JPH04279921A - Coordinate detector - Google Patents

Abstract

PURPOSE:To dispense with a constant voltage circuit and high accuracy for the source voltage of an A/D converter and to improve coordinate detecting accuracy. CONSTITUTION:This detector is equipped with first resistance film 101 and second resistance film 102 arranged confronting with each other, a power source supply means 103 which supplies potential to the first resistance film 101 or the second resistance film 102, a control means 104 which performs a first detecting operation which supplies power source potential Vs from the power source supply means 103 in the x-axial direction of the first resistance film 101 and detects coordinate potential VI from the second resistance film 102 when two sheets of film 101, 102 are brought into contact with each other at an arbitrary position P, and a second detecting operation which detects the source potential VS by switching arbitrarily, and an arithmetic means 105 which calculates the coordinate value xP of a contact point P from the x-axial potential VI and the source potential VS.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detection device suitable for touch panel switches and the like that input multiple items.

0002

[Prior Art] Conventionally, coordinate detection is provided with two opposing resistive films 1 and 2 as shown in FIG. 4, and the coordinate position of point P on the resistive film is detected by bringing both resistive films into contact at a point P. Device 2
00 is known. This coordinate detection device 200 includes a power source 3 and a constant voltage circuit 16 for applying a potential to two opposing uniform resistance films 1 and 2, changeover switches 5, 6, and 7, and an A/D converter 4. It is equipped with a CPU 17. The resistive films 1 and 2 are made of indium oxide (ITO) or the like. Electrodes 11 and 12 are provided on the resistive film 1 , the electrode 11 is connected to the changeover switch 5 , and the electrode 12 is connected to the changeover switch 6 . Further, an electrode 1 is placed on the resistive film 2.
Electrodes 13 and 14 are provided in a direction perpendicular to the directions of 1 and 12, electrode 13 is connected to changeover switch 5, and electrode 14 is connected to changeover switch 7.

[0003] When detecting the coordinate position of point P using this coordinate detection device 200, first, both resistive films 1 and 2 are brought into contact at point P by pressing down on the position of point P with a finger. The CPU 17 switches the changeover switches 5 and 6 as shown, and applies the potential of the constant voltage circuit 16 in the direction from the electrode 11 to the electrode 12 (hereinafter referred to as the x direction). Then, the potential v1 of the point P in the x direction is from the resistive film 2 to the electrode 1.
4. The signal is inputted to the A/D converter 4 via the changeover switch 7, and inputted to the CPU 17 as a digital signal to calculate the position of point P in the x direction, that is, the x coordinate xP.

FIG. 5 shows an equivalent circuit of this coordinate detection device 200.
Shown below. In this case, the equivalent resistance value of the resistive film 1 corresponding to the potential v1 in the x direction of point P is R1, the equivalent resistance value of the entire resistive film 1 is (R1 + R2), and the electrode 11 and the electrode 12 are
If the distance between the point P and the electrode 12 is L1, the distance between the point P and the electrode 12 is l1, and the potential of the constant voltage circuit 16 is V, then since the resistive film is uniform, v1 /V=R1 /(R1 +R2)
The formula is established, and the distance L1 is the resistance value (R1 + R2)
Since the distance l1 corresponds to the resistance value R1,
As shown in FIG. 6, the distance l1 in the x direction between the point P and the electrode 12 can be calculated from the formula l1 = v1 ×L1 /V. Here, if the position of the electrode 12 is x=0,
l1 represents the X coordinate xP of point P.

Next, the CPU 17 switches the changeover switches 5, 6,
7 in the direction opposite to the position shown in FIG. ) is input from the resistive film 1 to the A/D converter 4 via the electrode 12 and the changeover switch 6, and is input to the CPU 17 as a digital signal to determine the position of point P in the y direction, that is, the y coordinate yP. Calculated.

[0006]

However, in the conventional coordinate detection device 200 described above, if the potential of the power supply applied to the resistive film is not constant, the detection voltages v1 and v2 will fluctuate, causing errors. Further, fluctuations in the power supply voltage of the A/D converter 4 also affect the accuracy of the digital signal output. For this reason, it was necessary to provide a constant voltage circuit 16, etc., which is complicated and expensive.

Therefore, the present invention provides a contact-type coordinate detection device that does not require a constant voltage circuit, does not require much accuracy of the power supply voltage of the A/D converter, and can improve coordinate detection accuracy. The purpose is to provide

[0008]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 is constructed as shown in FIG. As shown in FIG. 1, this coordinate detection device 100 includes a first resistive film 101 and a second resistive film 1 that are arranged opposite to each other.
02 and this first resistive film 101 or second resistive film 10
When the power supply means 103 that applies a potential to the resistive film 101 and the two resistive films 101 and 102 are brought into contact at an arbitrary point P,
A power supply potential VS is applied from the power supply means 103 to the first resistive film 101 in the x-axis direction, and the second resistive film 102
A control means 104 that arbitrarily switches between a first detection operation for detecting the x-coordinate potential Vx and a second detection operation for detecting the power supply potential VS; and calculation means 105 for calculating the x-coordinate value xP of P.

As shown in FIG. When the power supply means 103 that applies a potential to the resistive film 102 and the two resistive films 101 and 102 are brought into contact at an arbitrary point P, the power supply means 1 is applied in the x-axis direction of the first resistive film 101.
A first detection operation in which a power supply potential VS is applied from 03 to the second resistive film 102 and an x-coordinate potential Vx is detected from the second resistive film 102; 101 to y-coordinate potential Vy
Control means 1 for arbitrarily switching between a second detection operation for detecting the power supply potential VS and a third detection operation for detecting the power supply potential VS.
04, the x-coordinate value xP of the contact point P is calculated from the x-coordinate potential Vx and the power supply potential VS, and the y-coordinate potential Vy
and a calculation means 105 for calculating the y-coordinate value yP of the contact point P from the power supply potential VS and the power supply potential VS.

[0010] The invention according to claim 3 provides a first panel including a first resistive film and a second resistive film arranged opposite to each other, and a third resistive film arranged opposite to each other. a second panel configured to include a resistive film and a fourth resistive film and provided at an angle to the first panel; a power supply means for applying a potential to either of the resistive films; When the first resistive film and the second resistive film are brought into contact at the first projection point of an arbitrary spatial point in the space determined by the panel and the second panel onto the first panel, A power supply potential is applied from the power supply means in the x-axis direction of the first resistive film, and the second
A first detection operation of detecting the x-coordinate potential from the resistive film, and applying a power supply potential in the y-axis direction of the second resistive film, and
A second detection operation for detecting the y-coordinate potential from the resistive film and a third detection operation for detecting the power supply potential are arbitrarily switched and performed, and a second projection point of the spatial point onto the second panel is performed. When the third resistive film and the fourth resistive film are brought into contact with each other,
a fourth detection operation of applying a power supply potential in the z-axis direction of the third resistive film and detecting the z-coordinate potential from the fourth resistive film;
a control means for arbitrarily switching and performing a fifth detection operation of detecting a power supply potential; and calculation means for calculating the y-coordinate value of the spatial point and the z-coordinate value of the spatial point from the z-coordinate potential and the power supply potential.

[0011]

According to the invention as set forth in claim 1 having the above configuration, switching between the first detection operation for detecting the x-coordinate potential Vx and the second detection operation for detecting the power supply potential VS is performed faster than the fluctuation speed of the power supply. By performing the calculation at high speed, it is possible to calculate the x-coordinate value xP of the contact point P with high accuracy, which does not include errors due to fluctuations in the power supply.

Similarly, as in the invention according to claim 2,
As for the x-coordinate value xP and y-coordinate value yP of the contact point P, highly accurate values that do not include errors due to power supply fluctuations can be obtained. Further, according to the third aspect of the invention, by using two panels, it is possible to obtain the x-coordinate, y-coordinate, and z-coordinate values of a spatial point with highly accurate values that do not include power supply fluctuation errors. Therefore, there is no need for a constant voltage circuit that keeps the power supply voltage constant, and a configuration that does not require much accuracy in the power supply voltage of the A/D converter can be achieved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the configuration of an embodiment of the present invention. Figure 2
The coordinate detection device 100A includes two uniform resistive films 1 and 2, a power supply 3 for applying a potential to the resistive films 1 or 2, and a power supply 3 for applying a potential to the resistive films 1 or 2 from the power supply 3. , and changeover switches 5, 6, and 7 for detecting the potential for calculating the coordinates of the contact point P from the resistive film 1 or 2.
, 10, selector switches 8, 9, 10 for detecting the potential of the power supply 3, an A/D converter 4 for converting the detected potential into a digital signal, and calculating and outputting the coordinate value of the point P from the digital signal. It is equipped with a CPU 15 that performs the following steps.

The embodiment shown in FIG. 2 differs from the conventional example shown in FIG. 4 in that changeover switches 8, 9, and 10 for measuring the potential of the power source 3 are provided. As a result, as shown in FIG.
7, 8, and 9 and switch the selector switch 10 to the terminal a side, it is possible to detect the potential v1 for calculating the coordinate value in the direction (x direction) of the electrodes 11 and 12 at the contact point P. .

That is, if the changeover switch 10 is switched to the terminal b side by the CPU 15, the power supply potential of the power supply 3 at this time, that is, the potential E1 at the electrode 11 can be detected. If this switching is performed by the CPU 15 at a sufficiently high speed, the potentials v1 and E
1 can be detected, and the influence of errors caused by voltage fluctuations can be removed. Here, the distance between the point P and the electrode 12 is determined by the formula l1 = v1 × L1 /E1, and if the position of the electrode 12 is set to x = 0, then the x coordinate value xP of the point P can be obtained by setting xP = l1. It will be done. Similarly, the coordinate value yP of the point P in the direction (y direction) of the electrodes 13 and 14 can also be detected without being affected by fluctuations in the power supply voltage. That is, the distance between the electrodes 13 and 14 is L2,
If the distance between the point P and the electrode 14 is l2, the potential corresponding to l2 is v2, and the potential of the power supply 3 at this time is E2, then l2 = v2 × L2 /E2, and the electrode 14
If the position of is y=0, then yP = l2 and y of point P
The coordinate value yP is determined.

In this case, the order of detection of each potential is, for example, V
1 →E1→V2 →E2 or E1 →V1
→E2 →V2 or V1 →V2 →E2 etc. The point is that the potential corresponding to the x-coordinate, the potential corresponding to the y-coordinate, and the potential of the power supply can be switched arbitrarily and at a sufficiently high speed. Here, the resistive film 1 corresponds to a first resistive film, the resistive film 2 corresponds to a second resistive film, and the power source 3 corresponds to a power supply means. In addition, the changeover switch 5
, 6, 7, 8, 9, 10 and the CPU 15 constitute a control means. The A/D converter 4 and the CPU 15 constitute calculation means. The potential E1 and the potential E2 correspond to a power supply potential, the potential v1 corresponds to an x-coordinate potential, and the potential v2 corresponds to a y-coordinate potential.

In the above embodiment, the coordinates (x
P, yP), but a device that detects only the linear coordinates of the contact point P (for example, xP) is also included within the scope of the present invention. That is, in FIG. 2, if the changeover switch 9 is removed and the changeover switches 5 and 6 are fixed only to the illustrated terminal side, the x-coordinate value x of the contact point P
Only P can be detected. This modification is shown in Figure 2.
If the embodiment shown in FIG. 1 is a two-dimensional coordinate detection device, it can be called a one-dimensional coordinate detection device. Of course, this may be configured so that only the y-coordinate value yP of the contact point P can be detected.

Furthermore, as another embodiment, FIG. 3 shows an apparatus for detecting spatial coordinates (three-dimensional coordinates). This device is a combination of the first panel 21, which is the two-dimensional coordinate detecting device, and the second panel 22, which is the one-dimensional coordinate detecting device. With this configuration, the coordinates (xP, yP, zP) of the spatial point P can be detected accurately in the same manner as described above without being affected by power fluctuations. Such a three-dimensional coordinate detection device can be used as a multi-item input device, and is also suitable for a data input device that inputs three-dimensional histogram data. In this case, the second panel 22 may be a two-dimensional coordinate detection device similar to the first panel 21.

The present invention is not limited to the above embodiments. In the above embodiment, the electrodes 11, 1 of the resistive film 1
2 and the electrodes 13, 14 of the resistive film 2 are at right angles to each other, and the coordinates (xP, yP) of point P are coordinates of the orthogonal coordinate system, but the electrodes 11, 12 and the electrodes 13, 14 are at an angle. Both resistive films may be arranged so as to cross each other. In this case, the coordinates P (xP, yP) represent coordinates in an oblique coordinate system. The same applies to the spatial coordinates P (xP, yP, zP). Further, it does not matter which terminal is switched first between the terminal a side and the terminal b side of the changeover switch 10.

[0020]

[Effects of the Invention] As explained above, according to the present invention,
This has the advantage that a constant voltage circuit is not required, the accuracy of the A/D converter is not required so much, and the coordinate detection accuracy can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention.

FIG. 2 is a diagram showing the configuration of an embodiment of the present invention.

FIG. 3 is a diagram showing the configuration of another embodiment of the present invention.

FIG. 4 is a diagram showing the configuration of a conventional example.

FIG. 5 is a diagram showing an equivalent circuit of a conventional example.

FIG. 6 is a diagram illustrating the operation of a conventional example.

[Explanation of symbols]

1, 2... Resistive film 3... Power supply 4... A/D converter 5, 6, 7, 8, 9, 10... Changeover switch 11, 12,
13, 14... Electrode 15... CPU 16... Constant voltage circuit 17... CPU 21... First panel 22... Second panel 100, 100A... Coordinate detection device 101... First resistive film 102... Second resistive film 103 …Power supply means 104…Control means 105…Calculation means 200…Coordinate detection devices a, b…Terminals L, l1, l2…Distance P…Contact point, spatial points R1, R2…Equivalent resistance

Claims (3)

[Claims] Claim 1: A first resistive film (1
01) and a second resistive film (102), a power supply means (103) for applying a potential to the first resistive film (101) or the second resistive film (102), and the two resistive films (102). 10
1, 102) at an arbitrary point (P), the power supply potential (VS ) is applied from the power supply means (103) in the x-axis direction of the first resistive film (101), and the The x-coordinate potential (Vx
) and a first detection operation for detecting the power supply potential (VS
), a control means (104) for arbitrarily switching and performing a second detection operation for detecting A coordinate detection device characterized by comprising: arithmetic means (105) for calculating (xP). 2. A first resistive film (1
01) and a second resistive film (102), a power supply means (103) for applying a potential to the first resistive film (101) or the second resistive film (102), and the two resistive films (102). 10
1, 102) at an arbitrary point (P), the power supply potential (VS ) is applied from the power supply means (103) in the x-axis direction of the first resistive film (101), and the The x-coordinate potential (Vx
), and a first detection operation for detecting the second resistive film (1
02) in the y-axis direction, and the y-coordinate potential (Vy
) and a second detection operation for detecting the power supply potential (VS
), a control means (104) for arbitrarily switching and performing a third detection operation for detecting (xP), and the y-coordinate potential (Vy
) and the power supply potential (VS ) to the contact point (P).
A coordinate detection device characterized by comprising: arithmetic means (105) for calculating a y-coordinate value (yP) of . 3. A first panel including a first resistive film and a second resistive film arranged opposite to each other, a third resistive film and a fourth resistive film arranged oppositely to each other; a second panel including a resistive film and provided at an angle to the first panel; power supply means for applying a potential to any of the resistive films; Second
When the first resistive film and the second resistive film are brought into contact at a first projection point of an arbitrary spatial point in the space determined by the panel and the first panel, the first a first resistive film that applies a power supply potential from the power supply means in the x-axis direction of the resistive film and detects an x-coordinate potential from the second resistive film;
a detection operation, a second detection operation of applying the power supply potential in the y-axis direction of the second resistive film and detecting the y-coordinate potential from the first resistive film, and a third detection operation of detecting the power supply potential.
The detection operation is arbitrarily switched and performed, and the third detection operation is performed at a second projection point of the spatial point onto the second panel.
When the resistive film and the fourth resistive film are brought into contact with each other, the third resistive film
arbitrarily switching between a fourth detection operation of applying the power supply potential in the z-axis direction of the resistive film and detecting the z-coordinate potential from the fourth resistive film, and a fifth detection operation of detecting the power supply potential; calculating an x-coordinate value of the spatial point from the x-coordinate potential and the power supply potential, and calculating a y-coordinate value of the spatial point from the y-coordinate potential and the power supply potential, and A coordinate detection device comprising: arithmetic means for calculating a z-coordinate value of the spatial point from the z-coordinate potential and the power supply potential.