JPH07130263A - Capacitor type sensor - Google Patents

Abstract

PURPOSE:To provide a sensor low in height with no overload in a strain motive part by constituting a force receiving part of a central shaft part in the strain distortion part and an overhung part protruded to the outward from this shaft part. CONSTITUTION:A force receiving part 3 is constituted of a dish-shaped unit 35 comprising a short shaft part 32 integrally formed with a strain distortion part 10 and a plate-shaped part 34 integrally formed with a cylinder part 33. A shaft part 30 is constituted of the short shaft part 32 and the cylinder part 33, and also constituting an overhung part 31 of the plate-shaped part 34. A erected peripheral part of the plate-shaped part 34 is placed adjacent to an annular part 11, and a press-in amount of the plate-shaped part 34 is restricted by contact with the annular part 11. An electrode part C is provided by plating in a total surface opposed to a cover unit 2 of the strain motive part 10, and four-divided electrode parts Cx+, Cx-, Cy+, Cy- are formed by etching parallelly to the electrode part C. Thus by decreasing height also with no overload acting in the strain distortion part 10, damaging a strain distortion unit 1 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitance type sensor.

[0002]

2. Description of the Related Art As a sensor of this type, for example, there is one shown in FIG. 7, which uses a highly rigid annular portion 11 as a strain generating portion 10 as well as the strain generating portion 10 described above. The strain-flexing portion 10 has a strain-generating body 1 provided with a shaft-shaped force receiving portion 3 in the center thereof, and a lid body 2 provided to cover the strain-generating portion 1. Is provided with a circular electrode portion C centered on the axis of the force receiving portion 3, and electrode portions Cx +, Cx −, Cy formed by dividing the circle into four on the inner surface of the lid body 2.
+ And Cy- are provided. In addition, this sensor includes the electrode portion C and each electrode portion Cx +, electrode portion Cx −, electrode portion C
An electronic device is provided which can convert the respective electrostatic capacities between y + and the electrode portion Cy-to the voltage Vx +, the electrode portion Vx −, the electrode portion Vy +, and the electrode portion Vy −, respectively.

Therefore, in this sensor, an external force acts on the force receiving portion 3 to cause the electrode portion C and each electrode portion Cx +, Cx −,
The distance between Cy + and Cy − changes and the electrode portion C changes.
When the respective electrostatic capacitances between the electrode portion Cx +, the electrode portion Cx −, the electrode portion Cy +, and the electrode portion Cy − are changed, the change amounts are the voltage Vx +, the electrode portion Vx −, the electrode portion Vy +, respectively. ,
It is converted into the electrode part Vy −.

However, in this sensor, since the strain-flexing portion 10 needs to be deformed to some extent, the force-receiving portion 3 must be relatively long, which causes a problem that the height becomes high. It was In addition, when an unnecessarily large external force acts on the force receiving portion 3, an overload acts on the strain generating portion 10, which causes a problem that the strain generating body 1 is damaged.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a capacitance type sensor which is short in height and in which an overload does not act on a strain generating portion.

[0006]

According to the present invention, the strain generating portion 10 is provided in the annular portion 11 having a high rigidity, and the strain generating portion 10 is provided.
On a strain-generating body 1 having a force-receiving portion 3 provided in the central portion thereof, a lid 2 arranged to face the strain-generating portion 10, and one of the facing surfaces of the strain-generating body 1 and the lid 2. A capacitance type sensor having an electrode portion C provided and electrode portions Cx +, Cx −, Cy +, Cy − provided on the other of the facing surfaces of the strain body 1 and the lid 2. In the above, the force receiving portion 3 is composed of a short shaft portion 30 standing upright in the center of the strain-flexing portion 10 and a protruding portion 31 protruding outward from the shaft portion 30, and a part of the protruding portion 31 is formed into the annular shape. The push-out amount of the overhanging portion 31 is regulated by abutting on the annular portion 11 in the vicinity of the portion 11.

[0007]

The present invention operates as follows. In this capacitance type sensor, the force receiving portion 3 includes a short shaft portion 30 standing upright in the center of the strain-flexing portion 10 and an overhang portion 3 extending outward from the short shaft portion 30.
Since it is composed of 1 and 1, the height is shorter than that described in the section of the prior art.

Further, a part of the protruding portion 31 is brought close to the annular portion 11, and the pushing amount of the protruding portion 31 is set to the annular portion 11.
Since it is regulated by abutting with, the overload does not act on the strain-flexing part 10 and the strain-generating body 1 is not damaged. In this sensor, when the outer portion of the overhanging portion 31 is pushed in, the overhanging portion 31 has a (pushing force) ×
A moment (distance from the shaft portion 30 to the pushing position) acts, and a force corresponding to the moment acts on the shaft portion 30 supporting the overhang portion 31. Therefore, the strain generating unit 10
Will be deformed, and the capacitance between the electrode portion C and each electrode portion Cx +, electrode portion Cx −, electrode portion Cy +, and electrode portion Cy − will change accordingly. Similar to the sensor described in the column, the change amount of each capacitance is calculated as follows: voltage Vx +, electrode portion Vx −, electrode portion Vy
+, The electrode portion Vy − can be converted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments. In this embodiment, the capacitance type sensor of the present invention is used as a cursor operating portion of a control display screen of an office automation equipment, and as shown in FIG. 1 and FIG. The pushing force of the button B acts on the force receiving portion 3 of the sensor through the protrusion T.

As shown in FIG. 3 and FIG. 4, the capacitance type sensor S of this embodiment is formed in a columnar shape as a whole, and has a flexure element 1, a lid body 2, and a force receiving portion. 3, a seat 4, and an electronic device (not shown). Strain body 1
As shown in FIG. 3 and FIG. 4, a thin plate-shaped strain generating portion 10 is formed in the annular portion 11 having a high rigidity in a plan view circular shape in the middle in the thickness direction thereof. 10 is provided with a force receiving portion 3 which is a means for deforming it.

In this embodiment, the force receiving portion 3 is, as shown in the figure, a short shaft portion 32 integral with the strain-flexing portion 10, a cylindrical portion 33 fitted on the short shaft portion 32, and this. Integrated dish-shaped portion 34
And a dish-shaped body 35 composed of
2 and the cylindrical portion 33 constitute the shaft portion 30 of the means column, and the dish-shaped portion 34 constitutes the projecting portion 31 of the means column. Then, the outer peripheral rising portion of the dish-shaped portion 34 is brought close to the annular portion 11 (gap G of about 1 to 3 mm), and the pressing amount of the dish-shaped portion 34 is regulated by contact with the annular portion 11.

As shown in FIG. 5, a circular electrode portion C is provided on the entire surface of the strain-flexing portion 10 facing the lid body 2. The electrode portion C is formed by plating. is there. As shown in FIGS. 3 and 4, the lid body 2 is formed of a circular plate having the same diameter as that of the annular portion 11, and the surface facing the strain-flexing portion 10 has an electrode portion C as shown in FIG. Electrode parts Cx +, Cx-, Cy +, Cy-
Are formed by an etching technique used for manufacturing a printed circuit board.

The seat 4 is, as shown in FIGS. 3 and 4,
It is formed of an annular plate having the same diameter as the lid 2. [Function of Electronic Device] The electronic device includes an electrode portion C and an electrode portion C.
x + mutual, electrode C and electrode Cx − mutual, electrode C and electrode Cy + mutual, electrode C and electrode Cy −
The change in the capacitance between them is measured by the voltage Vx +,
It is designed to be converted into Vx −, Vy +, Vy −,
The pushing force to push button B in the XX direction is [(Vx
+)-(Vx-)], and the pushing force to the pushing button B in the Y-Y direction is converted into [(Vy +)-(Vy-)], respectively, and the magnitudes of the absolute values of these voltages are converted. Is used to determine the moving speed of the cursor.

In the OA equipment adopting the capacitance type sensor of this embodiment, the sensor storage space can be lowered, and
The failure of the device due to the damage of the flexure element 1 is less likely to occur. Further, when the right and lower push-in buttons B are pushed at the same time, the cursor moves diagonally downward right. Further, by omitting the push-in button B, the protrusion T, and the panel surface P and directly pushing the peripheral portion of the force receiving portion 3 from above, a plurality of push-in buttons B cannot be pushed simultaneously.
By pressing an arbitrary position, the direction and the moving speed of the cursor can be adjusted according to the position and strength.

When the dish-like body 35 in the above embodiment is made of synthetic resin, even if an excessively strong pushing force is applied thereto, the dish-like body 35 bends to some extent, so that all of the pushing force is generated in the strain generating portion 10. Will not act as the deforming force of
Damage to the strain-flexing part 10 can be prevented. Further, in the above-mentioned embodiment, the electrode portions Cx +, Cx −, Cy +, C are provided on the side of the flexure element 1.
The y − may be provided with the electrode portion C on the lid body 2 side. On the other hand, when the strain body 1 is made of a conductive metal, the strain body portion 10 of the strain body 1 itself is an electrode. It functions as the portion C, and plating of the electrode portion C is unnecessary.

Further, in the above embodiment, a non-conductive member C having elasticity may be interposed between the electrode portion C and the electrode portions Cx +, Cx −, Cy +, Cy −. Then, instead of the method of forming the electrode portion of the above-mentioned embodiment, the electrode portion may be formed by insert molding a metal plate, or the electrode portion may be formed by screen printing.

[0017]

The present invention having the above-mentioned structure has the following effects. From the contents described in the action, it is possible to provide a capacitance type sensor having a short height and without causing an overload on the strain-flexing portion.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electrostatic capacitance sensor according to an embodiment of the present invention as an OA.
Sectional drawing when using it as a cursor operation part of the display screen for control of a device.

FIG. 2 is a plan view of a push button provided on a panel surface of the OA device.

FIG. 3 is a perspective view showing a partial cross section of the capacitance type sensor.

FIG. 4 is a sectional view of the capacitance type sensor.

FIG. 5 is a plan view of an electrode portion on the strain generating body side in the capacitance type sensor.

FIG. 6 is a plan view of an electrode portion on the lid side in the capacitance type sensor.

FIG. 7 is a cross-sectional view of a prior art capacitive sensor.

[Explanation of symbols]

 1 Strain element 2 Lid body 3 Force receiving part 10 Strain element 11 Annular part 30 Shaft part 31 Overhanging part

Claims (1)

[Claims] 1. A strain-generating body (1) comprising a strain-generating portion (10) in a highly rigid annular portion (11) and a force-receiving portion (3) provided at a central portion of the strain-generating portion (10). ), A lid (2) disposed opposite to the strain-flexing part (10), and an electrode part (C) provided on one of the facing surfaces of the strain-defining body (1) and the lid (2). ) And an electrode part (Cx +) (Cx −) provided on the other of the facing surfaces of the strain body (1) and the lid body (2).
In a capacitive sensor of the type having (Cy +) and (Cy −), the force receiving portion (3) has a short shaft portion (30) erected at the center of the strain-flexing portion (10) and an outer portion from this. And an overhanging portion (31) that overhangs toward one side.
A capacitance type sensor characterized in that a part of 1) is brought close to the annular portion (11) and the pushing amount of the overhanging portion (31) is regulated by contact with the annular portion (11).