JPH01318111A - Method for operating tablet device - Google Patents

Abstract

PURPOSE:To obtain a tablet device for attaining high resolution even in case of using an A/D converter with low quantum accuracy by impressing voltage between electrodes fixed to both the ends of a detecting plate, deciding approximate coordinates and impressing the voltage two electrodes most adjacent to the coordinates. CONSTITUTION:The title device is provided with coordinate detecting plates 1, 2 each of which has three or more electrodes X, Y in order to detect the coordinates of plural axes, these detecting plates 1, 2 are controlled by a detecting plate control part 3, the coordinates are decided by a coordinate deciding part 4 based on detecting signals obtained from the detecting plates 1, 2 and the decided result is outputted. In this case, an external instruction or a prescribed operating instruction is applied from a switch or the like on a body. In the tablet device, approximate coordinates are decided by the deciding part 4 by impressing voltage between the electrodes on both the ends of the detecting plates 1, 2 and then voltage is impressed between two electrodes 11, 21 most adjacent to the coordinates, so that the coordinates of high resolution can be decided.

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention is applicable to the use of handwritten information on information devices such as computers, etc.
The present invention relates to a method of operating a tablet device for inputting data.

(b) Conventional Technology An old-fashioned tablet device for inputting information is a resistance-type tablet that can obtain input seat ring information with a relatively simple structure. The prior art of such devices includes N
There are a voltage switching method and a current division method as seen in the ational technical report.

In this case, the resolution per unit length depends on the quantization accuracy of the A/D converter in the coordinate determination section, but the A/D converter with high quantization accuracy
D conversion m (more than 8 bits) is extremely expensive and requires a large amount of data processing, so low-priced tablets use an 8-pit A/D converter to increase the number of detection position points by Currently, both the Y-axis and Y-axis are set to 256 points or less.

In general, inputting images such as diagrams requires a large input area, but the size of human input for character recognition is extremely large compared to when writing on regular paper, considering ease of use, fatigue, and recognition rate. It is better to keep the same (λ size, which is much smaller than the image input); the latter means that the resolution per unit length must be high, and if the same tablet is used, the entire resolution must be high. Currently, the conditions are required and an expensive A/D converter with high quantization accuracy must be used.

(c) Problems to be Solved by the Invention The present invention was developed in view of the above circumstances, and is a tablet device that achieves high resolution while using a low-cost A/D converter in the coordinate determining section. It provides a method of operation.

(d) Means for Solving the Problems The operating method of the tablet device of the present invention is for detecting coordinates of multiple axes, and includes a plurality of coordinate detection plates each having three or more electrodes, and a method for detecting the coordinates of a plurality of axes. A detection plate control unit that controls the plate, a coordinate determination unit that determines the coordinates based on the detection signal obtained from the detection plate and outputs the result, and receives a predetermined operation instruction from an external instruction or a switch on the main body. In the main body consisting of the indicating section, first, approximate coordinates are detected by applying a voltage to the detection plate surface (electrodes at both ends);
By applying a voltage between two electrodes close to the detected coordinates, the coordinates of the area are detected with high resolution, and the first
By repeating the second operation, a tablet is realized in which the entire surface of the detection plate has high resolution.

(E) Function According to the present invention, since it is configured as shown in L, even if an inexpensive A/D converter with low quantization accuracy is used, the entire surface of the coordinate detection plate can be continuously provided with high resolution. I can do it 0, lIta,
Data processing is easy because the number of quantization bits is small.

(F) Embodiment FIG. 1 shows an embodiment of a device configuration employing the operating method of the tablet device of the present invention. Y-axis coordinate detection plate <1
), at least 3 or more, in this case 7 X electrodes (11)
are placed, and at least 3 or more are placed on the Y-axis coordinate detection plate (2).
In this case, seven Yt poles (21) are arranged, and these are controlled by the detection plate control section (3). When there is a press input on the tablet, a detection signal obtained from the detection plate is transmitted via the detection plate control unit (3) to the coordinate determination unit (4), which determines the coordinates and outputs the result. The operation of the tablet is transmitted from the instruction section (5) which receives the operation switch signal (51) of the tablet H or the external instruction signal (52) to the detection plate control section (3).

Figure 2 shows the relationship between the Y-axis coordinate detection plate (1), the Y-axis coordinate detection plate (2), and the detection plate control unit (3) when the voltage switching method shown in Figure 2 is adopted. It is something. The Y-axis and Y-axis coordinate detection plates (1) and (2) are in the form of resistive sheets, and two sheets are placed one on top of the other with four electric rubbers formed with dot-like insulating spacers or mesh-like insulating spacers interposed between them. It has a structure.

The operation will be explained below.

As the first operation, the entire surface of the detection plate is roughly quantized and the rough coordinates are determined.
Electrode changeover switch - <311), (312) to ■, ■ position, Y electrode changeover switch (321), (322) to ■
, ■ position is selected, and a voltage Vx is applied to both ends of the X electrode (11) of the Y-axis coordinate detection plate (1), which is the upper resistance sheet. When there is a press input P on the tablet, the partial pressure of the voltage Vx applied to the X electrode (11) at the suppression input point, that is, YI21! The analog information of the mark is the lower resistor] - Y
It can be detected from the Y electrode (21) of the axis coordinate detection plate (2).

Next, move on to the Y electrode changeover switch (3) in the detection plate control section (3).
21) and <322) to the ■ and ■ positions, and the XN and pole selector switches (311) and (312) to the ■ and ■ positions,
YTL of the Y-axis coordinate detection plate (2) which is the lower resistance sheet
A voltage Vy is applied across the pole (21). When there is a press input P on the tablet, the Y electrode (
21〉 partial pressure of the applied voltage vy, that is, the analog information of the X coordinate is detected by the Y-axis coordinate detection plate (1) which is the upper resistance sheet.
In this way, the partial pressures of the X-axis coordinate detection plate (1) and the Y-axis coordinate detection plate (2) can be detected from the coordinates of opposite sides by time division. By detecting through electrodes on the plate, it is possible to obtain analog information of the X coordinate and the X coordinate corresponding to the press input position.

This analog information is transmitted to the coordinate determination section (4) via the detection plate control section (3) shown in Fig. 1, and converted into digital information by an A/D converter in the determination section (not shown). The judgment result is output. When the quantization precision of the A/'D converter is 8 bits, the detection position of both axes (the number of points is roughly quantized from 0 to 256 between the ends of the coordinate detection plate 1, 1, 0, and 0). It turns out that the 1F input is the shaded area indicated by Q in FIG.

The second operation is to quantize the hatched area, which is the approximate coordinate position obtained in the first operation, with high resolution. First, X
Xf by the electrode changeover switches (311) and (312)
Select the poles (11) as ■ and ■ as shown in Figure 3, and set the voltage Vx
By applying , and selecting the X electrode pole 21) to [F], the 0-order X electrode changeover switch (321), (322) performs quantization between ■ and 0 of the X1'lt pole (11). By selecting the X electrode (21) as ■, ■, applying the voltage vy, and selecting the X electrode (11) as ■,
11), ■The quantization accuracy of the A/D converter that performs quantization between 0 is the same 8 bits, so the second operation has a lower decomposition residue per unit length than the first operation. It becomes 6 times.

By repeating the first and second operations described above and moving the shaded part along the movement of the press input P, the entire surface of the detection plate can be simply changed to the entire surface of the detection plate as in the first operation. Compared to the case where N-IDC-11 is quantized to the number of poles), it is possible to obtain a resolution that is twice as high as the number of poles of N-IDC-11.

The determination result in the first operation is that there are N x1Y map poles (
11) or (21), there is a risk that the shaded area will be selected incorrectly if the quantization accuracy is poor.

At this time, as shown in FIG. 4, based on the determination result in the first operation, among the electrodes ■, ■ which are close to the input point, the distance between the second and third nearest electrodes ■, ■, ■ is determined. The second operation is performed in step (3). In other words, the shaded area is selected by doubling the inter-electrode distance so that the coordinates can be detected at a position close to the center of the shaded area Q'.

In this case, since the distance between the electrodes is doubled, the resolution is half that of the above-mentioned method, but this can be solved by doubling the distance between the electrodes. By using the method described above, stable coordinate determination results can be obtained.

(G) Effects of the Invention As is clear from the above explanation, the method of the present invention has low quantization accuracy (even if a low-cost A/D converter is used, the entire surface of the coordinate detection plate can be continuously processed at high resolution). Because it can be used for image input that requires a large input area, it is also possible to realize a low-cost pret that is satisfactory even for handwritten characters that require high resolution.In addition, the number of quantization bits is small. Therefore, data processing can be simplified both in terms of hardware and software.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of a tablet arm that employs the operating method of the present invention, Fig. 2 is a diagram of the coordinate detection method of the method of the present invention, and Figs. 3 and 4 show coordinate detection areas. It is a schematic diagram. (1). X-axis coordinate detection plate, (2>... Y-axis coordinate detection plate, (3)... detection plate control unit, (4)... coordinate determination unit, (5)... Indication unit, (11)...XZ pole, (
21)...X electrode.

Claims (2)

[Claims] (1) In order to detect the coordinates of multiple axes, a plurality of coordinate detection plates each having three or more electrodes, a detection plate control unit that controls the detection plates, and a detection signal obtained from the detection plates are provided. In a tablet device that includes a coordinate determination section that determines coordinates based on the base and outputs the results, and an instruction section that receives predetermined operation instructions from an external instruction or a switch on the main body, firstly,
By applying a voltage to both end electrodes of the detection plate, the coordinate determining section determines the approximate coordinates, and secondly, by applying a voltage between the two electrodes closest to the determined coordinates, the coordinates are determined locally. A method for operating a tablet device, characterized in that a coordinate determining section determines coordinates with high resolution. (2) In the method for operating a tablet device according to claim (1), after the first operation, a voltage is applied between the second and third closest electrodes among the electrodes close to the determination coordinate. A method for operating a tablet device, characterized in that the second operation is determining the coordinates of the tablet device.