JP2991084B2 - Coordinate detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detecting device,
In particular, the present invention relates to a coordinate detection device that detects two-dimensional coordinates by detecting a short-circuit position of an orthogonal wiring.

[0002]

2. Description of the Related Art A conventional coordinate detecting apparatus for detecting two-dimensional coordinates by short-circuiting orthogonal wiring groups scans one wiring group, sequentially applies a voltage to the wiring, and detects a voltage of the other wiring group. To detect the coordinates. FIG. 3 shows an example of a conventional coordinate detecting device. FIG. 3 schematically shows the configuration of a device for detecting 4 × 4 coordinates.

Referring to FIG. 3, a coordinate detecting device includes a sensor panel 60 and an encoder 6 for detecting x-axis coordinates.
2. The shift register 63 scans the y-axis.
Wirings 64, 65, 66, 67 of the sensor panel are connected to the encoder 62, and wirings 68, 69, 70, 71 are connected to the shift register 63.

FIG. 4 is a perspective view for explaining a schematic configuration of the sensor panel 60. As shown in FIG. Referring to FIG. 4, a plurality of wirings 52, 5 made of a conductive material are provided on opposing surfaces of two insulating plates 50, 51 arranged in parallel with each other.
3 and 54, and the wirings 55 and 5
6, 57 are arranged.

Insulating plates 50 and 51 are separated from each other by a predetermined distance so that the wirings arranged on the respective surfaces do not normally short-circuit with each other. Wirings facing each other at the pressed location come into contact with each other and short-circuit.

Referring again to FIG. 3, the encoder 62 has four inputs and two bits, and outputs a voltage indicating the fact to the signal SNS when one of the four input terminals receives an input. Then, the XPOS outputs the number of the input terminal to which the input has been made to the wirings 72 and 73 in accordance with, for example, the combinations shown in Table 1 (that is, XPOS is position information).

[0007]

[Table 1]

In Table 1, V72 indicates the voltage of the wiring 72 ("H" is high level, "L" is low level) and V7
3 represents the voltage of the wiring 73.

The detection of coordinates is performed according to the following processing procedure. FIG. 5 is a timing chart for explaining the operation of the conventional example shown in FIG.

In FIG. 5, CLKY is a clock signal input to the shift register 63, and SPY is a start pulse indicating the start of scanning on the y-axis. Also, V68
To V71 indicate voltages of the wirings 68 to 71 connected to the outputs 1 to 4 of the shift register 63, respectively. And V64 to V67 are the encoder 62
5 shows the voltages of the wirings 64 to 67 connected to the inputs 1 to 4, respectively. SNS is an output of the encoder 62 and a signal indicating that there is an input,
V72 and V73 are wires 7 which are outputs of the encoder 62.
2, 73 signal voltages are shown.

Here, in the conventional example shown in FIG.
It is assumed that the wires 66 and 69 of the sensor panel 60 are short-circuited at the position indicated by 1, that is, the position of the coordinates (3, 2).

After the shift register 63 receives the start pulse signal SPY for starting the scanning on the y-axis, the shift register 63 synchronizes with the clock signal CLKY for the wiring 68 for y-axis coordinate detection.
The voltage is sequentially output to 69, 70, and 71.

The encoder 62 detects a short circuit with the wiring for detecting the y-axis coordinate selected by the shift register 63 among the wirings 64, 65, 66, and 67 for detecting the x-axis coordinate, and detects the coordinate value. Convert to

In this example, since a short circuit occurs at the coordinates (3, 2), a voltage appears on the x-axis detection wiring 66 when the y-axis coordinate detection wiring 69 is selected, and the coordinates are detected by the encoder 62. The signal SNS indicating that the operation has been performed and the x-axis coordinate value XPOS are output to the wirings 72 and 73 according to Table 1. In this case, V72 indicating the coordinate 3 on the x-axis is “L”,
V73 becomes "H".

[0015]

In the case of a coordinate input device, particularly a coordinate input device intended for manual input, the device itself necessarily has a certain size. In this case, x
There has been a problem that the length of the wiring for detecting the axis coordinate and the wiring for detecting the y-axis coordinate become long, and the wiring has a time constant due to the parasitic capacitance and resistance of each wiring, and the detection takes time.

In particular, in the conventional coordinate detecting device shown in FIG. 3, it takes time to charge the parasitic capacitance of the wiring every time a wiring for outputting a voltage is switched by scanning the wiring for y-axis coordinate detection.

In order to detect the coordinates of the short-circuited portion, it is necessary to scan the wiring for y-axis coordinate detection at least once, and charge / discharge the parasitic capacitance of the wiring when scanning the wiring for y-axis coordinate detection. Time cannot be ignored.

Further, in the conventional coordinate detection device, when scanning the y-axis coordinate detection wiring, it is necessary to change the voltage of the coordinate detection wiring at a high speed. Will receive radiation.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a coordinate detecting device for detecting coordinates by detecting a short-circuited position of an orthogonal wiring, thereby avoiding the influence of the parasitic capacitance of the wiring and performing high-speed coordinate detection. Is to provide a coordinate detecting device which can perform the following.

[0020]

In order to achieve the above object, the present invention is directed to a first embodiment in which first and second first planes are arranged in parallel with each other.
And a second group of wirings arranged on a second plane facing the first plane and orthogonal to the group of wirings 1 and in parallel with each other. Are located in a state where the wirings of the first wiring group and the wirings of the second wiring group come into contact with each other in a short-circuited state corresponding to the pressed position in a state where they are normally electrically insulated from each other. In the two-dimensional coordinate detecting device for detecting the coordinate value by detecting the following, each wire of the first wire group is connected to the first reference voltage via a resistor, and each wire of the second wire group is The second through a resistor
Of the first wiring group.
That is, a current flows through the resistor connected to the wiring,
A line whose voltage is different from the first reference voltage.
While searching for a line, among the wirings of the second wiring group,
The current flows through a resistor connected to the wiring, and the second base
Searched for wiring with a voltage different from the reference voltage, and short-circuited
Provided is a coordinate detecting device characterized by obtaining a coordinate value by detecting a wiring .

In the present invention, preferably, the first
Is larger than the voltage value of the voltage value of the reference voltage is a second reference voltage.

In the present invention, the first reference voltage and
A voltage between the second reference voltage and the first reference voltage
And a voltage higher than an intermediate voltage between the second reference voltages.
A third reference voltage, the first reference voltage and the second
A fourth reference which is lower than a voltage intermediate between the reference voltages
And providing a voltage between the fourth wiring group and the fourth wiring group.
Search for a wiring having a voltage lower than the reference voltage, and
A voltage higher than the fourth reference voltage among the wires of the line group;
It is characterized in that a wiring is searched for and a short-circuited wiring is detected .

In the present invention, preferably, the first
One end of the resistor connected to each wiring of the wiring group
Is connected to the negative input terminal of the first comparator.
A switch group, wherein each of the wirings of the second wiring group
Is connected to the positive terminal of the second comparator.
A second switch group for switching connection to an input terminal;
The third reference voltage is input to the positive input terminal of the first comparator.
The fourth reference voltage is connected to the negative input terminal of the second comparator.
Pressure is input, and the first and second switch groups are
A predetermined switching control signal is issued so that
And first and second control means for supplying the first and second signals.
Is short-circuited based on the output voltage of the comparator and the clock.
It is characterized by detecting a certain wiring .

In the present invention, preferably, the first flat
A first wiring group disposed in parallel with each other on the surface,
Orthogonal to the wiring group 1 on a second plane opposite to the first plane
And a second wiring group disposed in parallel with each other,
The first and second wiring groups are normally electrically insulated from each other.
Of the first wiring group corresponding to the pressed position
The wiring and the wiring of the second wiring group are in contact with each other and short-circuited.
Two-dimensional coordinates that detect the position of the state and detect the coordinate value
In the detection device, each wire of the first wire group has a resistance.
One end is commonly connected to a predetermined first reference voltage via
One end of each wiring of the second wiring group has a predetermined end via a resistor.
2 common to the first reference voltage and the first reference voltage.
A voltage between the second reference voltage and the first reference voltage;
The voltage is higher than the intermediate voltage of the second reference voltage.
A third reference voltage, the first reference voltage and the second reference voltage;
A fourth reference voltage which is lower than the intermediate voltage of the reference voltages;
And a third base among the wires of the first wiring group.
A wiring having a voltage lower than the reference voltage is searched for, and the second wiring
A wiring having a voltage higher than the fourth reference voltage among the wirings of the group.
A search for a wire in the first wire group and a
The search for wiring in the wiring group 2 is performed at the same time, and the short-circuited wiring
Is detected to obtain a coordinate value .

In the present invention, preferably, the first
A first switch group for switching and connecting the voltage at one end of the resistor connected to the wiring to the negative input terminal of the first comparator for each wiring of the second wiring group; A second switch group for switching and connecting a voltage at one end of the resistor connected to the wiring to a positive input terminal of a second comparator, and the third input terminal of the first comparator is connected to the third switch group. Is input to the negative input terminal of the second comparator, and the first and second switch groups are sequentially closed in synchronization with a predetermined clock. And first and second control means for supplying a predetermined switching control signal as described above.
And detecting the short-circuited wiring based on the output voltage of the comparator and the clock.

[0026]

According to the present invention, the wiring for x-axis coordinate detection is set to the first reference voltage REF1, and the wiring for y-axis coordinate detection is set to RE.
Connected to a predetermined second reference voltage REF2 different from F1;
By detecting the current by detecting the current when the x-axis coordinate detection wiring and the y-axis coordinate detection wiring are short-circuited, the parasitic capacitance of the coordinate detection wiring when detecting the coordinates of the short-circuit location Since the x-coordinate and the y-coordinate can be detected at the same time without charging / discharging, the detection time is greatly reduced. Further, according to the present invention, it is not necessary to change the voltage of the coordinate detection wiring at the time of coordinate detection, so that unnecessary electromagnetic radiation from the coordinate detection wiring is avoided.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of one embodiment of the present invention.
Referring to FIG. 1, in the present embodiment, a sensor panel 1, an x-axis coordinate detection circuit 2, a y-axis coordinate scanning circuit 3, comparators 4 and 5, a first reference voltage REF1 (an output voltage is VREF
1) and a second reference voltage REF2 (the output voltage is VREF
It is composed of voltage dividing resistors 6, 7, 8 inserted between 2) for generating a third reference voltage 44 and a fourth reference voltage 46.

Also in this embodiment, the sensor panel 1
Has a structure as shown in FIG.

Wirings 19, 20, 21, 2 for x-axis coordinate detection
2 and the y-axis coordinate detection wires 31, 32, 33, and 34 are electrically insulated from each other, but are connected to the x-axis coordinate detection wire at a position pressed from the surface of the sensor panel 1. The y-axis coordinate detection wiring is short-circuited.

Here, for the sake of explanation, it is assumed that the position indicated by 35 in FIG. 1 is pressed, and the x-axis coordinate detection wiring 21 and the y-axis coordinate detection wiring 32 are short-circuited.

X-axis coordinate detection circuit 2 and y-axis coordinate detection circuit 3
Have the same configuration, and each of the coordinate detection wires 19 to
A switch 11 that includes resistors 15 to 18 and 27 to 30 for current detection respectively corresponding to the reference numerals 22 and 31 to 34, and switches a voltage detection line by the first and second shift registers 9 and 10. -14 and 23-26.

Current detection resistors 15-18, 27-30
Are all the same.

The positive input of the first comparator 4 is the third reference voltage VREF3, and the negative input of the second comparator 5 is the fourth reference voltage VREF4. Note that the resistance values of the voltage dividing resistors 6, 7, and 8 are the third reference voltage V
REF3 is equal to VREF1 and (VREF1 + VREF2)
/ 2, and the fourth reference voltage VREF4 becomes
The voltage is set to be a voltage between (VREF1 + VREF2) / 2 and VREF2.

Referring to FIG. 1, coordinates (3,
When a short circuit occurs at the position 2), the wires 19, 20, 22, 31, 33, and 34 of the coordinate detection wires do not allow current to flow through the current detection resistors. 1, the reference voltage VREF1 and the wirings 31, 33, 34
A current flows through the reference voltage VREF2 and the wirings 21 and 32 due to a short circuit, and the current detection resistances 17 and 28 are equal, so that (VREF1 + VREF2) / 2.

The operation of detecting coordinates in the present embodiment will be described below with reference to the timing chart of FIG. 2, CLKX and CLKY are signals input to clock terminals CLKX and CLKY of the first and second shift registers 9 and 10, and SPX and SPY are signals of SPX and SPY of the first and second shift registers 9 and 10. The input signals are a start pulse signal for starting scanning on the x-axis and a start pulse signal for starting scanning on the y-axis.

V36 to V39 and V40 to V43 are first.
Outputs of the second shift registers 9 and 10 and voltages of wires 36 to 39 and 40 to 43 which are signal lines for controlling opening and closing of the switches 11 to 14 and 23 to 26 connected thereto. V45 is the voltage of the wiring 45, that is, the voltage of the negative input terminal of the first comparator 4, and V47 is the voltage of the wiring 47, that is, the voltage of the positive input terminal of the second comparator 5.

V44 and V46 are third and fourth reference voltages VREF3 and VREF4 generated by resistors 6, 7, and 8, respectively.
, And SNSX and SNSY indicate the output voltages of the first and second comparators 4 and 5, respectively.

In this embodiment, the actual coordinate detection is performed on the x-axis and the y-axis at the same time, but the x-axis and the y-axis will be described separately for easy understanding.

Referring to FIG. 2, first shift register 9
When a start pulse signal SPX having a width of one clock is input in a state where the clock signal CLKX is input to the switch, the voltage is output in the order of the switch control wirings 36 to 39 every clock thereafter (see V36 to V39).

The switches 11 to 14 apply this voltage (V36 to
(V39), the coordinate detection wirings 19 to 22 connected to each other and the wiring 45 connected to the negative input of the first comparator 4 are sequentially connected.

For this reason, the voltage V45 of the wiring 45 is
As shown in (3), when the voltage V38 for controlling the switch 13 connected to the wiring 21 corresponding to the X coordinate 3 is output, it becomes (VREF1 + VREF2) / 2, and at other times, it becomes the first reference voltage VREF1.

Since the third reference voltage VREF3 is input to the positive input of the first comparator 4, the voltage ("H") is output to the output SNSX of the first comparator 4 only when the x coordinate 3 is selected. "Level" is output, whereby the x coordinate is detected.

The detection of the y coordinate is performed in the same manner as in the case of the x coordinate as follows.

When a start pulse signal SPY having a width of one clock is input while the clock signal CLKY is input to the second shift register 10, a voltage is output in the order of the switch control wirings 40 to 43 every clock thereafter ( V
40-V43).

The switches 23 to 26 apply this voltage (V40 to
Upon receiving V43), the wirings 31 to 34 for coordinate detection and the wiring 47 connected to the positive input of the second comparator 5 are sequentially connected.

For this reason, the voltage V47 of the wiring 47 is
As shown in (2), when the voltage V41 for controlling the switch 24 connected to the wiring 32 indicating the y coordinate 2 is output, the voltage becomes (VREF1 + VREF2) / 2, and at other times, the voltage becomes the second reference voltage VREF2.

As a result, a voltage ("H" level) is output to SNSY only when Y coordinate 2 is selected, and the y coordinate is detected.

Since the detection of the x coordinate and the detection of the y coordinate do not interfere with each other, they can be performed simultaneously.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited only to the above embodiments.
Needless to say, various modes according to the principle of the present invention are included.

[0051]

As described above, according to the present invention,
There is no charge / discharge to the parasitic capacitance of the coordinate detection wiring when detecting the coordinates of the short-circuited portion, and the x-coordinate and the y-coordinate can be detected simultaneously at the same time, so that the detection time is greatly reduced. .

According to the present invention, when detecting coordinates,
It is unnecessary to change the voltage of the coordinate detection wiring, and thus there is an effect that unnecessary electromagnetic radiation from the coordinate detection wiring is avoided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of one embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a configuration of a conventional example.

FIG. 4 is a perspective view for explaining a configuration of a sensor panel.

FIG. 5 is a timing chart for explaining the operation of the conventional example.

[Explanation of symbols]

 Reference Signs List 1 sensor panel 2 x-axis coordinate detection circuit 3 y-axis coordinate detection circuit 4 x-axis comparator 5 y-axis comparator 6-8 reference voltage generating resistor 9 first shift register 10 second shift register 11-14 switch 15 -18 Current detection resistance 19-23 Coordinate detection wiring 23-26 Switch 27-30 Current detection resistance 31-34 Coordinate detection wiring 35 Coordinate location 36-43 Switch control wiring 44 Third reference voltage 45 Wiring 46 Fourth reference voltage 47 Wiring 50, 51 Insulating board 52-57 Coordinate detection wiring 60 Sensor panel 61 Short-circuit location 62 Encoder 63 Shift register 64-67 x Coordinate detection wiring 68-71 y Coordinate detection wiring 72 x Axis coordinate (lower) 73 x-axis coordinate (upper)

Claims (4)

(57) [Claims] A first wiring group disposed on a first plane in parallel with each other; and a second wiring group disposed on a second plane opposite to the first plane and orthogonal to and parallel to the wiring group. The second arranged
Wherein the first and second wiring groups are normally electrically insulated from each other at normal times, and the wirings of the first wiring group and the second wirings correspond to pressed locations. In a two-dimensional coordinate detecting device for detecting a coordinate value by detecting a position where a group of wirings are in contact with each other and in a short-circuit state , each wiring of the first wiring group is connected to a first reference voltage via a resistor. Each of the wirings of the second wiring group is connected to the second reference voltage via a resistor, and among the wirings of the first wiring group, the wiring of the first wiring group is connected to the second reference voltage.
A current flows through the resistor, and the voltage of the wiring is adjusted to the first reference.
Search for wiring that has a voltage different from the voltage, and
Of the wirings of the second wiring group, connected to the wiring and before the resistance
The current flows and becomes a voltage different from the second reference voltage.
A coordinate detecting device for detecting a short-circuited wiring to obtain a coordinate value by searching for a wiring that has been short-circuited . 2. The first reference voltage and the second reference voltage.
Between the first reference voltage and the second reference voltage.
A third reference voltage that is higher than the intermediate voltage
And an intermediate value between the first reference voltage and the second reference voltage.
A fourth reference voltage that is lower than the voltage is provided , and a fourth reference voltage of the wires of the first wiring group is lower than the fourth reference voltage.
Also search for a low voltage wiring, and check the wiring of the second wiring group.
Of these, search for wiring with a voltage higher than the fourth reference voltage.
Detecting a short-circuited wiring.
The coordinate detecting device according to the above. 3. A plurality of first motors arranged parallel to each other on a first plane.
One wiring group and a second plane facing the first plane.
And a second group arranged in parallel with each other at right angles to the wiring group 1.
And the first and second wiring groups are in a normal state.
The parts that are electrically insulated from each other and correspond to the pressed parts
Wiring and the second wiring group and the first wiring group of wirings Te
Are in contact with each other and short-circuited,
In the two-dimensional coordinate detecting device, one end of each of the wires of the first wire group has a predetermined end via a resistor.
One end of each of the wirings of the second wiring group is connected to a first reference voltage at a predetermined end via a resistor.
A voltage commonly connected to a second reference voltage and between the first reference voltage and the second reference voltage
And an intermediate value between the first reference voltage and the second reference voltage.
A third reference voltage that is higher than the first reference voltage;
Lower than the intermediate voltage between the reference voltage of
A fourth reference voltage, which is higher than the third reference voltage among the wirings of the first wiring group.
Also search for a low voltage wiring, and check the wiring of the second wiring group.
Search for wiring with a voltage higher than the fourth reference voltage
And searching for a wiring in the first wiring group and the second wiring.
A coordinate detecting device for simultaneously searching for wiring in a group and detecting a short-circuited wiring to obtain a coordinate value. 4. The method according to claim 1, wherein each of the wirings of the first wiring group is connected to the wiring.
The voltage at one end of the resistor is connected to the negative input terminal of the first comparator.
A first switch group for switching connection to the second wiring group, and the resistor connected to the wiring for each wiring of the second wiring group.
Switching the voltage at one end of the resistor to the positive input terminal of the second comparator
A second switch group, wherein the third reference voltage is connected to a positive input terminal of the first comparator.
Is input, the negative input of the second comparator said fourth reference voltage
Input, and synchronizes the first and second switch groups with a predetermined clock.
Supply a predetermined switching control signal so as to sequentially close
A first and second control means , based on output voltages of the first and second comparators and the clock;
2. The coordinate detecting device according to claim 1 , wherein a wire in a short-circuit state is detected.