JPH08101741A - Coordinate input device - Google Patents

Abstract

PURPOSE: To detect coordinate information and switch information in combination by electrostatically coupling a signal pen which has an AC power source with a pressure sensitive type coordinate input device which consists of a transparent conductive film having uniform resistance on its internal surface and a detection electrode. CONSTITUTION: A tablet 1 is formed by adhering a plastic film having a transparent conductive film of uniform resistance on its internal surface with a glass substrate having a uniform resistance value together in the X-axial and Y-axial directions holding spacers between them. When the signal pen 2 is brought into contact with the tablet 1, the voltage of the DC signal impressed from a control part 14 is divided, passed through analog switches 7 and 8, impedance conversion 9, and an amplification part 10 and A/D-converted, and then stored as a coordinate position signal in a temporary memory. Then the control part 14 outputs the input signal to a band-pass filter 12 and stops impressing DC signal to the table 1. At this time, the signal of an AC signal generator 5 in the signal pen 2 is outputted to the tablet 1 and the transparent conductive film and a stylus conductor 3 are electrostatically coupled with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to coordinate input in a pressure-sensitive tablet, and at the time of coordinate input, both a writing pressure and a switch signal of a pen signal are recognized by using a signal pen having a signal generator inside. Regarding what to make.

[0002]

2. Description of the Related Art In a conventional pressure-sensitive tablet, only a dedicated input pen or a finger is used for simple input and only position information of a pressed portion can be obtained.

[0003]

The input using the conventional pressure-sensitive tablet is a simple input with a dedicated input pen or finger, and only the position information of the pressed portion can be obtained. It could not have multiple meanings and could only be used for simple input purposes.

[0004]

The present invention has been made in view of the above-mentioned problems of the prior art, and has a transparent conductive film having a uniform resistance on its inner surface, and an electrode on the outer peripheral edge of the transparent conductive film. A plastic film of the substrate, a glass substrate having a uniform resistance value of the fixed substrate that is opposed and adhered to the plastic film of the movable substrate via a spacer, and electrode terminals arranged on the outer peripheral edge of the glass substrate having the resistance value. A tablet, a first analog switch for switching a direct current applied to the tablet to electrode terminals in the X and Y axis directions, a signal pen having an AC signal generator for applying an AC signal to the tablet, and the tablet Second analog switch for switching the detection signal from the X- and Y-axis directions, and the signal from the second analog switch as a coordinate position signal and a signal. A third analog switch for switching to an input detection signal, a bandpass filter for inputting the AC signal detected by the signal pen, an amplifier for amplifying the output of the bandpass filter, and impedance conversion for the coordinate position signal. An impedance conversion unit, an amplification unit that amplifies the signal converted by the impedance conversion unit, an analog-digital conversion unit that analog-digital converts the output signal of the amplification unit, and each of the analog switches. In a coordinate input device including a control unit and a control unit that performs a calculation process of a detection signal, the signal detection for the coordinate position detection and the third analog switch for detecting the detection signal of the signal pen are switched to alternately process. A coordinate input device for use is proposed.

[0005]

The coordinate input device of the present invention detects the coordinate position by pressing the surface of the movable substrate and electrically contacting the transparent conductive film with the glass substrate of the fixed substrate by using the resistance of the glass substrate as a dividing resistance with a direct current. By switching the AC signal of the signal detection pen with an analog switch and passing through a bandpass filter, not only the designation of coordinates but also other signals are detected.

[0006]

The details of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an electrical block diagram of an embodiment of the present invention. As shown in a vertical cross section in FIG. 5, the tablet 1 has a plastic film 21 of an upper press-deformable movable substrate having an inner surface of a transparent conductive film 19 having a uniform resistance composed of indium tin oxide (hereinafter referred to as ITO). A glass substrate 22 as a fixed substrate having a planar resistor 20 having a uniform resistance value on the surface thereof is adhered to each other via a spacer 23 made of an insulating material. The actual tablet 1 has a plastic film 21 in the X-axis direction,
The glass substrate 22 has a two-direction configuration in the Y-axis direction.

An AC signal generator 5 is built in the signal pen 2, and the AC signal is applied to the stylus conductor 3 of the signal pen 2 only when the switch 4 is pressed from the AC signal generator 5. When the stylus conductor 3 located at the tip of the signal pen 2 comes into contact with the board surface of the tablet 1 having the transparent conductive film 19, the control unit 14 receives a control signal A from the control unit 14 and the control unit 14 causes the tablet to operate. A DC signal is applied to the electrode terminal 15 at one end of the first transparent conductive film 17. At this time, the analog switch 6b is also selected to be connected to the electrode terminal 16 in the X-axis direction, and the electrode terminal 16 is grounded via the analog switch 6b. The DC signal applied to the tablet 1 is divided into a coordinate signal by the resistance value of the planar resistor 20 up to the position where the signal pen 2 contacts. This coordinate signal is transmitted from the electrode terminal 18 to the analog switch 7 via the Y-axis direction conductive film, and the analog switch 7 receives the voltage detected by the transparent conductive film 19 of the plastic film 21 by the control signal B from the control unit 14. V1 (see FIG. 3) is output to the analog switch 8 as an X-side coordinate signal. The analog switch 8 is the control unit 14
The coordinate signal input by the control signal C from
The output is switched to the dance conversion circuit 9 and the band pass filter 12.

Here, the actual operation will be described with reference to FIG.
When the signal pen 2 is input by abutting on the point P on the tablet 1 of the plastic film 21 having the transparent conductive film 19, the DC signal from the analog switch 6a is output from the analog switch 6a by the control signal A from the controller 14. Electrode terminal 1
5 is applied. At this time, as shown in FIG. 3, the resistance value of the transparent conductive film 19 is divided into R2 from the point P to the GND side and R1 from the point P to the detection electrode, and the DC signal applied from the control unit 14 is The coordinate signal V1 divided by R1 and R2 is applied to the analog switch 7 from the electrode terminal 18. The analog switch 7 is connected to the X side by the control signal B from the control unit 14 and applies the input coordinate signal V1 to the analog switch 8.
The analog switch 8 controls the signal applied from
A control signal C from 4 is connected to the impedance conversion unit 9, and the input coordinate signal is impedance-converted and output to the amplification unit 10. The coordinate signal V1 input by the amplification unit 10 is amplified and output to the A / D conversion unit 11.
The coordinate signal V1 input to the / D conversion unit is A / D converted and output to the control unit 14. The coordinate signal V1 input by the control unit 14 is stored in the temporary memory as a coordinate position signal.

Next, a DC signal is applied to the electrode terminal 17 of the Y-side tablet by connecting the analog switch 6a to the glass substrate 22 which is the fixed substrate of the tablet 1 by the control signal A from the control unit 14. . At this time, as shown in FIG. 4, the resistance value of the transparent conductive film 22 changes from point P to GND.
It is divided into R4 on the side and R3 from the point P to the detection electrode 15. Then, the DC signal applied from the control unit 14 is applied to the analog switch 7 from the electrode terminal 16 as the coordinate signal V2 obtained by dividing the DC signal by R3 and R4. The analog switch 7 is connected to the Y side by the control signal B from the control unit 14 and applies the input coordinate signal V2 to the analog switch 8. The analog switch 8 applies the signal applied from the analog switch 8 to the control unit 14 The control signal C from 1 is connected to the impedance conversion circuit 9, and the input coordinate signal V2 is impedance-converted and output to the amplifier 10. The coordinate signal V2 input by the amplifier 10 is amplified and output to the A / D converter 11. The coordinate signal V2 input to the A / D converter 11 is A / D converted and output to the controller 14. The coordinate signal V2 input by the controller 14 is stored in the temporary memory as a coordinate position signal. .

Next, the control unit 14 sends a control signal C to the analog switch 8 and outputs the input signal to the bandpass filter 12. At the same time, the control unit 14 stops the application of the DC signal to the tablet 1. , Then signal pen 2
If the switch 4 is pressed, the signal from the AC signal generator 5 inside the signal pen 2 is output to the tablet 1 through the stylus conductor 3. At this time, the transparent conductive film and the stylus conductor 3 are capacitively coupled to each other to pass the analog switches 7 and 8 through the transparent conductive film and pass only the frequency band of the AC signal generator 5 of the signal pen 2. And is output to the amplification unit 13. This amplifier 1
In 3, the input signal is amplified to a level recognizable by the control unit 14 and output to the control unit 14.

In the control section 14, the coordinate position signal V1 on the X side and the coordinate position signal V2 on the Y side stored in the memory are arithmetically processed to determine the coordinate with which the signal pen 2 is abutted, and further the signal pen 2 The state of the switch 4 can be detected.

[0012]

The coordinate detecting device according to the present invention is a pressure-sensitive input device which can obtain a coordinate position signal and capacitively couple it to a tablet with a signal pen to obtain a pen signal. It becomes possible to input a plurality of information by one input, that is, by detecting the coordinate information and the switch information in combination, it is possible to utilize for more advanced applications.

[Brief description of drawings]

FIG. 1 Electrical block diagram

FIG. 2 is an explanatory view of contact of a signal pen.

FIG. 3 X-side signal detection diagram

FIG. 4 Y-side signal detection diagram

[Figure 5] Tablet configuration diagram

[Explanation of symbols]

 1 Tablet 2 Signal Pen 3 Stylus Conductor 4 Switch 5 AC Signal Generator 6a Analog Switch 6b Analog Switch 7 Analog Switch 8 Analog Switch 9 Impedance Converter 10 Amplification Unit 11 A / D Converter 12 Bandpass Filter 13 Amplification Unit 14 Control unit 15 X-axis electrode terminal 16 Electrode terminal 17 Y-axis electrode terminal 18 Electrode terminal 19 Conductive film 20 Transparent conductive film 21 Plastic film substrate 22 Glass substrate 23 Spacer

Claims (1)

[Claims] 1. A plastic film of a movable substrate having a transparent conductive film having a uniform resistance on the inner surface thereof and having electrodes on the outer peripheral edge of the transparent conductive film, and a plastic film of the movable substrate and a plastic film of the movable substrate, which are oppositely bonded to each other via a spacer. A tablet composed of a glass substrate having a uniform resistance value of a fixed substrate and electrode terminals arranged on the outer peripheral edge of the glass substrate having the resistance value, and electrode terminals in the X and Y axis directions for applying a direct current to the tablet. A first analog switch for switching to, a signal pen including an AC signal generator for applying an AC signal to the tablet, and a second analog switch for switching a detection signal from the tablet in the X and Y axis directions,
A third analog switch for switching a signal from the second analog switch between a coordinate position signal and a signal pen detection signal, a bandpass filter for inputting an AC signal detected by the signal pen, and an output of the bandpass filter , An impedance conversion unit that impedance-converts the coordinate position signal, an amplification unit that amplifies the signal converted by the impedance conversion unit, and an analog output signal of the amplification unit. In a coordinate input device including an analog-digital conversion unit that performs digital conversion and a control unit that controls each of the analog switches and performs a calculation process of a detection signal, a signal detection signal for detecting the coordinate position and a detection signal of a signal pen are detected. A coordinate input device characterized by being switched by a third analog switch for detection and performing processing alternately.