JPH04162123A - Position detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

The present invention relates to a position detection device that is one of input devices for office automation equipment such as a computer.

[Conventional technology]

In recent years, a certain point (position) in the input device of the above OA equipment
As a position detection device used to input the coordinates of
There is something like the one shown in Figure 5. This position detection device is
A sheet resistance sheet 21 in which a plurality of point electrodes E, ~Emn are provided in the form of lattice points, and switching circuits 22, 22. ...and the point electrode E of the sheet resistance sheet 21
The conductor sheets 24 are arranged facing each other on the sides II to Emn, and the switching circuits 22, 22 . A power source 23 connected to one point electrode selected by ... and the conductive sheet 24,
Plural point electrodes Ell to E provided on the sheet resistance sheet 21
+an and the conductive sheet 24, spacers 25, 25. ..., the fixed resistor 26 provided between the conductor sheet 24 and the power supply 23, and the voltage Vs across the fixed resistor 26 are measured and switched to the indicated point Q indicated by pressing the position indicator 28. It is generally composed of a processing circuit 27 which calculates the resistance value between the point electrode selected by the circuit 22 and calculates the position of the indicated point Q on the sheet resistance sheet 21 indicated by the position indicator 28. The conductor sheet 24 is connected to a power source 23 via a fixed resistor 26.
However, since no current flows through the conductor sheet 24, the entire surface of the conductor sheet 24 is uniformly at the power supply voltage Vi. The position detection device having the above configuration is operated as follows. As shown in FIG. 6(a) to FIG. 6(b), the unique Q on the sheet resistance sheet 21 is pressed with the position indicator 28. Then, the sheet resistance sheet 2 which had been separated from the conductor sheet 24 by the spacers 25, 25, .
1 is deformed by the pressure of the position indicator 28 and comes into contact with the conductive sheet 24 at a point Q. At this time, for example, by turning on the switch 22a (see FIG. 5), point electrode E
If l 1 is connected to the power supply 23 and all other point electrodes are left electrically floating, the power supply 23 - fixed resistor 26
- Conductor note 24 - Contact point Q between conductor sheet 24 and sheet resistance note 21 - Point electrode E I +=Electricity flows in the order of power source 3, and a potential difference Vs is generated across the fixed resistor 26. In this case, by measuring the voltage Vs across the fixed resistor 26, the indicated point Q and the point electrode E l as shown in FIG.
The resistance value R0 between 1 and 1 is uniquely determined by the following formula (% formula %). In addition, the distance between the two points of the pointing point Q and the point electrode E l 1 on the sheet resistance sheet 21,
The relationship between R1 and the resistance value R1 can be expressed by an appropriate function. Therefore, for example, first, the switch 22a in the switching circuit 22 is turned on, and the resistance value R8 between the point Q indicated by the position indicator 28 and the point electrode El1 is determined by the processing circuit 27. Furthermore, based on this resistance value, the indicated point Q
The distance L1 between and the point electrode E is calculated. Next, the switch 22b in the switching circuit 22 is turned on, and the resistance value R2 between the point Q indicated by the position indicator 28 and the point electrode Etn is determined. Furthermore, based on this resistance value, the indicated point Q and the point electrode E are
Calculate the distance from 11. On the other hand, the coordinates of the indicated point Q on the sheet resistance sheet 21 are uniquely determined as the intersection of a circle with a radius around the point electrode E11 and a circle with a radius around the point electrodes E and n. It is decided. In this way, the two point electrodes E for the indicated point Q,
, , Eln, the position of the indicated point Q on the sheet resistance sheet 21 can be specified.

[Problem to be solved by the invention]

However, each of the conventional position detection devices described above has the following problems. That is, conventionally, as shown in FIG. 5, a wiring pattern is usually formed on the same resistive film side as the point electrodes E It - E l1In attached to the resistive film side of the sheet resistance sheet 21. There is. Therefore, the resistance distribution on the sheet resistance sheet 2■ is disturbed by the wiring pattern, and in the case of the above example, the point electrode E1
In some cases, the resistance value R and the distance ML between the reference point Q and the reference point Q do not correspond well. That is, there is a problem in that the position of the pointing point Q pointed by the position pointing device 28 may not be detected correctly. Further, the resistance value between two points that straddle the location of the wiring pattern wired on the sheet resistance notebook 21 cannot be measured. Therefore, point electrodes cannot be provided particularly in the center of the sheet resistance notebook 21 where the wiring patterns intersect in a complicated manner, and the number of point electrodes cannot be increased. In other words, there is a problem in that it is difficult to increase the position detection resolution of the point Q indicated by the position indicator 28. SUMMARY OF THE INVENTION An object of the present invention is to provide a position detection device that can accurately detect the position of a pointing point with high resolution without disturbing the resistance distribution on a sheet resistance sheet.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a plurality of point electrodes on a sheet resistance sheet formed by overlapping at least a base material and a resistive film, and points indicated on the sheet resistance sheet by a position indicator. and a selected point electrode, the point electrode is provided on the resistive film constituting the sheet resistance sheet, and the point electrode and the selected point electrode A wiring pattern for electrically connecting to an external device is provided on the base material constituting the sheet resistance sheet, and the point electrode and wiring pattern provided on the opposite side of the sheet resistance sheet are connected to the top surface resistance sheet. It is characterized in that it is connected by a conductive IE member that passes through it.

[Effect]

One of the plurality of point electrodes of the above-mentioned sheet resistance note provided on the above-mentioned resistance film connected to the wiring pattern provided on the above-mentioned base material of a surface resistance sheet formed by overlapping at least a base material and a resistive film. One is selected. Then, based on the resistance value between the indicated point on the sheet resistance sheet indicated by the position indicator and the selected point electrode,
The position of the indicated point is detected. At this time, as described above, the point electrodes are provided on the resistive film constituting the fixed point electrode sheet, while the wiring pattern is provided on the base material on the opposite side of the sheet resistance sheet. Therefore, the resistance distribution of the resistive film is not disturbed by the wiring pattern, and the arrangement of the point electrodes is not restricted.

【Example】

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments. FIG. 1 is a configuration diagram of a position detection device according to the present invention. This position detection device has approximately the same structure as the position detection device shown in FIG. 5 described above. In other words, multiple point electrodes D
A switching circuit that switches and selects the sheet resistance sheet l provided in the form of lattice points, ll-Dffln, and the point electrodes D II-D sin 2.2. ..., the conductive sheet 4, and the switching circuit 2.2. A power source 3 connected to one point electrode selected by ... and a conductive sheet 4, and a spacer 5
．． 5. ..., a fixed resistor 6, and a processing circuit 7 that measures the voltage Vf across the fixed resistor 6 and calculates the position on the sheet resistance sheet l indicated by the position indicator 8. Here, the position detecting device in this embodiment differs from the position detecting device shown in FIG. 5 in the following points. That is, the point electrode used in this embodiment has a structure as shown in FIG. That is, the sheet resistance sheet 1 is made by pasting together a base material 11 made of PET (polyethylene terephthalic acid) or glass, and a conductive thin film layer 12 as a resistive film made of 1To (indium tin oxide) or the like. A point electrode +3 is provided on the thin film layer 12. Furthermore, a wiring pattern 14 is formed on the base material 11 on the opposite side of the sheet resistance sheet 1. Then, this wiring pattern 14 and the point electrode 13 are connected to each other by a conductive member 15.
The base material II and the conductive thin film layer 12 are penetrated and connected. To explain this with reference to FIG. 1, the sheet resistance sheet l
Point electrode 13 (transparent sheet resistance sheet l) provided on the bottom surface of
(visible through the transparent sheet resistance sheet 1) is connected to the wiring pattern 4 provided on the upper surface of the sheet resistance sheet l by a conductive member 15 (visible through the transparent sheet resistance sheet 1) placed through the sheet resistance sheet I. It is being done. In other words, the point electrode 13 in this embodiment is a sheet resistance sheet l
A wiring pattern 14 is formed on the resistor wL (conductive thin film layer 12) side and connects this point electrode I3 to an external device.
is formed on the base material 11. In this way, by not forming the wiring pattern 14 on the resistive film, the resistance distribution on the sheet resistance sheet 11 is not disturbed by the influence of the wiring pattern I4. Therefore, for example, the resistance value R1 and the distance between the point electrode Ell and the indicator electrode Q can be well matched. Note that the conductive member I5 is
For example, it can be created by forming minute through holes in the base material 11 and the conductive 1iN film layer 12 and filling the holes with a conductive material. The position detecting device having the above configuration detects the position of the indicated point P using the same principle as the position detecting device shown in FIG. 5 described above. Specifically, the operation is performed through two steps described below. First, in the first step, as shown in FIG. 1, point electrodes D I-1 and D
+n switching circuit 2.2. ..., and based on the voltage Vf across the fixed resistor 6 determined by the processing circuit 7, the instructions indicated by the point electrode D I + and the position indicator 8 (see FIG. 3) are selected one by one by the processing circuit 7. The resistance value between point P and the point electrode, and the resistance value between n and the indicated point P are sequentially collected. Then, the distance from the point electrode D11 and the point electrode Den at the indicated point P is determined based on the above two resistance values, and the approximate position of the indicated point P is determined. Next, in the second step, the exact position of the indicated point P whose approximate position was determined in the first step is determined. That is, as shown in FIG. 4, a plurality of point electrodes (for example, D (k, f2), D (k
, 12+1), D (k+1.12) point electrodes)
Select one by one and do the same as above to select the above husband (kO)
Point electrodes D(k, of, D(kl!+1), D(k+1.j
) and the indicated point P is calculated. Then, based on the above-mentioned three distances regarding the obtained indicated point P, three positions of the indicated point P on the sheet resistance sort I are calculated. Then, by averaging the positions related to the indicated point P obtained in three ways in this way, the position of the indicated point P on the sheet resistance sheet 1 indicated by the position indicator 8 is determined more accurately. At this time, in this embodiment, point electrode D1. ~Dmn
is formed on the conductive thin film layer 12 of the sheet resistance sheet 1, and a wiring pattern 4 is formed on the base material 11 on the opposite side of the sheet resistance sheet 1. Therefore, there is no disturbance in the resistance distribution in the conductive thin film layer 12 due to the wiring pattern 14. As a result, the resistance value and distance between two points on the sheet resistance sort 1 are correctly correlated. In addition, the wiring pattern 14
is formed on the opposite side of the conductive thin film layer 12 with respect to the sheet resistance sheet l, and the point electrode 13 and the wiring pattern 14 are formed on the conductive member 15.
It is connected with. Therefore, the point electrode 13 can be provided separately from the wiring pattern 14, and the wiring pattern 14
It is possible to stably detect the resistance value between two points on the sheet resistance sort 1 and increase the number of point electrodes without the influence of . As a result, the accuracy of detecting the point P indicated by the position indicator 8 can be further improved. In the second step in the above example, three point electrodes are set near the approximate positions determined on the sheet resistance sort l in the first step, but the number is not limited to this number. . 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 sort 1, but it can also be easily constructed using a multiplexer or the like. In the above embodiment, the resistance value between the point electrode and the pointing point P is obtained by measuring the voltage across the fixed resistor 6, but the resistance value between the point electrode and the pointing point P is obtained by other methods. It is also possible to obtain a resistance value between .

【Effect of the invention】

As is clear from the above, the position detection device of the present invention is
At least point electrodes are provided on the resistive film of the sheet resistance sheet formed by overlapping a base material and a resistive film, and a wiring pattern is provided on the base material, so that the resistance film due to the wiring pattern is No disturbance in resistance distribution occurs. Therefore, the resistance value and distance between two points on the sheet resistance sheet can correspond correctly, and the position of the indicated point indicated by the position indicator can be detected correctly. In addition, since the point electrodes and the wiring pattern are provided on the opposite side of the sheet resistance sheet, restrictions on the point electrode arrangement and resistance value detection due to the wiring pattern are reduced, and the position of the indicated point is increased. Accurate detection with high resolution becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the position detection device of the present invention, FIG. 2 is a sectional view of the sheet resistance sheet at the position of the point electrode in FIG. 1, and FIG. A cross-sectional view of the sheet resistance sheet and the conductor sheet when a predetermined position of is pressed with a position indicator, 4th
The figure shows an example of point electrode selection in the second step by the position detecting device in FIG. 1, FIG. 5 is a block diagram of a conventional position detecting device, and FIG. 6 shows the sheet resistance sorting and FIG. 7, which is a cross-sectional view of the conductive sheet, is an explanatory diagram of calculation of the indicated point. 1... Planar resistance sorting, 2... Switching circuit, 3... Power supply, 4... Conductor sorting, 5...
Spacer, 6. Fixed resistor, 7. Processing device, 8. Position indicator, 11. Base material,
12 - Conductive thin film layer, 13... Point electrode,
14... wiring pattern, 15 conductive member,
D+~Dn, D++-Dmn"' electrodes.

Claims (1)

[Claims] (1) A plurality of point electrodes are provided on a sheet resistance sheet formed by overlapping at least a base material and a resistive film, and a plurality of point electrodes are provided between the indicated point on the sheet resistance sheet indicated by a position indicator and the selected point electrode. In the position detection device that detects the position of the indicated point based on the resistance value of the point electrode, the point electrode is provided on the resistive film constituting the sheet resistance sheet, and the point electrode is electrically connected to an external device. A wiring pattern is provided on the base material constituting the sheet resistance sheet, and the point electrodes and the wiring pattern, each provided on the opposite side of the sheet resistance sheet, are connected by a conductive member passing through the top resistance sheet. Characteristic position detection device.