JPH07120239B2 - Tablet position detection method and 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 method and apparatus for detecting the position of a tablet such as a resistance pressure type tablet.

[0002]

2. Description of the Related Art The present applicant has already proposed a resistance pressure sensitive tablet as shown in FIGS. This is an X-axis resistance plate 1 having X-axis electrodes 11 and 11 at both ends in the X-axis direction.
2 and Y having Y-axis electrodes 13 and 13 at both ends in the Y-axis direction
In a resistance pressure-sensitive tablet in which the axial resistance plate 14 faces each other and is arranged with a slight gap, the X-axis auxiliary is provided inside the X-axis electrodes 11 and 11 and the Y-axis electrodes 13 and 13, respectively. The electrodes 30 and 30 and the Y-axis auxiliary electrodes 31 and 31 are provided. In addition, the X-axis resistance plate 12 and the Y-axis resistance plate 14 are respectively the insulating substrate 4
Resistive layers 43 and 43 are formed on one side surface of the reference numerals 42 and 42, and the resistive layers 43 and 43 are opposed to each other to form a gap between the insulating spacer 44 at the outer peripheral edge and the dot spacers 15 at predetermined intervals, and a laminated body of these is formed. Are attached to the housing 41.

These X-axis auxiliary electrodes 30, 30 are
A / D conversion circuit 20 via switching contacts X ₂ and X ₃ , respectively
Is connected to the reference voltage input side, and one X-axis auxiliary electrode 30 is connected to the Y-axis position information detecting switching contact Y ₄ . Similarly, the Y-axis auxiliary electrodes 31 and 31 are coupled to the reference voltage input side of the A / D conversion circuit 20 via the switching contacts Y ₂ and Y ₃ , respectively, and one Y-axis auxiliary electrode 31 is connected to the X-axis.
It is connected to the switching contact X ₄ for detecting axis position information. The A / D conversion circuit 20 is coupled to the output terminal 21 via the arithmetic circuit 32. Note that 22, 23, 24, 25, 33, 3
4, 35 and 36 are contact resistances 26 and 2 between the resistance plate and the electrodes.
7, 28, 29, 37, 38, 39 and 40 are conductor resistances, and z is a contact resistance between the resistance plates 12 and 14.

In the above structure, the switching circuit 16
Is connected to the contacts X ₁ , X ₂ , X ₃ , X ₄ , X ₅ side, the + reference (AVR +) voltage on the X axis side is pressed by the pen 17 on the X axis auxiliary electrode 30 on the power source Vcc side. Since the X-axis side reference (AVR-) voltage is the voltage when the pen 17 presses the ground side X-axis auxiliary electrode 30, the voltage is applied between the electrodes 11 and 11 at both ends. The applied voltage Vx is the contact resistance 22, 2 of the electrodes 11, 11.
3. If it changes due to the resistance change of the conductor resistances 26 and 27,
Corresponding to this, the + reference (AVR +) voltage and the −reference (AVR−) voltage on the X-axis side also change. Regarding the contact resistances 33 and 34, the conductor resistances 37 and 38, and the contact resistance z of the X-axis auxiliary electrodes 30 and 30, the input impedance of the A / D conversion circuit 20 and the arithmetic circuit 32 is sufficiently larger than the resistance value of the tablet. So it can be almost ignored. The above characteristics are the same on the Y-axis side.

Next, the divided voltage when the pin 17 presses the predetermined point P is input to the A / D conversion circuit 20 via y ₂ of the Y-axis resistance plate 14 and the Y-axis auxiliary electrode 31. . The contact resistance 36 and the conductor resistance 40 at this time are also the same as the above A / D.
Since it is sufficiently smaller than the input impedance of the conversion circuit 20 and the arithmetic circuit 32, it can be almost ignored. As described above, the + reference (AVR +) voltage and the −reference (AVR−) voltage always change in response to the change in resistance, so that even if the voltage Vx of the position data changes due to change in resistance, the voltage is automatically changed. Corrected and output. + Reference (A
The VR +) voltage, the −reference (AVR−) voltage, and the position data voltage Vx are sent to the A / D conversion circuit 20 and converted into digital values, and are further operated by the operation circuit 32 to perform X operation.
Output as axis position information. When the changeover switch 16 is switched to the Y contacts Y ₁ , Y ₂ , Y ₃ , Y ₄ , and Y ₅ side, the Y-axis position information is output as a digital value in the same manner as described above.

[0006]

However, in the case of FIG. 5, since the X-axis auxiliary electrodes 30, 30 or the Y-axis auxiliary electrodes 31, 31 are formed by sticking silver,
When the pen 17 repeatedly presses and bends the X-axis auxiliary electrodes 30 and 30 or the Y-axis auxiliary electrodes 31 and 31, the auxiliary electrodes are cut and the contact resistance changes due to cracking. was there.

The present invention provides a method and apparatus for easily and accurately setting a + reference (AVR +) and a −reference (AVR−) without pressing the auxiliary electrode, that is, inside the auxiliary electrode. It is provided.

[0008]

According to the present invention, an X-axis resistance plate having X-axis electrodes formed on both ends of a resistance layer on an insulating substrate, and a Y-axis electrode formed on both ends of the resistance layer on an insulating substrate. A Y-axis resistance plate and a Y-axis resistance plate, which are overlapped with each other with a slight insulating gap, between the X-axis electrodes at both ends and the Y-axis at both ends.
The tablet position detecting method is characterized in that external resistances are respectively inserted between the shaft electrodes, and the + reference and −reference are derived from inside of both ends of these external resistances.

[0009]

The external resistance is divided into three parts by providing lead-out terminals slightly inward from both ends of the external resistance. These lead-out terminals have a voltage of + reference (AVR +) and −reference (AV) when they are pressed on the X-axis and Y-axis resistance plates and on a line slightly inside the auxiliary electrode with a pen.
R-). Therefore, correct + reference and − reference with no error can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the present invention inserts external resistors 47 and 47 between the X-axis auxiliary electrodes 30 and 30 at both ends and between the Y-axis auxiliary electrodes 31 and 31 at both ends. + A from points A and B on both sides of 47
The reference and the −reference are derived. First, the case of the X-axis resistance plate 12 will be described in detail. Similar to FIGS. 5 and 6, the X-axis resistance plate 12 has X-axis electrodes 11 and 11 formed at both ends thereof, and X-axis auxiliary electrodes 30 and 30 formed slightly inward of the X-axis electrodes 11 and 11, respectively. ing.

A resistor 47 is inserted between the X-axis auxiliary electrodes 30 and 30 via buffer circuits 45 and 46. The buffer circuit 45, 46 is interposed between the resistor 47.
This is because a current flows through the resistor 47 due to the parallel insertion of the X-axis resistance plate 12 with the X-axis resistance plate 12, and this current is suppressed as much as possible to prevent waste of power consumption. The resistor 47 is provided with lead terminals A and B slightly inward from both ends of the resistor 47.
Divide into 8, 49 and 50. These lead terminals A and B
Is on the X-axis resistance plate 12 and the X-axis auxiliary electrodes 30, 3
When the pen 17 presses on the a and b lines slightly inside 0, the voltages are + reference (AVR +) and −, respectively.
The position of the a and b lines can be arbitrarily set according to the derivation points of the derivation terminals A and B, for example, by the following method.

As shown in FIG. 2, the X-axis resistance plate 12 and the Y-axis resistance plate 14 have resistance layers 43, 43 formed on one side surface of the insulating substrates 42, 42, respectively.
It is the same as FIG. 5 that the insulating spacers 44 and the dot spacers 15 are made to face each other to form a gap, and these laminated bodies are attached to the housing 41. Therefore,
As an embodiment of the present invention, when the laminated body is surrounded by the housing 41, the laminated body is surrounded by the housing 41 slightly inside the upper portions of the auxiliary electrodes 30 and 31. And pen 17
Is substantially in contact with the inside of the inner peripheral edge portion 53 of the upper surface of the housing 41 and is pressed from above the laminated body, the voltage on the a or b line at a distance d from the auxiliary electrode 30 is + The reference (AVR +) or −reference (AVR−) is set.

Of course, when the laminated body is surrounded by the housing 41, even if it is not surrounded by the housing 41 to a position slightly inside the upper portions of the auxiliary electrodes 30 and 31, the mark indicating the a or b line is formed on the upper surface of the laminated plate. Line is written, the area outside the a or b line is colored differently from the inside so that it is not used, and the area outside the a or b line is made of a hard material similar to the housing 41. A thin plate may be attached. The lead terminals A and B of the resistor 47 are sequentially coupled to the A / D conversion circuit 20, the arithmetic circuit 32, and the output terminal 21 via buffer circuits 51 and 52, respectively.

In FIG. 1, only the X-axis resistance plate 12 is shown, but it goes without saying that the Y-axis resistance plate 14 has a similar structure.

Next, a second embodiment of the present invention will be described with reference to FIGS. The first embodiment of FIGS. 1 and 2 is
As described in FIG. 6, the contact resistances 22, 23, 24,
The resistance values of 25 and the conductor resistances 26, 27, 28, 29 are different for each tablet, and the correction work is very troublesome.
The case where 0 and 30 and the Y-axis auxiliary electrodes 31 and 31 are provided and applied to an improved one has been described.

However, the present invention is not limited to this case. In the second embodiment, as shown in FIGS. 3 and 4, X
The present invention can be applied even if the axial auxiliary electrodes 30 and 30 and the Y-axis auxiliary electrodes 31 and 31 are not provided. That is,
The inserted external resistor 47 is provided with lead-out terminals A and B slightly inward from both ends thereof so that the resistors 48, 49, and 50 have three terminals.
Although divided, these lead terminals A and B are connected to the X-axis resistance plate 12
The voltage when the pen 17 presses on the a and b lines slightly inside the X-axis electrodes 11 and 11 is +
Reference (AVR +) and-reference (AVR
-).

Then, as shown in FIG. 4, the X-axis resistance plate 1
When the stacked body of 2 and the Y-axis resistance plate 14 is surrounded by the housing 41, it is surrounded by the housing 41 slightly inside the upper portions of the electrodes 11, 11. Then, the voltage on the a (or b) line at a position separated by a distance d from the electrode 11 when the laminated body is pressed by the pen 17 in a state of being substantially in contact with the inner peripheral edge portion 53 of the upper surface of the housing 41 is + Reference (AVR +) or-Reference (AVR-)
To be set. Without surrounding with the housing 41,
On the upper surface of the laminated plate, write a mark line indicating the a or b line, or the area outside the a or b line should be colored differently from the inside so that it is not used, or the a or b line A hard thin plate similar to the housing 41 is attached to an area outside the same as in the first embodiment.

Also in FIGS. 3 and 4, the X-axis resistance plate 1 is used.
Although only 2 is described, it goes without saying that the Y-axis resistance plate 14 also has the same configuration.

[0019]

According to the present invention, an external resistance is inserted between the X-axis electrodes at both ends and between the Y-axis electrodes at both ends in the tablet, and a + reference and a-reference are provided from inside of both ends of the external resistance. Since the voltage is derived, the voltage when pressing the electrode of the tablet or the auxiliary electrode slightly inside the tablet becomes the accurate + reference and − reference with almost no error. Further, since the electrode or the auxiliary electrode is not pressed, there is no problem such as cutting or cracking of the electrode or the auxiliary electrode.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a tablet position detecting method and device according to the present invention.

2 is a cross-sectional view of the tablet according to FIG.

FIG. 3 is a circuit diagram showing a second embodiment of a tablet position detecting method and device according to the present invention.

4 is a cross-sectional view of the tablet according to FIG.

FIG. 5 is a cross-sectional view of a conventional tablet.

FIG. 6 is a circuit diagram showing a tablet position detecting method.

[Explanation of symbols]

11 ... X-axis electrode, 12 ... X-axis resistance plate, 13 ... Y-axis electrode,
14 ... Y-axis resistance plate, 15 ... Dot spacer, 16 ... Changeover switch, 17 ... Pen, 19 ... Resistor, 20 ... A / D conversion circuit, 21 ... Output terminal, 22, 23, 24, 25 ... Contact resistance, 26 , 27, 28, 29 ... Conductor resistance, 30 ... X
Axis auxiliary electrode, 31 ... Y-axis auxiliary electrode, 32 ... Arithmetic circuit, 3
3, 34, 35, 36 ... Contact resistance, 37, 38, 39,
40 ... Conductor resistance, 41 ... Housing, 42 ... Insulating substrate,
43 ... Resistance layer, 44 ... Insulation spacer, 45, 46 ... Buffer circuit, 47, 48, 49, 50 ... Resistor, 51, 52
... buffer circuit.

Claims (4)

[Claims] 1. An X-axis resistance plate having X-axis electrodes formed on both ends of a resistance layer on an insulating substrate and a Y-axis resistance plate having Y-axis electrodes formed on both ends of a resistance layer on an insulating substrate are slightly provided. In the tablet formed by superimposing with an insulating void, external resistances are inserted between the X-axis electrodes at both ends and between the Y-axis electrodes at both ends, and + reference and −reference are applied from slightly inside of both ends of these external resistances. A method for detecting the position of a tablet, characterized in that and are derived. 2. An X-axis resistance plate having X-axis electrodes formed on both ends of a resistance layer on an insulating substrate and a Y-axis resistance plate having Y-axis electrodes formed on both ends of the resistance layer on an insulating substrate are slightly provided. In a tablet formed by superimposing an insulating void, an external resistance is inserted between each of the X-axis electrodes at both ends and between each of the Y-axis electrodes at each of the ends, and + is provided at a position slightly inward of both ends of the external resistance. A position detecting device for a tablet, wherein a lead-out terminal for deriving a reference and a -reference is provided, and a portion up to the same potential as the lead-out terminal on the resistance layer is surrounded by a housing. 3. An X-axis resistance plate having X-axis electrodes formed on both ends of a resistance layer on an insulating substrate, and a Y-axis resistance plate having Y-axis electrodes formed on both ends of the resistance layer on an insulating substrate. In the tablet formed by superimposing with different insulating voids, an X-axis auxiliary electrode and a Y-axis auxiliary electrode are provided inside the X-axis electrode and the Y-axis electrode, respectively, and between the X-axis auxiliary electrodes at these ends and at the Y-axis at both ends. A tablet position detecting method, characterized in that external resistances are respectively inserted between the auxiliary electrodes, and the + reference and −reference are derived from inside of both ends of these external resistances. 4. An X-axis resistance plate having X-axis electrodes formed on both ends of a resistance layer on an insulating substrate and a Y-axis resistance plate having Y-axis electrodes formed on both ends of the resistance layer on an insulating substrate are slightly provided. In the tablet formed by superimposing with an insulating void, an X-axis auxiliary electrode and a Y-axis auxiliary electrode are provided inside the X-axis electrode and the Y-axis electrode, respectively, and between the X-axis auxiliary electrodes at both ends and the Y-axis at both ends. External resistances are inserted between the shaft auxiliary electrodes, and lead-out terminals for leading out + reference and -reference are provided at positions slightly inside both ends of the external resistances, and the potential at the lead-out terminals on the resistance layer is set. A position detecting device for a tablet, characterized in that a portion up to the equipotential is surrounded by a housing.