JPS605322A - Capacity coupled tablet - Google Patents

Abstract

PURPOSE:To improve the noise resisting property of a capacity coupled tablet, by preventing the occurrence of two input areas which are the same relative addresses at both ends of one column area and using the threshold level of signal detection at the time of column electrode scanning as the intersecting point of the changing pattern of a detect signal level related to column electrodes adjacent to each other. CONSTITUTION:X-electrode lines X1,X2,-Xn and X-column electrodes x1,x2-xn are arranged alternately, in parallel with each other, and at regular intervals in the X-direction of a tablet 100. When x-direction input areas XZ8 and XZ15 at both ends of a column electrode XB2 are noted, it can be known that the relative address of the XZ8 is ''8'' and the column position data goes to ''1'' for the left half (l8 in the figure) and ''2'' for the right half (r8 in the figure). Also, the relative address of the XZ15 goes to ''7'' and the column position data go to ''2'' for the left half (l15 in the figure) and ''3'' for the right half (r15 in the figure). Therefore, no overlap of the combination of relative addresses and column position data exists in any parts of the two input areas.

Description

[Detailed Description of the Invention] The invention relates to a capacitively coupled tablet, and particularly to a capacitively coupled tablet in which the tablet is equipped with digit electrodes and the structure of the electrode drive circuit and associated circuits is simplified. .

Capacitively coupled tablet input device
A sequential scanning signal is applied to the t-electrode line, and the position coordinates are specified from the timing when this scanning signal is detected by an input vent, and information is input. When this capacitively coupled tablet input device is used as an input device for multiple items including kanji, etc., the circuit configuration of the input device inevitably becomes complicated due to the large number of input areas. It took time. Therefore, the applicant of the present application previously filed an invention for simplifying the circuit configuration of an input device by equipping a capacitively coupled tablet with digit electrodes (Japanese Patent Application No. 56-214301). This will be explained in detail based on FIG. In the figure, 1
is a tablet on which a plurality of scanning electrode lines and digit electrodes are arranged, and 2 and 3 are tablets 10X and 10Y, respectively.
[Decoder for X and Y electrode lines that applies scanning signals to polar lines/
A driver (hereinafter simply referred to as [X, Yt polar line drive circuit]), 4 and 5 are decoders/drivers for X and Y digit electrodes (hereinafter referred to as (simply referred to as "l'-X, Y digit electrode drive circuit")
shows. As shown in FIGS. 2 and 3, the tablet 1 has an insulating plate 6 formed in a planar shape. A plurality of X electrode lines Xt-Xn and Y electrode lines Y1 to Y0 are arranged in parallel. These X and X electrode lines X1 to Xn.

A scanning signal is applied to Yl-Ym from the outside. X electrode wires X+ to X on the upper surface side of the insulating plate 6
A plurality of X-digit electrodes XAI-XA are further provided on the same surface as the X-digit electrodes XAI-XA for dividing the X-direction of the tablet 1 into predetermined digit order areas (see F in FIG. 1). This X-digit electrode XA
1 to XA are arranged for each unit, with a predetermined number (h-3 in the case of FIG. 1) of X electrode wires as one unit.

Specifically, for example, the X-digit electrode XAI has a plurality of X-digit electrode lines X1%X3 that are paired with each of the X-electrode lines X1 to X1 and are arranged in parallel and close to each other. The X-digit electrode lines X and %Xl are commonly connected at the upper end of the tablet 1 in FIG. 1 and are electrically integrated. Each X-digit electrode line x1 to x3 is an X-digit electrode line
! ~X1 has almost the same line width. The other X-digit electrodes XA2 to XAl1 are formed in exactly the same manner, and each of these X-digit electrodes X At -X As is scan-driven by the X-digit electrode drive circuit 4. . On the other hand, the X electrode lines X1 to Xil are divided into groups according to the aforementioned X-digit electrodes X A t -X A s. Then, the X electrode lines Xj, Xj+3, . . . at corresponding address positions within each group are commonly connected across the plurality of groups, and then connected to the X electrode line drive circuit 2. That is, by driving the X electrode line drive circuit 2, scanning signals are sequentially applied to the X electrode lines in each group simultaneously across a plurality of groups.
The number of drive elements constituting the electrode (line) drive circuit for coordinate detection in the X direction is the sum of the number of X electrode lines forming each group and the number S of groups.

Y electrode wire 'L - Y provided on the lower surface side of the insulating plate 6
-vc is divided into groups by a predetermined number t (t=3 in the case of Figure 1) in exactly the same way as in the case of the X electrode wire mentioned above, and the corresponding After the X electrode lines at the address positions are connected in common, they are connected to the X electrode line drive circuit 3. In addition, Y electrode line Y1
~ On the same plane as Ym, each group [, Y digit electrode Y At −
Equipped with Y Au. That is, the X electrode line Y1~
Y-digit electrode wires y1 to Ym are installed adjacent to and parallel to each Ym, and the right ends of the Y@electrode wires y to Ym in FIG. 1 are commonly connected to each digit. . and,
These X-digit electrodes YA1 to YAu are scan-driven by the X-digit electrode drive circuit 5.

Said X-digit electrode line y! ~Ym has approximately the same line width as the Y electrode lines Y1~Ym, and these X-digit electrode lines and Y
The electrode wires are the Xi electrode wires 1 to X! l or X digit electrode line x
The line width is formed to be somewhat thicker than the line width of 1 to X. Thereby, the signal levels on the top surface of the tablet 1 due to the X (digit) electrode line and the Y (digit) electrode line are set to be approximately the same.

In the tablet 1 described above, a pair of X electrode lines X' and X digit electrode lines Xj and a pair of Y electrode lines Y1 and Y digit! electric wire y
Input area Z1j where the intersection of 1 represents coordinates (j+i)
(See Figures 1 and 2) =5-, and over the entire area of the tablet 1, m
The input area of rows and n columns is set up in a square shape. The X electrode lines X1 to X! 1 and X digit electrode wire X! As shown in FIG. 2, a protective insulating layer 30 is further provided on the upper side of ~Xn by coating an insulating material, etc., and this insulating layer 30 and the insulating plate 6 are integrated. . Then, an information sheet (not shown) displaying predetermined items corresponding to the input area is placed on the tablet 1 formed in this way, and input can be made from above this information sheet. When the ben 8 (see FIG. 1) is brought into contact with the conductive member, each electrode wire and each digit electrode of the tablet 1 are capacitively coupled to each other.

The scanning signal applied to the Yt electrode line X and the X-digit electrode line can be detected.

Driving the tablet 1 configured as described above and inputting coordinates using the input pen 8 are performed as follows. First, when the operator wishes to input information, he first touches and presses the input pen 8f on a desired item on the information sheet. By pressing the taplet 6-1-1 of the input pen 8, a pen switch 8A built into the input pen 8 is closed, and a pen touch signal is sent to the control circuit 9 of the input device. When the control circuit 9 receives the bent touch signal, it immediately sends a control signal to the gate circuit 10 to open the gate circuit 1° and send the output of the pulse generator 11 to the total counter circuit 12. The output side of this counter circuit 12 is connected in advance to the X electrode line drive circuit 2, and this counter circuit 12 counts the pulse signal sent from the pulse oscillator 11 and calculates the total value of the counted value for the X electrode line drive circuit 2. Output to drive circuit 2. On the X electrode line drive circuit 2 side, the count value sent from the counter circuit 12 is decoded and converted, and scanning pulses for address detection are sequentially sent to the X electrode lines in each group. On the other hand, since the input pen 8 is in contact with the tablet 1 and is capacitively coupled to the tablet 1, when a scanning signal is applied to the input area related to the contact area of the input pen 8, this signal is Detected by pen 8. The detection signal detected by this human pen 8 is
After being amplified by an amplifier 16, the signal is sent to the control circuit 9 via a comparator 13 and a waveform shaping circuit 14 that allows only signals above a predetermined level to pass. This control circuit 9 is
As soon as the detection signal is input, the counter circuit 12
The output data register 15, which constantly inputs the count value of , sends out a reset signal. Therefore, this output data register 15 outputs the count value of the counter circuit 12 at the timing when the input pen 8 detects the signal, and thereby the relative value within the group related to the contact area of the input pen 8. Address data is obtained. On the other hand, the control circuit 9
After finishing scanning the X electrode line, it sends a control signal to the counter circuit 12.

By this control signal, the output side of the counter circuit 12 is switched to the X-digit electrode drive circuit 4, and at the same time, the count value is reset and a new count of the pulse signal sent from the pulse oscillator 11 is started.

This count value is decoded by the X-digit electrode drive circuit 4 and sequentially sends scanning pulses for digit detection to the X-digit electrodes XAI to XA of the tablet 1.

Among these scanning pulses, the scanning pulse applied to the X-digit electrode related to the part that the input ben 8 abuts is
, and a detection signal is output to the control circuit 9 in the same manner as described above. When the control circuit 9 receives the detection signal, it outputs a reset signal to an output data register 15 to which the count value of the counter circuit 12 is always input, and this output data register 15 outputs a reset signal to the input pen 8.
will output the digit position data related to the part that touched. Therefore, the output data register 15 first outputs relative address data by scanning the X electrode line,
Next, the digit position data obtained by scanning the X digit electrode is output, so the X coordinate of the contact area of the input pen 8 can be determined from these two data.

When the scanning of the X-digit electrode is completed, the control circuit 9 sends a control signal to the counter circuit 12, and based on this control signal, the counter circuit 12 switches its output side to the Y[polar line drive circuit 3]. At the same time, after the count value is reset, a new count of pulse signals is started. Thereafter, in exactly the same manner as described above, at step 9-, scanning of the Y'aL polar line and the X digit electrode and signal detection are performed, and the output data register 15 outputs relative address data and digit position data in the X direction. From these two data, the y-coordinate of the contact area of the detection pen 80 can be determined. By performing a predetermined code conversion on the x, y coordinate data obtained in this way, information on the item specified by the detection pen 8 can be input.

As a result, in the X direction, the coordinates divided into hXs can be detected using (h+s) drive elements, and in the X direction, the coordinates divided into tXu can be detected by (t- 1-u') drive elements can perform seat detection. Therefore, for example, the minimum number of drive bits required to drive a tablet with 64 x 64 items is 32 bits as h = s = t = u = B, which reduces the time required for coordinate detection and reduces the number of drive elements. It can be significantly reduced, and the electrode (
It is possible to simplify the circuit configuration of the drive circuit, control port, etc. In addition, with the reduction in the number of drive elements, the connector used to connect the 10-tablet and the electrode drive circuit can be simplified. etc. can be reduced and downsized.

Incidentally, the detection signal level of the input pen 8 capacitively coupled to the electrode wire of the tablet 1 changes depending on the point of contact with the tablet, and is strongest immediately above the electrode wire and gradually becomes weaker as it moves away from the electrode wire. For example, as shown in FIG. 4, the digit area boundary part of a tablet 1 is equipped with digit electrodes XAK with eight X electrode lines as one unit, and the X electrode lines and the X digit electrode lines are arranged at equal pitches. X-digit electrode wire X8
-1° to the X electrode line
The detection signal level related to K (the level after amplification by the amplifier 16) and the detection signal level related to the X-digit electrodes XAK and XAK+1 change as shown in FIG. In FIG. 5, the intersection point T1 of the detection signal level change patterns I and II related to -1 and X8KK on the adjacent X electrode line X8 is passed through the detection signal by the comparator 13 when performing XZ polar scanning. If it is a threshold value, one of the detection signals obtained by scanning the X electrode line will be one depending on the contact position, and
The boundary in the X direction of the input area Z is located between adjacent X electrode lines,
That is, it is on the X-digit electrode line (see the X-direction input area XZ in FIGS. 4 and 5). However, similarly for the X-digit electrode,
If the level T2 at the intersection of detection signal level change patterns ■ and ■ related to digit electrodes XAK and XAK+1 is the threshold value when performing X-digit electrode scanning, then the boundary in the X direction of the digit area is the X-digit electrode line X8. The middle point between +1 and x8, that is, the X electrode line
BK (see the X-direction digit area XFK in FIGS. 4 and 5), and is shifted by 1/2 pitch with respect to the boundary of the X-direction input area XZ. At this time, in the X-direction input area XZ8 in FIG. 5, the left half of the digit position data (see lsK in FIG. 5) is
.

The right half (see r8 in FIG. 5) ends up being +1. For this reason, the X direction input area X Z B (K-
1)'s right half molecule 1i (1(-1) and XZ8's left half A
! Even though the sK and X electrode lines are separated by 8 lines, the relative address data and digit position data are exactly the same, and a situation arises in which they cannot be distinguished from each other and cannot be made to correspond to different items. This also applies when the deviation between the electrode line and the digit electrode line is other than 1/2 pitch.

In order to avoid the above-mentioned inconvenience, the applicant has set the threshold of the comparator 13 at the time of digit electrode scanning to the detection signal level T3 for the X-digit electrode XAK+1 on the X-digit electrode line XgK in FIG. Lower it so that the boundary of the digit area and the boundary of the input area match the X in Figures 4 and 5.
(see Fx), each input area corresponds to a combination of relative address and digit position data on a one-to-one basis. (
In this case, when the input pen 8 touches the X-digit electrode line X 8 K and x8 between +1, two detection signals are output from the comparator 13 by scanning the X-digit electrode, but the output data register 15 outputs two detection signals. The data latched by the previous detection signal is replaced by the data latched later, and the digit position data becomes [, , +IJ. ) However, in the above technology, in order to detect the digit position, the threshold value for signal detection must be made extremely small, which inevitably leads to the drawback that the noise margin is low and noise is easily picked up. .

131 The present invention has been made in view of the above drawbacks, and by devising the correspondence between the electrode lines and the digit electrodes, even if the threshold for signal detection during scanning of the digit electrodes is set high, the address of the input area remains unchanged. The purpose is to provide a capacitive coupling tablet which can prevent data and digit position data from overlapping and thereby provide a large noise margin.

The present invention attempts to achieve the above object by providing a unit of digit electrodes each having a number smaller than the number of electrode wires in one group, which are scanned in parallel in synchronization with each group.

Hereinafter, one embodiment of the present invention will be described based on FIG. 6.

FIG. 6 is a partially omitted schematic diagram showing a tablet according to the present invention. In the figure, X electrode lines Xl are spaced at equal intervals in the X direction of the tablet 100.

X2.・-・For X-digit electrode line Xl, X2. ...X
□ are arranged in parallel alternately. Said X electrode wire X1.
X2°... is made up of eight wires as a group, and the same address positions of each group are commonly connected. On the other hand, the X-digit electrode line xlv
14-xz, . . . are commonly connected in units of less than the number of the X electrode wires forming a group, for example, 7 wires,
Each X-digit electrode XB1. XB2. ... is formed. However, at the left end of the X-digit electrode XB, an X-inviting electrode line Xo is further provided on the left side of the X-electrode line X1, so that the digit area can cover the input area related to the X-electrode line X1. ing.

Said X electrode wire X1. XZ, . . . The comparator 13 for X electrode line scanning
The threshold value is set at T in Figure 5, and as a result, the boundary of the input area Z is the middle between the X electrode lines, that is, the X digit on the polar line (the X direction input area in Figure 6). (See XZ).

On the other hand, the X invitation $iXB,, XB2. ... are connected to an external X-digit electrode drive circuit 4, and sequentially scan signals are applied thereto. The threshold for X-digit electrode scanning is set at T2 in FIG. 5, which allows the X-digit electrode line X8. X15. X22. ...The upper part is the boundary of the girder area t'] (X direction girder area XF in Fig. 6)
), a 1/2 pitch deviation occurs from the boundary of the X-direction input area XZ. For example, if we look at the X-direction input area Xl8 and XZ,5 at both ends of the digit electrode XB2, first,
For l8, the relative address data is "8.1", the digit position data is "1" in the left half (7a in Figure 6), and the right half (in the same diagram).
!゛8)7'l' r21 (!l: tr,,ri,
For Xl15, the relative address data is "7", the digit position data is "2" in the left half (IJxs in the same figure), "3" in the right half (yl5 in the same figure), and it cannot be entered in any part of the two input areas. There is no duplication in the combination of relative address data and station location data. Therefore, the two X-direction input areas xz
, and xz, 5 are each k Its tors, 115 tors r15
Although the staple data is different, since it is uniquely specified by relative address data and digit position data, each coordinate can be mutually identified and can be made to correspond to different items.

Although the X electrode line and the X-digit electrode in the X direction are not shown in FIG. 6, they can be configured in exactly the same way as in the X direction. In the above embodiment, the first relative address data of each digit area does not necessarily start from "1", but if it is inconvenient to output data of this size, it is necessary ((
Accordingly, a table memo IJf may be prepared and converted into relative addresses in numerical order, or further converted into definition codes and output. In fact, the number of X electrode wires in one group may be other than eight, and the number of digit electrodes in one unit may be less than the number of X electrode wires in one group, and may be different for each unit.

As explained above, according to the present invention, two input areas with the same relative address do not occur at both ends of one digit area, and the threshold value for signal detection during digit electrode scanning is set to This can be used as the intersection point of the change pattern of the detection signal level related to the digit electrode (see T2 in FIG. 5), and therefore it is possible to have a large noise margin.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a capacitively coupled tablet input device provided with digit electrodes according to the earlier application, FIG. 2 is a partial plan view showing the tablet in FIG. 1, and FIG. Cross-sectional view along line m-III of 4th
The figure is a partially omitted plan view showing an example of a tablet similar to the one in Figure 1 with eight electrode lines and eight digit electrode lines, and Figure 5 is a diagram showing the detected signal level after amplification of the input pen. , FIG. 6 is a partially omitted plan view showing an enlarged view of a tablet according to an embodiment of the present invention. 1.1oo...Tablet, 6...Insulating layer, Xl
+ x21"' t Xn "' X electrode wire, xll
, xI yl2 + "' t xn "' X-digit electrode line, XA,, XA2. -・-XA, XB,,XB2゜・
,,X-digit electrode, Yl, Y2. ...Yrn...X electrode wire, yl. yl, , -, ym, , -X digit electrode line, YA, , YA2.
,,,. YAu...X digit electrode. Patent applicant Bentel Co., Ltd. 18-

Claims (1)

[Claims] (1) A plurality of X and Y electrode wires are provided with an insulating layer in between, and a predetermined number of these X and Y electrode wires are divided into groups at the corresponding positions of each group. The Y electrode wires are commonly connected, and the X and Y digit electrode wires are arranged in parallel to form a pair with each of the X and Y [polar wires, and these X and Y digit electrode wires form the group. The number of wires smaller than the number of X, Y electrode wires is considered as one unit, and each unit is commonly connected.
A capacitive coupling tablet characterized by comprising digit electrodes.