JP3286767B2 - Capacitive sensor - Google Patents

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 and can be used, for example, as an operation unit for moving a cursor displayed on a display of a computer as desired.

[0002]

2. Description of the Related Art This type of sensor has been developed in-house and has already been filed (Japanese Patent Application No. 5-540). As shown in FIGS. 8, 9 and 10, this sensor has a substrate 90 having an input shaft portion 90a at a central portion, and a substrate 91 disposed opposite to the substrate 90. And electrode portions Cx +, Cx on the upper surface of the substrate 91.
x-, Cy +, and Cy- are respectively provided, and a thin elastic plate 92 is interposed between the upper and lower electrode portions. As shown in FIG. 8, an electronic device 93 is provided on the lower surface of the substrate 91 of the sensor. The electronic device 93 allows the electrode unit C to be located between the electrode units Cx + and between the electrode unit C and the electrode unit Cx−. Between each other, electrode part C and electrode part Cy +
A change in capacitance between the electrodes and between the electrode section C and the electrode section Cy- can be converted into a change in voltage.

Therefore, when the upper end of the input shaft 90a is displaced in the vertical and horizontal directions (XX direction, YY direction) with a finger, the gap between the electrode portions is opposed to the urging force of the elastic plate 92. The gap G of each part changes, and as a result, the amount of displacement (corresponding to the pressing force) of the input shaft portion 90a in the pressed direction can be taken out as a voltage output. When this sensor is used as a moving operation unit of a cursor displayed on a display, it is sufficient to incorporate the sensor so that only the upper end of the input shaft 90a protrudes from the upper wall of the keyboard KB as shown in FIG. , The magnitude of the cursor moving speed may be determined by the magnitude of the voltage output.

However, when this sensor is employed as a cursor operating section as described above, the displacement of the input shaft section 90a due to the force from a finger is 0.01 mm to 0.5 mm.
Since the degree of operation is small, the operational feeling is small. Therefore, it is difficult to finely adjust the moving direction and the moving speed of the cursor displayed on the display. In order to increase the amount of displacement of the input shaft 90a, it is conceivable to increase the length of the input shaft 90a as a means of increasing the size of the input shaft 90a. Then, the displacement cannot be so large.

In recent years, there has been a demand for the development of a capacitance type sensor which is low in bulk and whose input portion is largely displaced by an external force (for example, an operation force from a finger). It is desired not only to develop the sensor but also to improve the sensitivity of the sensor.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a capacitive sensor having a low bulk and a large displacement of an input section.

[0007]

According to a first aspect of the present invention, there is provided a capacitance type sensor, comprising: substrates 1, 2 which are disposed in parallel to each other and one of which is movable in parallel with respect to the other;
An electrode portion C provided on the opposing surface of the substrate 1, an electrode portion Cx +, Cx−, Cy +, Cy− provided at 90 ° intervals about the center of the opposing surface of the substrate 2; , 2 and an input portion J provided at the center of either one of the electrode portions Cx +, Cx−, Cy +, Cy in a plan view in a state where no force acts on the input portion J.
Each of the outer portions of-has protruded from the electrode portion C, and when one of the substrates 1 and 2 is moved in parallel with the other, the electrode portions C and 2 correspond to the direction and amount of the movement. The opposing area between Cx +, between electrode portions C and Cx−, between electrode portions C and Cy +, and between electrode portions C and Cy− changes, so that the capacitance changes. The force in the X-axis direction acting on J is determined by the electrode portion C and the electrode portion Cx.
+, Cx−, the difference between the two capacitances, the force acting on the input portion J in the Y-axis direction becomes the electrode portion C and the electrode portions Cy +, C +
The difference between the two capacitances between y and each other is detected.

According to a second aspect of the present invention, there is provided a capacitance type sensor of the present invention, which is made of a conductive material and functions as an electrode portion C, and is disposed in parallel with and opposed to the substrate 1. A substrate 2, electrode portions Cx +, Cx−, Cy +, Cy− provided at 90 ° intervals about the center of the opposing surface of the substrate 2, and a central portion of one of the substrates 1 and 2 And an input unit J provided, wherein one of the substrates 1 and 2 is provided so as to be movable in parallel with respect to the other, and in a state where no force is applied to the input unit J, the electrode unit is viewed in a plan view. Cx +, Cx-, C
The outer portions of y + and Cy- protrude from the electrode portion C, and when one of the substrates 1 and 2 is moved in parallel with the other, the electrodes correspond to the direction and amount of the movement. Between parts C and Cx +, between electrode parts C and Cx-,
The opposing area between the electrode portions C and Cy + and between the electrode portions C and Cy− change so that the capacitance changes, and the force acting on the input portion J in the X-axis direction is Due to the difference between the two capacitances between C and the electrode portions Cx + and Cx−, the force acting on the input portion J in the Y-axis direction is equal to the electrode portion C and the electrode portion C.
The difference between the two electrostatic capacitances between y + and Cy- is detected respectively.

[0009]

The present invention has the following functions. (Effect of Claim 1) In this capacitance type sensor, when an external force is applied to the input portion J and one of the substrates 1 and 2 is translated (displaced) with respect to the other, the electrode portion C Since the opposing areas of the electrode portions Cx +, the electrode portions C and the electrode portions Cx-, the electrode portions C and the electrode portions Cy +, and the electrode portions C and the electrode portions Cy- change, the capacitance between them changes. . Therefore, the displacement (direction and amount) of the input unit J is the same as the sensor described in the section of the prior art.
Can be detected as a voltage change.

As described above, in this sensor, when an external force is applied to the input portion J, one of the substrates 1 and 2 moves in parallel with respect to the other. Unlike the type in which the thin elastic plate is compressed to displace the input shaft portion, the displacement amount can be considerably increased even if the input shaft portion is not lengthened or not. (Function of the Invention of Claim 2) In this capacitance type sensor, the substrate 1 functions as the electrode portion C, and has the same function as that of the invention of claim 1.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention; (Embodiment 1) In this embodiment, in order to adopt the capacitance type sensor of the present invention as a moving operation section of a cursor displayed on a display, as shown in FIG. An input shaft 10 serving as an operation unit is projected from a circular opening h provided on the upper wall of the keyboard KB. In this embodiment, the size of the opening h is set so that the moving range of the input shaft 10 is about ± 10 mm in the XY directions.

As shown in FIG. 1, the capacitance type sensor includes a substrate 1 having an input shaft 10, a substrate 2 disposed in parallel with the substrate 1, and an opposing surface of the substrate 1. An electrode part C provided at the center and an electrode part group C ′ provided at 90 ° angular intervals about the center of the opposing surface of the substrate 2.
And an electronic device 3 disposed on the lower surface of the substrate 2.

The substrate 1 is formed of a circular synthetic resin plate as shown in FIGS. 1 and 2, and the input shaft 10 provided at the center of the upper surface thereof is mounted on the keyboard KB when the input shaft 10 is mounted on the keyboard KB. 5-10mm from upper wall of keyboard KB
It is set to protrude to the extent. On the other hand, an electrode portion C formed by printing copper in a circular shape is provided in the center of the lower surface of the substrate 1 as shown in FIGS.

As shown in FIG. 2, the substrate 2 is formed of a circular synthetic resin plate having a diameter larger than that of the substrate 1 and is provided with a recess 20 at the center of the upper surface thereof. On the bottom surface, as shown in FIGS. 1 and 3, a copper-printed electrode portion C ′ (electrode portions Cx +, Cx−, Cy +, Cy−) formed by dividing a circle into four at a position facing the electrode portion C. )
Is provided.

The substrates 1 and 2 are provided in such a manner that the substrate 1 is placed on the substrate 2 as shown in FIG. 1, and the substrate 1 is returned to the origin (an external force does not act on the input shaft 10). Sometimes, the center of the substrate 1 is returned to a position corresponding to the center of the substrate 2 by a spring or the like). When the substrate 1 is at the origin position, the center of the electrode portion C and the electrode portions Cx +, Cx +, as shown in FIG. Cx−, Cy +, and Cy− are arranged so as to oppose each other in the recess 20 so as to coincide with the center of the arrangement.

The electronic device 3 includes an electrode portion C and each electrode portion Cx.
+, Cx−, Cy +, Cy−, and the respective opposing areas (the shaded areas in FIGS. 3, 4, and 5) and the corresponding capacitances can be converted into voltages Vx +, Vx−, Vy +, Vy−, respectively. There are things. In this embodiment, the translation amount of the input shaft 10 in the XX direction is [(Vx +)-(Vx
−)], The translation amount of the input shaft unit 10 in the YY direction is converted into [(Vy +) − (Vy−)], and the voltage value determines the moving speed of the cursor. . That is, since the capacitance type sensor is configured as described above, the input shaft 10 is operated with a finger to
To the right side in the X-X direction with respect to the substrate 2 (the positional relationship between the electrode portions C and C 'at this time is shown in FIG. 4).
In this case, the output voltage becomes (Vx +)-(Vx-)> 0, and the cursor moves to the right at a speed corresponding to the absolute value of [(Vx +)-(and Vx-)]. Conversely, when the object is translated to the left in the X-X direction, the output voltage becomes (Vx
+)-(Vx-) <0, and the cursor is [(Vx +)
− (Vx−)] at the speed corresponding to the absolute value of (−Vx−)]. The same applies to the case where the input shaft 10 is operated with a finger to move the substrate 1 in parallel with the substrate 2 in the YY direction as shown in FIG.

In this sensor, the input shaft portion 10 translates up to ± 10 mm in parallel due to the operation force applied to the input shaft portion 10. Therefore, the movement (displacement) of the input shaft portion 10 is considerably larger than that of the sensor described in the section of the prior art. Become. Therefore,
The operational feeling of the input shaft unit 10 is large, and fine adjustment of the moving direction and moving speed of the cursor displayed on the display is easy. (Embodiment 2) Also in this embodiment, the sensor of the present invention is used as a moving operation section of a cursor displayed on a display, but has a more practical structure than the sensor of Embodiment 1 described above. . Hereinafter, the capacitance type sensor will be described with reference to FIG.

In this capacitance type sensor, as shown in the figure, a holding plate 6 having an opening h is screwed to the substrate 2 to form a housing portion K, and the substrate 1 is housed in the housing portion K. And the distal end of the input shaft 10 protrudes from the opening h. Then, a Teflon coating T is applied to the surface of the electrode portion C of the substrate 1 and to the surface of the electrode portion C ′ of the substrate 2, respectively.
C is applied so that both Teflon-coated TC surfaces are slidably in contact with each other. Therefore, the parallel movement of the input shaft unit 10 by the finger becomes smooth.

Although the electrode portion C 'shown in the above embodiment is formed by dividing a circle into four parts, the present invention is not limited to this. If the electrode portions having the same shape are arranged at 90 ° angular intervals, the above-mentioned configuration is adopted. It has the same operation and effect as. In particular, the electrode portion C ′
The electrode portions Cx +, Cx−, Cy +, Cy− of FIG. 7 are formed in a tapered band shape with an inner end portion tapered by 90 °, as shown in FIG. Within this range, the relationship between the amount of movement of the input shaft 10 and the output voltage V does not change rapidly, and the relationship can be improved.

In the above embodiment, the electrode portion C is provided on the substrate 1.
Is provided with the electrode portion C ′ on the substrate 2.
The electrode portion C ′ may be provided on the substrate 2, and the electrode portion C may be provided on the substrate 2. Further, when the substrate 1 is made of a conductive material, the substrate 1 itself functions as the electrode portion C,
There is no need to provide the electrode section C separately from the substrate 1.

In the above-described embodiment, the input portion J described in the section of the means has a shaft shape. However, the input portion J is not limited to this, and may be, for example, a concave portion. In short, the input unit J only needs to be able to transmit the operating force or another external force to the substrate 1 or the substrate 2.

[0022]

Since the present invention has the above configuration, it has the following effects. From the description of the operation, it is possible to provide a capacitive sensor having a low bulk and a large displacement of the input unit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view when an electrostatic capacity sensor according to an embodiment of the present invention is mounted in a keyboard as an operation unit for moving a cursor displayed on a display.

FIG. 2 is a perspective view of the capacitance type sensor.

FIG. 3 is a diagram showing the state of electrodes on the upper substrate and the electrodes on the lower substrate when the upper substrate of the capacitive sensor is in the home position return state.

FIG. 4 is a diagram showing a state when the electrode on the upper substrate has moved in the XX direction from the state shown in FIG. 3;

FIG. 5 is a diagram showing a state when the electrodes on the upper substrate have moved in the YY direction from the state shown in FIG. 3;

FIG. 6 is a sectional view of a capacitive sensor according to another embodiment of the present invention.

FIG. 7 is a diagram showing another embodiment of the electrode section on the upper and lower substrates.

FIG. 8 is a cross-sectional view when a capacitance type sensor according to the related art is mounted in a keyboard as an operation unit for moving a cursor displayed on a display.

FIG. 9 is a diagram showing an electrode portion of an upper substrate of a capacitance type sensor according to the prior art.

FIG. 10 is a diagram showing an electrode portion of a lower substrate of a capacitance type sensor according to the prior art.

[Explanation of symbols]

 C electrode part Cx + electrode part Cx- electrode part Cy + electrode part Cy- electrode part 1 substrate 2 substrate 10 input shaft part

Claims (2)

(57) [Claims] 1. A substrate 1 and 2 disposed in parallel and one of which is movable in parallel with respect to the other, an electrode portion C provided on a facing surface of the substrate 1, and a center of the facing surface of the substrate 2. Electrode portions Cx +,
Cx−, Cy +, Cy−, and an input portion J provided at the center of one of the substrates 1 and 2, and in a state where no force acts on the input portion J, the input portion J is viewed in plan. The outer portions of the electrode portions Cx +, Cx−, Cy +, and Cy− are in a state of protruding from the electrode portion C, and when one of the substrates 1 and 2 is moved in parallel with the other, the direction of the movement is performed. The facing area between the electrode parts C and Cx +, between the electrode parts C and Cx-, between the electrode parts C and Cy +, and between the electrode parts C and Cy- changes depending on the amount and the capacitance, and the capacitance is changed. The force acting on the input portion J in the X-axis direction is a difference between two capacitances between the electrode portion C and the electrode portions Cx + and Cx−, and the force acting on the input portion J is Y. The axial force is the difference between the two capacitances between the electrode part C and the electrode parts Cy +, Cy-, which is Capacitive sensor, characterized in that is adapted to be detected. 2. A substrate 1 made of a conductive material and functioning as an electrode portion C, a substrate 2 arranged in parallel to the substrate 1 and facing the substrate 1, and a substrate 90 centered on the center of the facing surface of the substrate 2. ° Electrodes Cx +, Cx provided at angular intervals
−, Cy +, Cy−, and an input unit J provided at a central portion of one of the substrates 1 and 2.
2 is provided so as to be able to move in parallel with respect to the other, and in a state where no force is applied to the input portion J, each of the outer portions of the electrode portions Cx +, Cx-, Cy +, and Cy- in plan view. When one of the substrates 1 and 2 is moved in parallel with the other, the electrode portions C and Cx + correspond to the direction and amount of the movement.
The opposing area between the electrode portions C and Cx-, between the electrode portions C and Cy +, and between the electrode portions C and Cy- changes, so that the capacitance changes. The force in the X-axis direction acting on the input portion J is the difference between the two capacitances between the electrode portion C and the electrode portions Cx + and Cx−. A capacitance type sensor which is configured to be detected by a difference between two capacitances between the parts Cy + and Cy−.