JP2638331B2 - Coordinate input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device such as a tablet used for inputting characters, figures, and the like to a personal computer or a word processor.

[0002]

2. Description of the Related Art As means for inputting handwritten characters and figures to a computer or a word processor, for example, a liquid crystal display and an electrostatic induction type tablet are combined.
2. Description of the Related Art An input device has been put to practical use in which characters and figures input to an electrostatic induction type tablet are input as if an operator wrote on paper with a writing instrument and displayed on a liquid crystal display.

Conventionally, as an electrostatic induction type tablet used for such an application, a transparent electrode such as indium oxide is formed on a transparent glass or plastic film, and a pulse voltage is sequentially applied to this electrode. One is generally used, for example, there is a configuration as shown in FIG.

The coordinate input unit 3 of this electrostatic induction type tablet
1 is a glass substrate 32 on which transparent electrodes X1, X2,..., Xm (collectively indicated by X) are formed;
A glass substrate 33 on which 1, Y2,..., Yn (collectively indicated by Y) are formed is disposed at a small interval so that the electrode forming surfaces face each other. It is placed on the display.

The transparent electrodes X and Y are connected to a column electrode shift register 34 and a row electrode shift register 35, respectively.
Is connected to the timing generation circuit 36. From the timing generation circuit 36, the shift register 34,
The shift data and the clock signal are sent to 35, and the electrodes X 1, X 2,.
In addition, from the row electrode shift register 35, the electrodes Y1, Y2,
, Yn are sequentially applied with a pulse voltage.

When a position detecting pen (hereinafter simply referred to as a detecting pen) 37 is brought close to the surface of the coordinate input section 31, a stray capacitance between the electrodes provided at the tip of the detecting pen 37 and the electrodes X and Y causes the stray capacitance. Then, a voltage is induced on the electrode at the tip of the detection pen 37. The voltage induced in the detection pen 37 is amplified by the amplifier 38, and the X coordinate detection circuit 39 and the Y coordinate
It is input to the coordinate detection circuit 40.

The X coordinate detection circuit 39 and the Y coordinate detection circuit 40 detect the X coordinate and the Y coordinate based on the output from the amplifier 38 and the timing signal from the timing generation circuit 36, respectively. The non-displayed liquid crystal display displays the position indicated by the detection pen 37 on the display based on the coordinate signal from the electrostatic induction type tablet.

However, in the case of this electrostatic induction type tablet, since the reflectance and the transmittance are different between the portion having the transparent electrodes X and Y of the coordinate input section 31 and the portion having no transparent electrodes X and Y, the electrodes are arranged in a grid on the display screen. Is seen, which causes the quality of the liquid crystal display to deteriorate.

In view of the above, a tablet integrated with a display as shown in FIG. 7 has recently been proposed as a tablet that eliminates such disadvantages.

In this display-integrated tablet, the display electrodes of the liquid crystal display also serve as position detection electrodes, and position detection and display are performed in a time-division manner.

In FIG. 7, a liquid crystal panel 501 includes common electrodes Y1 to Yn (collectively indicated by Y) and segment electrodes X1 to Xm (collectively indicated by X) arranged in directions crossing each other. The liquid crystal layer is interposed therebetween, and the liquid crystal layer at the intersection of each common electrode Y and segment electrode X is a pixel. That is, here, pixels of nxm dots are arranged in a matrix.

[0012] This display-integrated tablet has the advantage that the grid-like electrode pattern is not seen and the screen is easy to see, as compared with the above-mentioned tablet on a liquid crystal display. Also, there is an advantage that the cost can be reduced and the size and weight can be easily reduced.

A common drive circuit 502 for driving the common electrode Y and a segment drive circuit 503 for driving the segment electrode X are connected to a display control circuit 505 and a position detection control circuit 506 via a switching circuit 504. It is connected to the. The switching circuit 504 is switch-controlled by the control circuit 507, and during the display period, the display control circuit 505
Are output to the drive circuits 502 and 503, and the output from the position detection control circuit 506 is output to the drive circuits 502 and 503 during the position detection period.

In the display period, the display control circuit 505
Are shift data S, inverted signal FR, clock CP1,
CP2 and display data D0 to D3 are output.

The clock CP1 is a clock having a cycle of a scanning period for scanning one row of pixels.
4 is input to the clock input terminal CK of the common drive circuit 502 and the latch pulse input terminal LP of the segment drive circuit 503 from the output terminal CP10. The shift data S is a pulse signal for specifying each common electrode Y, is output from the output terminal S0 of the switching circuit 504, and is synchronized with the clock CP1 from the shift data input terminal D101 of the common drive circuit 502. Is entered.

In accordance with the shift of the shift data S, a drive signal is output from the output terminal of the common drive circuit 502 corresponding to the shift position to the common electrode Y. This drive signal is generated based on bias voltages V0 to V5 supplied from DC power supply circuit 512. Clock CP2
Is a clock whose period is a period obtained by dividing a scanning period for scanning pixels of one column into a plurality of periods. The clock is output from the output terminal CP20 of the switching circuit 504, and the segment driving circuit 5
03 clock input terminal XCK.

The display data D0 to D3 are supplied to the switching circuit 504.
Is output from the output terminal Dout of the segment drive circuit 503, is input to the input terminals D0 to D3 of the segment drive circuit 503, and is sequentially taken into a register inside the segment drive circuit 503. When the display data corresponding to the pixels of one row is taken in, the display data is latched at the timing of the clock CP1 input to the latch pulse input terminal LP, and the drive signal corresponding to each display data is driven by the segment drive. The signal is output from the output terminal of the circuit 503 to the segment electrode X. This drive signal is also generated based on the bias voltages V0 to V5 supplied from the DC power supply circuit 512. The inversion signal FR is a signal for periodically inverting the polarity of the voltage applied to the liquid crystal layer to prevent the liquid crystal from being deteriorated by electrolysis.

By the operation of the common drive circuit 502 and the segment drive circuit 503, the pixels of the liquid crystal panel 501 are driven according to the row order, and an image corresponding to the display data is displayed on the liquid crystal panel 501.

On the other hand, during the position detection period, the position detection control circuit 506 controls the shift data Sd, the inverted signal FRd, the clocks CP1d and CP2d, and the drive data D0d to D0d.
3d is output.

The clock CP1d is a clock having a cycle of a scanning period for scanning the common electrodes for one row, and is output from the output terminal CP10 of the switching circuit 504 to the common driving circuit 50.
2 clock input terminal CK and the segment drive circuit 50
3 and a latch pulse input terminal LP. Also,
The shift data Sd is a pulse signal for specifying each common electrode Y, is output from the output terminal S0 of the switching circuit 504, and is input from the shift data input terminal D101 of the common drive circuit 502 in synchronization with the clock CP1d. You.

According to the shift of the shift data Sd,
A drive signal is output to the common electrode Y from an output terminal of the common drive circuit 502 corresponding to the shift position. This drive signal is generated based on bias voltages V0 to V5 supplied from DC power supply circuit 512. Clock CP2
d is a clock having a cycle of a scanning period for scanning the segment electrodes X for one column, and is output from the output terminal CP20d of the switching circuit 504 and input to the clock input terminal XCK of the segment driving circuit 503.

The drive data D0d to D3d are supplied to the switching circuit 5
The signal is output from the output terminal Dout of the segment driving circuit 503, input to the input terminals D0 to D3 of the segment driving circuit 503, and sequentially taken into the register inside the segment driving circuit 503. 1
When drive data corresponding to the segment electrodes X for a row is taken in, these drive data are latched at the timing of the clock CP1d input to the latch pulse input terminal LP, and drive signals corresponding to each drive data are output. The signal is output from the output terminal of the segment drive circuit 503 to the segment electrode X. This drive signal is also created based on the bias voltages V0 to V5 supplied from the DC power supply circuit 512. The inversion signal FRd is a signal for periodically inverting the polarity of the voltage applied to the liquid crystal layer to prevent the liquid crystal from being deteriorated by electrolysis.

FIG. 8 is a timing chart showing the drive timing of the display-integrated tablet during the position detection period. As shown in FIG. 8, the position detection period is X
It is divided into a coordinate detection period and a subsequent Y coordinate detection period. In the X coordinate detection period, the segment electrodes X are sequentially driven by a lines, and in the Y coordinate detection period, the common electrodes Y are sequentially driven by b lines.

The reason why the pulse voltage is applied simultaneously for each of the plurality of detection pens is to improve the detection accuracy by increasing the induced voltage of the detection pen 508 and to shorten the detection period. The induced voltage of the detection pen 508 is amplified by the amplifier 509, and based on the output of the amplifier 509 and the timing signal from the control circuit 507, the X coordinate detection circuit 51
0 detects the X coordinate, and the Y coordinate detection circuit 511 detects the Y coordinate.

[0025]

However, in the above-mentioned prior art, since the coordinate detection operation is performed using a so-called retrace period between displays, there is a time constraint on the coordinate detection. is there. Therefore, when the number of electrodes is large, such as when a liquid crystal display having a large number of display pixels is used, the time required for coordinate detection becomes long, and the conventional detection method cannot scan the entire detection area within the retrace period.

For this reason, coordinate detection is performed by changing the display duty ratio or changing the clock frequency to scan the entire detection area, but as a result, the display quality due to the decrease in contrast is reduced. There are problems such as deterioration and cost increase.

An object of the present invention is to provide a coordinate input device which can improve the above-mentioned drawbacks, shorten the coordinate detection time, and perform coordinate detection with high accuracy.

[0028]

According to a first aspect of the present invention, there is provided a coordinate input device having a coordinate detection area in which a first conductor group arranged in parallel and a second conductor group arranged in parallel are arranged in a grid. A detection panel, a first drive circuit for applying a signal to the first conductor group, a second drive circuit for applying a signal to the second conductor group,
A control circuit for controlling the timing of supplying a signal to the first conductor group and the second conductor group, position indicating means for detecting coordinates by contacting or approaching the coordinate detection panel, and input coordinates based on the detection signals The coordinate input area is divided into a plurality of areas, and a signal having a different waveform is first supplied to each conductor group in each area to locate the position indicating means. Then, the designated coordinates are detected by supplying a scanning signal line-sequentially only to the conductor group in the area where the position indicating means is located. A coordinate input device according to a second aspect of the present invention is the coordinate input device according to the first aspect, wherein each conductor group in the coordinate detection panel and the position indicating means are capacitively coupled. And A coordinate input device according to a third aspect of the present invention is the coordinate input device according to the first aspect, wherein each conductor group in the coordinate detection panel and the position indicating means are coupled by electromagnetic induction. I do. The coordinate input device according to claim 4, wherein a display panel having a display area in which the first conductor group arranged in parallel and the second conductor group arranged in parallel are arranged in a lattice, and a signal is transmitted to the first conductor group. A first driving circuit for applying a signal, a second driving circuit for applying a signal to the second conductor group, a control circuit for controlling a timing for supplying a signal to the first conductor group and the second conductor group, and a control circuit for the display panel. Position indicating means for detecting coordinates by touching or approaching, and coordinate detecting means for detecting input coordinates based on the detection signal, further comprising displaying an image on the display panel and approaching or approaching the display panel surface. In a coordinate input device including a switching control circuit that controls a switching circuit that switches in time division between coordinate detection for determining the position of the position indicating means and a switching circuit, the display area is divided into a plurality of areas, and a conductor group in each area is first divided. By supplying a signal having a different waveform to the area, the area where the position indicating means is located is determined, and then the scanning coordinates are supplied line-sequentially only to the conductor group within the area where the position indicating means is located, so that the indicated coordinates are obtained. It is characterized by detecting. According to a fifth aspect of the present invention, there is provided the coordinate input device according to the fourth aspect, wherein each conductor group in the display panel and the position indicating means are capacitively coupled. According to a sixth aspect of the present invention, in the coordinate input device according to the fourth aspect, each conductor group in the display panel and the position indicating means are electromagnetically inductively coupled.

[0029]

According to the present invention, the input coordinates specified by the position detecting means are first detected as to which of the unit areas formed by dividing the coordinate area into a plurality of unit areas.
Subsequently, the relative position within the unit area is detected. Thereafter, base point coordinates that are absolute coordinates in the unit area,
The input coordinates on the coordinate input unit are calculated based on the relative position in the unit area.

[0030]

FIG. 1 is a block diagram showing a configuration of a coordinate input device according to an embodiment of the present invention. This coordinate input device is a so-called display-integrated tablet, in which a display electrode of a liquid crystal display also serves as a position detection electrode, and performs position detection and display in a time sharing manner.

In FIG. 1, the liquid crystal panel 1 has common electrodes Y1 to Yn (collectively indicated by Y) and segment electrodes X1 to Xm (collectively indicated by X) arranged in directions intersecting each other. A liquid crystal layer is interposed between the common electrodes Y and the liquid crystal layer at the intersection of each common electrode Y and each segment electrode X constitutes each pixel. That is,
In the liquid crystal panel 1 of this embodiment, pixels of nxm dots are arranged in a matrix.

This display-integrated tablet has the advantage that the grid-like electrode pattern is not seen and is easy to see, as compared with the tablet having the tablet placed on the above-mentioned liquid crystal display. Therefore, there is an advantage that cost reduction and reduction in size and weight are facilitated.

A common drive circuit 2 for driving the common electrode Y and a segment drive circuit 3 for driving the segment electrode X are connected to a display control circuit 5 and a position detection control circuit 6 via a switching circuit 4. And connected to. The switching circuit 4 is switch-controlled by a control circuit 7, and outputs the output from the display control circuit 5 to the driving circuits 2, 3 during the display period.
And outputs the output from the position detection control circuit 6 to the drive circuits 2 and 3 during the position detection period.

In the display period, the display control circuit 5 outputs the shift data S, the inverted signal FR, and the clock C from the output terminal.
P1 and CP2 and display data D0 to D3 are output, respectively.

The clock CP1 is a clock having a cycle of a scanning period for scanning one row of pixels. The clock CP1 is supplied from the output terminal CP10 of the switching circuit 4 to the clock input terminal CK of the common drive circuit 2 and the latch pulse of the segment drive circuit 3. Input to the input terminal LP. The shift data S is a pulse signal for specifying each common electrode Y, is output from the output terminal S0 of the switching circuit 4, and is transmitted from the shift data input terminal D101 of the common drive circuit 2 to the clock CP1.
Input in synchronization with.

In response to the shift of the shift data S, a drive signal is output from the output terminal of the common drive circuit 2 corresponding to the shift position to the common electrode Y. This drive signal is applied to the bias voltage V0 supplied from the DC power supply circuit 16.
To V5. The clock CP2 is a period obtained by dividing a scanning period for scanning pixels of one column into a plurality of periods.
The output terminal CP of the switching circuit 4
20 and is input to the clock input terminal XCK of the segment drive circuit 3.

The display data D0 to D3 are output from the output terminal Dout of the switching circuit 4 and input to the input terminals D0 to D3 of the segment driving circuit 3,
The data is sequentially taken into an internal register. When the display data corresponding to the pixels of one row is taken in, the display data is latched at the timing of the clock CP1 input to the latch pulse input terminal LP, and the drive signal corresponding to each display data is driven by the segment drive. The signal is output from the output terminal of the circuit 3 to the segment electrode X. This drive signal is also created based on the bias voltages V0 to V5 supplied from the DC power supply circuit 16. The inversion signal FR is a signal for periodically inverting the polarity of the voltage applied to the liquid crystal to prevent the liquid crystal from being deteriorated by electrolysis.

By the operation of the common drive circuit 2 and the segment drive circuit 3, the pixels of the liquid crystal panel 1 are driven according to the row order, and an image corresponding to the display data is displayed on the liquid crystal panel 1.

On the other hand, during the position detection period, the position detection control circuit 6 outputs the shift data Sd and the inverted signal FR from the output terminal.
d, clocks CP1d and CP2d, and drive data D
0d to D3d are output.

The clock CP1d is a clock having a cycle of a scanning period for scanning the common electrode Y for one row. The output terminal CP10 of the switching circuit 4 connects the clock input terminal CK of the common drive circuit 2 to the segment drive circuit 3 Is input to the latch pulse input terminal LP. The shift data Sd is a pulse signal for specifying each common electrode Y, is output from the output terminal F0 of the switching circuit 4, and is synchronized with the clock CP1d from the shift data input terminal D101 of the common drive circuit 2. Is entered.

According to the shift of the shift data Sd,
A drive signal is output to the common electrode Y from an output terminal of the common drive circuit 2 corresponding to the shift position. This drive signal is applied to the bias voltage V supplied from the DC power supply circuit 16.
It is generated based on 0 to V5.

The clock CP2d is a clock having a cycle of a scanning period for scanning one column of the segment electrodes X, is output from the output terminal CP20d of the switching circuit 4, and is input to the clock input terminal XCK of the segment driving circuit 3. You.

The driving data D0d to D3d are supplied to the switching circuit 4
Are output from the output terminals Dout of the segment driving circuit 3 and input to the input terminals D0 to D3 of the segment driving circuit 3 and sequentially taken into the registers inside the segment driving circuit 3. When drive data corresponding to one row of the segment electrodes X is taken in, the clock CP1 input to the latch pulse input terminal LP
At timing d, these drive data are latched,
A drive signal corresponding to each drive data is input from the output terminal of the segment drive circuit 3 to the segment electrode X. This drive signal is also created based on the bias voltages V0 to V5 supplied from the DC power supply circuit 16. Note that the inversion signal FRd is a signal for periodically inverting the polarity of the voltage applied to the liquid crystal to prevent the liquid crystal from being deteriorated by electrolysis.

When a position detecting pen (hereinafter, simply referred to as a detecting pen) 8 is brought close to the surface of the liquid crystal panel 1, a distance between an electrode provided at the tip of the detecting pen 8 and the electrodes X, Y to which voltage is applied is increased. , A voltage is induced on the electrode of the detection pen 8. The voltage induced in the detection pen 8 is
Amplified by the amplifier 9, the X coordinate area discriminating circuit 10,
X coordinate relative position detection circuit 11, Y coordinate area determination circuit 1
3 and the Y coordinate relative position detection circuit 14.

The X-coordinate calculation circuit 12 calculates and outputs the X-coordinate based on the outputs from the X-coordinate area determination circuit 10 and the X-coordinate relative position detection circuit 11. The Y coordinate calculation circuit 15 calculates and outputs the Y coordinate based on the outputs from the Y coordinate area determination circuit 13 and the Y coordinate relative position detection circuit 14.

In the coordinate input device of this embodiment, the liquid crystal panel 1 also functions as a coordinate input unit. That is, the pixel where the electrodes X and Y intersect is the coordinate. Therefore, it is possible to calculate the coordinates input and instructed by the detection pen 8 based on the application timing of the scanning voltage to the electrodes X and Y and the detection timing of the voltage induced on the detection pen 8.

In the coordinate input device of this embodiment, a coordinate area in which a plurality of coordinates are arranged is divided into a plurality of unit areas,
First, it is determined to which unit area the input-instructed coordinates belong, and then a relative position within the unit area is detected. After that, the coordinates indicated by the input are calculated based on the coordinates as the base point of the unit area and the relative position.

FIGS. 2 and 3 are diagrams for explaining the basic principle of the electrode division scanning method used in the coordinate input device of the present embodiment. The area detecting operation in the present embodiment is executed as follows. First, m segment electrodes X (1) to X (m) are divided into eight regions Xa to Xh as shown in Table 1 below.

[0049]

[Table 1]

The n common electrodes Y (1) to Y (n)
Is divided into eight regions Ya to Yh as shown in Table 2 below.

[0051]

[Table 2]

First, m segment electrodes X (1) to X
(M), the electrodes X (1) to X (1) as shown in FIG.
A pulse voltage, which is a scanning voltage, is simultaneously applied to X (m / 2) in the scanning period P1 shown in FIG. next,
As shown in FIG. 2 (2), electrodes X (1) to X (m / 4),
A pulse voltage is simultaneously applied to X (m / 2 + 1) to X (3m / 4) in the scanning period P2 shown in FIG.
Next, as shown in FIG. 2 (3), the electrodes X (1) to X (m +
8), X (m / 4 + 1) to X (3m / 8), X (m / 2
+1) to X (5m / 8), X (3m / 4 + 1) to X (7
m / 8), a pulse voltage is applied simultaneously in the scanning period P3 shown in FIG. An X region discrimination signal is obtained by applying voltages in these three types of patterns. Thereafter, in the intra-region relative position detection period shown in FIG. 4, the segment electrodes X in each region are sequentially scanned by applying a pulse voltage simultaneously for each region to obtain an intra-region relative position detection signal.

Next, the n common electrodes Y (1) -Y
Of (n), first, as shown in FIG.
Scanning period P4 shown in FIG. 4 for (1) to Y (n / 2)
, A pulse voltage which is a scanning voltage is simultaneously applied.
Next, as shown in FIG. 3B, the electrodes Y (1) to Y (n / n /
4) A pulse voltage is simultaneously applied to Y (n / 2 + 1) to Y (3n / 4) in the scanning period P5 shown in FIG. Next, as shown in FIG.
(N / 8), Y (n / 4 + 1) to Y (3n / 8), Y
(N / 2 + 1) to Y (5n / 8), Y (3n / 4 + 1)
To Y (7n / 8), a pulse voltage is applied simultaneously in the scanning period P6 shown in FIG. By applying voltages in these three types of patterns, a Y area determination signal is obtained. Thereafter, the common electrode in each area is simultaneously scanned line-sequentially with a pulse voltage for each area to obtain an intra-area relative position detection signal.

That is, in this embodiment, the position detection period is
As shown in FIG. 4, it is divided into an X coordinate detection period and a subsequent Y coordinate detection period, and the X coordinate detection period and the Y coordinate detection period are respectively defined as a region determination period and a relative detection period in the region. I know.

Table 3 below shows the correspondence between the applied voltage levels in the scanning periods P1 to P3 and P4 to P5 in the region determination period and the regions Xa to Xh and Ya to Yh.

[0056]

[Table 3]

Therefore, it is possible to determine to which area the coordinates indicated by the input of the detection pen 8 on the liquid crystal panel 1 belong based on the voltage waveform pattern detected in the area determination period.

During the relative position detection period within the area during the X coordinate detection period, the segment electrodes X are sequentially driven (scanned) by a lines at a time, and during the relative position detection period within the area during the Y coordinate detection period, the common electrode Y is set to b. By driving one by one,
The induced voltage of the detection pen 8 is increased.

FIG. 5 shows the detection pen 8 during the position detection period.
FIG. 6 is a waveform chart showing an example of a detection signal output from the oscilloscope. As shown in FIG. 5, the detection signal obtained from the detection pen 8 is also
The area where the detection pen 8 is located is determined by the combination of the three signals of the area determination signal in the area determination period in the first half of the X coordinate detection period. The X-coordinate relative position detection circuit 11 determines the relative coordinates in each region from the relative position detection signal in the second half relative position detection period. The coordinates of the base point of each area are determined in advance, and the X coordinate calculation circuit 12 calculates the absolute coordinates in the X direction by adding the coordinates of the relative position within the area to the coordinates of the base point of each area.

The area where the detection pen 8 is located is determined by the combination of three area determination signals in the area determination period in the first half of the Y coordinate detection period.
3 and the Y coordinate relative position detection circuit 14 detects the relative coordinates in the area based on the relative position detection signal in the second half relative area detection period. Similarly to the above, the coordinates of the base points of the regions Ya to Yh are determined in advance, and the Y coordinate calculation circuit 15 adds the coordinates of the relative position in the region to the coordinates of the base point of each region to obtain the absolute coordinates in the Y direction. Is calculated.

As described above, according to this embodiment, it is not necessary to scan all the electrodes line-sequentially when detecting the input coordinates by the detection pen 8 as in the prior art, and the position detection period is shortened. be able to. Therefore, even if the number of electrodes is increased to improve the resolution of the liquid crystal panel 1, the position detection period does not become long, and the influence on the display period can be reduced. Therefore, coordinate detection can be performed accurately and efficiently without deteriorating display quality or increasing costs.

In this embodiment, the case where the detection area is divided into eight in both the X and Y directions and three types of voltage application patterns are used for the area discrimination has been described. Coordinate detection is performed by combining voltage application for area determination by dividing the area into a plurality of areas and voltage sequential scanning of electrodes for detecting a relative position in each area. Also, the voltage application pattern for area determination is not limited to the pattern described in the above embodiment. Further, the coordinate detection method of the present invention may be used for only one of the X coordinate detection and the Y coordinate detection, and the other may be performed by a conventional detection method.

In this embodiment, a display integrated tablet using a liquid crystal display has been described.
The present invention is not limited to this, and can be implemented in a conventional electrostatic induction type tablet that is not a display integrated type, an EL panel, or the like.

[0064]

As described above, according to the present invention, the input coordinates designated by the position detecting means are first detected as to which of the unit areas obtained by dividing the coordinate area into a plurality of unit areas. Subsequently, the relative position within the unit area is detected. Thereafter, input coordinates on the coordinate input unit are calculated based on base point coordinates, which are absolute coordinates in the unit area, and relative positions in the unit area. This eliminates the need to detect the input coordinates while scanning the first and second strip electrodes line-sequentially as described in connection with the related art, so that the coordinate detection time is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a display-integrated tablet according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an X coordinate detection operation in the present embodiment.

FIG. 3 is a diagram for explaining a Y coordinate detection operation in the present embodiment.

FIG. 4 is a timing chart for explaining a coordinate detection operation in the present embodiment.

FIG. 5 is a waveform chart showing an example of a detection signal detected by a detection pen 8;

FIG. 6 is a circuit diagram showing a configuration of a conventional electrostatic induction tablet.

FIG. 7 is a circuit diagram showing a configuration of a display-integrated tablet as a conventional example.

8 is a timing chart for explaining a position detection operation in the display-integrated tablet shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Common drive circuit 3 Segment drive circuit 4 Switching circuit 5 Display control circuit 6 Position detection control circuit 7 Control circuit 8 Position detection pen 9 Amplifier 10 X coordinate area discrimination circuit 11 X coordinate relative position detection circuit 12 X coordinate calculation circuit 13 Y coordinate area discriminating circuit 14 Y coordinate relative position detecting circuit 15 Y coordinate calculating circuit 16 DC power supply circuit

Claims (6)

(57) [Claims] A first conductor group arranged in parallel with a second conductor group arranged in parallel;
Has a coordinate detection area where conductors are arranged in a grid
Coordinate detection panel, and a first conductor group for applying a signal to the first conductor group.
A drive circuit and a second drive circuit for applying a signal to the second conductor group
And a tie for supplying a signal to the first conductor group and the second conductor group.
A control circuit for controlling the
Position indicating means for detecting coordinates by touching or approaching;
Coordinate detecting means for detecting input coordinates based on the detection signal;
In the coordinate input device provided with, the coordinate input area is divided into a plurality of areas, and
Position signal by supplying signals with different waveforms for each conductor group in the area
The area where the means is located is determined, and then the position indicating means is located.
Scanning signals are supplied line-sequentially only to conductor groups in the area where
By detecting the indicated coordinates.
Standard input device. 2. The method according to claim 2, wherein each of the conductor groups in the coordinate detection panel is connected to the conductor group.
The position indicating means is capacitively coupled.
The coordinate input device according to claim 1. 3. A conductor group in the coordinate detection panel and
Characterized in that it is electromagnetically inductively coupled to the position indicating means.
The coordinate input device according to claim 1. 4. The parallel first conductor group and the second conductor group
Table having a display area in which conductor groups are arranged in a grid pattern
Display panel and a first drive circuit for applying a signal to the first conductor group
A second drive circuit for applying a signal to the second conductor group;
Timing for supplying signals to the conductor group and the second conductor group
A control circuit for controlling and abutting or approaching the display panel
Position indicating means for detecting the coordinates by detecting
Coordinate detecting means for detecting the input coordinates based on the
Displaying an image by the display panel and the display panel surface
Determine the position of the position indicating means approaching or approaching
Control the switching circuit that switches between coordinate detection and time-sharing
In a coordinate input device provided with a switching control circuit, the display area is divided into a plurality of areas,
Position indicating means by supplying signals of different waveforms for each conductor group
Is determined, and then the position indicating means is positioned.
Supply scan signals to only conductor groups in the
Is used to detect the indicated coordinates.
Power device. 5. The conductor group and the position in the display panel
And a pointing means which is capacitively coupled.
A coordinate input device according to claim 4. 6. The conductor group and the position in the display panel.
Claims characterized in that the indicating means is electromagnetically coupled with the indicating means.
Item 5. The coordinate input device according to item 4.