JP2002131149A - Force detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a force detecting device of less area of an electrode pattern on a substrate. SOLUTION: Four electrodes Dx+, Dx-, Dy+, and Dy- are arranged on X and Y axes at every 90 deg. on a substrate, with conductive lands DG provided outside the electrodes. An operation button 2 is provided at a position facing the electrode and conductive land while an elastic displacement electrode 3 is provided on the side facing the electrode and conductive land of the operation button. When no press-in force is applied on the operation button 2, the electrode and conductive land do not contact the displacement electrode 3 while, when the operation button 2 is applied with a press-in force, the displacement electrode 3 contacts the conductive land DG to generate an electrostatic capacity, corresponding to magnitude and direction of the force, between the displacement electrode and each electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a force detecting device.

[0002]

2. Description of the Related Art As a force detecting device, for example, there is one as shown in FIG.

In this force detecting device, as shown in FIG. 10, when the button portion 90 is pushed vertically to the substrate 94, the lower end of the shaft portion 91 integrated with the button portion 90 turns on the thin switch 93. Button (switching function), button
When the 90 is tilted and pushed in, the displacement electrode 92 made of conductive rubber is displaced, and the displacement electrode 92 and the electrodes Dx +, Dx−, D on the substrate 94 are displaced.
The distance between y + and Dy- changes, and the output voltages of the X-axis and the Y-axis change (joystick function).

However, if a thin switch is arranged in the center, the X and Y-axis force detecting electrodes must be arranged outside the thin switch 93, and a conductive rubber displacement electrode 92 is further arranged outside. Therefore, the area of the electrode pattern on the substrate 94 becomes large, which is disadvantageous in mounting.

[0005] Although the thin switch is arranged in the center in the above, there is also a demand that the area of the electrode pattern on the substrate 94 be as small as possible even in the case where the thin switch is not arranged in the center.

[0006] Therefore, in the industry of manufacturing, selling and using force detecting devices, there is a long-awaited desire to develop a force detecting device capable of reducing the area of an electrode pattern on a substrate. Therefore, it has been awaited to develop a force detection device capable of reducing the area of an electrode pattern on a substrate.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a force detecting device capable of reducing the area of an electrode pattern on a substrate. An object of the present invention is to provide a force detection device capable of reducing the area of an upper electrode pattern.

[0008]

Means for Solving the Problems (Invention of Claim 1)
This force detecting device has four electrodes disposed on a substrate at 90 ° intervals on the X and Y axes, and a conductive land disposed outside the electrode, and an operation button located at a position facing the electrode and the conductive land. And a displacement electrode having elasticity is provided on a side of the operation button opposite to the electrode and the conductive land, and if no pushing force is applied to the operation button, the electrode and the conductive land come into contact with the displacement electrode. Without
When a pressing force is applied to the operation button, the displacement electrode comes into contact with the conductive land, and a capacitance corresponding to the magnitude and direction of the force is generated between the displacement electrode and each electrode. (Invention of Claim 2) This force detection apparatus calculates the electrostatic capacity generated between the displacement electrode and the four electrodes by using an appropriate method with respect to the invention of Claim 1, and calculates X axis,
A signal indicating the magnitude and direction of the force in the Y-axis direction can be output. According to the present invention, a thin switch is disposed on an upper portion of a substrate surrounded by four electrodes, and a force perpendicular to the substrate is applied to an operation button. When added, the thin switch is closed. (Invention of claim 4) In this force detecting device, two electrodes are arranged on an X axis or a Y axis on a substrate, and a conductive land is arranged outside the electrode, and the force detecting device is opposed to the electrode and the conductive land. The operation button is provided at a position where the operation button is provided, and an elastic displacement electrode is provided on the side of the operation button opposite to the electrode and the conductive land. A capacitance corresponding to the magnitude and direction of the force is generated between the electrode and each electrode. (Invention of Claim 5) This force detecting apparatus is the same as that of the invention of Claim 4 described above, but calculates each capacitance generated between the displacement electrode and the two electrodes by using an appropriate method. A signal indicating the magnitude and direction of the force in the axis or Y-axis direction can be output. (Invention of claim 6) In this force detection device, a thin switch is arranged on a substrate sandwiched between two electrodes, and a force perpendicular to the substrate is applied to the operation button. Then, the thin switch is closed. (Invention according to claim 7) This force detection device relates to the invention according to any one of claims 1 to 6, wherein the displacement electrode comprises:
It is made of conductive rubber or conductive elastomer. (Invention according to claim 8) This force detection device relates to the invention according to any one of claims 1 to 6, wherein the displacement electrode comprises:
It is formed by applying conductive ink or conductive paint to non-conductive rubber or non-conductive elastomer.

The function of the force detecting device of the present invention will be clarified in the following embodiments of the present invention.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings showing embodiments. [Embodiment 1] FIG. 1 is a sectional view of a force detecting device S according to Embodiment 1 of the present invention, and FIG. 2 is a diagram showing a conductive land DG, electrodes Dx +, Dx on a substrate 1 constituting the force detecting device S.
FIG. 2 shows a plan view of −, Dy +, Dy−, and the thin switch 5. (Regarding the configuration of the force detecting device S)
As shown in FIG. 1, a substrate 1, an operation button 2 arranged opposite to the substrate 1, a displacement electrode 3 arranged on the lower surface of the operation button 2, and the operation button 2
And a fixture 4 fixed thereon.

The substrate 1 is made of a thin printed circuit board as shown in FIG. 1, and has four circular electrodes Dx +, Dx-, Dy + and D divided on the upper surface as shown in FIG.
y− is arranged on the XY axis at an equal distance from the origin O, and the electrodes Dx +, Dx−,
An annular conductive land DG surrounding Dy + and Dy- is provided. Here, in this embodiment, the electrodes Dx +, D
As shown in FIG. 1 and FIG. 2, a thin switch 5 is disposed on a portion of the substrate 1 surrounded by x−, Dy +, and Dy−. The electrodes Dx +, Dx−, Dy +, Dy− and the conductive lands DG were formed by printing a copper layer formed on the substrate 1 with a solder layer, gold plating or silver plating, or carbon printing. And is formed by welding solder, and is covered with an insulating film R.

As shown in FIGS. 1 and 3, the operation button 2 comprises a hard portion 20 made of polycarbonate and a soft portion 21 made of non-conductive rubber or non-conductive elastomer. ing.

As shown in FIG. 1, the hard portion 20 has a push-in portion 20a formed in an inverted dish shape in cross section and the push-in portion.
The lower end of the hanging bar 20b is formed in a hemispherical shape.

The soft portion 21 mainly supports the operation buttons 2 on the substrate 1 and, as shown in FIG. A fixing part 22 to be attached;
a and a thin portion 23 connecting the fixed portion 22 to the fixed portion 22.

The displacement electrode 3 has a soft portion 21 as shown in FIG.
Are provided on the surface facing the electrodes Dx +, Dx-, Dy +, Dy- and the conductive land DG, and as shown in FIG. 3, are formed of an annular thin plate of conductive rubber or conductive elastomer. It should be noted that the distance between the displacement electrode 3 and the conductive land DG is still non-contact even when the operation button 2 is vertically pushed into the substrate 1 by a small distance and the hanging bar 20b turns on the thin switch 5. The dimensions are set as follows.

As shown in FIG. 1, the mounting member 4 has an L-shaped cross section and is annular in a plan view, and the operation button 2 is mounted in such a manner that the fixing portion 22 is pressed against the substrate 1.

The thin switch 5 has a thickness of several millimeters, and more specifically, a metal dome having a small amount of depression.
As a tactile switch with 50.

Here, as shown in FIG.
And the conductive land DG are in contact with each other, capacitances Cx +, Cx-, Cy +, Cy- are formed between the displacement electrode 3 and the electrodes Dx +, Dx-, Dy +, Dy-, When the operation button 2 is not depressed, the lower end of the hanging bar 20b is brought into contact with the thin switch 5 (or non-contact with a slight gap). The electrodes Dx +, Dx-, Dy +, and Dy- are applied with a voltage of a fixed period or a fixed voltage, and the conductive land DG is connected to 0 V of the power supply.

In this embodiment, the operation of [(Cx +)-(Cx-)] and [(Cy +)-(Cy-)] is performed as shown in FIG.
Signals in the X-axis direction and the Y-axis direction according to the magnitude and direction of the force pressing the operation button 2 are obtained. (Regarding the Function of the Force Detector S) When the operation button 2 is pressed in the Z-axis direction (perpendicular to the substrate 1), the thin portion 23 is deformed, and as shown in FIG.
The hanging bar 20b pushes the metal dome 50 of the thin switch 5 to turn on the switch. At this time, since the distance between the displacement electrode 3 and the conductive land DG is set as described above, as shown in FIG.
Is not in a connected state, so that the displacement electrode 3 and the electrode Dx
+, Dx-, Dy +, Dy-
Cx-, Cy +, and Cy- do not occur. Next, as shown in FIG. 5, when the operation button 2 is tilted and pushed in, the distance between the displacement electrode 3 and the electrode Dx + decreases, and the displacement electrode 3 and the conductive land DG come into contact with each other. Become. On the other hand, electrodes Dx +, Dx
Since voltages are applied to −, Dy +, and Dy−, when the displacement electrode 3 reaches the GND potential, the displacement electrode 3 and the electrode D
x +, Dx-, Dy +, Dy-
+, Cx-, Cy +, Cy- are generated. At this time, the capacitance is the displacement electrode 3 and the electrodes Dx +, Dx−, Dy +,
Since it is inversely proportional to the distance to y−, the capacitance Cx + becomes the largest value, and (Cx −) <[(Cy +) = (Cy)
−)] <(Cx +)... The relation of equation (1) is established. Here, since the displacement electrode 3 and the soft part 21 are made of an elastic body, when the operation button 2 is pressed strongly, the deformation is performed according to the magnitude of the force. Therefore, the capacitances Cx +, Cx−, Cy +, Cy− increase with the distance between the electrodes while maintaining the relationship of the above equation (1). The same can be said for the forces in other directions.

Therefore, signals in the X-axis direction and the Y-axis direction corresponding to the magnitude and direction of the force pressing the operation button 2 are obtained. When the force for tilting the operation button 2 described in the above is applied, it is possible to apply the force with a human finger while consciously not turning on the thin switch 5.

From the above, it is possible to turn on the thin switch 5 or change the X-axis and Y-axis output signals by adjusting the direction and intensity of the force pressing the operation button 2. It turns out that it is possible.

Further, in the force detection device S of the present invention, since the area of the conductive land DG can be reduced, it is apparent that the force detection device S is very advantageous in terms of mounting on equipment. Conversely, when the force on the operation button 2 is removed,
The displacement electrode 3 is separated from the conductive land DG on the substrate 1, and at that time, the displacement electrode 3 and the electrodes Dx +, Dx-, Dy +, Dy
-The capacitances Cx +, Cx-, Cy +, Cy- are not generated between them. This phenomenon occurs even if the displacement electrode 3 and the rubber constituting the soft portion 21 are slightly distorted by the force applied to the operation button 2 and do not return to the original position.
The capacitance Cx +, Cx−, Cy +, Cy− is “0” irrespective of the minute distortion of the displacement electrode 3 and the soft portion 21 because the displacement occurs reliably when the displacement electrode 3 is separated from the conductive land DG.
(The stray capacitance is so small that it can be ignored.) That is,
The outputs of the X axis and the Y axis shown in FIG. 6 are reliably returned to the original state, and almost no hysteresis occurs.

Therefore, if the present invention is applied to a joystick, it is possible to provide a joystick with good reproducibility and little hysteresis in the output. [Embodiment 2] FIG. 7 is a sectional view of a force detection device S according to Embodiment 2 of the present invention, and FIG. 8 is a diagram showing a conductive land DG and electrodes Dx + and Dx on a substrate 1 constituting the force detection device S.
2 shows a plan view of a negative switch 5 and a displacement electrode 3 provided on the operation button 2 side.

This force detection device S is similar to the first embodiment,
As shown in FIG. 7, a substrate 1, an operation button 2, a displacement electrode 3,
Although it is composed of the fixture 4 and the thin switch 5, the magnitude of the force and the direction of the force in one axis direction (X axis or Y axis) are to be detected. Are different.

As shown in FIGS. 7 and 8, a conductive land DG, an electrode Dx +, a thin switch 5, an electrode Dx-, and a conductive land DG are sequentially arranged on a straight line L on the upper surface of the substrate 1.

As shown in FIG. 7, the operation button 2 is of a seesaw button type which can be pushed in while being inclined in one axis direction.

The displacement electrode 3, the fixture 4, the thin switch 5, and the circuit for converting capacitance to voltage are the same as those in the first embodiment.

Since the force detecting device S has the above-described configuration, as shown in FIG. 9, when one end of the operation button 2 of the seesaw button type is pushed in, the displacement electrode 3 and the electrode Dx are pressed.
+, Dx-, and capacitances Cx +, Cx- are generated, and a uniaxial signal corresponding to the capacitances is output. When the center of the operation button 2 is pressed, the hanging rod 20b is turned into the thin switch 5 Switch is turned on by pushing the metal dome part 50 of
Becomes Since these functions have been described in the first embodiment, they will not be described here. (Other Embodiments) In the above embodiment, the displacement electrode 3 is a common electrode. However, the present invention is not limited to this. In other words, according to the second embodiment, the mutually separated Dx +
And a Dx− side displacement electrode may be provided.

In the above-described embodiment, a tactile switch is used as a thin switch, but any switch having the same function can be used.

[0030]

The present invention has the following effects since it has the above-described configuration.

As is clear from the description of the embodiments of the present invention, it is possible to provide a force detecting device capable of reducing the area of the electrode pattern on the substrate, and furthermore, it is possible to provide a force detecting device on the substrate while having a switching function. A force detection device capable of reducing the area of the electrode pattern can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a force detecting device according to a first embodiment of the present invention.

FIG. 2 is a plan view of conductive lands, electrodes, and thin switches arranged on a substrate constituting the force detecting device.

FIG. 3 is a diagram when an operation button and a displacement electrode constituting the force detection device are viewed from below.

FIG. 4 is a cross-sectional view when the operation button is pressed vertically to a substrate.

FIG. 5 is a cross-sectional view when the operation button is pressed obliquely with respect to a substrate.

FIG. 6 is a diagram of an application circuit that can be employed in this embodiment.

FIG. 7 is a sectional view of a force detection device according to a second embodiment of the present invention.

FIG. 8 is a plan view of conductive lands, electrodes, and thin switches arranged on a substrate constituting the force detection device.

FIG. 9 is a cross-sectional view when the operation button is pressed obliquely with respect to a substrate.

FIG. 10 is a cross-sectional view of a prior art force detection device.

FIG. 11 is a plan view of conductive lands, electrodes, and thin switches arranged on a substrate constituting a force detection device according to the related art.

[Explanation of symbols]

 S Force detection device Dx + electrode Dx- electrode Dy + electrode Dy- electrode DG Conductive land 1 Substrate 2 Operation button 3 Displacement electrode 4 Attachment 5 Thin switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Okada 4-244-1, Sakuragicho, Omiya-shi, Saitama 4th floor of the building (72) Inventor Nobumitsu Taniguchi 4-244-1, Sakuragicho, Omiya-shi, Saitama Tsuzuki Building 4th floor F term (reference) 2F051 AA21 AB06 DA02

Claims (8)

[Claims] 1. Four electrodes X, X at 90 ° intervals on a substrate
A conductive land is disposed on the Y-axis and a conductive land is disposed outside the electrode, an operation button is provided at a position facing the electrode and the conductive land, and an elastic displacement is provided on a side of the operation button facing the electrode and the conductive land. If the electrode is provided and the pressing force is not applied to the operation button, the electrode and the conductive land are not in contact with the displacement electrode, and when the operation button is pressed and the displacement electrode is in contact with the conductive land. A force detecting device for generating a capacitance between the displacement electrode and each electrode according to the magnitude and direction of the force. 2. The method according to claim 1, wherein each of the capacitances generated between the displacement electrode and the four electrodes is calculated using an appropriate method, and a signal indicating the magnitude and direction of the force in the X-axis and Y-axis directions can be output. The force detection device according to claim 1, wherein 3. A thin switch is disposed on an upper portion of a substrate surrounded by four electrodes, and when a force perpendicular to the substrate is applied to an operation button, the thin switch is closed. The force detection device according to claim 1. 4. An electrode is disposed on an X-axis or a Y-axis on a substrate, a conductive land is disposed outside the electrode, and an operation button is provided at a position facing the electrode and the conductive land. A displacement electrode having elasticity is provided on a side of the operation button opposite to the electrode and the conductive land,
When a pressing force is applied to the operation button, the displacement electrode comes into contact with the conductive land, and a capacitance corresponding to the magnitude and direction of the force is generated between the displacement electrode and each electrode. Force detection device. 5. A method for calculating each capacitance generated between a displacement electrode and two electrodes by using an appropriate method and outputting a signal indicating the magnitude and direction of a force in the X-axis or Y-axis direction. The force detecting device according to claim 4, wherein 6. A thin switch is arranged on a substrate sandwiched between two electrodes, and the thin switch is closed when a force perpendicular to the substrate is applied to an operation button. Item 5. The force detection device according to Item 4. 7. The force detecting device according to claim 1, wherein the displacement electrode is made of a conductive rubber or a conductive elastomer. 8. The displacement electrode according to claim 1, wherein the displacement electrode is formed by applying a conductive ink or a conductive paint to a non-conductive rubber or a non-conductive elastomer. Force detector.