JP3165404B2 - Single piece electric resistance pressure sensitive coordinate input 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 single-piece resistive pressure-sensitive coordinate input device, and performs a coordinate test by switching one resistive film, a substrate, and a transistor.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventional electric resistance pressure sensitive input device comprises upper and lower two-layer resistive films X and Y and a control circuit. On the X-layer resistance film, a pair of electrodes X + and X− connected by a resistance film are arranged in the X-axis direction, and on the Y-layer resistance film, a pair of electrodes Y + and Y connected by the resistance film. -Is arranged in the Y-axis direction. A constant voltage is alternately applied to one side of the resistive electrodes of both layers,
When a voltage is applied to one point outside the resistive films of both layers,
The voltage value after the contact pressure of both resistive films can be measured from the electrode on the side where no current flows, whereby the X and Y coordinates of the contact pressure point can be determined. The circuit control having such a structure mainly includes four junctions (I / O (input / output)) X +, X-, Y +, Y
-Controls the paths and switches of transistors Q1-Q4. The X + and X- electrodes on the X-layer resistive film are connected to the transistors Q1 and Q2, respectively. The Y + and Y- electrodes on the Y-layer resistive film are connected to the transistors Q3 and Q4, respectively.
And the X + electrode and the Y + electrode are connected to the transistors Q1,
It is connected to a constant voltage Vcc by Q3. When a voltage contacts a certain point on the outside of the two-layer resistive film, the transistor Q
1 is open, X + electrode is connected to positive voltage, transistor Q
2 is also opened, X- is grounded, transistors Q3 and Q4 of the Y + and Y- electrodes connected to the Y layer are cut off, and the Y layer is turned off. Therefore, the X layer and the Y layer resistive films come into contact with each other,
The A / D (analog / digital) -X of the electrode measures the voltage VX and further derives the X coordinate by conversion. When the transistor Q3 is opened, the Y + electrode is connected to Vcc, the transistor Q4 is also opened, the Y- electrode is grounded, the X + and X- electrodes Q1 and Q2 connected to the X layer are cut off, and the X layer is cut off. A / D-Y of the X-electrode measures the voltage VY, and the Y coordinate is derived by conversion. In the above structure, since Vcc is constantly switched between the two resistive films, the Y-electrode of the Y layer and the X-electrode of the X layer
The voltage values VX and VX obtained by the electrodes become unstable. Further, since VX and VY are conducted by the two-layer resistive film, the electric resistance between the X-electrode from the pressing point PX of the X-layer resistive film and the electric resistance between the Y-electrode from the press point PY of the Y-layer resistive film. Shows a linear change, while at the same time the voltage must switch constantly between the two resistive films and have to carry current alternately, so that the two layers must be arranged very uniformly. In addition, the fact that the resistive films must be made of the same material is a major obstacle in manufacturing. Noise is generated by alternately passing current, and the voltage becomes unstable.

[0003]

SUMMARY OF THE INVENTION The main object of the present invention is to:
An object of the present invention is to provide an electric resistance pressure-sensitive coordinate input device. An electrode frame surrounds the periphery of a single resistive film, contacts are provided on each of the squares of the electrode frame, and a guide hole installed on one side of the copper foil layer on the front of the board is connected to the control circuit. When a pressure test is performed and the resistive film receives a contact pressure, the input of coordinates is achieved by the switch function of the control circuit. Thus, the present invention overcomes the disadvantages of conventional input devices, such as noise generation and voltage instability due to the use of two pieces of resistive film.

[0004]

In order to solve the above-mentioned problems, a coordinate input device according to the present invention includes a periphery surrounded by an electrode frame.
Single enclosed resistive film and copper of equal area
A substrate with a foil layer on the front and a
Control circuit, and the square of the electrode frame
The four contacts on the front of the board are
Connect to each other and use the control circuit on the back of the board.
Connected to the electronic switch on the circuit, and installed on one side of the board.
The drawn hole is used for the electronic switch of the control circuit.
When the resistive film and the substrate are connected, a certain voltage
Pressure is applied and coordinate input is performed by mutual switching of electronic switches
It is characterized by the ability to perform tests
You.

[0005]

As shown in FIG. 2, the resistive film 1 installed in the present invention has an electrode frame 11 at the edge, and contacts 111, 11
2, 113 and 114 are provided respectively. These contacts and the four contacts 21 on the front of the control circuit 22
Is connected to the circuit 22 on the rear surface of the substrate 2 and connected to the transistors Q1 to Q6 to control a voltage source and a ground terminal on the circuit, and is connected to I / O, LT, LB, RT and RB. I do. The front surface of the substrate 2 is a copper foil layer 23, the area of which is equal to that of the resistive film 1, and a guiding hole 231 extends on one side surface thereof. Alternatively, the device is in a command waiting state. With the above structure, the control circuit 22 is a device that applies voltage by associating the four contacts 21 on the front surface of the substrate 2 with the four contacts 111, 112, 113, 114 of the electrode frame 11. As described above, by reducing the distance between the electrode frame 11 and the control circuit 22 to the minimum range, the coordinate test can be performed with a voltage corresponding to the voltage source without losing the voltage applied to the electrode frame.

The control circuit I / O, LT, LB,
RT and RB control the conduction and opening / closing of the transistors Q1 to Q6.
Control the blocking state. Since the A / D converter of the control circuit is directly connected to the A / DX, the transistor Q
The relationship between the states 1 to Q6 and the control leads is shown as follows. LT Q1 output LB Q2 Q3 output 0 ON Vcc 0 ON OFF Vcc 1 OFF Vcc 1 OFF ON OV RT Q4 Q5 output RB Q6 Output 0 ON OFF Vcc 0 OFF OV 1 OFF ON OV 1 ON OV 11 Transistor Q1 output Contact point 111
Since the resistance of the electrode frame 11 is extremely low, the same voltage flows from the left side of the resistive film 1, that is, from the upper left to the lower left of the electrode frame 11. The lower right contact point 113 of the electrode frame 11 is grounded via the transistor Q6,
The electrodes on the right side of the resistive film 1 and from the lower right to the upper right become OV, and the voltage of the resistive film exhibits a linear change from left to right, and decreases with increasing right (see FIG. 3). Further, at the time of pressing, the resistive film which is the pressing point and the copper foil layer 23 of the control circuit are in contact with each other, and the transistor Q7 is in the cutoff state. Therefore, the pressing point is equivalent to being directly connected to the A / D converter. A /
When DX performs A / D switching, the pressing point X direction voltage -Vx
And the coordinates of the pressed point can be calculated. The upper left corner and the lower right corner of the electrode frame 11 on the coordinate of the pressing point Y direction maintain a constant voltage and ground state, and do not perform mutual switching. By controlling the connection by LB, the transistors Q2 and Q3 apply voltage and ground to the contact 114 of the electrode frame 11, and the transistors Q4 and Q5 apply voltage and ground to the contact 112 of the electrode frame 11 by connection control of RT. give. When the pressure point indicates PY, LB is at a high potential, shutting off transistor Q2 and conducting and grounding Q3. RT at low potential turns on transistor Q4, connects it to Vcc, and turns off Q5. At this time, a constant voltage is applied to the contacts 111 and 112 of the electrode frame 11, and the contacts 113 and 114 are grounded. Therefore, the upper side of the electrode frame 11 is Vcc, the lower side is grounded, and the resistance film 1
Exhibit a linear change from top to bottom. When the contact indicates PY, the connecting transistor Q7 is also turned off, which is equivalent to connecting the pressing point directly to the A / D converter. The voltage −VY in the point Y direction is known, and the Y coordinate of the pressed point can be calculated.

The upper left corner of the electrode frame 11 on the resistive film 1 is
Connected to Vcc by transistor Q1, lower right corner is Q6
By grounding by, one side of the resistive film is kept +,
The opposite side is grounded, resulting in an equivalent circuit as shown in FIG. When the pressing point measures PX and PY, switching is performed only from the upper right corner and the lower left corner of the electrode frame.

As shown in FIG. 2, in the input and command standby state, the transistor Q2 is turned on, the transistor Q3 is turned off, and the contact 114 of the electrode frame 11 is connected to Vcc. When the transistor Q4 is turned on and the transistor Q5 is turned off, the contact 112 of the electrode frame 11 is also connected to Vcc. At this time, the resistance film becomes +, the copper foil layer 23 receives the electric resistance R1, and the transistor Q7 is grounded. In the input / command standby state, A / D-X is connected to the electric resistance R1, the transistor Q7 is grounded, and the value of A / D becomes zero. When A / D-X passes through the electric resistance R (resistive film 1) at the time of pressing, the value becomes +, and A / D switching is performed in the Y direction . As a result, the obtained voltage is as follows. VY = Vcc × R / (R1 + R) Therefore, VY becomes a high voltage equivalent to Vcc, and the control circuit determines that the voltage on A / DX is a certain value (for example, 2.Vcc = + 5V R1 = 10K R = 50K ) . When it is determined that the voltage exceeds 5 V), a pressing state is set. In the opposite case, no pressing is performed, and it is possible to prevent misunderstanding of the pressing state due to contact.

The above-mentioned copper foil layer 23 can be replaced with an electrically resistive film surface having conductivity and elasticity. In this way, if this electric resistance film surface is adhered on the end surface of the resistance film 1, the resistance film 1
Can be directly adhered to the substrate 2, the pressure-sensitive resistive film 23 is transmitted onto the resistive film 1, and the coordinates can be input by the method described above.

[0010]

According to the present invention, an electrode frame and a controller are provided.
By reducing the distance between the roll circuits to the minimum range
Without losing the voltage applied on the electrode frame,
A coordinate test can be performed with a voltage equivalent to a voltage source.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure of a conventional coordinate input device.

FIG. 2 is an explanatory diagram showing the structure of the coordinate input device of the present invention.

FIG. 3 is an explanatory diagram illustrating the operation curve.

FIG. 4 is an explanatory diagram illustrating the operation mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Resistive film 11 Electrode frame 111, 112, 113, 114 Contact (electrode frame) 2 Substrate 21 Contact (substrate) Q1-Q6, Q7 Electronic switch (transistor) 22 Control circuit 23 Copper foil layer 231 Guide hole

Claims (1)

(57) [Claims] 1. The periphery is surrounded by an electrode frame (11).
A single resistive film (1) and an area equal to this resistive film (1)
(2) having a copper foil layer (23) of
Control circuit (22) installed on the back of the board (2)
And each of the squares of the electrode frame (11)
Installed contacts (111, 112, 113, 114)
Are four contacts (21, 21, 21, 21) on the front of the substrate (2).
21) and the controller on the back of the board.
The electronic switch (Q1, Q2, Q
3, Q4, Q5, Q6) and the substrate (2)
The guide hole (231) installed on one side is
Connected to the electronic switch (Q7) of the
When the film (1) and the substrate (2) are polymerized, one is formed on the resistive film (1).
A constant voltage is applied and the electronic switches (Q2, Q3, Q
4, Q5, Q7) to perform coordinate input test
Ukoto-RESISTOR-PRESSURE SENSITIVE coordinate input apparatus characterized by can.