JPH04162121A - Method and device for detecting position - Google Patents

Abstract

PURPOSE:To detect a position indicated by a position indicating device with desired accuracy by juxtaposing plural electrodes onto a surface resistance sheet having the electrodes at its both sides and then switching and selecting two of those provided electrodes. CONSTITUTION:The switches 2a and 2b of a switching circuit 2 are turned on so that the electricity is supplied to the electrodes A1 and A2 set at both sides of a surface resistance sheet 1. Thus a potential difference Va is produced between both electrodes A1 and A2 and a gradient potential is produced on the sheet 1. In such conditions, a point P is depressed on the sheet 1 by a position indicating device 7. Thus the depressed point P comes into contact with a conductor sheet 4, and the rough position of the point P is obtained. Then the electrodes AK and AK-1 holding the rough position of the point P therebetween are selected and the switches 2c and 2d are turned on. Then the accurate position of the point P is obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to improvements in a position detection device and a position detection method, which are one of input devices for office automation equipment such as computers.

[Conventional technology]

Conventionally, a certain point (position) in the input device of the above-mentioned OA equipment
As a position detection device used when manually calculating the coordinates of
There is something like the one shown in Figure 5. This position detection device is
electrode B, connected to a power source 35; B, a sheet resistance sheet 31 provided on both sides, and a conductive sheet 3 placed opposite to the sheet resistance sheet 31.
2, a plurality of spacers 33, 33 .・・・
. . , and a processing device 36 that processes signals from the conductive sheet 32 and the like. The position detection device having the above configuration operates as follows. First, electrodes B provided on both sides of the sheet resistance sheet 31,
, B, a potential difference Vs is applied between them. At this time, assume that a gradient potential proportional to the position in the X direction in FIG. 5 appears on the sheet resistance sheet 31, as shown in FIG. 7, for example. In this state, when one point Q on the sheet resistance sheet 31 is pressed by the position indicator 34, the spacers 33, 33. The sheet resistance sheet 31 and the conductor track 32, which were electrically separated by...
As shown in FIG. 6(b), the sheet resistance sheet 31 at the position Q pressed by the position indicator 34 is deformed and comes into electrical contact with the conductive note 32. The conductor path 32 is connected to a processing device 36, and the input impedance of this processing device 36 is set to be sufficiently high. Therefore, the potential of the conductor sheet 32 is the same as that of the sheet resistance sheet 3 indicated by the position indicator 34.
The value is equal to the potential difference Vq at point Q located at X=Xq on 1. Therefore, based on the value of the potential Vq at point Q input to the processing device 36 via the conductor sheet 32, the potential difference VQ is determined from the relationship between the position in the X direction and the potential difference as shown in FIG. X of the position indicated by the position indicator 34 from
The directional coordinates XQ are found. The position detecting device shown in FIG. 8 is an improved version of the position detecting device shown in FIG. That is, a plurality of electrodes B3 to Bn are arranged between the electrodes B provided on both sides of the sheet resistance sheet 31 in FIG. The sheet resistance sheet 31 is divided into several regions by ~Bn. Then, a potential difference is sequentially applied to the electrodes at both ends of each region, thereby increasing the gradient of the potential gradient within each region as shown in FIG.

[Problem to be solved by the invention]

However, each of the conventional position detection devices described above has the following problems. First, the position detection device shown in FIG.
There is a problem that the distance at which two points can be identified in a direction cannot be set finely, and the resolution of position detection is low. In addition, in the position detection device shown in Fig. 8, the gradient potential within each region increases and the resolution of position detection increases, but when calculating the gradient potential within each region, all the multiple electrodes are operated. Therefore, there is a problem that the detection time becomes longer and the number of coordinates detected per unit time decreases. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a position detection device that can efficiently detect a designated coordinate position with high resolution.

[Means to solve the problem]

In order to achieve the above object, a first invention provides a potential difference between electrodes provided on both sides of a sheet resistance sheet to generate a gradient potential on the sheet resistance sheet, and a position indicator to control the sheet resistance sheet. A position detection device detects the position on the sheet resistance sheet indicated by the position indicator by detecting the potential difference generated by indicating the position on the sheet resistance sheet on both sides of the sheet resistance sheet. The plurality of electrodes arranged in parallel between the electrodes provided on the sides and the plurality of electrodes arranged in parallel on the above-mentioned sheet resistance sheet are switched and selected, and connected to the potential difference supply circuit, thereby increasing the above-mentioned sheet resistance. The present invention is characterized in that it includes a switching circuit that generates a gradient potential between the selected two electrodes on the sheet in accordance with the spacing between the electrodes. Further, in the position detection method of the second invention, using the position detection device of the first invention, first, two electrodes provided on both sides of the sheet resistance sheet are selected by the switching circuit. A gently sloped potential is generated between the wide electrodes provided on both sides to obtain a low position detection resolution, and the approximate position on the sheet resistance sheet indicated by the position indicator can be easily and efficiently detected. Next, adjacent electrodes sandwiching the detected approximate position on the sheet resistance sheet are selected by the switching circuit to generate a steeply sloped potential between the adjacent narrow electrodes to detect a high position. The present invention is characterized in that it obtains resolution and detects an accurate position on the sheet resistance sheet indicated by the position indicator.

[Effect]

In the first invention, two of the plurality of electrodes arranged in parallel between the electrodes provided on both sides of the sheet resistance sheet are selected by the switching circuit and connected to the potential difference supply circuit. Then, a gradient potential is formed between the selected two electrodes on the sheet resistance sheet with a gradient depending on the spacing between the electrodes. Then, a potential difference generated when a position on the surface resistance sheet is indicated by the position indicator is detected by the processing device, and the position indicator J determines the indicated surface resistance according to the detected potential difference. The position on the sheet is detected with accuracy according to the slope of the gradient potential provided on the sheet resistance sheet. Therefore, by selecting two electrodes with an interval corresponding to the desired detection accuracy of the position on the sheet resistance sheet using a switching circuit, the position on the sheet resistance sheet indicated by the position indicator can be detected with the desired accuracy. It can be done. Further, according to the second invention, using the first invention,
First, widely spaced electrodes provided on both sides of the sheet resistance sheet are selected by the switching circuit to form a gradual potential gradient. Then, the approximate position of the position indicated by the position indicator can be easily and efficiently determined using the low position detection resolution. Then, adjacent narrowly spaced electrodes sandwiching the determined approximate position on the sheet resistance sheet are selected by the switching circuit to form a steep gradient potential. The position on the sheet resistance sheet indicated by the position indicator can be accurately determined due to the high position detection resolution achieved by the steeply sloped potential.

【Example】

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments. FIG. 1 is a perspective view of the position detection device of the present invention. Electrodes A,,A, are provided on both sides, and a plurality of electrodes A, ~An are connected between the electrodes A,,A,.
A! sheet resistance sheet l and sheet resistance sheet 1 arranged in parallel to each other.
A switching circuit 2 that switches and selects a plurality of electrodes A1 to An provided on the sheet resistance sheet 1; a potential difference supply circuit 3 that provides a potential difference between the plurality of electrodes A1 to An provided on the sheet resistance sheet 1; A plurality of electrodes A are interposed between the conductor sheet 4 and the sheet resistor sheet 4 to keep them in electrical contact with each other, and -Spacers 5, 5 . ... and a processing device 6 that calculates the position of the position indicator 7 based on the potential input from the conductor sheet 4. The position detection device having the above configuration is operated in two steps as follows. First, in the first step, as shown in FIG. 2(a), spacers 5, 5. ..., each electrode AI-An is in an electrically floating state. In this state, in order to supply electricity to the electrodes A, , A, the switches 2 a and 2 b in the switching circuit 2 are turned on, thereby applying a potential difference Va to the electrodes A, , A□ on both sides. A gradient potential as shown in FIG. 4(a) is generated on the resistor sheet l. In this state, as shown in FIG. 2(b), one point P on the sheet resistance sheet l is pressed with the position indicator 7. Then, the point P pressed by the position indicator 7 on the sheet resistance sheet 1 comes into contact with the conductor sheet 4. The conductor sheet 4 is connected to the processing device 6, and the input impedance of this processing device 6 is sufficient. It is set high. Therefore, the potential of the conductor sheet 4 becomes equal to the potential difference vp at the point P located at x-Xp on the sheet resistance sheet 1 pressed by the position indicator 7. Therefore, based on the value of the potential difference Vp at point P input to the processing device 6 through the conductive sheet 4, from the relationship between the position in the X direction and the potential difference as shown in FIG. direction point P
Find the approximate location of. Next, in the second step, the exact position of the point P whose approximate position was determined in the first step is determined. That is, the electrodes A k and A k-1 sandwich the approximate position of the point P determined in the first step above.
The two electrodes Ak are selected by turning on the switches 2c and 2d. A potential difference vb is applied between A k-1 to generate a gradient potential as shown in FIG. 4(b). In this case, the other electrodes A, ~Ak-2, Ak+1 ~An are kept electrically floating as described above so that they do not affect the identification of the position of point P. In this case, as shown in FIG. 4(b), two electrodes Ak
, Ak-1 is narrow, so a very large gradient potential can be obtained between the electrodes Ak and Ak-1. Therefore, the distance at which two points can be identified in the X direction can be made finer, and the resolution of position detection can be increased. The potential at point P on the conductor sheet 4 obtained in this state ■
P' is input to the processing device 6, and the exact position of point P is determined from the relationship between the position in the X direction and the potential difference as shown in FIG. 4(b). That is, in the present embodiment, in the first step, the position indicator is detected by using a gradient potential with a small slope (i.e., low detection position resolution) as shown in FIG. 7 in the conventional example shown in FIG. To efficiently and easily obtain the approximate position of point P indicated in step 7. After that, in the second step, a high detection position resolution is obtained by using a gradient potential with a large slope as shown in FIG. 9 in the conventional example shown in FIG. 8, and the accurate position of the point P is determined. At this time, in the second step, a potential difference is generated only between the two electrodes that sandwich the approximate position of point P, which is already known. The coordinates of point P can be determined in a short time without the need for manual operations. The electrodes A, -An provided on the sheet resistance sheet 1 in the above embodiment are all arranged in parallel in one direction. Therefore, in the surface resistance route 1, one direction of the point P indicated by the position indicator 7 (X direction in FIG. 1)
All you need to know is the location. Therefore, two-dimensional coordinate detection may be performed using the sheet resistance sheet 1 in this embodiment as described below. That is, in the embodiment shown in FIG. 3, the sheet resistance sheets la and 1b having the above-mentioned configuration are superimposed via a spacer so that the directions of the electrodes are orthogonal to each other. That is, the sheet resistance sheet l in FIGS. 1 and 2 is the sheet resistance sheet la in FIG. 3, and the conductor sheet 4 in FIGS. 1 and 2 is the sheet resistance sheet Ib in FIG. 3. When detecting the coordinate in the X direction in FIG. 3 of the point indicated by the position indicator, a gradient potential is applied to the sheet resistance net Ia, while the sheet resistance sheet lb is made to act as the conductive sheet. Also,
When detecting coordinates in the X direction, a gradient potential is applied to one-sided resistive sheet Ib, which causes sheet resistor 1a to act as a conductive sheet. In this way, by time-sharing both of the above operations, two-dimensional coordinate detection can be performed accurately and efficiently. In the above embodiment, the electrode A on the sheet resistance sheet 1
, , A, and the potential difference Vb between the other electrodes Ak and Ak-1 may be the same value. In the above embodiment, the electrodes A, ,A in the first step
, and the gradient direction of the gradient potential between the electrodes Ak-1., in the second step. The gradient direction of the gradient potential between Ak does not necessarily have to be the same direction. Each electrode A1 to A on the sheet resistance sheet I in the above embodiment
n is a spacer 5.5. ...The electrodes provided on the top and not energized are electrically floating. However, the method of electrically floating each electrode is not limited to the above embodiment. The switching circuit 2 in the above embodiment is composed of a large number of switches for turning on and off electricity to each electrode provided on the sheet resistance sheet 1, but it can also be easily constructed using a multiplexer or the like.

【Effect of the invention】

As is clear from the above, in the position detection device of the first invention, a plurality of electrodes are arranged in parallel between the electrodes in a sheet resistance sheet having electrodes on both sides, and among the plurality of electrodes arranged in parallel, The two electrodes are switched and selected by a switching circuit to generate a gradient potential on the sheet resistance sheet with a slope corresponding to the interval between the two selected electrodes, so that the position on the sheet resistance sheet is By selecting two electrodes with an interval corresponding to the detection accuracy, the position indicated by the position indicator can be detected with desired precision. Further, in the position detection method of the second invention, using the position detection device of the first invention, first, in the first step, the distances provided on both sides of the sheet resistance sheet having electrodes on both sides are determined. Two wide electrodes are selected by a switching circuit,
A gradient potential with a gentle gradient is created between two selected wide electrodes on the sheet resistance sheet 1. Then, the coordinate position indicated by the position indicator can be detected easily and efficiently in a short time with low position detection resolution. Next, in a second step, adjacent narrowly spaced electrodes sandwiching the approximate position detected as described above are selected by the switching circuit, and a steep slope is formed between the two selected narrow electrodes. Generate electric potential. The position indicated by the position indicator is accurately detected with high position detection resolution due to the rapid gradient potential. That is, by using the above-described first step and second step in combination, the indicated coordinate position can be detected efficiently with high position detection resolution.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the position detection device of the present invention, and FIG. 2 shows the state of the sheet resistance sheet and conductive sheet when a predetermined position on the sheet resistance sheet in the first embodiment is pressed by a position indicator. 3 is an explanatory diagram of a sheet resistance sheet in an embodiment different from that in FIG. 1; FIG. 4 is a diagram showing the gradient potential between electrodes in the first step and second step in each of the above embodiments; FIG. 5 is a block diagram of a conventional position detection device, FIG. 6 is a cross-sectional view of the sheet resistance sheet and conductor sheet in FIG. 5, FIG. 7 is a diagram showing the gradient potential between electrodes in the conventional example, Figure 8 is a diagram showing a sheet resistance sheet in a conventional example different from Figure 5;
FIG. 9 shows the gradient potential between each electrode in the sheet resistance sheet shown in FIG. 1... Surface resistance sheet, 2... Switching circuit, 3...
・Potential difference supply circuit, 4... Conductor sheet, 5.
...Spacer, 6...Processing device, 7...
Position indicator, A, ~An...electrode.

Claims (2)

[Claims] (1) A potential difference is generated between electrodes provided on both sides of the sheet resistance sheet to generate a gradient potential on the sheet resistance sheet, and a position indicator is used to indicate a position on the sheet resistance sheet. The position detection device detects the position on the sheet resistance sheet indicated by the position indicator by detecting the position on the sheet resistance sheet by detecting the position on the sheet resistance sheet. A plurality of electrodes and two electrodes among the plurality of electrodes arranged in parallel on the sheet resistance sheet are switched and selected and connected to a potential difference supply circuit, and a voltage is applied between the two selected electrodes on the sheet resistance sheet. 1. A position detection device comprising a switching circuit that generates a gradient potential according to the spacing between electrodes. (2) Using the position detection device according to claim 1, first, two electrodes provided on both sides of the sheet resistance sheet are selected by the switching circuit, and a wide electrode provided on both sides of the sheet resistance sheet is selected. A gradual gradient potential is generated between the electrodes to obtain a low position detection resolution, and the approximate position on the sheet resistance sheet indicated by the position indicator can be easily and efficiently detected. Adjacent electrodes sandwiching the approximate position on the sheet resistance sheet are selected by the switching circuit to generate a steep gradient potential between the adjacent narrow electrodes to obtain high position detection resolution, and the position indicator A position detection method characterized by detecting the exact position indicated above on the surface resistance sheet.