JPH07253851A - Method for detecting coordinate for tablet incorporated with display device - Google Patents

Abstract

PURPOSE:To reduce the deterioration in the detection accuracy at the start and end of detection by applying a scanning pulse to electrodes so that a rising and a trailing of the scanning pulse are generated simultaneously in an electrode group in the detection coordinate direction so as to detect a position of a detection conductor on a matrix panel. CONSTITUTION:The rising and trailing scanning pulses are scanned sequentially for electrode groups R1-R100 in the detection coordinate direction to enter the detection scanning mode. In succession to the scanning of the electrode R100, the detection scanning pulse is applied sequentially from a row electrode group R1 to a row electrode group R100 sequentially simultaneously. A pen 210 is used to detect a position of the detection conductor on a matrix panel by using electrostatic coupling between the pen 210 and the row electrode groups R1-R100. Thus, the deterioration in the detection accuracy at the start and end of detection is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detection method for a display-integrated tablet in which a tablet for coordinate input is integrated with a matrix display.

[0002]

2. Description of the Related Art FIG. 9 is a principle diagram of a capacitively coupled display-integrated tablet. In FIG. 9, 801
Is a pen as a detecting conductor, r1 to r10 are electrodes of the matrix panel, E1 is a counter electrode of the electrodes r1 to r10, and C1 to C10.
Is a capacitance between the pen 801 and the electrodes r1 to r10, P1 to P7 are scanning pulses for detection for scanning the electrodes r1 to r10, and D1 is a pen.
The detection signal detected by 801 and D2 are differential signals of the detection signal D1.

A pen which is a conductor for detection on a matrix panel
When 801 is brought closer, the coupling capacitance between the electrodes r1 to r10 of the matrix panel and the pen 801 increases. The larger the coupling capacitance between the electrodes among the electrodes r1 to r10 close to the pen 801, the larger the capacitance. Therefore, the scanning pulse P for detection is applied to the electrode group.
When 1 to P7 are sequentially applied, this detection scan pulse P
As 1 to P7 gets closer to the pen 801, the intensity of the detection signal D1 detected by the pen 801 becomes larger and becomes the maximum when scanning the electrode close to the pen 801 and the differential signal D2 of the detection signal D1 is obtained.

FIG. 10 shows an example of a voltage waveform applied to an electrode group of a matrix panel of a conventional display-integrated tablet. Tw is a display period, Td is a detection scanning period, t1
Is a scanning period of one line in the display period Tw, t2 is a scanning period of one line in the detection scanning period Td, R1 to R5 are row electrode groups, and P1 to P5 are for display applied to the row electrode groups R1 to R5. Scan pulses, S1 to S4, are a group of column electrodes, P
6 to P9 are signal pulses according to the display data applied to the column electrode groups S1 to S4.

In the display period Tw, the row electrode groups R1 to R are provided.
5, the display scanning pulses P1 to P5 are sequentially applied, and in synchronism with the display scanning pulse, signal pulses P6 to P9 according to display data are applied to the column electrode groups S1 to S4 to perform display. In the detection scanning period Td, the scanning pulse for detection is applied to m electrodes of the row electrode groups R1 to R5, and sequentially,
Scan the row electrode group. When the detection scanning pulse approaches the pen, the intensity of the signal detected by the pen increases. The position of the pen in the row direction can be detected by detecting the time when the detection signal shows the peak value or the time when the differential signal waveform D2 (see FIG. 9) of the detection signal becomes 0.
The position of the pen can be detected in the same manner in the row direction.

[0006]

However, in the coordinate detection method as described above, for example, in the case where the electrode potentials of the row electrode group and the column electrode group of the matrix panel are in a steady state,
When a scanning pulse for detection is applied to the row electrode group,
There is a problem that the potential of the column electrode also changes via the capacitance between the column electrode groups.

FIG. 11 is a diagram showing a scan sequence of a matrix panel in a conventional detection scan period. P1 ~
P400 is a scanning pulse for detection applied to the electrode group, Ton is a period in which only switching from OFF to ON exists, Toff
Is Vp during the period when only switching from ON to OFF exists.
Is a signal detected by the pen, and Sd is a differential waveform of the detection signal Vp.

At the start of scanning, the row electrode group is OF
Since there is a period Ton that only changes from F to ON, O
The potential of the column electrode keeps changing until N → OFF switching occurs. After Ton, the potential of the opposite electrode is attenuated by the voltage fluctuation and returns to the steady state. At the end of scanning, ON → O
Since there is a period Toff where there is only a change to FF, the potential of the counter electrode fluctuates. Since the change in the potential of the counter electrode occurs in the entire panel, for example, when the electrode group of the back substrate is scanned with respect to the pen of the matrix panel,
The signal intensity of the potential change of the electrode on the front side substrate detected by the pen has a magnitude that cannot be ignored when compared with the intensity of the detection signal Vp of the scanning pulses P1 to P400 for detection applied to the electrode on the back side substrate. Become. This potential change of the electrode on the surface side occurs at the start and end of the detection scan and is superimposed on the signal from the detection scan pulse, so that there is a problem that the detection accuracy at the start and end of the detection deteriorates. It was

In view of the above point, the present invention has an object to provide a coordinate detection method for a display-integrated tablet in which deterioration of detection accuracy at the start and end of detection is alleviated.

[0010]

In order to achieve the above object, the present invention has a matrix panel having a row electrode group and a column electrode group, a drive circuit for driving the row electrode group and the column electrode group, and a coordinate detecting section. In a display-integrated tablet including a display conductor and a detection conductor, a display scanning pulse is sequentially applied to the row electrode group from the drive circuit during a display period, and the column electrode group is synchronized with the display scanning pulse. Then, a signal pulse corresponding to the display data is applied, and during the detection period, the drive circuit sequentially applies the detection scanning pulse to the electrode group in the detection coordinate direction to bring the detection conductor close to the matrix panel. At, the scanning pulse for detection detected by capacitive coupling generated between the detection conductor and the electrode group in the detection coordinate direction is supplied to the coordinate detection unit, and A detection scanning period in which the coordinates of the position of the detection conductor are detected, and before the detection scanning is started, a pre-stage scanning pulse is applied from the drive circuit to all or some of the electrodes in the detection coordinate direction. A pre-scanning period for performing pre-scanning, or, after the detection scanning, a post-scanning period for applying post-scanning by applying a post-scanning pulse to all or some of the electrodes in the detection coordinate direction,
Alternatively, with respect to both the front-stage scanning period and the rear-stage scanning period, the voltage is applied from the drive circuit during the transition period from the front-stage scanning period to the detection scanning period and the transition period from the detection scanning period to the rear-stage scanning period. The scanning pulse is applied so that the rising and the falling of the scanning pulse simultaneously occur in the electrode group in the detection coordinate direction, and the position of the detection conductor on the matrix panel is detected.

[0011]

With the above-described structure, the present invention scans all or a part of the electrode group in the detection coordinate direction before the detection is started to change the potential of the counter electrode, and turns OFF in the electrode group in the detection coordinate direction. By starting the detection scanning continuously from the preceding scanning after the change of ON, ON → OFF occurs, the influence of the potential change of the counter electrode group can be alleviated. Similarly, after the detection is completed, scanning is continuously performed from the detection scan for a while so that OFF → ON and ON → OFF changes occur in the electrode group in the detection coordinate direction even when the detection is completed. Mitigates the effects of group potential changes.

[0012]

1 and 2 are scanning sequence diagrams in a detection period of an electrode group of a matrix panel of a display-integrated tablet according to a first embodiment of the present invention. FIG. 1 shows the start of the detection scan, and FIG. 2 shows the end of the detection scan.

1 and 2, R1 to R102 and R301 to R400 are electrodes of the matrix panel, and P1 to P102.
And P301 to P400 are scanning pulses for detection applied to the electrodes for performing the detection scanning of the electrodes, Tb is a preceding scanning period before starting the scanning, Td is a scanning scanning period, Ta is a scanning subsequent period, Ton Is a period in which switching of the voltage level exists only in the OFF → ON direction, Toff is a period in which switching of the voltage level exists only in the ON → OFF direction, Vs is the potential of the counter electrode group of the electrode group performing the scanning, V1 indicates the initial voltage of the counter electrode, and ΔV indicates the displacement of Vs.

First, the scanning pulse P1 for detection shown in FIG.
Before applying P102 to the electrode groups R1 to R102, the electrodes R1 to R100 are sequentially scanned during the preceding scanning period Tb, and detection scanning is started. Following the scanning of the electrode R100, the scanning pulse P1 for detection is sequentially output from the electrodes R1 to R400 of FIG. 1 and FIG.
~ P400 is applied. When performing such a scan,
In the period Tb of the previous stage scanning, there is a period Ton that only changes the voltage from OFF to ON, and during this period, the counter electrode E1 (see FIG. 9) is present.
However, by starting the detection scanning continuously from the previous scanning period Tb (detection scanning period Td), OFF → ON, ON → OF
Since the voltage of F is switched, it is possible to suppress the change of the potential Vs of the counter electrode at the start of the detection scan.

Next, the end of detection will be described. As shown in FIG. 2, after the end of the detection scanning, the period Ta of the subsequent scanning is entered, but the electrodes R301 to R400 are sequentially scanned following the scanning of the electrode R400 in the detection scanning. When such a scan is carried out, at the end of the latter scanning (the latter scanning period Ta)
, There is a period Toff of only a voltage change from ON to OFF, and therefore the potential Vs of the counter electrode changes during this period. However, by starting the subsequent scanning continuously from the detection scanning, the detection end time is detected. Also in OFF → ON, ON → O
Since the voltage of the FF is switched, it is possible to suppress the change in the potential Vs of the counter electrode at the end of the detection scan.

FIG. 3 is a diagram showing the structure of a display-integrated tablet in the first embodiment of the present invention. Figure 3
, 201 is a liquid crystal panel (matrix panel), 202,
203, 204, 205 are row electrode drivers, 206, 207, 208, 209
Is a column electrode driver, 210 is a detection pen, and 211 is a row electrode driver 202, 203, 204, 205 and a column electrode driver 206, 2.
The timing generator 212 for controlling 07, 208, 209 is a coordinate detector for comparing the detection signal from the pen 210 with the address signal from the timing generator 211 to detect the coordinates of the pen 210. Electrode groups S1 to S640 are column electrode groups. In this configuration, the column electrode groups S1 to S640 are present on the front substrate close to the pen 210, and the row electrode groups R1 to R400 are the pen electrodes 210.
It is assumed that it exists on the substrate on the back side far from.

The operation of this embodiment configured as described above will be described.

In the display period, the row electrode driver 20
2, 203, 204, 205 sequentially apply a display scanning pulse from R1 to R400 of the row electrode group, and in synchronization with the display scanning pulse, the column electrode drivers 206, 207, 208, 209 Display is performed by applying signal pulses corresponding to display data to S1 to S640 of the electrode group.

In the detection period, as a pre-stage scan, the row electrode driver 202 sequentially moves from the row electrode group R1 to R100.
The scanning pulse for detection of the preceding stage is applied to perform the preceding scan. Following the previous scan, the row electrode drivers 202, 203, 20
A scanning pulse for detection is sequentially applied to R1 to R400 of the row electrode group in the order of 4,205 to perform detection scanning. The scanning pulse for detection is capacitively coupled between the pen 210 and the row electrode group,
Although detected by the pen 210, the detected signal intensity becomes strong when the scanning pulse for detection is applied to the electrode close to the pen. The signal detected by the pen 210 is supplied to the coordinate detection unit 212. In this coordinate detection unit 212, the timing generation unit 211 supplies the time point when the detection signal shows a peak value or a certain specified value, the time point when the differential signal of the detection signal shows 0, or a certain specified value. The position of the pen 210 in the row direction is specified by comparison with the address of the scanning pulse for detection. After the end of the detection scanning, as the subsequent scanning, the scanning pulse for detection of the succeeding stage is sequentially applied from the row electrode driver 205 to R301 to R400 of the row electrode group to carry out the succeeding stage scanning.

Subsequently, detection in the column direction is carried out. Similar to the detection in the row direction, as the pre-stage scanning, the pre-stage scanning is performed by sequentially applying the pre-stage detection scanning pulse from S1 to S160 of the column electrode group from the column electrode driver 206. Subsequent to the preceding scanning, a scanning pulse for detection is sequentially applied to S1 to S640 of the column electrode group in the order of the column electrode drivers 206, 207, 208 and 209 to perform the detection scanning. The specification of the coordinate position of the pen 210 in the column direction is similar to that in the row direction. After the end of the detection scan, the column electrode driver 209 performs S481 to S of the column electrode group as the second stage scan.
The subsequent scanning pulse for detection is sequentially applied to 640 to perform the latter scanning.

As described above, the coordinate position of the pen 210 can be specified.

In the first embodiment, the pre-stage scanning, the detection scanning and the post-stage scanning were performed on both the row electrode group and the column electrode group, but the detection from the column electrode group which is the electrode group on the front side substrate is performed. Since the signal intensity is much larger than the signal intensity due to the potential variation generated in the row electrode group which is the electrode group on the back side substrate, the potential variation of the row electrode group may have almost no effect on the detection signal. In such a case, detection can be performed without performing the pre-stage scanning and the post-stage scanning only for the electrode group on the back surface side substrate and not for the electrode group on the front surface side substrate.

Further, in the scanning order of the first embodiment, the preceding scan is performed on the electrode group connected to the row electrode driver 202 and the subsequent scan is performed on the electrode group connected to the row electrode driver 205. Alternatively, for example, as the scanning order, it is also possible to perform the previous scanning with the electrode group connected to the row electrode drivers 202 and 203 and the subsequent scanning with the electrode group connected to the row electrode drivers 204 and 205. Is. In this case, since all the electrodes are scanned the same number of times, the difference in the effective value of the applied voltage between the electrodes due to the difference in the number of scans can be eliminated.

Further, although the case where the pre-stage scanning and the post-stage scanning are performed is shown, only the pre-stage scanning is performed because of the balance between the intensity of the detected signal and the intensity of the signal due to the potential fluctuation of the counter electrode.
It is also possible to adopt a form in which only the latter scanning is performed.

FIG. 4 is a scanning sequence diagram during the detection period of the electrode group of the matrix panel of the display-integrated tablet in the second embodiment of the present invention.

Reference numeral 301 denotes a liquid crystal panel (matrix panel), 302
˜305 are row electrode drivers, and (1) ˜ (8) are scanning orders of the row electrode drivers.

When coordinate detection is performed by the liquid crystal panel 301 of FIG. 4, for example, when scanning of the row electrode group is performed in the detection period as row electrode drivers 302 → 302 → 303 → 304 → 305 → 305, the row electrode driver 302 , 305, the pixels on the row electrodes connected to the row electrodes 305 and 305 have a larger number of scans than the pixels on the row electrodes connected to the row electrode drivers 303 and 304, and the effective value voltage is higher. Can occur. In order to correct this, for example, as shown in (1) to (8) showing the scanning order on the left side of the row electrode drivers 302 to 305 in FIG. 302 → 302 → 303 → 304 → 305 → 3
05 or 302 → 302 → 303 → 304 → 305 → 305 as shown in Fig. 4 (b)
→ 303 → 304, and the method of performing the correction scanning of the row electrodes connected to the row electrode drivers 303 and 304 before the preceding scanning, or the method of performing the correction scanning after the latter scanning is completed. Is also possible. Note that the correction scanning does not have to be continuous with the preceding scanning and the succeeding scanning. Although only the row electrode direction is shown in FIG. 4, the same applies to the column electrode direction.

Further, if this is performed with the same polarity for the column electrode group and the row electrode group, the DC component applied to the pixel becomes 0, and the deterioration of the liquid crystal due to the DC component of the detection signal can be prevented.

Next, the coordinate detection method for the display-integrated tablet according to the third embodiment of the present invention will be described.

5A and 5B are views showing an example of a matrix panel in which a row electrode group is divided into two upper and lower rows. FIG. 5A is a plan view and FIG. 5B is a sectional view of FIG. In FIG. 5, A1 indicates an upper area to which the row electrode groups R1 to R200 belong, and A2 indicates a lower area to which the row electrode groups R201 to R400 belong. Considering the case of scanning a matrix panel having such a configuration,
When the row electrode in the upper area A1 is switched from ON to OFF, the potential of the column electrode in the upper area A1 changes, but the potential of the column electrode in the lower area A2 does not change. Similarly, when the row electrode of the lower area A2 is switched from ON to OFF, the potential of the column electrode of the lower area A2 changes, but the potential of the column electrode of the upper area A1 does not change.

Therefore, in the case of a matrix panel having such a divided structure, for example, when starting the detection scanning from the electrode R1, unless the preceding scanning is performed by the row electrode group of the upper area A1, the upper area A1 is obtained. To the row electrode group of
Since there is no simultaneous switching of F → ON and ON → OFF, the potential of the counter electrode fluctuates. Further, if detection scanning is continuously performed from the upper area A1 in the lower area A2, when scanning is moved from the upper area A1 to the lower area A2, the electrode group in the lower area A2 is switched from ON to OFF. Therefore, the potential of the counter electrode in the lower area A2 changes.

FIG. 6 shows the potential V of the counter electrode when scanning is continuously performed from the upper area A1 to the lower area A2 shown in FIG.
It is a figure showing the variation of s, and in the detection period Tdr, the upper area A1 (row electrode group R1 ...
The potential Vs of the counter electrode fluctuates when scanning is moved from R200) to the area A2 (row electrode groups R201 to R400) below.

FIG. 7 shows a scanning sequence diagram during the detection period of the electrode group of the matrix panel of the display-integrated tablet in the third embodiment of the present invention for suppressing the potential fluctuation of the counter electrode. In the figure, Tdr
Is a detection period, Tb is a front scanning period, Ta is a rear scanning period, Td is a detection scanning period, and R1 to R400 are electrodes.

As shown in FIG. 7, the row electrode group R1 to R400 is divided into two upper and lower groups R1 to R200 and R201 to R400,
The pre-scan, detection scan, and post-scan are performed for each group. First, the row electrodes R1 to R100 are scanned in the preceding stage shown in the period Tb, subsequently, the row electrodes R1 to R200 are detected in the period Td, and the row electrodes R101 to R200 are scanned in the latter stage shown in the period Ta. Next, the row electrodes R201 to R300 are scanned in the preceding stage shown in the period Tb, the row electrodes R200 to R400 are detected and scanned in the period Td, and finally the row electrodes R301 to R400 are scanned in the latter stage shown in the period Ta. As a result, fluctuations in the potential of the counter electrode can be suppressed.

If the substrate having the divided electrode group is used as the back substrate, it is not necessary to divide the detection scan into a plurality of times, and the detection becomes easier.

FIG. 8 is a diagram showing a scanning sequence in the detection period of the electrode group of the matrix panel of the display-integrated tablet in the fourth embodiment of the present invention.

In FIG. 8, 701 is a liquid crystal panel (matrix panel), 702 to 705 are row electrode drivers, 706 to 709 are column electrode drivers, and (1) to (8) and (9) to (16) are row electrodes. , The scanning order of the column electrode driver. Liquid crystal panel shown in FIG.
In 701, it is assumed that the row electrode group is arranged on the back side substrate with respect to the detection pen and the column electrode group is arranged on the front side substrate with respect to the detection pen. Consider a case where the front-stage scanning and the rear-stage scanning are performed only in the coordinate detection in the row electrode direction of the back substrate, and the front-stage scanning and the rear-stage scanning are not performed in the column-direction coordinate detection.

In this case, in the coordinate detection in the row direction, the electrode group connected to the row electrode drivers 702 and 703 shown in the scanning order (1) and (2) is scanned as the pre-stage scanning shown in the period Tb.
Scanning order (3), (4), (5), (6) in the detection scanning shown in the period Td
The row electrode driver indicated by is scanned in the order of 702, 703, 704, 705, and the scanning order (7), (8) is set as the second stage scanning shown in the period Ta.
The row electrode drivers 704 and 705 indicated by are scanned. Then, in the coordinate detection in the column direction, the column electrode driver shown in the scanning order (9), (10), (11), (12) is used in the detection scanning shown in the period Td.
The coordinate detection itself is completed by scanning in the order of 6,707,708,709. However, while the electrode group in the row direction is scanned twice, but the electrode group in the column direction is scanned only once, a DC component remains in the voltage applied to the pixel. Therefore, as shown in FIG. 8, the scanning sequence (13), (14), (15), (16) is performed on the electrode group in the column direction by performing the compensation scanning shown in the period Tc in order to apply the compensation voltage after the detection scanning. By doing so, the residual DC component can be eliminated.

Although the compensation scanning is performed after the detection scanning in FIG. 8, it may be performed before the detection scanning. Also, instead of performing sequential scanning, the voltage pulse required to eliminate the residual DC component is applied simultaneously from the column electrode driver to all of the column electrode groups, or the column electrode group is divided into several groups. It is also possible to apply a compensation voltage for each group.

As in all the embodiments, it goes without saying that the electrodes to which the scanning pulse is applied are not limited to the order of the embodiments when performing the pre-stage scanning and the post-stage scanning. In addition, while the detection scanning is being performed, ON → OF
It suffices that scanning is performed so that switching of F, OFF → ON occurs at the same time.

[0041]

As described above, according to the present invention,
By performing the first-stage scanning and the second-stage scanning, the potential fluctuation of the counter electrode can be suppressed during the period of performing the detection scan, and the deterioration of the detection accuracy due to the potential fluctuation of the counter electrode can also be suppressed.

[Brief description of drawings]

FIG. 1 is a diagram showing a scanning sequence during a detection period of an electrode group of a display-integrated type tablet according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a scanning sequence during a detection period of an electrode group of the display-integrated tablet according to the first embodiment of the present invention.

FIG. 3 is a diagram showing the configuration of a display-integrated tablet in the first embodiment of the present invention.

FIG. 4 is a diagram showing a scanning sequence during a detection period of an electrode group of a matrix panel of a display-integrated type tablet according to a second embodiment of the present invention.

FIG. 5 is a diagram showing an example of a matrix panel in which a row electrode group is divided into two upper and lower rows.

FIG. 6 is a diagram showing variations in the potential of the counter electrode in FIG.

FIG. 7 is a diagram showing a scanning sequence during a detection period of an electrode group of a matrix panel of a display-integrated type tablet according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a scanning sequence in a detection period of an electrode group of a matrix panel of a display-integrated type tablet according to a fourth example of the present invention.

FIG. 9 is a principle diagram of a capacitively coupled display-integrated tablet.

FIG. 10 is a diagram showing an example of a voltage waveform applied to an electrode group of a matrix panel of a conventional display-integrated tablet.

FIG. 11 is a diagram showing a scan sequence of a matrix panel in a conventional detection scan period.

[Explanation of symbols]

Ta ... Late scan period, Tb ... Previous scan period, Tc
... Compensation scanning period, Td ... Detection scanning period, Tdr ... Detection period, Ton ... Voltage level switching only in the OFF → ON direction, Toff ... Voltage level switching in ON → OFF direction only 201, 301, 701 ... Liquid crystal panel (matrix panel), 202-205, 302-305, 702-705 ... Row electrode driver, 206-209, 706, 709 ... Column electrode driver, 210 ...
Pen for detection, 211 ... Timing generation unit, 212 ... Coordinate detection unit, P1 to P400 ... Scanning pulse for detection, R1 to R4
00 ... Row electrode group, S1 to S640 ... Column electrode group, Vs ... Potential of counter electrode of electrode group performing scanning, .DELTA.V ... Vs
Displacement of V1, the initial voltage of the counter electrode.

Continuation of the front page (72) Inventor Kai Kato 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A display-integrated tablet comprising a matrix panel having a row electrode group and a column electrode group, a drive circuit for driving the row electrode group and the column electrode group, a coordinate detecting section and a detecting conductor, From the drive circuit to the row electrode group,
Display scanning pulses are sequentially applied, and a signal pulse corresponding to display data is applied to the column electrode group in synchronization with the display scanning pulse. During the detection period, the driving circuit causes electrodes in the detection coordinate direction. A scanning pulse for detection is sequentially applied to the groups, and the detection conductors are brought close to the matrix panel, so that detection is performed by capacitive coupling generated between the detection conductors and the electrode group in the detection coordinate direction. The detection scanning pulse is supplied to the coordinate detection unit, a detection scanning period for detecting the coordinates of the position of the detection conductor,
Prior to the start of the detection scan, the drive circuit applies a pre-scan pulse to all or some of the electrodes in the detection coordinate direction to perform the pre-scan, and the pre-scan period includes the pre-scan. In the transition period from the period to the detection scanning period, the scanning pulse is applied so that the rising and the falling of the scanning pulse applied from the drive circuit occur simultaneously in the electrode group in the detection coordinate direction, and the detection conductor is applied. The coordinate detection method for a display-integrated tablet, wherein the position of the tablet is detected on the matrix panel. 2. A display-integrated tablet comprising a matrix panel having a row electrode group and a column electrode group, a drive circuit for driving the row electrode group and the column electrode group, a coordinate detection unit and a detection conductor, From the drive circuit to the row electrode group,
Display scanning pulses are sequentially applied, and a signal pulse corresponding to display data is applied to the column electrode group in synchronization with the display scanning pulse. During the detection period, the driving circuit causes electrodes in the detection coordinate direction. A scanning pulse for detection is sequentially applied to the groups, and the detection conductors are brought close to the matrix panel, so that detection is performed by capacitive coupling generated between the detection conductors and the electrode group in the detection coordinate direction. The detection scanning pulse is supplied to the coordinate detection unit, a detection scanning period for detecting the coordinates of the position of the detection conductor,
After the detection scanning, with respect to all or a part of the electrode group in the detection coordinate direction, a rear scanning period in which a rear scanning pulse is applied to perform rear scanning, from the detection scanning period to the rear scanning period. In the transition period, the scanning pulse is applied so that the rising and the falling of the scanning pulse applied from the drive circuit occur simultaneously in the electrode group in the detection coordinate direction, and the position of the detection conductor on the matrix panel is changed. A coordinate detection method for a display-integrated tablet characterized by detecting. 3. A display-integrated tablet comprising a matrix panel having a row electrode group and a column electrode group, a drive circuit for driving the row electrode group and the column electrode group, a coordinate detection unit and a detection conductor, From the drive circuit to the row electrode group,
Display scanning pulses are sequentially applied, and a signal pulse corresponding to display data is applied to the column electrode group in synchronization with the display scanning pulse. During the detection period, the driving circuit causes electrodes in the detection coordinate direction. A scanning pulse for detection is sequentially applied to the groups, and the detection conductors are brought close to the matrix panel, so that detection is performed by capacitive coupling generated between the detection conductors and the electrode group in the detection coordinate direction. The detection scanning pulse is supplied to the coordinate detection unit, a detection scanning period for detecting the coordinates of the position of the detection conductor,
Before the detection scanning, a pre-scanning period in which the pre-scanning is performed by applying a pre-scanning pulse from the drive circuit to all or some of the electrodes in the detection coordinate direction, and after the detection scanning. , All of the electrodes in the detection coordinate direction,
Or, for a part of the electrodes, a rear scanning period in which a rear scanning pulse is applied to perform a rear scanning, a transition period from the front scanning period to the detection scanning period, and a detection scanning period to the rear scanning period. In both of the transition periods, the scanning pulse is applied so that the rising and the falling of the scanning pulse applied from the drive circuit occur simultaneously in the electrode group in the detection coordinate direction, and the scanning conductor is applied on the matrix panel. A coordinate detection method for a display-integrated tablet, which is characterized by detecting the position in a tablet. 4. In the coordinate detection of the electrode group close to the detection conductor among the row electrode group or the column electrode group, the pre-scanning and the post-scan are not performed, and the row electrode group or the column electrode group is used for the detection. 2. The coordinate detection of an electrode group distant from a conductor is performed by performing a pre-stage scan, a post-stage scan, or both a pre-stage scan and a post-stage scan.
2. A coordinate detection method for a display-integrated tablet according to 2 or 3. 5. In the front-stage scanning and the rear-stage scanning,
The compensation voltage is applied to the electrode to which the scan pulse is not applied when the scan pulse is applied to only a part of the electrode group in the detection coordinate direction.
2. A coordinate detection method for a display-integrated tablet according to 2, 3, or 4. 6. When the electrode group is divided into two or more groups, when detecting the coordinate direction of a counter electrode group of the divided electrode group, the electrode group of the detected coordinate direction is divided. 6. The coordinate detection method for a display-integrated tablet according to claim 1, 2, 3, 4 or 5, wherein the group is divided into groups corresponding to groups, and pre-scanning, detection scanning, and post-scanning are performed for each group. . 7. An electrode group divided into two or more groups is arranged at a position far from the detection conductor, and an electrode group not divided is arranged at a position close to the detection conductor. The coordinate detection method for a display-integrated tablet according to claim 1, 2, 3, 4, or 5. 8. Of the row electrode group or the column electrode group, only in the coordinate detection of the electrode group far from the detection conductor,
When the pre-scanning, the post-scanning, or both the pre-scanning and the post-scanning are performed, the voltage applied to the pixel formed at the intersection of the row electrode group and the column electrode group is made alternating in the detection period. The compensation voltage is applied to an electrode group close to the detection conductor.
2. A coordinate detection method for a display-integrated tablet according to 2, 3, 4, 5, 6 or 7. 9. The coordinate detection method for a display-integrated tablet according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the matrix panel is a liquid crystal panel.