TW201805977A - Pressure sensitive static switch and electrical device - Google Patents

Abstract

The present invention provides a pressure sensitive static switch using a conductive plate having an operation area. The technical means of the pressure sensitive static switch provided by the present invention includes a conductive plate connected to a reference potential and having an operation area; an electrode disposed opposite to the conductive plate; and an elastic body disposed between the conductive plate and the electrode.

Description

Pressure-sensitive electrostatic switch and electrical device

The invention relates to a pressure-sensitive electrostatic switch and an electrical device.

In recent years, a touch panel (also referred to as a touch panel) for detecting a touch switch for operation input is disposed on a display element such as a liquid crystal display element included in a mobile device, a mobile phone device, or a car navigation device. Screens, etc.) are widely available. As one form of the touch switch, a capacitive touch switch has been proposed (for example, refer to Patent Document 1).

The principle of the capacitive touch switch is briefly described with reference to FIG. 1. As shown in FIG. 1, a general touch switch 1 is disposed opposite to a circuit substrate 4, and an operation panel 2 and an electrode 3 are formed as insulators on the circuit substrate 4. In the touch switch 1, by detecting the capacitance change between the electrode 3 and the finger F when the finger F approaches, it is detected whether there is a touch operation and a position where the touch operation is performed. In this way, the touch switch 1 is made to function as a switch by performing processing in accordance with the detection.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-134278.

The general capacitive touch-on relationship such as the touch switch 1 can be input only by bringing the finger F close to the operation panel or by slightly touching the finger to the operation panel, thereby improving operability. On the other hand, there is a problem that an unexpected input (processing) is performed simply by approaching a finger by accident. In addition, there is a problem in that a conductor such as a metal cannot be used as a material of the operation panel because a change in capacitance cannot be captured. Therefore, as described in Patent Document 1, the metal particles can be added to the insulating material to make it metallic, but there are limitations in improving the appearance, design, and texture, and the use of touch switches. The problem.

Therefore, one object of the present invention is to provide a pressure-sensitive electrostatic switch and an electric device having the pressure-sensitive electrostatic switch. The pressure-sensitive electrostatic switch can use a conductive plate such as a metal in an operation area.

In order to solve the above-mentioned problems, the present invention is, for example, a pressure-sensitive electrostatic switch having a conductive plate connected to a reference potential and having an operating area; The electrode is disposed so as to face the conductive plate; and the elastic body is interposed between the conductive plate and the electrode.

In the aforementioned pressure-sensitive electrostatic switch, an opening may be formed in the elastic body at a position corresponding to the operation region.

In the pressure-sensitive electrostatic switch, the conductive plate may have a structure having a light transmitting portion.

The pressure-sensitive electrostatic switch may further include a circuit board provided with an electrode and a light-emitting element; the light-emitting element is configured to be disposed at a position where light emitted from the light-emitting element can be visually confirmed through a light transmitting portion and an opening. .

In the aforementioned pressure-sensitive electrostatic switch, a recessed portion may be formed in the elastic body at a position corresponding to the operation region.

In the pressure-sensitive electrostatic switch, the conductive plate may be made of a metal plate.

In the pressure-sensitive electrostatic switch, the conductive plate may include an insulating member and a conductive layer formed in at least a portion of the insulating member facing the electrode.

In the aforementioned pressure-sensitive electrostatic switch, the conductive plate may be supported by an elastic body.

The present invention may also be an electrical device having the aforementioned pressure-sensitive electrostatic switch.

According to the present invention, a conductive plate such as a metal can be used in the operating area of the pressure-sensitive electrostatic switch. In addition, it is possible to prevent a situation where an unexpected input is made due to the approach or contact of a finger or the like. In addition, The exemplified effects are not intended to limit the interpretation of the invention.

1‧‧‧touch switch

2‧‧‧ operation panel

3‧‧‧ electrode

4‧‧‧circuit board

10‧‧‧Pressure-sensitive electrostatic switch

20‧‧‧Conductive plate

21a‧‧‧operation area

21b‧‧‧ opposite

22, 22a, 22b, 22c, 22d, 22e‧‧‧ button processing

23‧‧‧Insulating member

24‧‧‧ conductive layer

30‧‧‧circuit board

31, 31a, 31b, 31c, 31d, 31e‧‧‧ electrodes

32, 32a, 32b, 32c, 32d, 32e‧‧‧LED

40‧‧‧ Elastomer

41, 41a, 41b, 41c, 41d, 41e‧‧‧ opening

50‧‧‧Capacitance detection controller

F‧‧‧finger

FIG. 1 is a diagram for explaining a general capacitive touch switch.

In FIG. 2, (A) is a figure which shows the external appearance example of the pressure sensitive electrostatic switch of one embodiment, and (B) is a figure which shows the structural example of the pressure sensitive electrostatic switch of one embodiment.

In FIG. 3, FIG. 3 (A) is a diagram showing a conductive plate according to an embodiment, FIG. 3 (B) is a diagram showing a circuit board according to an embodiment, and FIG. 3 (C) is a diagram showing an embodiment Illustration of elastomer.

FIG. 4 is a diagram showing a configuration example of a pressure-sensitive electrostatic switch according to an embodiment.

5 is a diagram for explaining an operation example of the pressure-sensitive electrostatic switch according to the embodiment.

FIG. 6 is a diagram showing an electrical configuration example of a pressure-sensitive electrostatic switch according to an embodiment.

FIG. 7 is a diagram showing another example of the electrical configuration of the pressure-sensitive electrostatic switch according to the embodiment.

FIG. 8 is an explanatory diagram of a modification.

9 (A) and 9 (B) are explanatory diagrams of modification examples.

Hereinafter, embodiments and the like of the present invention will be described with reference to the drawings. The explanation is performed in the following order.

<1. Embodiment>

<2. Modifications>

It should be noted that the embodiments and the like shown below are examples of configurations for embodying the technical idea of the present invention, and the present invention is not limited to the illustrated configurations. In addition, the embodiments and the like shown below do not specify members shown in the scope of the patent application to members of the embodiments. In particular, the descriptions of the dimensions, materials, shapes, the relative arrangement, and the directions of up and down, left, right, and other directions of the constituent members described in the embodiments are not intended to limit the scope of the present invention. The meaning of limitation is merely a mere illustration. In addition, the size and positional relationship of the components shown in each drawing may be exaggerated to make the description clear. In addition, in order to prevent the illustration from becoming complicated, only some element symbols may be shown. Furthermore, in the following description, the same names and symbols refer to the same or homogeneous members, and repeated descriptions are appropriately omitted. In addition, each element constituting the present invention may be implemented by a plurality of elements composed of the same element and a single element serving as a plurality of elements, or conversely, a function of one element may be shared by a plurality of elements.

<1. Embodiment>

"About the overall structure of a pressure-sensitive electrostatic switch"

FIG. 2 (A) is a perspective view showing an appearance example of a pressure-sensitive electrostatic switch (pressure-sensitive electrostatic switch 10) according to an embodiment of the present invention. As shown in FIG. 2 (A), the pressure-sensitive electrostatic switch 10 is, for example, a thin plate as a whole.

FIG. 2 (B) is a diagram (a cross-sectional view) illustrating a configuration example of the pressure-sensitive electrostatic switch 10. The pressure-sensitive electrostatic switch 10 includes, for example, a conductive plate 20, a circuit board 30, and an elastic body 40. One surface of the conductive plate 20 is an operation area surface 21a, and a pressing operation (pressing operation) on the operation area surface 21a is performed by an operation body such as a finger or a pen from above (B) in FIG. 2. The conductive plate 20 is processed to indicate a specific operation area, and these are indicated by appropriately simplifying element symbols 22a, 22b, 22c, 22d, and 22e.

A predetermined number (five in this embodiment) of electrodes 31 (31a, 31b, 31c, 31d, 31e) are formed on the circuit board 30, and these electrodes 31 are opposed to the conductive plate 20 (with operation 21b) The area surface 21a is disposed so as to face the opposite side).

An elastic body 40 is interposed between the conductive plate 20 and the circuit substrate 30. Openings 41 (41a, 41b, 41c, 41d, 41e) are formed in the elastic body 40, for example. In the pressure-sensitive electrostatic switch 10 according to this embodiment, the conductive plate 20 and the elastic body 40 are bonded by a double-sided tape or the like, and the conductive plate 20 is supported by the elastic body 40.

"About conductive plate"

Next, each part of the pressure-sensitive electrostatic switch 10 will be described in detail with reference to FIGS. 3 (A) to 3 (C). FIG. 3 (A) is a view showing a conductive plate 20 according to the embodiment. The conductive plate 20 is made of, for example, a metal such as aluminum or stainless steel, and is a thin plate-shaped metal plate as a whole. Conductive plate The 20 series is set to a thickness (for example, 0.3 mm to 0.5 mm (millimeters)) to the extent that it flexes so as to slightly protrude toward the facing surface 21b side by a pressing operation.

By processing the conductive plate 20 in accordance with the purpose of the pressure-sensitive electrostatic switch 10, the user can recognize a specific operation area and a process performed when the operation area is pressed. (A) of FIG. 3 is a processing example which shows the case where the pressure sensitive electrostatic switch 10 implemented on the conductive plate 20 is used as a switch which changes the playback aspect of audio. For example, the conductive plate 20 is implemented with: button processing 22a, which is simulated as a button for playing / stopping audio playback; button processing 22b, which is simulated as a button for fast-forwarding audio playback; button processing 22c, which is simulated as Next button to migrate to the next track (track); button processing 22d, simulated as a button to reverse audio playback; and button processing 22e, simulated to migrate to the previous track (track) Previous button.

In this embodiment, each button processing 22 is performed by forming a through hole in the conductive plate 20. The user can visually confirm the light emitted from a light-emitting element described later through the through hole. That is, the button processing 22 included in the conductive plate 20 functions as a light transmitting portion.

"About circuit boards"

Next, a circuit board 30 according to the embodiment will be described. FIG. 3 (B) is a diagram showing a circuit board 30 according to the embodiment. The position on the circuit board 30 opposite to the operation area of the conductive plate 20 or the position near the position Into a rectangular electrode 31.

In addition, the circuit board 30 of this embodiment is provided with a light emitting element. The light-emitting element is constituted by, for example, an LED (Light Emitting Diode). For example, the circuit board 30 is provided with five LEDs 32 (32a, 32b, 32c, 32d, 32e) corresponding to the number of operating portions of the conductive plate 20. ). The LED 32 is provided at a position where the user can visually confirm the light emitted (emitted) by the LED 32 through the opening 41 and the button processing 22, and may be provided near the electrode 31 as an example. For example, an LED 32a is provided in the center of the substantially rectangular electrode 31a. Similarly, LEDs are provided at substantially the center of the other electrodes. The LED32 is connected to a control circuit (not shown), such as a microcomputer, and the LED32 is controlled to turn on / off the light by the control circuit.

"About Elastomers"

Next, the elastic body 40 of the embodiment will be described. FIG. 3 (C) is a view showing an elastic body 40 according to the embodiment. The elastic body 40 is, for example, a thin plate-shaped rubber sheet having a thickness of about 1.0 mm to several mm. The elastic body 40 is partially deformed in response to a pressing operation, and is not limited to rubber as long as the deformed part will recover after the pressing operation. A circular opening 41 is formed in the elastic body 40 at a position corresponding to the operation area of the conductive plate 20.

FIG. 4 is a view of the pressure-sensitive electrostatic switch 10 which is laminated and integrated with the aforementioned conductive plate 20, circuit board 30, and elastic body 40 as viewed from the conductive plate 20 side. For example, in the conductive plate 20, button processing 22a is performed. The electrode 31 a and the LED 32 a are disposed at positions facing each other, and the opening 41 a of the elastic body 40 is located between the button processing 22 a and the electrode 31 a and the like. In addition, for example, the electrode 31b and the LED 32b are disposed at positions facing the position where the button processing 22b is performed in the conductive plate 20, and the opening 41b of the elastic body 40 is located between the button processing 22b and the electrode 31b and the like. The same applies to other parts. When a pressing operation is performed on the portion of the button processing 22, the LED 32 located immediately below the position where the pressing operation is performed will emit light. The light from the LED 32 is transmitted through the opening 41 and the button processing 22. The user can recognize that the input is accepted by visually confirming the light, and the pressure-sensitive electrostatic switch 10 can be configured as an illuminated switch.

"Example of operation of pressure sensitive electrostatic switch"

Next, an operation example of the pressure-sensitive electrostatic switch 10 will be described with reference to FIG. 5. Hereinafter, an example in which a pressing operation is performed on the operation region in which the button processing 22 a has been performed on the conductive plate 20 will be described. A pressing operation is performed on the operation area where the button processing 22a has been performed. This pressing operation is an operation that requires a force that can flex the conductive plate 20 by a predetermined degree or more. That is, the pressure-sensitive electrostatic switch 10 is a switch that does not react simply by being approached or contacted.

A position (hereinafter referred to as an operation part) where the pressing operation is performed in the conductive plate 20 is flexed, and an elastic body 40 located near the lower part of the operation part in association with this is flexed. When the operating portion in the conductive plate 20 is flexed, the distance between the operating portion and the electrode 31a changes, and the capacitance therebetween also changes. By detecting the change in the capacitance, the operation site can be detected.

In a case where the elastic body 40 is not interposed between the conductive plate 20 and the circuit board 30, the change in the capacitance between the operation site and the electrode 31 is small, and it is difficult to detect the change. However, by interposing the elastic body 40, the displacement of the relative position between the operation site and other sites caused by the pressing operation can be increased, and the change in the capacitance of the operation site can be increased. Thereby, the change in the capacitance between the operation site and the electrode 31 can be reliably detected, and the operation site can be accurately identified.

In addition, in this embodiment, a structure is formed in which a space is formed at a position corresponding to the operation area (button processing 22a). Specifically, the opening 41a is located directly below the button processing 22a to form a structure in which space is formed . Therefore, the operation portion can be flexed compared to other portions. Therefore, the relative positional displacement between the operation part and other parts can be made larger, and the capacitance change of the operation part can be made larger.

When the operation site is detected, control to make the LED 32a emit light (turn on the light) is performed by a control circuit (not shown). The opening 41a is formed in the elastic body 40 and the button processing 22a is formed as a through hole in the conductive plate 20. Therefore, the user can visually confirm the light emitted by the LED 32a, and the user feels like the button processing 22a is lit. Feel.

"About the composition of electricity"

FIG. 6 is a diagram showing an electrical configuration example of the pressure-sensitive electrostatic switch 10. Make The low-voltage reference power line GND and the high-voltage reference power line VCC, which are ground potentials (ground), are connected to the capacitance detection controller 50. The capacitance detection controller 50 is mounted on the circuit board 30, for example. The conductive plate 20 is connected to the low-voltage reference power line GND. The capacitance C (Ca, Cb, Cc, Cd, Ce) between the conductive plate 20 and each electrode 31 is represented in a schematic manner. The capacitance C [F (farad)] can be obtained by the following formula (1).

In addition, S in the formula (1) represents an area [m ² ] of an electrode, and d represents a distance [m] between metal plates. Further, ε ₀ is a vacuum dielectric constant ^{(8.854 × 10 -12), ε} r is the dielectric constant ratio ε _r ≒ 1.0 lines in the case of air.

In equation (1), S, ε ₀ , and ε _r are constant values. Only the distance d is changed by the pressing operation, and the capacitance C is also changed by the change. The capacitance detection controller 50 determines an operation site based on a change in the capacitance C between the conductive plate 20 and the electrode 31. In addition, as a method for detecting the change in the capacitance C by the capacitance detection controller 50, a relaxation oscillation method, a charge transfer method, a CSA (CapSence Successive Approximation) method, and a series capacitor voltage division comparison method can be applied. And so on.

FIG. 7 is a diagram showing another example of the electrical configuration of the pressure-sensitive electrostatic switch 10, and is an example in which the pressure-sensitive electrostatic switch 10 includes a capacitance detection controller 51. In addition, the configuration shown in the same figure has been proposed by the present inventors, and the details thereof have been disclosed in Japanese Patent Laid-Open Publication (Japanese Patent Laid-Open No. 2016-9452). The matters described in Japanese Patent Application Laid-Open No. 2016-9452 can also be applied to the present invention. Since even a small capacitance can be detected by the capacitance detection controller 51, even a capacitance change caused by a slight deflection can be detected.

According to the pressure-sensitive electrostatic switch of the embodiment described above, a conductive plate made of metal or the like can be used in the operation area. Therefore, the appearance, design, texture, and the like can be improved more than before, and the use as a touch switch can be expanded. In addition, since the input operation requires a certain amount of force that can deflect the conductive plate, it is possible to prevent erroneous input due to an accidental approach by a finger or the like. In addition, it is not necessary to use a large number of special parts in order to achieve the functions and effects described in the foregoing embodiments, but the present invention can be realized by a simple configuration of a pressure sensitive electrostatic switch.

`` Application example ''

The present invention can be implemented as an electrical device having the aforementioned pressure-sensitive electrostatic switch 10. Examples of the electrical device incorporating the pressure-sensitive electrostatic switch 10 include a device that requires a pressing operation with a certain force or more. In other words, it is not suitable from the standpoint of proximity or contact due to safety or other reasons. Enter the machine. Specific examples of such electrical devices include: freezer, gas, or IH (induction heating) Cooking appliances such as kitchen utensils and induction cookers; kettles; air-conditioning equipment such as vehicle-mounted devices, lighting equipment, electric fans; and tableware dryers.

<2. Modifications>

As mentioned above, although the embodiment of this invention was demonstrated concretely, this invention is not limited to the said embodiment, Various deformation | transformation is possible.

The conductive plate 20 is not limited to a metal plate. For example, as shown in FIG. 8, the conductive layer 24 may be formed in a thin plate-shaped insulating member 23 and at least a portion of the insulating member 23 facing the electrode 31. The conductive layer 24 is formed of, for example, a transparent conductive film such as ITO (Indium Tin Oxide). The conductive layer 24 is connected to a reference potential such as a ground potential. As shown in FIG. 8, the conductive layer 24 may be formed over the entire facing surface facing the electrode 31 of the insulating member 23. The insulating member 23 may have a plate shape or a film shape, and its shape may be any shape. In addition, in this case, by forming the insulating member 23 with a light-transmitting member such as glass or acrylic, the entire conductive plate 20 can function as a light-transmitting portion. That is, the light transmitting portion is not limited to a through hole formed by the conductive plate 20. In addition, the conductive plate 20 may be configured without a light transmitting portion.

In the aforementioned embodiment, the number of operating regions of the conductive plate 20 may be appropriately changed. In addition, the means (identification means) for identifying the operating area of the conductive plate 20 is not limited to a through-hole like button processing 22, a method of attaching a decorative sheet or the like, or pressing the conductive plate 20 ( press), or a combination of these. In addition, the operation of the conductive plate 20 The operation area may not include the aforementioned identification means, or the entire conductive plate 20 may be used as the operation area. The recognition means may be a simple shape such as a rectangle or a triangle, or may be a process performed when the operation area is not displayed while being displayed.

In the aforementioned embodiment, as an example of the reference potential, although the potential of the low-voltage reference power supply line connected to the conductive plate 20 is used as the ground potential, other reference potentials such as a fixed potential at a predetermined level may be used.

In the foregoing embodiment, the electrode 31 in the circuit board 30 is shown as a substantially rectangular shape, but the shape may be appropriately changed to a circle, a round shape, a triangle, or the like.

In the foregoing embodiment, although the number of operation areas (button processing 22) of the conductive plate 20 is the same as the number of the electrodes 31, the number does not have to be the same. It is also possible to adopt a method in which a plurality of electrodes correspond to one operation area.

The type, number, and light emission pattern of the light-emitting elements provided on the circuit board 30 may be appropriately changed, and the light-emitting elements may not be provided on the circuit board 30. In addition, the light-emitting element may be configured such that the light is always turned on from when the power is turned on regardless of the presence or absence of operation.

The opening 41 of the elastic body 40 is not limited to a circular shape, and may be a rectangular shape, a round shape, a triangular shape, or the like as shown in FIG. 9 (A), and the shape thereof may be appropriately changed. In addition, instead of the opening 41, a recessed portion recessed from the conductive plate 20 toward the circuit substrate 30 may be formed in the elastic body 40. As shown in FIG. Same plane.

The elastic body 40 is not limited to rubber, and a spring, sponge, or the like may be used. For example, when a plurality of springs are used as the elastic body 40, the plurality of springs may be respectively disposed in the vicinity of the electrode 31.

The aforementioned pressure-sensitive electrostatic switch 10 is not limited to an on / off switch. For example, it is also possible to perform a stepwise detection of a change in capacitance in accordance with the amount of deflection of the conductive plate 20 and to perform control in accordance with the stepwise change. In addition, the light emission intensity and color of the LED 32 may be changed stepwise in response to the stepwise change of the capacitance.

In addition, although the above-mentioned pressure-sensitive electrostatic switch 10 has an operation area arranged in a row, the operation area may be arranged in a plurality of rows, that is, two-dimensionally.

The shape of the pressure-sensitive electrostatic switch 10 is not limited to a thin plate shape, and may be formed in a suitable shape such as a cylindrical shape or a spherical shape. The shape of the conductive plate 20 or the like may also be formed in a suitable shape in accordance with the shape. In addition, the pressure-sensitive electrostatic switch 10 can be arranged vertically or obliquely and can be pressed in a horizontal direction or obliquely. In this case, each configuration (the conductive plate 20, the circuit board 30, the elastic body 40, and the like) of the pressure-sensitive electrostatic switch 10 may be configured to be supported by a predetermined support member.

A vibrator or an actuator may be provided on the circuit board 30 so that a feedback operation such as vibration may be performed at a position where the operation is performed in response to a pressing operation.

The structures, methods, steps, shapes, materials, and numerical values listed in the above embodiments and modifications are merely examples, and different structures, methods, steps, shapes, materials, and numerical values may be used as needed, or These may be replaced with conventional ones. In addition, the configurations, methods, procedures, shapes, materials, and numerical values of the embodiments and modifications can be combined with each other as long as no technical contradiction occurs.

10‧‧‧Pressure-sensitive electrostatic switch

20‧‧‧Conductive plate

21a‧‧‧operation area

21b‧‧‧ opposite

22a, 22b, 22c, 22d, 22e‧‧‧ button processing

30‧‧‧circuit board

31a, 31b, 31c, 31d, 31e‧‧‧ electrodes

40‧‧‧ Elastomer

41a, 41b, 41c, 41d, 41e‧‧‧ opening

Claims (9)

A pressure-sensitive electrostatic switch includes: a conductive plate connected to a reference potential and having an operating area; electrodes arranged so as to face the conductive plate; and an elastic body sandwiched between the conductive plate and the electrode . The pressure-sensitive electrostatic switch according to claim 1, wherein an opening is formed in the elastic body at a position corresponding to the operation area. The pressure-sensitive electrostatic switch according to claim 2, wherein the conductive plate is configured to have a light transmitting portion. The pressure-sensitive electrostatic switch according to claim 3, which includes a circuit board on which the electrode and the light-emitting element are provided; the light-emitting element is configured to be visually confirmed from the light-emitting element through the light-transmitting portion and the opening. The position of the emitted light. The pressure-sensitive electrostatic switch according to claim 1, wherein a recess is formed in the elastic body at a position corresponding to the operation area. The pressure-sensitive electrostatic switch according to any one of claims 1 to 5, wherein the conductive plate is made of a metal plate. The pressure-sensitive electrostatic switch according to any one of claims 1 to 5, wherein the conductive plate includes an insulating member and a conductive layer formed in at least a portion of the insulating member facing the electrode. The pressure-sensitive electrostatic switch according to any one of claims 1 to 5, wherein the conductive plate is configured to be supported by the elastic body. An electrical device having the pressure-sensitive electrostatic switch according to any one of claims 1 to 8.