TWI728462B - Touch sensor and wiring device - Google Patents

Abstract

The present invention aims to provide a touch sensor and wiring appliance that can improve the detection accuracy of touch operation. The touch sensor includes a substrate (30), a sensing electrode (31), and a first ground electrode (32). The substrate (30) has a first layer (L1) and a second layer (L2). The sensing electrode (31) is formed on the first layer (L1). The first ground electrode (32) is formed on the second layer (L2) so as to overlap with the sensing electrode (31) in at least a part in the thickness direction of the substrate (30), and form parasitics between it and the sensing electrode (31) capacitance. At least one of the sensing electrode (31) and the first ground electrode (32) has a plurality of ones formed in the area where the sensing electrode (31) and the first ground electrode (32) overlap in the thickness direction of the substrate (30) Through hole (320).

Description

Touch sensors, wiring appliances

The present invention generally relates to touch sensors and wiring appliances, and more specifically, it relates to electrostatic capacitive touch sensors and wiring appliances.

Conventionally, there has been a switch device (wiring appliance) including a touch sensor unit (touch sensor) (for example, refer to Document 1 (JP2015-187918A).

The switch device of Document 1 includes a switch body and an operating unit.

The operating unit has a touch sensing part that detects human operations (touch operations), and a flat box-shaped housing that houses the touch sensing part, and is configured to use the front surface of the housing as the detection surface of the touch sensing part .

The switch device is configured to switch the power supply from the external power source to the load according to the detection result of the touch sensing part.

In touch sensors, it is expected that the detection accuracy of touch operations will be improved.

The present invention is made in view of the above-mentioned reasons, and its object is to provide a touch sensor and a wiring appliance that can improve the detection accuracy of touch operation.

One aspect of the touch sensor of the present invention is an electrostatic capacitive touch sensor for detecting touch operation. The touch sensor includes a substrate, a sensing electrode, and a ground electrode. The substrate has a first layer and a second layer. The sensing electrode is formed on the first layer. The ground electrode is formed on the second layer so as to overlap with the sensing electrode in at least a part in the thickness direction of the substrate, and a parasitic capacitance is formed between the ground electrode and the sensing electrode. At least one of the sensing electrode and the ground electrode has a plurality of through holes formed in a region where the sensing electrode and the ground electrode overlap in the thickness direction of the substrate.

A wiring appliance of one aspect of the present invention includes the touch sensor and a control circuit that controls the load according to the detection result of the touch operation of the touch sensor.

[Form to implement invention]

The embodiments and modifications described below are only examples of the present invention, and the present invention is not limited to the embodiments and modifications. Even in addition to the embodiments and modified examples, various changes can be made in accordance with designs and the like as long as they do not depart from the scope of the technical idea of the present invention.

The wiring appliance 10 of this embodiment will be described with reference to Figs. 1 to 5.

The wiring tool 10 of this embodiment is a switch device that controls the power supply from the power source 40 to the load 41. The wiring appliance 10 uses, for example, a mounting frame 100 (see FIG. 2), and is embedded and arranged in a hole formed in a wall in advance. The power source 40 is, for example, a commercial power source. The load 41 is, for example, an electric appliance such as a lighting fixture and a ventilation fan.

The wiring tool 10 includes a switch main body 1 and an operation unit 2. In this embodiment, in the wiring appliance 10, the direction in which the switch body 1 and the operation unit 2 are arranged is defined as the front-rear direction, and the side of the operation unit 2 viewed from the switch body 1 is defined as the front, and the switch viewed from the operation unit 2 The 1 side of the main body is specified as the rear. In addition, the vertical direction in the state where the wiring tool 10 is embedded and arranged on the wall is defined as the vertical direction of the wiring tool 10. In addition, the left-right direction when the wiring tool 10 is viewed from the front in a state where the wiring tool 10 is embedded and arranged on a wall is defined as the left-right direction of the wiring tool 10. However, these regulations are not intended to limit the direction of use of the wiring appliance 10.

First, the switch body 1 will be explained.

The switch body 1 is configured to control the power supply from the power source 40 to the load 41. The switch body 1 includes a switching element 11, a control circuit 12, a power supply circuit 13, a first communication unit 14, and a second communication unit 15. The switch body 1 further has a connector 16, a pair of power terminals 171A, 171B, a pair of load terminals 172A, 172B, and a pair of signal terminals 173A, 173B.

The switching element 11 is, for example, a semiconductor switching element. In more detail, the switching element 11 is, for example, a bidirectional thyristor. The switching element 11 has two main terminals and a control terminal (gate terminal). The switching element 11 is electrically connected between the power terminal 171B and the load terminal 172B. The switching element 11 is electrically connected to the series circuit of the power supply 40 and the load 41 through the power supply terminal 171B and the load terminal 172B. That is, the two main terminals of the switching element 11 are electrically connected to the series circuit of the power supply 40 and the load 41 through the power supply terminal 171B and the load terminal 172B. The control terminal of the switching element 11 is electrically connected to the control circuit 12.

The switch body 1 has a microcomputer with, for example, a processor and a memory. Furthermore, the program stored in the memory is executed by the processor, and the microcomputer has the function of the control circuit 12. The program executed by the processor is pre-recorded in the memory of the microcomputer. It can also be recorded on a non-temporary recording medium such as a memory card, or it can be provided through telecommunication lines such as the Internet.

The control circuit 12 controls the on/off of the switching element 11. In addition, the control circuit 12 controls the first communication unit 14 and the second communication unit 15.

The power supply circuit 13 is configured to convert the AC voltage output by the power supply 40 into a DC voltage. The power supply circuit 13 is, for example, an AC/DC converter. The power supply circuit 13 outputs the DC voltage converted from the AC voltage to the control circuit 12. The power circuit 13 is electrically connected between the power terminal 171B and the load terminal 172A. The power supply circuit 13 is electrically connected to the power supply 40 through the power supply terminal 171B and the load terminal 172A. The power circuit 13 is electrically connected to the control circuit 12. The power supply circuit 13 converts the AC voltage supplied from the power supply 40 into a DC voltage and outputs it to the control circuit 12.

The control circuit 12 operates by the power supplied from the power circuit 13. In addition, the control circuit 12 is based on the power supplied from the power supply circuit 13 and supplies the power to the operation unit 2 through the connector 16. That is, the power supply circuit 13 supplies power to the operation unit 2 through the control circuit 12.

The pair of power terminals 171A and 171B are electrically connected to each other. The power supply terminal 171A is used for, for example, transmission wiring.

The first communication unit 14 is a communication interface capable of wired communication. The first communication signal portion 14 is electrically connected to a pair of signal terminals 173A and 173B. The pair of signal terminals 173A and 173B are connected to a pair of signal lines. The pair of signal terminals 173A and 173B are electrically connected to a pair of signal lines through the pair of signal terminals 173A and 173B. The first communication unit 14 is electrically connected to a pair of signal lines through a pair of signal terminals 173A and 173B. A pair of signal terminals 173A, 173B are electrically connected to a pair of signal terminals 173A, 173B of the switch body 1 of another wiring appliance 10 through a pair of signal wires. That is, a plurality of wiring appliances 10 can be provided, and a pair or a plurality of pairs of signal lines can be provided. The two wiring appliances 10 are electrically connected to each other by a pair of signal wires. In addition, the first communication unit 14 is electrically connected to the control circuit 12.

The first communication unit 14 receives, through a pair of signal terminals 173A, 173B, for example, a control signal (first control signal) transmitted from another wiring appliance 10 using a pair of signal lines. The first communication unit 14 outputs the received first control signal to the control circuit 12. In addition, the first communication unit 14 transmits, for example, a control signal (second control signal) from the control circuit 12 to another wiring appliance 10 via a pair of signal terminals 173A and 173B and a pair of signal lines.

The second signal 15 is a communication interface capable of wireless communication using radio waves as a medium. In the present embodiment, the second communication unit 15 is configured to be able to perform wireless communication using a small-power wireless (specific small-power wireless) communication method that does not require permission. Regarding low-power wireless, various countries have stipulated specifications such as frequency bands used according to purposes, etc., or antenna power. In Japan, low-power wireless that uses radio waves in the 400MHz band or 900MHz band is regulated. In addition, the second communication unit 15 may also be configured to perform wireless communication using a Bluetooth (registered trademark) communication method using radio waves in the 2.4 GHz band.

The second communication unit 15 is electrically connected to the control circuit 12. The second communication unit 15 receives, for example, a control signal (third control signal) transmitted by wireless communication from the control device. The second communication unit 15 outputs the received third control signal to the control circuit 12. In addition, the second communication unit 15 transmits, for example, a control signal (fourth control signal) from the control circuit 12 to the control device by wireless communication.

The connector 16 is used to electrically and mechanically connect the switch body 1 and the operating unit 2. The connector 16 is electrically connected to the control circuit 12.

The switch body 1 further has a housing 18 (refer to FIG. 2). The housing 18 is formed of, for example, alloy resin. The housing 18 is formed in, for example, a rectangular box shape. The switching element 11, the control circuit 12, the power supply circuit 13, the first communication unit 14, the second communication unit 15 and the like are housed in the housing 18 in a state where they are mounted on the board. In addition, the connector 16 is exposed from the front surface of the housing 18. A pair of power terminals 171A and 171B, a pair of load terminals 172A and 172B, and a pair of signal terminals 173A and 173B are exposed from the rear surface of the housing 18.

Next, the operation unit 2 will be described.

The operation unit 2 is configured to accept an operation (touch operation) input by a person, for example. The operating unit 2 is installed in front of the switch body 1. The operation unit 2 outputs, for example, an operation signal according to an input operation to the switch body 1.

The operation unit 2 has a touch sensor 3, a connector 21, and a housing 22 (refer to FIG. 3).

The touch sensor 3 is an electrostatic capacitive touch sensor, which detects touch operations performed by a human finger, for example, by a change in parasitic capacitance (electrostatic capacitance). Touch operations include click operations, long press operations, slide operations, drag operations, flick operations, zoom operations, etc.

The housing 22 includes a base 23 and a panel 24. The housing 22 is formed into a flat rectangular box shape with a base 23 and a panel 24.

The base 23 is formed of, for example, synthetic resin. The base 23 has a rectangular bottom wall 230 and a rectangular frame-shaped peripheral wall 231 protruding from the peripheral edge of the bottom wall 230 to the front. The substrate 30 of the touch sensor 3 is stored in the storage space surrounded by the bottom wall 230 and the peripheral wall 231. The base plate 30 is fixed to the bottom wall 230 of the base 23 with a plurality of screws.

The panel 24 is formed of a synthetic resin material such as polycarbonate. The panel 24 is formed in a rectangular flat plate shape. The panel 24 is transparent and electrically insulating. The panel 24 preferably has high light diffusibility by mixing in light diffusing materials, concave-convex processing, screen printing, and the like. The panel 24 is mounted on the front surface 303 of the substrate 30 with a light-transmitting and electrically insulating adhesive sheet 25 to cover the opening of the base 23. The front surface 240 of the panel 24 has the function of an operation surface for the user to perform touch operations.

The substrate 30 is a multilayer printed substrate. A plurality of sensing electrodes 31 are formed on the front surface 303 of the substrate 30 (refer to FIG. 4A). A first ground electrode 32 (ground electrode) is formed on the inner layer of the substrate 30 (see FIG. 4B). A parasitic capacitance is formed between each of the plurality of sensing electrodes 31 and the first ground electrode 32. In addition, multiple electronic components including resistors, capacitors, inductors, and the like are mounted on the back surface 304 of the substrate 30. A plurality of electronic components has a detection unit 34 (refer to FIG. 1 and FIG. 4D) for detecting touch operation according to the change of parasitic capacitance. The detailed structure of the substrate 30 will be described later.

The detection unit 34 has, for example, a microcomputer with a processor and a memory. Furthermore, the processor executes the program stored in the memory, and the microcomputer has the function of the detection unit 34. The program executed by the processor is pre-recorded in the memory of the microcomputer. It can also be recorded on a non-temporary recording medium such as a memory card to provide it, or it can be provided through telecommunication lines such as the Internet.

The detection unit 34 monitors the parasitic capacitance of each sensing electrode 31. For example, when a user touches the front surface 240 (operation surface) of the panel 24 with a finger, a new parasitic capacitance is formed between the user's finger and the sensing electrode 31. That is, a parasitic capacitance is formed between the sensing electrode 31 and the first ground electrode 32, and between the sensing electrode 31 and the user's finger. Therefore, the parasitic capacitance of the sensing electrode 31 increases. The detection unit 34 detects the touch operation by detecting the change (increase) of the parasitic capacitance of the sensing electrode 31.

In addition, a connector 21 is provided on the rear surface 304 of the substrate 30 (FIG. 1 and FIG. 4D ). The connector 21 is used to electrically and mechanically connect the switch body 1 and the operating unit 2. The connector 21 is electrically connected to the detection unit 34. The connector 21 is exposed from the bottom wall 230 of the base 23 of the housing 22. The operating unit 2 is installed on the switch body 1, and the connector 21 is mechanically and electrically connected to the connector 16 of the switch body 1.

When the detection unit 34 detects a touch operation, it outputs a signal (operation signal) according to the detected touch operation to the control circuit 12 of the switch body 1 through the connector 21.

The control circuit 12 controls the switching element 11 according to the operation signal from the operation unit 2. That is, the control circuit 12 controls the on/off of the switch element 11 according to the operation signal from the operation unit 2. In this way, the control circuit 12 can control the power supply from the power source 40 to the load 41. That is, the control circuit 12 controls the load 41 according to the detection result of the touch operation of the touch sensor 3. In addition, the control circuit 12 transmits the control signal from the first communication unit 14 by wired communication in accordance with the operation signal from the operation unit 2. Furthermore, the control circuit 12 transmits a control signal from the second communication unit 15 by wireless communication in accordance with the operation signal from the operation unit 2. In the wiring appliance 10 that has received the control signal, the control circuit 12 controls the on/off of the switch element 11 and controls the power supply from the power source 40 to the load 41 by pressing the received control signal.

Next, the detailed structure of the substrate 30 will be described with reference to FIGS. 4A to 4D.

The substrate 30 is a four-layer printed circuit board having a first layer L1 (refer to FIG. 4A), a second layer L2 (refer to FIG. 4B), a third layer L3 (refer to FIG. 4C), and a fourth layer L4 (refer to FIG. 4D). The substrate 30 is formed by bonding a plurality of substrates having electrical insulation properties such as glass or epoxy substrates with, for example, prepregs. In the present embodiment, the first outer layer substrate 3021 and the second outer layer substrate 3022 are respectively adhered to both surfaces of the inner layer substrate 3020 to form the first layer L1 to the fourth layer L4. In the thickness direction (front-rear direction) of the substrate 30, a first layer L1, a second layer L2, a third layer L3, and a fourth layer L4 are sequentially formed from the front. The first layer L1 is the surface of the first outer layer substrate 3021 on the side opposite to the inner layer substrate 3020 side. The second layer L2 is the surface on the side of the first outer layer substrate 3021 of the inner layer substrate 3020. The third layer L3 is the surface of the inner layer substrate 3020 on the second outer layer substrate 3022 side. The fourth layer L4 is the surface on the side opposite to the inner layer substrate 3020 side of the second outer layer substrate 3022. In other words, the first layer L1 is the surface on the opposite side of the surface facing the inner layer substrate 3020 of the first outer layer substrate 3021. The second layer L2 is a surface of the inner layer substrate 3020 that faces the first outer layer substrate 3021. The third layer L3 is a surface of the inner layer substrate 3020 that faces the second outer layer substrate 3022. The fourth layer L4 is the surface on the side opposite to the surface of the second outer layer substrate 3022 that faces the inner layer substrate 3020. That is, the first layer L1 is a layer on the front surface 303 (first surface) side of the substrate 30, and the fourth layer L4 is a layer on the back surface 304 (second surface) side of the substrate 30.

As shown in FIG. 4A, a plurality of (twelve in this embodiment) sensing electrodes 31 are formed on the first layer L1 of the substrate 30. The sensing electrode 31 is composed of a conductive member such as copper foil, and is formed on the surface of the first layer L1, that is, the first outer layer substrate 3021, by photolithography.

In this embodiment, twelve sensing electrodes 31 are formed on the first layer L1 of the substrate 30, two in the left and right directions, and six in the vertical direction. The shape of each sensing electrode 31 is rectangular. Each sensing electrode 31 is individually electrically connected to the detection portion 34 provided on the rear surface (the fourth layer L4) of the substrate 30. In the touch sensor 3, a plurality of sensing electrodes 31 are arranged and formed on the substrate 30. In this way, not only the click operation (long-press operation) of the touch operation can be detected, but also the touch operation accompanying movement such as sliding operation, drag operation, flick operation, zoom operation, etc. can be detected.

In addition, a plurality of sensing electrodes 31 can also be electrically connected. For example, the two sensing electrodes 31 arranged in the left-right direction can also be electrically connected. At this time, the touch operation accompanying the movement in the up and down direction can be detected.

As shown in FIG. 4B, the first ground electrode 32 is formed on the second layer L2 of the substrate 30. The first ground electrode 32 is made of a conductive member such as copper foil, and is formed on the surface of the second layer L2, that is, the inner layer substrate 3020, by a photolithography technique or the like. The first ground electrode 32 is electrically connected to the detection unit 34.

The outer shape of the first ground electrode 32 is rectangular. The first ground electrode 32 is formed on the second layer L2 so as to completely overlap the plurality of sensing electrodes 31 in the thickness direction (front-rear direction) of the substrate 30. In other words, the plurality of sensing electrodes 31 overlap the first ground electrode 32 in the thickness direction of the substrate 30, respectively. The “overlap” mentioned here means that when viewed from the thickness direction of the substrate 30, each sensing electrode 31 overlaps the first ground electrode 32. Between each sensing electrode 31 and the first ground electrode 32, there is a first outer layer substrate 3021, a prepreg, and the like.

As shown in FIG. 4B, the first ground electrode 32 has a plurality of through holes 320 formed in an area A1 overlapping each sensing electrode 31 in the thickness direction of the substrate 30. That is, each sensing electrode 31 partially overlaps the plurality of through holes 320 in the thickness direction of the substrate 30. As shown in FIGS. 4B and 5, in this embodiment, the first ground electrode 32 is formed in a mesh shape, and the plurality of through holes 320 are formed in a mesh. The "mesh" referred to here means that the shape of the electrical component is a net-like shape, and it does not mean that the electrical component is woven. A plurality of through holes 320 are formed in a regular arrangement in a direction along the surface of the substrate 30. In addition, the plurality of through holes 320 have the same opening shape and the same size. The opening shape of each through hole 320 is a square, and each side is inclined at 45 degrees or -45 degrees to the up and down direction. That is, the diagonal of each through hole 320 is along the up-down direction or the left-right direction. However, the through hole 320 formed at the peripheral edge of the first ground electrode 32 and the peripheral edge of the circular hole 301 that penetrates the substrate 30 has a different shape from the other through holes 320.

The inner side of each through hole 320 is filled with a prepreg having electrical insulation that connects the inner layer substrate 3020 and the first outer layer substrate 3021 to each other. That is, the inner side of each through hole 320 is provided with an insulating member having electrical insulation. In other words, there is no conductive member with conductivity inside each through hole 320.

As shown in FIG. 4C, a second ground electrode 33 is formed on the third layer L3 of the substrate 30. The second ground electrode 33 is composed of a conductive member such as copper foil, and is formed on the surface of the third layer L3, that is, the inner layer substrate 3020, by a photolithography technique or the like. The second ground electrode 33 is formed on the entire surface of an area where a conductive member can be formed in the third layer L3. The second ground electrode 33 has a function of grounding the circuit of the sensing circuit formed by a plurality of electronic components mounted on the back surface 304 of the substrate 30. In addition, the second ground electrode 33 is electrically connected to the first ground electrode 32.

On the fourth layer L4 of the substrate 30, there are formed pads for mounting a plurality of electronic components (including the detection portion 34 and the connector 21), wirings for electrically connecting the plurality of electronic components, and the like. The pads and wiring are made of conductive members such as copper foil, and are formed on the surface of the fourth layer L4, that is, the second outer layer substrate 3022, by photolithography. In addition, in FIG. 4D, descriptions of pads, wiring, etc. are omitted.

In addition, in the center of the substrate 30 in the left-right direction, a plurality of (five in this embodiment) circular holes 301 are formed side by side in the vertical direction. Five circular holes 301 penetrate through the substrate 30. Five light-emitting diodes 35 are mounted on the fourth layer L4 of the substrate 30 so as to span five circular holes 301 (refer to FIG. 4D). Each light emitting diode 35 is installed so that light can pass through the circular hole 301 and irradiate to the front. The light radiated from the light emitting diode 35 passes through the circular hole 301, and is irradiated to the front of the panel 24 through the light-transmitting adhesive sheet 25 (refer to FIG. 3) and the panel 24 (refer to FIG. 3).

(advantage) In the touch sensor 3 of this embodiment, the mesh-shaped first ground electrode 32 is formed on the second layer L2 of the substrate 30. The first ground electrode 32 is formed with a plurality of through holes 320 in the region A1 where the sensing electrodes 31 formed on the first layer L1 of the substrate 30 overlap in the thickness direction of the substrate 30. Therefore, a part of each sensing electrode 31 overlaps the plurality of through holes 320 of the first ground electrode 32 in the thickness direction of the substrate 30. Therefore, in the touch sensor 3 of this embodiment, the parasitic capacitance between each sensing electrode 31 and the first ground electrode 32 is compared with a structure in which a plurality of through holes 320 are not formed in the first ground electrode 32. Smaller.

As described above, when the user touches the front surface 240 (operating surface) of the panel 24 with a finger, a new parasitic capacitance is formed between the user's finger and the sensing electrode 31, so the parasitic capacitance of the sensing electrode 31 increases. The detection unit 34 detects the touch operation by detecting the change (increase) of the parasitic capacitance of the sensing electrode 31 when the touch operation is performed. As the parasitic capacitance between the sensing electrode 31 and the first ground electrode 32 increases, the proportion of the change in the parasitic capacitance of the sensing electrode 31 before and after the touch operation decreases. Therefore, as the parasitic capacitance between the sensing electrode 31 and the first ground electrode 32 increases, the detection sensitivity of the touch operation of the detection unit 34 decreases.

The touch sensor 3 of this embodiment is structured such that the parasitic capacitance between the sensing electrode 31 and the first ground electrode 32 is small. Therefore, the touch sensor 3 of the present embodiment has higher detection sensitivity of touch operation than a structure in which a plurality of through holes 320 are not formed in the first ground electrode 32, and the detection accuracy of touch operation can be improved. .

Furthermore, in order to reduce the parasitic capacitance of the sensing electrode 31, it is considered to omit the structure of the first ground electrode 32. At this time, a parasitic capacitance is formed between the sensing electrode 31 and the second ground electrode 33 formed on the third layer L3 of the substrate 30. The second ground electrode 33 is formed on the third layer L3. The third layer L3 is a layer on the side opposite to the first layer L1 where the sensing electrode 31 is formed with respect to the second layer L2. Therefore, in the thickness direction of the substrate 30, the distance between the sensing electrode 31 and the second ground electrode 33 is longer than the distance between the sensing electrode 31 and the first ground electrode 32. Therefore, by omitting the first ground electrode 32, the parasitic capacitance of the sensing electrode 31 can be reduced.

However, in the structure where the first ground electrode 32 is omitted, the noise immunity of the sensing electrode 31 is reduced. When the noise immunity is low, it is easy to receive the noise caused by the wireless signal, etc., and the touch operation may be detected by mistake. In addition, when noise immunity is low, noise is likely to be emitted from the sensing electrode 31.

In the touch sensor 3 of this embodiment, a first ground electrode 32 is formed on the second layer L2, and the first ground electrode 32 has a function of a noise shield for suppressing noise. Therefore, the touch sensor 3 of the present embodiment has improved noise immunity compared to a structure in which the first ground electrode 32 is omitted. Thereby, false detection of touch operation is suppressed, and the detection accuracy of touch operation can be improved.

As described above, in the touch sensor 3 of this embodiment, the first ground electrode 32 has a plurality of through holes 320 formed in a mesh shape. Therefore, in the touch sensor 3 of this embodiment, the detection sensitivity of the touch operation and the noise immunity are improved, so that the detection accuracy of the touch operation can be improved. In the first ground electrode 32, the ratio of the plurality of through holes 320 to the area A1 overlapping the sensing electrode 31 in the thickness direction of the substrate 30 is preferably 30% or more and 95% or less.

In addition, the wiring appliance 10 of the present embodiment includes a second communication unit 15 (communication unit) that transmits a wireless signal according to the detection result of the touch operation of the touch sensor 3. In the touch sensor 3 of this embodiment, the opening size X1 (refer to FIG. 5) of each through hole 320 of the first ground electrode 32 is set to a level that suppresses the noise caused by the wireless signal sent by the second communication unit 15 influences. The opening size X1 is the maximum value of the opening size of the through hole 320. In this embodiment, the opening shape of the through hole 320 is a square. Therefore, the opening size X1 is the size of the diagonal line of the opening of the through hole 320 (refer to FIG. 5).

The opening size X1 of each through hole 320 is set to prevent each sensing electrode 31 from receiving the wireless signal transmitted from the second communication unit 15. The opening size X1 of each through hole 320 is set according to the frequency of the wireless signal transmitted by the second communication unit 15. Specifically, the opening size X1 of each through hole 320 is less than a quarter of the wavelength of the wireless signal transmitted by the second communication unit 15. The wavelength of the wireless signal is expressed by the following formula (1).

λ=c÷f×k　…(1) In formula (1), λ is the wavelength of the wireless signal, c is the speed of light [m/s], f is the frequency of the wireless signal [Hz], and k is the wavelength reduction rate of the substrate 30. The wavelength shortening rate k is expressed by the following formula (2).

k=1/√ε _r (2) In the formula (2), ε _r is the relative permittivity of the substrate 30.

For example, when the frequency f of the wireless signal is 1 [GHz] and the relative permittivity of the substrate 30 is 4, the wavelength λ is expressed by the following formula (3).

λ=3×10 ⁸ ÷(1×10 ⁹ )×1/√4=0.15[m]=150[mm] …(3) The opening size X1 of each through hole 320 is a quarter of the wavelength λ of the wireless signal One or less is preferable, one-eighth or less of the wavelength λ is preferable, and one-tenth or less of the wavelength λ is more preferable. When the aperture size X1 is one-eighth of the wavelength λ, it is 18.75 [mm], and when it is one-tenth of the wavelength λ, it is 15 [mm].

By forming the opening size X1 of each through hole 320 to the above-mentioned value, each sensing electrode 31 can be suppressed from receiving the wireless signal transmitted from the second communication unit 15 and the noise of the sensing electrode 31 can be suppressed. In addition, since the first ground electrode 32 is formed between the sensing electrode 31 and the switch body 1 (the second communication unit 15), the noise of the sensing electrode 31 can be further suppressed.

(Modification) In the following, modified examples are listed. In addition, the modified examples described below can be appropriately combined with the above-mentioned embodiments.

(Modification 1) The shape of the first ground electrode 32 is not limited to the shape shown in FIGS. 4B and 5. As shown in FIG. 6, in the first ground electrode 32A, each through hole 320A may form a square with each side along the up-down direction or the left-right direction.

In addition, the shape of the first ground electrode 32 is not limited to the opening shape of each through hole 320 being a square (tetragonal) mesh shape. As shown in FIG. 7, the opening shape of each through hole 320B of the first ground electrode 32B may also be circular. In addition, as shown in FIG. 8, each through hole 320C of the first ground electrode 32C may be formed in a slit shape. In the example shown in FIG. 8, the opening of the through hole 320C is formed along an oblique direction inclined to the up-down direction.

(Modification 2) In the above embodiment, the first ground electrode 32 is configured to include a plurality of through holes 320, but it is not limited to this. As shown in FIG. 9A, each sensing electrode 31D can also be configured to include a plurality of through holes 310D.

In the example shown in FIG. 9A, each sensing electrode 31D is formed in a mesh shape, and the plurality of through holes 320D are formed as a plurality of meshes. Furthermore, in this modification, as shown in FIG. 9B, the first ground electrode 32D is formed on the entire surface of the region where the conductive member can be formed in the second layer L2.

In this modification example, a plurality of sensor electrodes 31D formed in a mesh shape are formed on the first layer L1 of the substrate 30. That is, each sensing electrode 31D has a plurality of through holes 320D formed in a region overlapping the first ground electrode 32D formed on the second layer L2 of the substrate 30 in the thickness direction of the substrate 30. Therefore, in the thickness direction of the substrate 30, the first ground electrode 32D partially overlaps the plurality of through holes 310D of the sensing electrode 31D. Thereby, in the touch sensor 3 of this modification example, the parasitic capacitance between each sensing electrode 31D and the first ground electrode 32D is smaller than that of a structure in which a plurality of through holes 310D are not formed in each sensing electrode 31D. In this way, the detection accuracy of the touch operation can be improved.

In this modification, the first ground electrode 32D is formed on the entire surface of the area where the conductive member can be formed in the second layer L2. In this way, the noise received by each sensing electrode 31D can be further suppressed.

In addition, the opening area of each through hole 310D of each sensing electrode 31D is preferably smaller than the contact area of the finger and the panel 24 when the user performs a touch operation on the front surface 240 (operating surface) of the panel 24.

Moreover, as shown in FIG. 9B, the first ground electrode 32D is formed on the entire surface of the area where the conductive member can be formed in the second layer L2, but it is not limited to this. On the second layer L2 of the substrate 30, a first ground electrode 32 formed in a mesh shape and having a plurality of through holes 320 may be formed (see FIG. 4B). That is, the touch sensor 3 may also have a structure in which both the sensing electrodes 31D and the first ground electrode 32 form a mesh.

(Other modifications) In the above example, a plurality of (twelve) sensing electrodes 31 are formed on the first layer L1 of the substrate 30, and the number of the plurality of sensing electrodes 31 is not limited to twelve, and it may be other numbers. In addition, the number of sensing electrodes 31 may also be one.

The shape of the sensing electrode 31 is not limited to a rectangle, and may also have other shapes (for example, a circle). In addition, the plurality of sensing electrodes 31 are not limited to the same outer shape and shape, and the same size may be different outer shape and size.

In the above example, the first ground electrode 32 is also formed with a plurality of through holes 320 in areas other than the area A1 (refer to FIG. 4B) overlapping the plurality of sensing electrodes 31 in the thickness direction of the substrate 30, but it is not limited to this. . The first ground electrode 32 may form a conductive member on the entire surface of a region other than the region A1.

In the above example, the structure is such that a plurality of sensing electrodes 31 overlap a first ground electrode 32 in the thickness direction of the substrate 30, but it is not limited to this. It can also be configured that a plurality of first ground electrodes are formed on the second layer L2 of the substrate 30, and the plurality of first ground electrodes overlap with the plurality of sensing electrodes 31 in the thickness direction of the substrate 30.

In the above example, the substrate 30 is a four-layer substrate, but it is not limited to this. The substrate 30 may be a double-sided substrate having only the first layer L1 and the second layer L2, or a three-layer or five-layer or more substrate.

(Compilation) The touch sensor (3) of the first aspect is an electrostatic capacitive touch sensor for detecting touch operation. The touch sensor (3) includes a substrate (30), sensing electrodes (31, 31D), and ground electrodes (first ground electrodes 32, 32A, 32B, 32C, 32D). The substrate (30) has a first layer (L1) and a second layer (L2). The sensing electrodes (31, 31D) are formed on the first layer (L1). The ground electrodes (32, 32A, 32B, 32C, 32D) are formed on the second layer (L2) so as to overlap with the sensing electrodes (31, 31D) in at least part of the thickness direction of the substrate (30), and to overlap with the sensing electrodes (31, 31D). A parasitic capacitance is formed between the electrodes (31, 31D). At least one of the sensing electrodes (31, 31D) and the ground electrodes (32, 32A, 32B, 32C, 32D) has the sensing electrodes (31, 31D) and the ground electrodes (32) formed in the thickness direction of the substrate (30) , 32A, 32B, 32C, 32D) multiple through holes (320, 320A, 320B, 320C, 310D) in the overlapping area (A1).

According to this aspect, since the detection sensitivity of the touch operation and the noise immunity are improved, the detection accuracy of the touch operation can be improved.

The touch sensor (3) of the second aspect is in the first aspect. Among the sensing electrodes (31) and the ground electrodes (32, 32A, 32B, 32C), only the ground electrodes (32, 32A) , 32B, 32C) are formed with a plurality of through holes (320, 320A, 320B, 320C).

According to this aspect, since the detection sensitivity of the touch operation and the noise immunity are improved, the detection accuracy of the touch operation can be improved.

The touch sensor (3) of the third aspect is in the second aspect, and the substrate (30) further has a third layer (L3) and a fourth layer (L4). The first layer (L1) is a layer on the first surface (303) side of the substrate (30). The second layer (L2) is an inner layer of the substrate (30), and first ground electrodes (32, 32A, 32B, 32C) as ground electrodes are formed. The third layer (L3) is a layer formed on the inner side of the substrate (30) on the side opposite to the first layer (L1) with respect to the second layer (L2), and a second ground electrode (33) is formed. The fourth layer (L4) is a layer formed on the second surface (304) side of the substrate (30) opposite to the third layer (L3) on the opposite side of the second layer (L2), and is configured to detect touch operations The electronic components (detection section 34).

According to this aspect, it is possible to suppress the noise of the sensing circuit constituted by the electronic parts for detecting the touch operation from being transmitted to the sensing electrode (31).

The touch sensor (3) of the fourth aspect is in the first aspect, the sensing electrode (31D) and the ground electrode (32D) only have a plurality of through holes (310D) formed in the sensing electrode (31D) ).

According to this aspect, since the detection sensitivity of the touch operation and the noise immunity are improved, the detection accuracy of the touch operation can be improved.

The touch sensor (3) of the fifth aspect is in any one of the first to fourth aspects, and the plurality of through holes (320, 320A, 320B, 320C, 310D) are along the substrate (30) The direction of the surface is regularly arranged and formed.

According to this aspect, in the direction along the surface of the substrate (30), the difference in the detection sensitivity of the touch operation can be reduced.

The touch sensor (3) of the sixth aspect is in any of the first to fifth aspects, the sensing electrode (31, 31D) and the ground electrode (32, 32A, 32B, 32C, 32D) At least one of them forms a mesh, and the plurality of through holes (320, 320A, 320B, 320C, 310D) are formed into a plurality of meshes.

According to this aspect, since the detection sensitivity of the touch operation and the noise immunity are improved, the detection accuracy of the touch operation can be improved.

The touch sensor (3) of the seventh aspect is in any one of the first to sixth aspects, and the opening size (X1) of each of the plurality of through holes (320) is the detection result of the touch operation Less than a quarter of the wavelength (λ) of the transmitted wireless signal.

According to this aspect, the noise received by the sensing electrodes (31, 31D) due to wireless signals can be suppressed.

The wiring device (10) of the eighth aspect includes the touch sensor (3) of any one of the first to the seventh aspects, and the detection of touch operations based on the touch sensor (3) As a result, the control circuit (12) that controls the load (41).

According to this aspect, since the detection sensitivity of the touch operation and the noise immunity are improved in the touch sensor (3), the detection accuracy of the touch operation can be improved.

1: Switch body 2: Operation unit 3: touch sensor 10: Wiring appliances 11: Switching element 12: Control circuit 13: Power supply circuit 14: Department of Communication 1 15: Section 2 Communications Department 16: connector 18: shell 21: Connector 22: shell 23: Pedestal 24: Panel 25: Adhesive sheet 30: substrate 31: Sensing electrode 31D: Sensing electrode 32: The first ground electrode (ground electrode) 32A: The first ground electrode (ground electrode) 32B: The first ground electrode (ground electrode) 32C: The first ground electrode (ground electrode) 32D: The first ground electrode (ground electrode) 33: 2nd ground electrode 34: Inspection Department (Electronic Parts) 35: LED 40: Power 41: Load 100: installation frame 171A: Power terminal 171B: Power terminal 172A: Load terminal 172B: Load terminal 173A: signal terminal 173B: signal terminal 230: bottom wall 231: The Wall 240: front 301: round hole 303: Front (1st surface) 304: Back (2nd surface) 310D: Through hole 320: Through hole 320A: Through hole 320B: Through hole 320C: Through hole 320D: Through hole 3020: Base material for inner layer 3021: Base material for the first outer layer 3022: Base material for the second outer layer A1: area L1: Layer 1 L2: Layer 2 L3: Layer 3 L4: Layer 4 X1: Opening size

FIG. 1 is a block diagram of a wiring device including a touch sensor according to an embodiment of the present invention. Figure 2 is a perspective view of the wiring appliance. Fig. 3 is an exploded perspective view of the operation unit included in the wiring appliance. 4A is a schematic diagram of the first layer of the substrate of the touch sensor. Fig. 4B is a schematic view of the second layer of the substrate. Fig. 4C is a schematic diagram of the third layer of the substrate. Fig. 4D is a schematic view of the fourth layer of the substrate. Fig. 5 is an enlarged view of the first ground electrode formed on the second layer of the substrate. 6 is a schematic diagram of the second layer of the substrate of the touch sensor according to the first modification of an embodiment of the present invention. FIG. 7 is a schematic diagram of the second layer of the substrate of the touch sensor according to a second modification of an embodiment of the present invention. FIG. 8 is a schematic diagram of the second layer of the substrate of the touch sensor according to a third modification of an embodiment of the present invention. 9A is a schematic diagram of the first layer of the substrate of the touch sensor according to a fourth modification of an embodiment of the present invention. Fig. 9B is a schematic view of the second layer of the substrate.

21: Connector

30: substrate

31: Sensing electrode

32: The first ground electrode (ground electrode)

33: 2nd ground electrode

34: Inspection Department (Electronic Parts)

35: LED

301: round hole

303: Front (1st surface)

304: Back (2nd surface)

320: Through hole

3020: Base material for inner layer

3021: Base material for the first outer layer

3022: Base material for the second outer layer

A1: area

L1: Layer 1

L2: Layer 2

L3: Layer 3

L4: Layer 4

Claims (8)

A touch sensor, which is an electrostatic capacitive touch sensor for detecting touch operation, comprising: a substrate having a first layer and a second layer; sensing electrodes formed on the first layer; and grounding An electrode is formed on the second layer to overlap with the sensing electrode in at least part of the thickness direction of the substrate, and a parasitic capacitance is formed between the ground electrode and the sensing electrode; the sensing electrode and the ground electrode At least one of them has a plurality of through holes, and the plurality of through holes are formed in the area where the sensing electrode and the ground electrode overlap in the thickness direction of the substrate; the plurality of through holes are in the thickness direction of the substrate The area ratio of the area where the sensing electrode and the ground electrode overlap is 30% or more and 95% or less. A touch sensor, which is an electrostatic capacitive touch sensor for detecting touch operation, comprising: a substrate having a first layer and a second layer; sensing electrodes formed on the first layer; and grounding An electrode is formed on the second layer to overlap with the sensing electrode in at least part of the thickness direction of the substrate, and a parasitic capacitance is formed between the ground electrode and the sensing electrode; the sensing electrode and the ground electrode At least one of them has a plurality of through holes, and the plurality of through holes are formed in the area where the sensing electrode and the ground electrode overlap in the thickness direction of the substrate; at least one of the sensing electrode and the ground electrode A mesh is formed, and the plurality of through holes are formed into a plurality of meshes. A touch sensor, which is an electrostatic capacitive touch sensor for detecting touch operation, comprising: a substrate having a first layer and a second layer; sensing electrodes formed on the first layer; and grounding An electrode is formed on the second layer to overlap with the sensing electrode in at least part of the thickness direction of the substrate, and a parasitic capacitance is formed between the ground electrode and the sensing electrode; the sensing electrode and the ground electrode At least one of them has a plurality of through holes, and the plurality of through holes are formed in the area where the sensing electrode and the ground electrode overlap in the thickness direction of the substrate; the opening size of each of the plurality of through holes is according to the The detection result of the touch operation is less than a quarter of the wavelength of the wireless signal sent. For example, the touch sensor of the first item in the scope of the patent application, wherein the plurality of through holes are formed in a regular arrangement along the direction of the surface of the substrate. For example, the touch sensor of any one of items 1 to 4 of the scope of patent application, wherein, in the sensing electrode and the ground electrode, only the ground electrode is formed with the plurality of through holes. For example, the touch sensor of item 5 of the scope of patent application, wherein the substrate further has a third layer and a fourth layer, and the first layer is a layer on the first surface side of the substrate in the thickness direction of the substrate , The first layer, the second layer, the third layer and the fourth layer are arranged in the order of the first layer, the second layer, the third layer and the fourth layer, the second The layer is the inner layer of the substrate and forms the first ground electrode as the ground electrode, The third layer is an inner layer of the substrate and forms a second ground electrode; the fourth layer is a layer on the second surface side of the substrate and is configured with electronic components for detecting the touch operation. For example, the touch sensor according to any one of items 1 to 4 of the scope of patent application, wherein the plurality of through holes are formed only in the sensing electrode in the sensing electrode and the ground electrode. A wiring appliance, including: the touch sensor of any one of items 1 to 7 of the scope of patent application; and a control circuit, which controls the load according to the detection result of the touch operation of the touch sensor .

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