JPS61131114A - Coordinate signal detector - Google Patents

Abstract

PURPOSE:To simplify the structure of a tablet and an electric circuit and to reduce the manufacturing man-hour and cost by arranging an electrode at opposite sides of the 1st and 2nd plane resistors respectively along the side and making the arranging direction of the electrodes orthogonal mutually to each other. CONSTITUTION:An insulator 5 having plural through-holes 6 is arranged above the plane resistor 1 and the plane resistor 7 is arranged on the insulator 5. Electrodes 8, 9 are arranged on both sides of the resistor 7 at the opposite face to the resistor 1 in an orthogonal direction to the arranging direction of the electrodes 2, 3. When the resistor is used as a receiver and the resistor 7 is used for a driver, and when the operator uses a detector 12 to depress the resistor 7 of an optional point P, the resistor 7 is pressed downward and deformed, the resistor 4 of the plane resistor 1 and the resistor 10 of the plane resistor 7 are contacted together. A distance (x) from a voltage applying electrode, e.g., 8 is decided by a obtaining a phase difference of a referenced sinusoidal signal from the detected voltage at the depressed point P. When the driver and receiver are used conversely, a distance (y) is decided similarly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flat coordinate detection device called a so-called tablet. By mutually using these signals, coordinates can be detected without using a special signal detection unit.

(Conventional technology) A coordinate detection device using a conventional tablet.

Usually, it has a plurality of electrodes arranged in a matrix, a scanning signal is applied to the plurality of electrodes in time series, and the scanning signal is detected by a detector to determine the coordinate position.

(Problems to be Solved by the Invention) When a time-series busy scanning signal is applied to a plurality of electrodes arranged in an IJ box shape and this scanning signal is detected by a detector, The structure of the electrode becomes complicated,
Furthermore, in electrical circuits, drivers and receivers are required to correspond to the number of electrodes in a matrix, and a switching circuit that can simplify this and accommodate the number of electrodes even if the number of drivers and receivers is reduced is needed. It was necessary.

(Means for solving problems) The present invention has been made in view of the above problems.

Two planar resistors having uniform resistance distribution and flexibility are placed opposite each other, and the two planar resistors are operated as drivers or receivers to suppress deformation of the two planar resistors. The coordinate position signal of the contact point is determined by detecting the phase difference from signals having different phases applied to electrodes arranged on opposite sides of the planar resistor.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram of the configuration of a tablet for detecting coordinate signals, in which electrodes 2 and 3 made of a conductor are arranged at both ends of a first planar resistor 1, and there is a uniform gap between the electrodes 2 and 3. A resistor 4 having a resistance distribution is arranged. For example, the resistance value increases or decreases in proportion to the increase or decrease in the distance between two points to be measured.

carbon film, palladium, gold, indium oxide,
It is composed of a film etc. deposited with chromium or the like. An insulator 5 made of an insulating material and having a plurality of through holes 6 is arranged above the first planar resistor 1 , and a second planar resistor 7 is arranged above the insulator 5 . At both ends of the second planar resistor 7 on the first planar resistor 1 side, the first
Electrodes 8 and 9 made of a conductor are arranged in a direction perpendicular to the extending direction of each electrode 2 and 3 of the planar resistor 1, and the space between these electrodes 8 and 9 is a uniform conductor similar to the first planar resistor. A 1° resistor having a resistance distribution is arranged. At least one of the first and second planar resistors 1 and 7 is constructed using a flexible synthetic resin film as a substrate.

Next, the basic principle of signal detection will be explained with reference to the longitudinal sectional view of the main part of the tablet in FIG.
A planar resistor 1 is placed thereon.

On top of the first planar resistor 1, an insulator 5 having a through hole and a second planar resistor 7 are sequentially placed and fixed with an adhesive or the like. A sine wave voltage of As1nθ is applied to the electrode 8 of the second planar resistor 7 in FIG.
A cosine wave voltage delayed by 90 phase shift from the voltage of Aco
sθ is applied. Each electrode 8 of this second planar resistor 7,
When a voltage is applied to 9, the first planar resistor 1 becomes a receiver.
2. The case where the second planar resistor 7 is a driver will be explained. When the operator presses the second planar resistor 7 at an arbitrary point P downward with the detector 12 (a detector is not particularly required, a finger may be used), the second planar resistor 7 is compressed and deformed downward. , the resistor 4 of the first planar resistor 1 and the resistor 10 of the second planar resistor 7 come into contact. In this state, the electrodes 2 and 3 of the first planar resistor 1 as a sensor are connected to each other by a switch.
It is considered to be electric potential. The voltage induced in the electrodes 2 and 3 is expressed by the following equation.

V1=A, /' = 1-x)"+x" s in (θ+
α) From the above equation, from the detected voltage at any pressing point and point P, the distance It can be determined by This is the position P where each electrode 2, 3 of the first planar resistor 1 as a sensor is pressed because it is electrically connected by a switch.
The voltage drop due to the distance between the electrodes 2 and 3 can be ignored.

Next, an actual circuit will be explained with reference to FIG.

A sine wave sin θ and a cosine wave eOJθ are transmitted from the oscillator 13 that generates an AC signal to the electrodes 2° 3.8 of each of the planar resistors 1 and 7.
Switches SW1 to SW4 are connected so that the voltage is applied to 9. sjnθ is connected to the normally open terminals of switches SWl and SW3, and +Cogθ is connected to the normally closed terminals of switches SW2 and SW4. Each switch SW1~ in Figure 3
SW4 is controlled by a control circuit 14, and FIG. 1 shows a case where the first planar resistor 1 is a driver and the second planar resistor 7 is a sensor. As is clear from the above explanation of the operation, since the second planar resistor 7 operates as a sensor, the voltage detected at the electrodes 8 and 9 is applied to the switch SW3.
is applied to the X phase detector 15 via SW4, and this
A phase difference with the applied signal sin θ is detected by the phase detector 15, and this phase difference signal is applied to the AD conversion circuit 16. This AD conversion circuit 16 is controlled by the control circuit 14 and outputs an X coordinate signal.

To detect the Y-coordinate position signal, the control circuit 14 inverts the switches SW1 to SW4, so that the second planar resistor 7 operates as a driver, the first planar resistor 1 operates as a sensor, and the first The voltage detected from each electrode 2, 3 of the planar resistor 1 is applied to the Y-phase detector 17, and the applied sin θ phase difference is detected by the Y-phase detector 17.

This phase difference is converted into a digital value by the AD conversion circuit 18 and
Output as a coordinate signal.

By combining the X coordinate signal and the Y coordinate described above, the pressed coordinate position of the tablet is detected.

Note that the switch was explained using a contact point.

It is also possible to increase the speed by using an analog switch instead of a contact point.

Furthermore, in this embodiment, the phase difference is detected in order to avoid the influence of noise, etc., but a potential gradient is applied to the voltage applied to each electrode, the detected voltages are compared, and used as a coordinate position signal. It is also possible.

Furthermore, detection accuracy can be improved by making the insulator extremely thin and increasing the number of through holes.

(Effect of the invention) The present invention G'''as above')' - has a structure like L-'0 and'
The structure and electrical circuit of one bullet are simplified.

This has the effect of reducing manufacturing man-hours and costs.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory configuration diagram of the tablet, FIG. 2 is a vertical cross-sectional view of the main part of the tablet, and FIG. 3 is an electrical block diagram explaining the operation. . 1.7・・・・・・・・・Planar resistor, 2, 3, 8
．． 9...... Electrode 4.10...-
......Resistor, 5...Insulator, 6...Through hole, 13...
・・・・・・・Oscillator, 14・・・・・・・・・・・・
Control circuits 15, 17... Phase detector, 16.18... AD conversion circuit, SWl, SW2. SW3. SW4・・・・・・・・・
···switch

Claims (1)

[Claims] a flexible first planar resistor having a uniform resistance distribution; a second planar resistor facing the first planar resistor through an insulating plate having a plurality of through holes; A coordinate signal detection device characterized in that the second planar resistors are arranged so as to extend on opposing sides, and the electrodes of the respective planar resistors are arranged in a direction perpendicular to each other.