection electrode of the electronic pen 6 based on the coordinate detection timing signal from the control circuit 9, and detects the tip coordinate of the electronic pen 6.

When the tip coordinate of the electronic pen 6 is detected by the coordinate detecting circuit 7, the coordinate detecting circuit 7 outputs an x coordinate signal and ay coordinate signal representing the tip coordinate.
The display data signal for displaying the point image at the tip position of the electronic pen 6 on the display panel 1 based on the x-coordinate signal and the y-coordinate signal is the display data signal generating means (which is directly related to the present embodiment). Since it is not present, it is generated by (not shown) and input to the display control circuit 4. as a result,
By the switching operation of the switching circuit 8 based on the control of the control circuit 9 and the operations of the display control circuit 4, the row electrode driving circuit 2, and the column electrode driving circuit 3, a dot image is displayed at the tip position of the electronic pen 6 on the display panel 1. Is displayed.

In this way, characters, symbols and pictures can be written on the display panel 1 by the electronic pen 6 as if we were writing on paper with a writing instrument. At the same time, an input character or an input symbol can be recognized by a recognition means (not shown) from the changes in the x-coordinate signal and the y-coordinate signal, and the recognition result can be used to create a document or control instructions. Of course, it can also be used as a response means to the icon displayed on the display panel 1.

FIG. 12 is a diagram showing operation timing of the display-integrated tablet device. One cycle Tv of the vertical synchronizing signal V, which is one of the synchronizing signals, is the display period of one screen.
(y-coordinate detection period) T1 and x-coordinate detection period T2 are divided, and the x-coordinate detection period T2 is equal to the vertical blanking period Tb. Then, the division into the detection period (y-coordinate detection period) T1 and the x-coordinate detection period T2 is performed by the switching circuit 8 switching selection between the display control circuit 4 or the detection control circuit 5.

FIG. 13 is a timing chart of various signals in the operation of the display-integrated type tablet device.
Hereinafter, the operation of the display-integrated tablet device will be described in detail with reference to FIG.

The synchronizing signals input to the display control circuit 4, the detection control circuit 5 and the control circuit 10 include a horizontal synchronizing signal H in addition to the vertical synchronizing signal V. Vertical sync signal V
Has a cycle corresponding to one screen display period, and the horizontal synchronizing signal H has a cycle corresponding to one horizontal screen display period.
Further, in this embodiment, eight cycles of the horizontal synchronizing signal H correspond to one cycle of the vertical synchronizing signal V. Six of the eight horizontal synchronizing signals H are allocated to the display period (y coordinate detection period) T1, and the remaining two cycles are allocated to the x coordinate detection period T2.

When the switching circuit 8 is switched to the display control circuit 4 side by the control signal from the control circuit 9, the display period (y coordinate detection period) T1 starts. Then, the row electrode drive circuit 2 causes the horizontal synchronization signal H from the display control circuit 4.
The scanning pulse of the row electrode scanning signal g generated in synchronism with one cycle is sequentially applied to each row electrode G to scan the row electrode G. Then, the voltage of the scanning pulse is applied to the gate electrode of the TFT 11 via the row electrode G, and the TFT 11 is turned “on”.

On the other hand, the column electrode driving circuit 3 synchronizes with the scanning of the row electrodes G and outputs a column electrode driving signal s ₁ having a voltage level according to the display contents of the picture elements associated with each row electrode G. Apply to S. Then, through the column electrode S, TF
The voltage of the drive pulse is applied to the source electrode of T11,
As described above, the signal voltage is applied to the pixel electrode 12 connected to the drain electrode of the TFT 11 which is turned “on” by the scanning of the row electrode G by the row electrode drive circuit 2. In this way, the image is written in the picture element according to the display content.
However, in FIG. 13, the voltage levels of all the column electrode drive signals are expressed equally.

At this time, a voltage is induced at the tip electrode of the electronic pen 6 due to the scanning pulse of the row electrode scanning signal g applied from the row electrode driving circuit 2 to each row electrode G. The coordinate detection circuit 7 detects the generation timing of this induced voltage and detects the y coordinate of the tip of the electronic pen 6. That is,
In the display period (y-coordinate detection period) T1, the scanning pulse sequentially applied to the row electrodes G is used as a scanning pulse for image display and a scanning pulse for y-coordinate detection.

When the switching circuit 8 is switched to the display control circuit 4 side by the control signal from the control circuit 9, the x coordinate detection period T2 starts. Then, the column electrode drive circuit 3 generates the column electrode scanning signal s ₂ . Then, the scanning pulse of the column electrode scanning signal s ₂ is sequentially applied to the three column electrodes S every one cycle of the horizontal synchronizing signal H, and all the column electrodes S are sequentially scanned in two cycles of the horizontal synchronizing signal H. .

At this time, a voltage is induced in the tip electrode of the electronic pen 6 due to the scanning pulse of the column electrode scanning signal s ₂ applied from the column electrode driving circuit 3 to each column electrode S.
The coordinate detection circuit 7 detects the generation timing of the induced voltage and detects the x coordinate of the tip of the electronic pen 6. That is, in the x coordinate detection period T2, the scan pulse sequentially applied to the column electrode S is used as the scan pulse for x coordinate detection.

In order to prevent the liquid crystal from deteriorating, it is necessary to control the molecular alignment by an AC voltage. Therefore, the voltage of the counter electrode 14 is kept constant and the level of the voltage of the column electrode drive signal s ₁ output from the column electrode drive circuit 3 with respect to the voltage of the counter electrode 14 is inverted every frame.
As a result, as shown in the lowermost row in FIG. 13, the potential level of the pixel electrode 12 connected to the same row electrode G via the TFT 11 is inverted every time a scanning pulse is applied to the row electrode G, and the pixel electrode 12 is opposed. The polarity with respect to the potential of the electrode 14 is inverted.

[0018]

However, the above-mentioned display-integrated tablet device has the following problems. First, in the display period, an image is displayed on the display picture element by charging an equivalent capacitance composed of the picture element electrode 12 of the display picture element on the picture element matrix, the counter electrode 14 and the liquid crystal sandwiched between both electrodes. indicate. At that time, in order to increase the charging time to the equivalent capacitance, the TFT 1 related to the pixel electrode concerned
The pulse width of the scanning pulse of the row electrode drive signal g applied to the gate electrode of No. 1 via the row electrode G (that is, the TFT1
In many cases, the "on" time of 1) is set to the end of one cycle of the horizontal synchronizing signal H. Therefore, the timings of the rising and falling edges of the scanning pulse applied to the adjacent row electrode G are too close to each other, and the trailing edge of the scanning pulse applied to a certain row electrode G is applied to the next row electrode G. The rising of the scanning pulse generated is canceled, and the fluctuation of the induced voltage induced in the tip electrode of the electronic pen 6 is suppressed. Therefore, the row electrode G located at the tip of the electronic pen 6
However, there is a problem that an induced voltage that exhibits a remarkable peak cannot be obtained when is scanned.

Next, as described above, the display panel 1 is driven by an AC voltage in order to prevent deterioration of the liquid crystal. At that time, the level of the voltage of the column electrode drive signal s ₁ sequentially applied from the column electrode drive circuit 3 to the column electrode S with respect to the voltage of the counter electrode 14 is set for each frame (that is, the vertical synchronization signal V
Every 1 cycle). However, in that case, the display screen flickers and the display quality deteriorates. Therefore, in order to increase the inversion frequency of the reference voltage level of the column electrode drive signal s ₁ , as shown in FIG. 14, the column electrode drive signal s _{1 is} generated in one cycle of the horizontal synchronization signal H and one cycle of the vertical synchronization signal V. The voltage level of may be inverted.

In this case, since the voltage change of the column electrode drive signal s ₁ is transmitted to the row electrode G during the scanning of the row electrodes, the tip of the electronic pen 6 is also affected by the voltage transmitted to the row electrode G. A voltage will be induced at the electrodes. Therefore, noise is superimposed on the regular induced voltage signal (hereinafter referred to as a detection signal) from the electronic pen 6 related to the scanning of the row electrodes, which causes a problem that the accuracy of y-coordinate detection deteriorates as it is.

In that case, the y-coordinate detection accuracy can be improved by separating only the normal detection signal from the detection signal from the electronic pen 6. However, as described above, since the width of the scanning pulse of the row electrode driving signal g is also set to be close to one cycle of the horizontal synchronizing signal H, the scanning pulse of the row electrode driving signal g is changed in the display period. Since the generation timing and the change timing of the voltage of the column electrode drive signal s ₁ are close to each other, it is not easy to separate the two. Further, in practice, the level of the row electrode drive signal g whose voltage changes in synchronization with the horizontal synchronizing signal H1 cycle as shown in FIG. 14 changes variously according to the display contents (omitted in FIG. 14). ) Do. Therefore, a change in the voltage level applied to the column electrode S due to a change in display content has a considerable influence on the detection signal from the electronic pen 6 irregularly. It is more and more difficult to separate the normal detection signal and the noise.

Therefore, an object of the present invention is to provide an active matrix type display-integrated tablet device capable of increasing the detection accuracy of the electronic pen tip coordinates when scanning the electrode connected to the control terminal of the switching element, and the same. It is to provide a driving method.

[0023]

In order to achieve the above object, the invention according to claim 1 provides a pair of transparent substrates in which an electro-optical substance is sandwiched so as to face each other, and a matrix is provided on one of the transparent substrates. A plurality of picture element electrodes arranged in a line, and a plurality of switching elements connected to each of the picture element electrodes,
A plurality of first electrodes and second electrodes connected to the switching elements, first electrode driving means and second electrode driving means for driving the first and second electrodes, respectively, and the first and second electrodes. The input pen means electrostatically coupled to the electrodes and the first and second electrode driving means drive the first and second electrodes to selectively operate the switching elements to display an image on the electro-optical material. Position detecting means for detecting first position information indicating an input position by the input pen means based on a signal from the input pen means when the first electrode is driven during the electro-optical substance driving period for writing And a second position representing the input position by the input pen means based on a signal from the input pen means when the second electrode drive means drives the second electrode outside the electro-optical substance drive period. Emotion In the display-integrated tablet device having the second position detecting means for detecting the position information, the first electrode driving means and the position information detection signal for detecting the first position information when driving the first electrode, It is characterized in that it is configured to output a drive signal having an image display signal for writing an image on the electro-optical material.

According to a second aspect of the invention, in the display-integrated type tablet device according to the first aspect of the invention, the generation timing of the position information detection signal in the drive signal from the first electrode driving means is the above. The predetermined timing is different from the timing of the induced voltage generated in the signal from the input pen means when the second electrode drive means drives the second electrode during the electro-optical material drive period. I am trying.

According to a third aspect of the present invention, in the display-integrated tablet device according to the second aspect of the invention, the first electrode driving means includes a sequential output section for generating and sequentially outputting the image display signals. A position information detection signal including a slit having a predetermined width in the image display signal, which includes a gate unit for blocking a part of the image display signal output from the sequential output unit for a predetermined period at the predetermined timing. Is generated to generate the drive signal.

According to a fourth aspect of the present invention, in the display-integrated type tablet device according to the second aspect of the invention, the position information detection signal of the first electrode driving means is independent of the image display signal. It is characterized by having a configuration for generating the formed drive signal.

According to a fifth aspect of the present invention, in the display-integrated type tablet device according to the second aspect, the first electrode driving means continuously forms the position information detection signal and the image display signal. It is characterized in that it is configured to generate the above described drive signal.

The invention according to claim 6 is the display-integrated type tablet device according to any one of claims 1 to 5, wherein the first electrode driving means outputs the position information detection signal. The present invention is characterized in that the detection circuit for generating and the display circuit for generating the image display signal are formed by one semiconductor integrated circuit.

The invention according to claim 7 is the display-integrated type tablet device according to any one of claims 1 to 6, wherein the first electrode is a row electrode and the second electrode is the second electrode. Is a column electrode, the first electrode driving means is a row electrode driving circuit, and the second electrode driving means is a column electrode driving circuit.

The invention according to claim 8 is the display-integrated tablet device according to any one of claims 1 to 7, wherein the first position detecting means is the electro-optical material driving device. When detecting the first position information representing the position of the input pen means within the period, the signal from the input pen means is cut out within a predetermined period including the rising or falling of the position information detection signal, and this cutout is cut out. It is characterized in that it is provided with a configuration for carrying out the first position information detection based on the received signal.

The invention according to claim 9 has a plurality of row electrodes arranged in parallel and a plurality of column electrodes orthogonal to the row electrodes on a transparent substrate, and one column in which a control terminal is connected to the row electrodes. An active matrix type display panel having a plurality of switching elements arranged on the transparent substrate at an intersection of the electrodes with an input terminal connected to the electrodes, and a row electrode and a column electrode of the display panel are electrostatically coupled. An electronic pen having an electrode at the tip, a display control circuit for outputting a display control signal and display data, a detection control circuit for outputting a scan control signal, and a row electrode scanning signal based on the display control signal during a display period. And a row electrode drive circuit for generating a column electrode drive signal based on the display control signal and display data in the display period, and a x-coordinate detection period in the display period. A column electrode driving circuit that generates a column electrode scanning signal based on the scanning control signal, and a voltage induced in the electrode of the electronic pen due to the row electrode scanning signal input to each row electrode in the display period. The y coordinate of the tip of the electronic pen is detected based on
In the coordinate detection period, a display having a coordinate detection circuit for detecting the x-coordinate of the tip of the electronic pen based on the voltage induced in the electrode of the electronic pen due to the column electrode scanning signal input to each column electrode. In the integrated tablet device, the row electrode driving circuit is configured to control the electronic components at a predetermined timing different from the generation timing of the induced voltage induced in the electrodes of the electronic pen due to the column electrode driving signal applied to the column electrodes. A row electrode that generates a signal having a coordinate detection pulse for inducing an induced voltage in the electrode of the pen and an image display pulse for applying a voltage to the control terminal of the switching element in the display panel as the row electrode scanning signal. It is characterized in that a scanning signal generation unit is provided.

The invention according to claim 10 is the invention according to claim 9.
In the display-integrated type tablet device according to the invention, the row electrode scanning signal generator of the row electrode driving circuit shifts a pulse of a shift data signal as a display control signal input from the display control circuit to display the image. Shift means for sequentially outputting the pulse for use, and gate means for blocking a part of the image display pulse output from the shift means for a predetermined period at the predetermined timing, during the image display pulse. It is characterized in that the row electrode scanning signal in which the coordinate detection pulse formed of a slit having a predetermined width is inserted is generated.

The invention according to claim 11 is the invention according to claim 9.
In the display-integrated type tablet device according to the invention, the row electrode scanning signal generator of the row electrode driving circuit shifts the pulse of the first shift data signal as the display control signal input from the display control circuit, The first shift means for sequentially outputting the image display pulse and the pulse of the second shift data signal as the display control signal input from the display control circuit are shifted at the predetermined timing to generate the coordinate detection pulse. The present invention is characterized in that a second shift means for sequentially outputting is provided, and the coordinate detection pulse generates the row electrode scanning signal formed independently of the image display pulse.

The invention according to claim 12 is the invention according to claim 9.
In the display-integrated tablet device according to the invention, the row electrode scanning signal generation unit of the row electrode drive circuit shifts the pulse of the shift data signal as the display control signal input from the display control circuit at the predetermined timing. A shift means for sequentially outputting the image display pulse is provided, and the row electrode scanning signal in which the coordinate detection pulse and the image display pulse are continuously formed is generated.

The invention according to claim 13 is the invention according to claim 9.
In the display-integrated tablet device according to any one of claims 12 to 12, the coordinate detection circuit detects the coordinate detection pulse when detecting the y coordinate of the tip of the electronic pen in the display period. The present invention is characterized in that a voltage signal output from the electrode of the electronic pen is cut out within a predetermined period including rising or falling and coordinate detection is performed based on the cut out voltage signal.

According to the fourteenth aspect of the present invention, during the display period, the row electrode scanning signal generated based on the display control signal is sequentially input to the row electrodes of the active matrix type display panel so that the row electrodes are turned on. While scanning, the column electrode drive signal generated based on the display control signal and the display data is input to the column electrodes of the display panel to display an image on the display panel, and the row electrode scanning input to each of the row electrodes is performed. The y-coordinate of the tip of the electronic pen is detected based on the voltage induced on the electrode of the electronic pen due to the signal, and the column electrode scanning signal generated based on the scanning control signal is detected during the x-coordinate detection period. The column electrodes of the display panel are sequentially input to scan the column electrodes, and the electronic pen is based on the voltage induced in the electrodes of the electronic pen due to the column electrode scanning signals input to the column electrodes. A method of driving a display-integrated tablet device for detecting the x-coordinate of the tip of the display device, wherein the row electrode scanning signals sequentially input to the row electrodes when scanning the row electrodes of the display panel are applied to the column electrodes. The coordinate detection pulse for inducing the induced voltage in the electrode of the electronic pen at a predetermined timing different from the generation timing of the induced voltage induced in the electrode of the electronic pen due to the applied column electrode drive signal, and A row electrode scanning signal having an image display pulse for applying a voltage to the control terminal of the switching element in the display panel.

The invention according to claim 15 provides the invention according to claim 1.
The drive method for a display-integrated tablet device according to a fourth aspect of the present invention, wherein the coordinate detection pulse of the row electrode scanning signal is a slit having a predetermined width formed in the image display pulse. .

The invention according to claim 16 is the first aspect.
According to a fourth aspect of the present invention, there is provided a method of driving a display-integrated type tablet device, wherein the coordinate detection pulse of the row electrode scanning signal is formed independently of the image display pulse.

The invention according to claim 17 is the first aspect.
According to a fourth aspect of the present invention, there is provided a method of driving a display-integrated type tablet device, wherein the coordinate detection pulse of the row electrode scanning signal is formed continuously with the image display pulse.

[0040]

In the invention according to claim 1, during the electro-optical material driving period, the first and second electrode driving means are operated by the first and second electrode driving means.
The electrodes are driven to selectively operate each switching element, and an image is written on the electro-optical material sandwiched between the pair of transparent substrates facing each other. At that time, the first
A first position detecting means indicates an input position by the input pen means based on a signal from the input pen means when a position information detection signal of a drive signal from the electrode driving means is output to the first electrode. 1 Position information is detected.
On the other hand, outside the electro-optical substance driving period, the second electrode is driven by the second electrode driving means, and the second electrode is driven based on the signal from the input pen means at that time.
The second position information representing the input position is detected by the position detecting means.

Thus, when the first position information of the input position by the input pen means is detected during the electro-optical material driving period, an image for writing an image on the electro-optical material from the first electrode driving means. The first and second position information representing the input position by the input pen means is detected based on the position information detection signal different from the display signal.

In the invention according to claims 2 to 5, when the first position information indicating the input position by the input pen means is detected during the electro-optical material driving period, the first electrode driving means is used. A predetermined timing different from the timing of the induced voltage generated in the signal from the input pen means when the second electrode drive means drives the second electrode within the electro-optical substance drive period in the drive signal from It is detected based on the position information detection signal generated in.

Further, in the invention according to claim 6, the position information detection signal for detecting the first position information indicating the input position by the input pen means during the electro-optical material driving period is:
It is generated by a detection circuit that forms the first electrode driving means that is a semiconductor integrated circuit.

Further, in the invention according to claim 7, from the input pen means when the position information detection signal of the drive signal from the row electrode drive means is output to the row electrode within the electro-optical substance drive period. Based on the signal, the first position detecting means detects the first position information indicating the input position by the input pen means. On the other hand, outside the electro-optical material driving period, the column electrode driving means drives the column electrodes, and the second position detecting means indicates the input position based on the signal from the input pen means at that time. The second position information is detected.

In the invention according to claim 8, when detecting the first position information indicating the input position of the input pen means during the electro-optical substance driving period, the first position detecting means detects the position information. The signal output from the input pen means is cut out within a predetermined period including the rising or falling of the signal. Then, the first position information detection is performed based on the cut out signal. In this way, the first position information is accurately detected by using only the signal from the input pen means due to the position information detection signal when the first electrode is driven.

Further, in the invention according to claims 9 to 13, an active matrix type display panel having a plurality of row electrodes, a plurality of column electrodes orthogonal to the row electrodes, and a plurality of switching elements, and the row electrodes. And an electronic pen that is electrostatically coupled to the column electrodes, a display control circuit, a detection control circuit, a row electrode drive circuit that generates a row electrode scanning signal during the display period, and a column electrode drive signal during the display period. On the other hand, a column electrode drive circuit for generating a column electrode scanning signal in the x coordinate detection period and the y coordinate of the tip of the electronic pen are detected in the display period, while the tip of the electronic pen is detected in the x coordinate detection period. When the y-coordinate of the tip of the electronic pen is detected by the display-integrated type tablet device having the coordinate detection circuit for detecting the x-coordinate, the output from the row electrode drive circuit. It is detected based on the coordinate voltage detection pulse of the electrode drive signal. In this way, the y coordinate of the tip of the electronic pen can be accurately detected based on a signal different from the image display pulse in the row electrode drive signal without being affected by the noise based on the image display pulse or the row electrode drive signal. .

[0047]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. The basic configuration of the display-integrated tablet device of the present invention is the same as that of the display-integrated tablet device shown in FIG. In the following description, the numbers in FIG. 11 are used as necessary, and the detailed description of the components related to the numbers used will be omitted. This invention is shown in FIG.
With respect to the row electrode drive circuit 2 in FIG. 1, the row electrode drive circuit 2 will be mainly described below.

According to the present invention, the row electrode scanning signals g _a , g _b , g having the waveforms shown in FIG. 9 are displayed in the display period.
A row electrode G connected to the gate electrode of the TFT 11 with _c and g _d
Scanning the TFT 11 to display an image.
Is set to "ON", the pulse width of the scanning pulse of the row electrode scanning signal g is set in the vicinity of one cycle of the horizontal synchronizing signal H, and the column electrode for supplying the display charge to the pixel electrode 12 connected to the TFT 11 is set. Even if the level of the reference voltage of the drive signal s ₁ is inverted in one cycle of the horizontal synchronizing signal H, the tip electrode of the electronic pen 6 has a peak when the row electrode G at the tip position is scanned. That is, a large induced voltage is obtained.

By the way, when the row electrode G is scanned by the row electrode scanning signals g _a , g _b , g _c , g _{d having} a waveform as shown in FIG. 9, noise from the electronic pen 6 due to the column electrode driving signal s _{1 is} generated. The reason why the normal detection signal having no influence is obtained is as follows.

FIG. 10 shows that the voltage of the column electrode drive signal s ₁ applied to the column electrode S during the display period is induced in the tip electrode of the electronic pen 6 due to the change in synchronization with the horizontal synchronizing signal H. The waveform of a detection signal is shown. As can be seen from the figure, the detection signal resulting from the voltage change of the column electrode drive signal s ₁ is
The maximum value is exhibited immediately after the change of the voltage. Then, after that, the voltage gradually converges toward the reference voltage, reaches the reference voltage at a time point (b), and the voltage is maintained until the voltage of the column electrode drive signal s ₁ changes next time. That is, the period from the time point (b) to the falling time point (a) of the horizontal synchronizing signal H is
The detection signal maintains a stable state regardless of the voltage change of the column electrode drive signal s ₁ .

[0051] As the timing of applying the scanning pulse for the coordinate detection in the row electrode G in the display period, there is no influence of the voltage change of the column electrode driving signals s _1, moreover column electrode drive signal s ₁ of the voltage Ideally, it is temporally distant from the change point (C) of. Therefore, the row electrode drive circuit 2 according to the present invention turns on the TFT 11 when the time from the falling time point (a) of the horizontal synchronizing signal H to the time point (b) in the display period is “T ₀ ”. "
The row electrode scanning signals g _{a to} g _d to which the coordinate detection pulse PY is added are generated at the position where the time “T ₀ ” has elapsed from the fall of the horizontal synchronizing signal H with respect to the image display pulse PT. Yes (see FIG. 9). The time “T ₀ ” is set optimally in consideration of the impedance of the column electrode S and the response speed of the tip electrode of the electronic pen 6.

<First Embodiment> FIG. 1 is a diagram showing a part of a row electrode scanning signal generating section in a row electrode driving circuit 2 of the present embodiment. FIG. 2 shows the row electrode scanning signal generating section. 6 is a timing chart of various signals that are input and output. In this embodiment, the row electrode scanning signal g _a in FIG. 9 is generated. The row electrode scanning signal g _a has a waveform in which the coordinate display pulse PY is cut at the timing “T ₀ ” in the image display pulse PT in the conventional row electrode scanning signal g.

As shown in FIG. 1, the row electrode scanning signal generating portion of the row electrode driving circuit 2 in this embodiment includes a shift register 21, inverters 22 and 23, and AND gates 24 and 2.
5,26,27 make up one unit. The shift data signal s generated by the display control circuit 4 is input to the data input terminal D of the shift register 21. Further, the first clock signal ck1 which is an inverted signal of the horizontal synchronization signal H is input to the clock terminal CK. Then, the pulse of the shift data signal s is shifted in synchronization with the first clock signal ck1 and output from the output terminals Q1, Q2, Q3, Q4.

The first clock signal ck1 is input to the inverter 22. On the other hand, the second clock signal ck2 obtained by delaying the phase of the first clock signal ck1 by the time “T ₀ ” is input to the inverter 23. The AND gate 24 has an output terminal Q1 of the shift register 21.
, The output signal from the inverter 22, and the output signal from the inverter 23 are input. Similarly, each of the AND gates 25, 26, 27 has one of the output signals from the output terminals Q2, Q3, Q4 of the shift register 21, the output signal from the inverter 22 and the output signal from the inverter 23. Is entered. And AND gate 2
4 outputs _a row electrode scanning signal g _a 1. Similarly, each of the AND gates 25, 26, 27 outputs any one of the row electrode scanning signals g _a 2, g _a 3, g _a 4.

The operation of the row electrode scanning signal generator having the above structure will be described with reference to FIG. The pulses of the shift data signal s are shifted in synchronization with the fall of the first clock signal ck1 and the AND gates 24, 25, 26, 27
Row electrode scanning signals g _a 1, g _a 2, g
_a 3, to form a pulse PT for image display in g _a 4. At this time, the row electrode scan signals g _a 1, g _a 2, g _a 3, g are maintained during the period in which the level of the first clock signal ck1 is “H” and the level of the output signal of the inverter 22 is “L”. _a 4 level is "L"
Therefore, the width of the image display pulse PT is properly regulated.

The second clock signal ck2 is a signal for forming the coordinate detection pulse PY on the image display pulse PT set as described above, and the level of the second clock signal ck2 is "H". "And gate 2 only for the period
The output levels of 4, 25, 26 and 27 become "L". Thus, the coordinate inspection pulse PY is cut into the image display pulse PT. At that time, as described above, the second clock signal ck2 changes the first clock signal ck1 from the time "T ₀ ".
Since the signal is delayed by the phase, the coordinate inspecting pulse PY is formed at a position where time "T ₀ " has elapsed from the fall of the horizontal synchronizing signal H. Therefore, formed on the generation timing of the coordinate detection pulse PY has no influence of the voltage change of the column electrode driving signals s _1, yet temporally distant ideal position from a change point of the reference voltage of the column electrode drive signal s ₁ Is done.

Based on the induced voltage induced in the tip electrode of the electronic pen 6 due to the row electrode scanning signal g _a thus formed and applied to the row electrode G, the coordinate detection circuit 7 causes the electronic pen 6 to move. The y coordinate of the tip is detected. In this case, the coordinate detection circuit 7 receives the coordinate detection pulse PY in the image display pulse PT generation period based on the coordinate detection timing signal from the control circuit 9, as shown in FIG.
Electronic pen 6 within the set period "E" including the occurrence period
Only the detection signal from is cut out and used. By doing so, the y coordinate can be detected without being affected by the rising or falling of the image display pulse PT.

As described above, in this embodiment, the shift register 21 generates the image display pulse PT of the row electrode scanning signal, and the inverter 23 and the AND gates 24, 25, 26 and 27 display the image. A row electrode in which the coordinate detection pulse PY is formed at a position where time "T ₀ " has elapsed from the fall of the horizontal synchronizing signal H on the pulse PT, and the coordinate detection pulse PY is cut into the image display pulse PT. Generate _a scanning signal g _a . Therefore, according to the present embodiment, the voltage induced in the tip electrode of the electronic pen 6 due to the coordinate detection pulse PY applied to the row electrode G of the display panel 1 is applied to the column electrode S. The noise based on the column electrode drive signal s ₁ is not superimposed, and the y coordinate of the tip of the electronic pen 6 can be accurately detected.

In this embodiment, the coordinate detection pulse PY is used as the image display pulse PT of the row electrode scanning signal g _a.
Since it is cut, the charging time for the pixel electrode 12 is shortened accordingly. Therefore, it is necessary to set the pulse width of the image display pulse PT so that the charging time can be sufficiently obtained.

<Second Embodiment> This embodiment relates to generation of the row electrode scanning signal g _b in FIG. FIG. 3 is a diagram showing a part of the row electrode scanning signal generation unit in the row electrode driving circuit 2 of the present embodiment, and FIG. 4 is a timing chart of various signals input to and output from the row electrode scanning signal generation unit. is there.
In the following description, the same components as those shown in FIG. 1 will be assigned the same reference numerals as those in FIG. The row electrode scanning signal g _b generated in this embodiment has a waveform in which the coordinate detection pulse PY generated at the timing “T ₀ ” is formed independently of the image display pulse PT.

As shown in FIG. 3, the row electrode scanning signal generator of the row electrode drive circuit 2 in this embodiment is composed of a first shift register 21 and a second shift register 21 '.
Two shift registers, inverter 22, AND gate 2
4,25,26,27,24 ', 25', 26 ', 27' and OR gates 28,29,30,31 form one unit.

The operation of the row electrode scanning signal generator in this embodiment will be described below with reference to FIGS. 3 and 4. The first shift register 21, the inverter 22, and the AND gates 24, 25, 26, 27 are the display control circuit 4
Based on the first shift data signal s1 and the first clock signal ck1 (inverted signal of the horizontal synchronizing signal H) from, the row electrode scanning signal as shown in FIG. 4 is operated in the same manner as in the first embodiment. An image display pulse PT of g _b is formed.

On the other hand, the second shift register 21 'and the AND gates 24', 25 ', 26', 27 'have the following image based on the second shift data signal s2 and the second clock signal ck2. The coordinate detection pulse PY is formed independently of the display pulse PT.

That is, the second clock signal ck2 is
It is a signal obtained by delaying the phase of the first clock signal ck1 by the time "T ₀ " described above. Therefore, the second shift data 2
From the output terminals Q1 to Q4 of 1 ', the pulse of the second shift data s2 is shifted in synchronization with the second clock signal ck2, and the time "T ₀ " from the rising of the first clock signal ck1.
The signals are sequentially output with a timing delayed by only. Thus the second
The signals output from the output terminals Q1 to Q4 of the shift register 21 'and the second clock signal ck2 are AND gates 24',
25 ', 26', 27 'are input. A pulse signal (coordinate detection pulse PY) in which the output signal from the second shift register 21 'is cut at the falling edge of the second clock signal ck2 from the AND gates 24', 25 ', 26', 27 '.
Is output.

The image display pulse PT output from the AND gate 24 and the coordinate detection pulse PY output from the AND gate 24 'are input to the OR gate 28. Similarly, each image display pulse PT output from each of the AND gates 25, 26, 27 and the AND gate 25 ′,
The coordinate detection pulse PY output from each of 26 'and 27' is input to one of the OR gates 29, 30 and 31. Then, from each of the OR gates 28, 29, 30, 31 as shown in FIG. 4, a row electrode scanning signal g having an image display pulse PT and a coordinate detection pulse PY which are independent from each other is provided.
_b is output.

At this time, as described above, since the second clock signal ck2 is a signal obtained by delaying the phase of the first clock signal ck1 by the time "T ₀ ", the coordinate detection pulse PY is generated.
Is formed at a position after a lapse of time "T ₀ " from the fall of the horizontal synchronizing signal H. Therefore, formed on the generation timing of the coordinate detection pulse PY has no influence of the voltage change of the column electrode driving signals s _1, yet temporally distant ideal position from a change point of the reference voltage of the column electrode drive signal s ₁ Is done.

Based on the induced voltage induced at the tip electrode of the electronic pen 6 due to the row electrode scanning signal g _b thus formed and applied to the row electrode G, y of the tip of the electronic pen 6 is generated.
Detect coordinates. In that case, as shown in FIG. 9, the image display pulse is obtained by extracting and using only the detection signal from the electronic pen 6 within the period "E" set including the coordinate detection pulse PY generation period. The y coordinate can be detected without being affected by the rising or falling of PT.

By applying the coordinate detection pulse PY in the row electrode scanning signal g _b, the TFT 1 connected to the row electrode G to which the coordinate detection pulse PY is applied.
Since "1" is "on", a picture element different from the picture element to be displayed may be displayed. Therefore, in the present embodiment, as shown in FIG. 4, the coordinate detection pulse PY is formed prior to and close to the image display pulse PT. In this way, there is no problem because the image once written in the unintended picture element is immediately erased at the timing when the next image display pulse PT is applied.

<Third Embodiment> This embodiment relates to generation of the row electrode scanning signal g _c in FIG. FIG. 5 is a diagram showing a part of the row electrode scanning signal generation unit in the row electrode driving circuit 2 of the present embodiment, and FIG. 6 is a timing chart of various signals input to and output from the row electrode scanning signal generation unit. is there.
In the following description, the same components as those shown in FIG. 3 will be assigned the same reference numerals as those in FIG. In the row electrode scanning signal g _c generated in this embodiment, the coordinate detection pulse PY generated at the timing “T ₀ ” is the image display pulse PT.
Has a waveform continuously added to.

As shown in FIG. 5, the row electrode scanning signal generator of the row electrode driving circuit 2 in this embodiment is composed of a first shift register 21 and a second shift register 21 '.
Two shift registers, inverter 22, AND gate 2
4,25,26,27 and OR gate 28,29,30,3
One unit constitutes one unit.

The operation of the row electrode scanning signal generator in this embodiment will be described below with reference to FIGS. 5 and 6. As shown in FIG. 6, the row electrode scanning signal g _c generated according to this embodiment is the same as the second clock signal ck2 for the coordinate detection pulse PY of the row electrode scanning signal g _b generated according to the second embodiment. It can be generated by not cutting at the falling edge. Therefore, in this embodiment,
AND gates 24 ', 25', 26 ', 27' for cutting the coordinate detection pulse PY from the row electrode scanning signal generator in the second embodiment at the falling edge of the second clock signal ck2.
It has a configuration in which is deleted.

That is, as in the case of the second embodiment, the first shift register 21, the inverter 22 and the AND gates 24, 25, 26, 27 are connected to the first shift data signal s1 from the display control circuit 4 and the first shift data signal s1. 1 clock signal ck1
Based on the image display pulse P of the row electrode scanning signal g _c
Form T. On the other hand, the second shift register 21 '
Synchronizes the first clock signal ck1 with the second clock signal ck2 signal whose phase is delayed by the time “T ₀ ” described above, shifts the pulse of the second shift data s2, and sequentially outputs the coordinate detection pulse PY. To be done.

Thus, the image display pulse PT output from the AND gate 24 and the second shift register 21 '.
The coordinate detection pulse PY output from the output terminal Q1 of the above is input to the OR gate 28. Similarly, each image display pulse PT output from each of the AND gates 25, 26, 27 and the output terminals Q2, Q of the second shift register 21 '.
Each coordinate detection pulse PY output from each of Q3 and Q4 is input to any of the OR gates 29, 30, and 31.
Then, from each of the OR gates 28, 29, 30, 31 as shown in FIG. 6, a continuous image display pulse PT and a coordinate detection pulse PY (hereinafter, a continuous image display pulse PT and a coordinate detection pulse PY are shown. Are collectively referred to as a scan pulse) and a row electrode scan signal g _c is output.

At this time, since the second clock signal ck2 is a signal obtained by delaying the phase of the first clock signal ck1 by the time "T ₀ ", the coordinate detection pulse PY is generated at the column electrode drive timing. no influence of the voltage change of the signal s _1, yet it is being formed into temporally distant ideal position from the change point of the voltage of the column electrode drive signal s _1. Also,
As shown in FIG. 9, during the y-coordinate detection, within the period “E” set including the rising of the scanning pulse of the row electrode scanning signal g _c (that is, the rising of the coordinate detecting pulse PY). By extracting and using only the detection signal from the electronic pen 6, the y-coordinate detection can be performed without being affected by the trailing edge of the image display pulse PT.

<Fourth Embodiment> This embodiment relates to generation of the row electrode scanning signal g _d in FIG. FIG. 7 is a diagram showing a part of the row electrode scanning signal generating unit in the row electrode driving circuit 2 of the present embodiment, and FIG. 8 is a timing chart of various signals input to and output from the row electrode scanning signal generating unit. is there.
In the following description, the same components as those shown in FIG. 5 will be assigned the same reference numerals as those in FIG. The row electrode scanning signal g _d generated in this embodiment is a waveform in which the coordinate detection pulse PY generated at the timing “T ₀ ” and the image display pulse PT are continuous, as in the case of the third embodiment. have.

In the case of the third embodiment, as can be seen from FIGS. 5 and 6, the shift data signal s1 for generating the coordinate detecting pulse PY and the image display pulse PY are generated.
It is a shift data signal different from the shift data signal s2 for generating T, and the coordinate detection pulse PY is formed outside the image display pulse PT. On the other hand, in the present embodiment, the coordinate detection pulse PY and the image display pulse PT are generated based on the same shift data signal s, and the coordinate detection pulse PY is included in the image display pulse PT. To form.

As shown in FIG. 7, the row electrode scanning signal generating section of the row electrode driving circuit 2 in this embodiment includes a shift register 21, an inverter 22, and AND gates 24, 25, 2.
6,27,32,33,34,35 and the flip-flop 36 constitute one unit.

The operation of the row electrode scanning signal generator in this embodiment will be described below with reference to FIGS. 7 and 8. Similar to the case of the third embodiment, the shift register 2
1. Inverter 22 and AND gate 24, 25, 26, 2
Reference numeral 7 forms the image display pulse PT of the row electrode scanning signal g _d based on the shift data signal s and the first clock signal ck1 from the display control circuit 4. On the other hand, the flip-flop 36 is an SR flip-flop, and when the level of the first clock signal ck1 input to the set input terminal S becomes "H", the level of the second clock signal ck2 input to the reset input terminal R changes. Output terminal Q until "H"
A signal of level "L" is output from (inversion).

Thus, the AND gates 24, 25, 2
The image display pulse PT output from each of the reference numerals 6 and 27 is input into any of the AND gates 32, 33, 34, and 35, and the signal output from the output terminal Q (inversion) of the flip-flop 36 is applied to each AND gate. It is input to the gates 32, 33, 34 and 35. Then, as shown in FIG. 8, the front portion of the image display pulse PT is cut by the output signal of the flip-flop 36, and the coordinate detection pulse PY and the image display pulse PT are continuously formed (hereinafter, The continuous image display pulse PT and the coordinate detection pulse PY are collectively referred to as a scan pulse), and the row electrode scan signal g _d is generated.

At that time, the second clock signal ck2 input to the reset input terminal R of the flip-flop 36 is input.
Is the first clock signal ck input to the set input terminal S
1 is a signal whose phase is delayed by the time “T ₀ ”. Thus, the rise timing of the coordinate detection pulse PY is no influence of the voltage change of the column electrode driving signals s _1, moreover temporally distant ideal position from the change point of the voltage of the column electrode drive signal s ₁ It is formed. Also,
As shown in FIG. 9, during the y-coordinate detection, within the period “E” set including the rising of the scanning pulse of the row electrode scanning signal g _d (that is, the rising of the coordinate detection pulse PY). By extracting and using only the detection signal from the electronic pen 6, the y coordinate can be detected without being affected by the fall of the image display pulse PT.

As described above, in each of the above-described embodiments, the row electrode scanning signal generating section of the row electrode drive circuit 2 is used for the operation shown in FIG.
The row electrode scanning signal g _a in which the coordinate detection pulse PY is inserted in the image display pulse PT as shown in FIG. 2 and the row electrode scanning signal g in which the coordinate detection pulse PY is formed independently of the image display scanning pulse PT _b , the coordinate detection pulse PY of the image display pulse PT in the row electrode scanning signal g _c or the row electrode scanning signal g _a in which the coordinate detection pulse PY in the row electrode scanning signal g _b and the image display pulse PT are continuous. A row electrode scanning signal g _d with the front portion cut off is generated. At this time, the rising or falling timing of the coordinate detection pulse PY is set after the lapse of the time "T ₀ " after the falling of the horizontal synchronizing signal H. Accordingly, the coordinate detection pulse PY, no influence of the voltage change of the column electrode driving signals s _1, moreover can be formed temporally distant ideal position from the change point of the voltage of the column electrode drive signal s _1.

Further, the row electrode drive circuit and the like in each of the above embodiments can be easily constructed without adding any special circuit to the conventional circuit. Therefore, by forming each row electrode drive circuit and the like by a semiconductor integrated circuit, cost reduction and size reduction can be achieved as compared with the conventional display integrated tablet device.

In the above embodiment, the display panel 1 having the six row electrodes G and the six column electrodes S is taken as an example for simplification of description. However, the actual display panel 1 includes, for example, 480 row electrodes G and 640 column electrodes S.

In each of the above-described embodiments, the row electrode scanning signal generator of the row electrode driving circuit 2 is described only for one unit, but the actual row electrode scanning signal generator is for each unit of the row electrode G. Are formed in parallel by a number corresponding to the number of. Further, the circuit configuration of the row electrode scanning signal generation section in the present invention is not limited to the circuit configuration in each of the above embodiments. The point is that the circuit configuration can generate a row electrode scanning signal having a waveform as shown in FIG.

In each of the above embodiments, the counter electrode drive signal has a constant DC level. However, the present invention can also be applied to the case where the counter electrode is easily driven by the counter electrode drive signal such as the so-called AC drive whose level changes in synchronization with the voltage change of the column electrode drive signal. However, in this case, it is necessary to set the detection pulse in the row electrode scanning signal so as not to be affected by the voltage changes of the column electrode driving signal and the counter electrode driving signal.

[0086]

As is apparent from the above, the display-integrated type tablet device according to the invention according to claim 1 is provided with a pair of transparent substrates in which an electro-optical substance is sandwiched, and a switching device provided on one transparent substrate. Pixel electrodes connected to the element,
First and second electrode driving means for driving the first electrode and second electrode connected to the switching elements, input pen means for electrostatically coupling with the first and second electrodes, and the electro-optical material First position detecting means for detecting first position information indicating an input position by the input pen means during the electro-optical substance driving period for writing an image on the input position, and the input position outside the electro-optical substance driving period. The first electrode driving means in the display-integrated type tablet device having the second position detecting means for detecting the second position information indicating the driving signal has a position information detection signal and an image display signal when driving the first electrode. Is configured to output
The position information detection signal can be set such that the position information detection signal can be detected without being affected by noise caused by the image display signal when detecting the position information and noise generated when the second electrode is driven outside the electro-optical material driving period.

Further, the display-integrated type tablet device of the invention according to any one of claims 2 to 7 is characterized in that when detecting the first position information indicating the input position by the input pen means during the electro-optical substance driving period. The position information detection signal of the drive signal output from the first electrode drive means is the signal from the input pen means when the second electrode drive means drives the second electrode during the electro-optical substance drive period. Since it is generated at a predetermined timing different from the timing of the induced voltage generated, the signal from the input pen means at the time of detecting the first position information includes noise due to the image display signal and the electro-optical material drive. The noise when the second electrode is driven outside the period is not superimposed. Therefore, it is possible to accurately detect the first position information indicating the input position by the input pen means.

Further, in the display-integrated type tablet device of the invention according to claim 8, when detecting the first position information indicating the input position of the input pen means during the electro-optical substance driving period,
The first position detecting means cuts out the signal output from the input pen means within a predetermined period including the rising or falling of the position information detecting signal, and detects the first position information based on the cut out signal. Therefore, only the signal from the input pen means is used due to the position information detection signal when the first electrode is driven, and the first position information is accurately detected.

Further, in the display-integrated type tablet device of the invention according to claim 9 to claim 13, the y of the tip of the electronic pen is provided.
When detecting the coordinates, a predetermined timing different from the generation timing of the induced voltage induced in the electrode of the electronic pen due to the column electrode drive signal applied to the column electrode output from the row electrode drive circuit is detected. A coordinate detection pulse of a row electrode drive signal having a coordinate detection pulse for inducing an induced voltage in the electrode of the electronic pen at a timing and an image display pulse for applying a voltage to the control terminal of the switching element in the display panel. It detects based on the voltage of. Therefore, based on a signal different from the image display pulse in the row electrode drive signal, the y coordinate of the tip of the electronic pen can be accurately detected without being affected by noise based on the image display pulse or the row electrode drive signal.

Further, according to the driving method of the display-integrated type tablet device of the invention according to claims 14 to 17, the row electrode scanning signal sequentially input to the row electrodes when scanning the row electrodes of the display panel. Is for inducing an induced voltage in the electrode of the electronic pen at a predetermined timing different from the generation timing of the induced voltage induced in the electrode of the electronic pen due to the column electrode drive signal applied to the column electrode. Since it is a row electrode scanning signal having a coordinate detection pulse and an image display pulse for applying a voltage to the control terminal of the switching element in the display panel, the coordinate detection pulse of the row electrode scanning signal is applied to the row electrode. At this time, noise based on the column electrode drive signal is not superimposed on the voltage induced in the electrode of the electronic pen. Therefore, according to the present invention, it is possible to improve the detection accuracy of the tip coordinates of the electronic pen when scanning the row electrode to which the control terminal of the switching element is connected.

[Brief description of drawings]

FIG. 1 is a partial circuit diagram of a row electrode scanning signal generator in a row electrode driving circuit of a display-integrated type tablet device according to the present invention.

FIG. 2 is a timing chart of various signals input to the row electrode scanning signal generation unit shown in FIG.

FIG. 3 is a partial circuit diagram of a row electrode scanning signal generator different from FIG.

FIG. 4 is a timing chart of various signals input to the row electrode scanning signal generation unit shown in FIG.

FIG. 5 is a partial circuit diagram of a row electrode scanning signal generation unit different from FIGS. 1 and 3.

FIG. 6 is a timing chart of various signals input to the row electrode scanning signal generation unit shown in FIG.

FIG. 7 is a partial circuit diagram of a row electrode scanning signal generator different from FIGS. 1, 3 and 5.

8 is a timing chart of various signals input to the row electrode scanning signal generation unit shown in FIG.

9 is a waveform diagram of a row electrode scanning signal generated by the row electrode scanning signal generating section shown in FIGS. 1, 3, 5, and 7. FIG.

FIG. 10 is a waveform diagram of a detection signal induced in the tip electrode of the electronic pen due to a change in the reference voltage of the column electrode drive signal.

FIG. 11 is a block diagram of a display-integrated tablet device using an active matrix system.

12 is a diagram showing an operation timing of the display-integrated type tablet device shown in FIG.

13 is a timing chart of various signals in the operation of the display-integrated type tablet device shown in FIG.

14 is a timing chart of various signals different from those in FIG. 13 in the operation of the display-integrated type tablet device shown in FIG.

[Explanation of symbols]

2 ... Row electrode drive circuit, 21, 21 '... Shift register, 22, 23 ... Inverter, 24-27, 24'
~ 27 ', 32-35 ... AND gate, 28-31 ... OR gate, 36 ... Flip-flop.

Claims (17)

[Claims] 1. A pair of transparent substrates in which an electro-optical material is sandwiched so as to face each other, a plurality of pixel electrodes arranged in a matrix on one of the transparent substrates, and connected to each of the pixel electrodes. Plural switching elements, plural first electrodes and second electrodes connected to the respective switching elements, and first electrode driving means and second electrode driving means for driving each of the first and second electrodes. And input pen means for electrostatically coupling the first and second electrodes, and driving the first and second electrodes by the first and second electrode driving means to selectively operate the switching elements. During the electro-optical material driving period for writing an image on the electro-optical material,
First position detecting means for detecting first position information indicating an input position by the input pen means based on a signal from the input pen means when the electrode is driven; and, outside the electro-optical substance driving period, It has a second position detecting means for detecting second position information indicating the input position by the input pen means based on a signal from the input pen means when the second electrode driving means drives the second electrode. In the display-integrated type tablet device, the first electrode driving means writes a position information detection signal for detecting the first position information and an image in the electro-optical material when driving the first electrode. A display-integrated type tablet device, which is configured to output a drive signal having an image display signal. 2. The display-integrated type tablet device according to claim 1, wherein the generation timing of the position information detection signal in the drive signal from the first electrode drive means is the second within the electro-optical substance drive period. A display-integrated type tablet device, wherein the predetermined timing is different from the timing of the induced voltage generated in the signal from the input pen means when the second electrode is driven by the electrode driving means. 3. The display-integrated type tablet device according to claim 2, wherein the first electrode driving means outputs a sequential output section for generating and sequentially outputting the image display signal, and the sequential output section. The drive signal is provided with a gate unit for blocking a part of the image display signal for a predetermined period at the predetermined timing, and the position information detection signal including a slit having a predetermined width is inserted in the image display signal. A display-integrated tablet device characterized in that 4. The display-integrated tablet device according to claim 2, wherein the first electrode drive means generates the drive signal in which the position information detection signal is formed independently of the image display signal. A display-integrated tablet device having a configuration. 5. The display-integrated tablet device according to claim 2, wherein the first electrode driving means generates the drive signal in which the position information detection signal and the image display signal are continuously formed. A display-integrated tablet device characterized in that 6. The display-integrated tablet device according to claim 1, wherein the first electrode driving unit includes a detection circuit that generates the position information detection signal, and the image display signal. A display-integrated type tablet device, comprising a structure in which a display circuit for generating is formed by one semiconductor integrated circuit. 7. The display-integrated tablet device according to claim 1, wherein the first electrode is a row electrode, the second electrode is a column electrode, and the first electrode is a column electrode. The electrode driving means is a row electrode driving circuit,
The display-integrated type tablet device, wherein the second electrode driving means is a column electrode driving circuit. 8. The display-integrated tablet device according to any one of claims 1 to 7, wherein the first position detecting means changes the position of the input pen means during the electro-optical substance driving period. When detecting the first position information represented, the signal from the input pen means is cut out within a predetermined period including the rising or falling of the position information detection signal, and the first position is cut based on the cut out signal. A display-integrated type tablet device having a configuration for performing information detection. 9. A transparent substrate having a plurality of parallel row electrodes and a plurality of column electrodes orthogonal to the row electrodes,
An active matrix type display panel having a plurality of switching elements arranged on the transparent substrate at intersections of the two electrodes, the control terminals being connected to the row electrodes and the input terminals being connected to the column electrodes; An electronic pen having at its tip an electrode that is electrostatically coupled to a row electrode and a column electrode of a display panel, a display control circuit that outputs a display control signal and display data, a detection control circuit that outputs a scan control signal, and a display period Is a row electrode drive circuit which generates a row electrode scanning signal based on the display control signal, and a column electrode drive signal which is generated based on the display control signal and display data in the display period. Is a column electrode drive circuit that generates a column electrode scanning signal based on the scan control signal, and a row electrode scan input to each row electrode during the display period. The y coordinate of the tip of the electronic pen is detected based on the voltage induced in the electrode of the electronic pen due to the signal, while the column electrode scanning signal input to each column electrode is detected in the x coordinate detection period. In a display-integrated tablet device having a coordinate detection circuit for detecting the x-coordinate of the tip of the electronic pen based on the voltage induced in the electrode of the electronic pen, the row electrode drive circuit applies the row electrode to the column electrode. The coordinate detection pulse for inducing the induced voltage in the electrode of the electronic pen and the display at a predetermined timing different from the generation timing of the induced voltage induced in the electrode of the electronic pen due to the generated column electrode drive signal. Row electrode scanning signal generation for generating a signal having a pulse for image display for applying a voltage to a control terminal of a switching element in a panel as the row electrode scanning signal Display-integrated type tablet device characterized by comprising a. 10. The display-integrated tablet device according to claim 9, wherein the row electrode scanning signal generation unit of the row electrode drive circuit is a pulse of a shift data signal as a display control signal input from the display control circuit. Shift means for shifting and sequentially outputting the image display pulse, and gate means for blocking a part of the image display pulse output from the shift means at the predetermined timing for a predetermined period, A display-integrated type tablet device, wherein the row electrode scanning signal is generated by inserting a coordinate detection pulse having a slit of a predetermined width into the image display pulse. 11. The display-integrated tablet device according to claim 9, wherein the row electrode scanning signal generator of the row electrode driving circuit is a first shift data signal as a display control signal input from the display control circuit. Of the second shift data signal as the display control signal input from the display control circuit, and the first shift means for sequentially outputting the pulse for image display by sequentially shifting the pulse of And a second shift means for sequentially outputting the coordinate detection pulse, the coordinate detection pulse generating the row electrode scanning signal formed independently of the image display. Integrated tablet device. 12. The display-integrated type tablet device according to claim 9, wherein the row electrode scanning signal generating section of the row electrode driving circuit is a pulse of a shift data signal as a display control signal input from the display control circuit. Is provided at the predetermined timing to sequentially output the image display pulse, and the row electrode scanning signal in which the coordinate detection pulse and the image display pulse are continuously formed is generated. A display-integrated tablet device characterized in that 13. The display-integrated tablet device according to claim 9, wherein the coordinate detection circuit detects the y coordinate of the tip of the electronic pen during the display period. A configuration in which the voltage signal output from the electrode of the electronic pen is cut out within a predetermined period including the rising or falling of the coordinate detection pulse, and coordinate detection is performed based on the cut out voltage signal A display-integrated tablet device characterized in that 14. In a display period, row electrode scanning signals generated based on a display control signal are sequentially input to row electrodes of an active matrix type display panel to scan the row electrodes, while the display control signal and The column electrode drive signal generated based on the display data is input to the column electrode of the display panel to display an image on the display panel, and the row electrode scanning signal input to each row electrode causes the electronic pen to move. Based on the voltage induced on the electrodes, y at the tip of the electronic pen
Coordinates are detected, and in the x-coordinate detection period, the column electrode scanning signal generated based on the scanning control signal is sequentially input to the column electrodes of the display panel to scan the column electrodes and input to the column electrodes. A method of driving a display-integrated tablet device for detecting the x-coordinate of the tip of the electronic pen based on the voltage induced in the electrode of the electronic pen due to the generated column electrode scanning signal, The row electrode scanning signal sequentially input to the row electrodes when scanning the row electrodes generates an induced voltage induced in the electrodes of the electronic pen due to the column electrode driving signal applied to the column electrodes. A coordinate detection pulse for inducing an induced voltage in the electrode of the electronic pen at a predetermined timing different from the timing, and an image display pulse for applying a voltage to the control terminal of the switching element in the display panel. A method of driving a display-integrated type tablet device, comprising: 15. The driving method for a display-integrated tablet device according to claim 14, wherein the coordinate detection pulse of the row electrode scanning signal is a slit having a predetermined width formed in the image display pulse. A method for driving a display-integrated tablet device, which is characterized by being present. 16. The method for driving a display-integrated tablet device according to claim 14, wherein the coordinate detection pulse of the row electrode scanning signal is formed independently of the image display pulse. And a method of driving a display-integrated type tablet device. 17. The method for driving a display-integrated type tablet device according to claim 14, wherein the coordinate detection pulse of the row electrode scanning signal is formed continuously with the image display pulse. A method of driving a tablet device with integrated display.