JP6774444B2 - Switch and input device for both housing - Google Patents

Description

The present invention relates to a switch that also serves as a housing of an electronic device and an input device that uses the switch that also serves as a housing.

Conventionally, there are those in which a plurality of operation buttons are provided on the side surface of a housing that constitutes an outer frame of an electronic device such as a smartphone.

In the mobile terminal described in Patent Document 1, a through hole is formed on the side surface of the housing, and the operation button is housed in the through hole so that the operation button faces in a direction orthogonal to the thickness direction of the housing. ..

JP 2013-098650

However, in the conventional operation button configuration, a through hole must be formed in advance in the housing, and a button member which is a separate member must be prepared, which complicates the manufacturing process. In addition, if an electronic device is to be made waterproof, a packing for attaching it around the operation button is required, which increases the number of parts. Further, since the operation buttons have a shape protruding from the side surface of the housing, the design of the electronic device is restricted.

An object of the present invention is to provide a housing-combined switch that is easy to assemble and has excellent design.

In order to achieve the above object, the first invention comprises a housing having a plate-shaped portion that is elastically deformed, a pressure-sensitive sensor body arranged on the inner surface of the housing of the plate-shaped portion, and a pressure-sensitive sensor body. It is a switch that also serves as a housing, with a back plate placed on top.

The second invention is, in the first invention, a housing-combined switch further including an elastic member arranged between the plate-shaped portion and the pressure-sensitive sensor body.

With this configuration, it is not necessary to separate the operation buttons from each other, and it is not necessary to provide a through hole in the housing. Therefore, it is possible to obtain a housing-combined switch that is easy to assemble and has excellent design.

A third invention is, in the first or second invention, a plate-shaped portion is a housing-combined switch which is a bottom surface portion of a recess formed in the housing.
Is.

In this way, the thickness of the plate-shaped portion becomes thinner than that of the other portion of the housing, so that the plate-shaped portion is easily bent and the sensitivity of the pressure sensor can be improved.

A fourth invention is, in the first to third inventions, a housing combined switch in which the back plate is fixed by a claw portion protruding from the inner surface of the housing.

In this way, the back plate is securely fixed by the claws within a range that does not interfere with other parts arranged in the housing, so that the sensitivity of the pressure sensor body can be improved.

A fifth aspect of the present invention is, in the first to fourth inventions, the housing is a flat box-shaped shape, and the recess is a housing-combined switch formed on the side surface of the housing.

A sixth aspect of the present invention is a housing-combined switch, which is a resistance-changing pressure-sensitive sensor whose resistance value changes when the pressing force changes, in the first to fifth inventions.

In the seventh invention, the housing-combined switch of the sixth invention, the voltage source for driving the pressure-sensitive sensor body, and the voltage generated in the pressure-sensitive sensor body are used as input signals, and the DC component is removed from the input signal. It is an input device including a pressure detection control unit having an amplifier circuit including a filter.

In this way, the DC component is removed from the input signal and only the change in the input signal is amplified, so that the signal reflecting only the pressure change can be passed to the amplifier or the like, and the accuracy is accurate even if the pressure change is minute. It can be detected well.

According to the present invention, it is possible to provide a housing-combined switch that is easy to assemble and has excellent design.

It is a schematic block diagram of the input device by embodiment of this invention. It is a perspective view of the input device by embodiment of this invention. It is sectional drawing of the chassis-combined switch cut by the line I-I of FIG. It is sectional drawing of the pressure-sensitive sensor by embodiment of this invention. It is a circuit diagram of the pressure detection control part by embodiment of this invention. It is sectional drawing of the pressure-sensitive sensor by the modification of this invention.

Next, an embodiment of the invention will be described with reference to the drawings.
<Embodiment>

With reference to FIGS. 1 to 3, the input device 1 according to the embodiment of the present invention is a device for inputting information by a contact operation from an operator. The input device 1 includes a display 2 and a housing combined switch 10. A touch panel, a liquid crystal display device, a control board, and the like are built under the display. The operator can input information by touching the display 2 and the housing combined switch 10. In the present embodiment, the input device 1 will be described as a smartphone.

(1) Case-combined switch The housing-combined switch 10 includes a housing 20, a pressure-sensitive sensor 30, and a back plate 40. A recess 21 is formed in the housing 20, and the bottom surface of the recess 21 is a plate-shaped portion 22. The pressure-sensitive sensor 30 and the elastic member 50 are housed in the recess 21. The back plate 40 is arranged so as to close the opening of the recess 21, and the back plate 40 is fixed by the claw portion 23 formed in the housing 20. Further, the FPC 60 connected to the pressure sensor 30 is taken out along the bottom surface of the housing 20. The FPC 60 is connected to a control board built in the input device 1.

The housing 20 has a flat box shape having a bottom surface and side surfaces rising from the bottom surface. The housing 20 is made of a highly rigid material and is made of a metal or plastic such as aluminum, titanium, or magnesium. A recess 21 is formed on the inner surface on the upper right side of the housing 20. The recess 21 can be formed by a method such as cutting or injection molding. The bottom surface of the recess 21 is a plate-shaped portion 22, and the plate-shaped portion 22 is a switch portion. When operating using the housing combined switch 10, the plate-shaped portion 22 is pressed or rubbed for operation. A step portion 24 is formed on the outer surface on the upper right side of the housing 20. The step portion 24 has a shape in which the surface of the housing 20 is dug into a concave shape. The Young's modulus of the plate-shaped portion 22 is, for example, 1 to 100 GPa, preferably 10 to 100 GPa. The thickness of the plate-shaped portion 22 is, for example, 1 mm.

An L-shaped claw portion 23 is formed so as to protrude from the inner surface of the housing 20. The claw portion 23 has a first claw portion 23a projecting substantially vertically from the inner surface of the housing 20 and a second claw portion 23b substantially perpendicular to the first claw portion 23a and parallel to the inner surface of the housing 20. including. The claw portions 23 are formed at two positions in the housing 20, and the two claw portions 23 are formed so that the second claw portions 23b face each other. The distance between the two claws 23 is approximately the same as the length of the back plate 40. The back plate 40, which will be described later, is inserted into the space formed by the two claw portions 23.

The back plate 40 is fixed to the housing 20 by the claw portion 23. The back plate 40 has a flat rectangular parallelepiped shape and has a size that closes the opening of the recess 21. The back plate 40 is made of a highly rigid material, and a metal such as aluminum or stainless steel can be used. The Young's modulus of the back plate 40 is, for example, 60 to 300 GPa, preferably 100 to 300 GPa. The thickness of the back plate 40 is, for example, 1 to 2 mm, preferably 1.5 to 2 mm.

A pressure sensor 30 and an elastic member 50 are arranged between the back plate 40 and the plate-shaped portion 22. The pressure-sensitive sensor 30 and the elastic member 50 have a flat rectangular parallelepiped shape like the back plate 40, but are smaller in size than the back plate 40 and have substantially the same size as the plate-shaped portion 22. The pressure-sensitive sensor 30 is a resistance-changing pressure-sensitive sensor whose resistance value changes when pressure is applied. The elastic member 50 is arranged between the pressure sensor 30 and the plate-shaped portion 22. The material of the elastic member 50 is, for example, a foam such as polyurethane, polypropylene, or acrylic. The elastic member 50 has a thickness in the range of 100 to 1500 μm and a stress during 25% compression in the range of 0.001 to 0.5 MPa, preferably 0.001 to 0.1 MPa. The elastic member 50 is adhered to the surface of the pressure sensor 30 on the plate-shaped portion 22 side with an adhesive.

In the housing combined switch 10, a recess 21 and a claw portion 23 are formed on the inner side surface of the housing 20, a step portion 24 is formed on the outer surface, a pressure sensitive sensor 30 and an elastic member 50 are arranged in the recess 21, and then the claw portion 23. It can be assembled by inserting the back plate 40 into the space formed by.

According to the housing combined switch 10 of the present embodiment, it is not necessary to make the operation button a separate member, and it is not necessary to provide a through hole in the housing, so that the assembly is easy. Further, by providing the step portion 24, the operation location becomes easy to understand. Further, although the housing 20 is made of a material having high rigidity and is hard to bend, the plate-shaped portion 22 is bent by providing the recess 21 and the stepped portion 24 to make the plate-shaped portion 22 thinner than the other parts of the housing. This makes it easier to transmit pressure to the pressure sensor 30.

(2) Pressure-sensitive sensor With reference to FIG. 4, the pressure-sensitive sensor 30 in the present embodiment is a resistance-changing pressure-sensitive sensor. The pressure sensor 30 has an upper base material 32 and a lower base material 33 arranged via the gap 31. The spacer 34 functions as an adhesive for fixing the upper base material 32 and the lower base material 33.

A pressure sensitive layer 35 is formed on the upper base material 32 on a surface facing the lower base material 33.
The lower base material 33 is formed with a first electrode 36 and a second electrode 37 on a surface facing the upper base material 32. The first electrode 36 is, for example, a drive electrode, and the second electrode 37 is, for example, a sense electrode. The first electrode 36 and the second electrode 37 have a combination of a pair of alternately arranged comb teeth.
Note that FIG. 4 shows a state in which a load is not applied to the pressure sensor 30, but a state in which the pressure sensor 30 is not pressed because an initial load is applied when the switch 10 is attached to the housing. Then, the pressure sensitive layer 35 comes into contact with the first electrode 36 and the second electrode 37.

The material of the upper base material 32 and the lower base material 33 is a flexible insulating film, for example, polyethylene terephthalate, polyethylene naphthalate, polyimide, polyetherimide and the like.

The first electrode 36 and the second electrode 37 are, for example, a silver paste or a copper paste, and are preferably thermosetting conductive pastes. The electrode material may be a metal foil other than the paste, a sputter film, a vapor deposition film, a laminate film, or the like.

The material of the pressure-sensitive layer 35 may be a general resistance material such as carbon or a pressure-sensitive ink. The composition constituting the pressure-sensitive ink is composed of a material whose resistance value changes according to an external force.

When the housing combined switch 10 is pressed by the operator, the plate-shaped portion 22 bends and deforms. As a result, the pressure-sensitive sensor 30 is also pressed via the elastic member 50, so that the upper base material and the lower base material are in closer contact with each other as compared with the non-pressed state. Then, the area where the pressure sensitive layer 35 contacts the electrodes increases, and the sensor resistance between the electrodes decreases.

(3) Control of Input Device The input device 1 comprises a pressure sensor 30 whose resistance value changes according to the applied pressure, a constant voltage source 100 for driving the pressure sensor, and a pressure detection control unit 200. Have.

The pressure detection control unit 200 includes a high-pass filter unit 210 for removing a DC component, a resistance circuit 220 for determining a reference potential, an operational amplifier 230 for amplifying an input signal, and a low-pass filter unit 240 for removing signal noise. ..

In order to measure the resistance value Rfs of the pressure-sensitive sensor 30, the pull-up resistor Rpu and the pressure-sensitive sensor resistor Rfs are connected in series, and a drive voltage Vcc is applied to both ends. The voltage between Rpu and Rfs is determined by the value of Rfs, and this is passed to the high-pass filter unit 210 as an input signal Vi.

The high-pass filter unit 210 is configured by, for example, connecting a capacitor and a resistor in series. It cuts off the DC component and low-frequency alternating current, and selectively passes only high-frequency alternating current.

In the pressure detection control unit 200, a DC component derived from the partial pressure of the pull-up resistor Rpu and the pressure-sensitive sensor resistor Rfs is generated. Since this DC component depends on the resistance value of the pressure-sensitive layer and the amount of compression of the elastic body, it varies from product to product. By removing this DC component with the high-pass filter unit 210, only the change in the pressure-sensitive sensor resistance Rfs can be extracted. The input signal from which the DC component has been removed is inverting and amplified by the operational amplifier 230. The low-pass filter unit 240 is designed to remove high-frequency noise derived from the environment and power supply. The cutoff frequency of the high-pass filter unit is, for example, 0.1 Hz, and the cutoff frequency of the low-pass filter unit 240 is, for example, 100 Hz. The amplification factor of the operational amplifier 230 is, for example, about 20 times.

The reference potential is determined by the voltage division between R4 and R5 in the resistance circuit 220, and the output signal Vo is output by adding the change of the input signal to the reference potential. Since the reference potential is a known value at the design stage, it is possible to easily determine whether the switch is on or off by comparing the comparative potentials Vth and Vo, which are larger than the reference potential.

In order to reduce the power consumption of this circuit, the resistance of Rfs and Rpu should be large, preferably 50 kΩ to 1 MΩ. At this time, since the impedance of the input unit 250 becomes high and the amplification factor decreases, it is preferable to insert a voltage follower circuit or the like to separate the input unit 250 and the pressure detection control unit 200.

According to the pressure detection control unit 200, since the DC component can be removed from the input signal Vi, it is possible to avoid individual variation of the pressure sensitive sensor 30 and amplify the input signal reflecting only the pressure change by the operational amplifier 230. it can. Since the plate-shaped portion 22 of the housing-combined switch 10 is made of a highly rigid material, the pressure change is small even if the thickness of the plate-shaped portion is reduced, but it is configured like the pressure detection control unit 200 described above. Therefore, it is possible to amplify a minute pressure change. Therefore, even when a seamless design without a button member is adopted for the switch portion, the pressure can be detected with high accuracy.

In the above embodiment, in the pressure sensor 30, the two types of electrodes are provided on the same base material, but the arrangement structure of the electrodes is not limited. For example, the two types of electrodes may be provided on opposite substrates. With reference to FIG. 6, the pressure-sensitive sensor 30A, which is a modification of the pressure-sensitive sensor 30, has an upper base material 32A and a lower base material 33A arranged via a gap 31. The spacer 34A functions as an adhesive for fixing the upper base material 32A and the lower base material 33A.

The upper base material 32A has a first electrode 36A formed on a surface facing the lower base material 33A. The first electrode 36A is, for example, a drive electrode. A pressure sensitive layer 35A is further formed on the upper base material 32A so as to cover the first electrode 36A.
The lower base material 33A has a second electrode 37A formed on a surface facing the upper base material 32A. The second electrode 37A is, for example, a sense electrode. A pressure-sensitive layer 35A is further formed on the lower base material 33A so as to cover the second electrode 37A.

In the above embodiment, the step portion 24 is formed in the housing 20, but the step may not be formed.

In the above embodiment, the elastic member 50 is adhered to the surface of the pressure sensor 30 on the plate-shaped portion 22 side by an adhesive, but the elastic member may not be adhered to the pressure sensor.

In the above embodiment, the pressure sensor 30 and the FPC 60, which is a separate member, are connected, but the pressure sensor and the FPC may be integrated. Further, the FPC 60 may be equipped with a pressure detection control unit.

In the above embodiment, the claw portion 23 is divided into two, but the claw portion may be connected so as to cover the back plate. In this case, since the back plate is firmly fixed, the pressure is easily transmitted to the pressure sensor.

In the above embodiment, the switch portion is provided on the upper right side surface of the housing, but the place where the switch portion is provided is not limited. It may be provided on a part of one of the four sides of the housing, or may be provided on the entire side. Further, it may be provided at a plurality of locations in one side, or may be provided on two opposing sides or two orthogonal sides. It may be provided in two or more places.

In the above embodiment, the smartphone has been described as an example, but the input device is not limited to this. The present invention can also be applied to electronic devices such as tablet PCs and smart watches.

1 Input device 2 Display 10 Housing combined switch 20 Housing 21 Recess 22 Plate-shaped part 23 Claw part 24 Step part 30 Pressure-sensitive sensor 40 Back plate 50 Elastic member 60 FPC
100 Constant voltage source 200 Pressure detection control unit 210 High-pass filter unit 220 Resistance circuit 230 Operational amplifier 240 Low-pass filter unit 250 Input unit

Claims (6)

A housing having a plate-like portion thinner than other portions by forming a recess on the inside and a concave step portion on the outside,
A pressure sensor body arranged in the recess,
And a back plate arranged on the front Kikan圧sensor body housing combined switch. The housing-combined switch according to claim 1, further comprising an elastic member arranged between the plate-shaped portion and the pressure-sensitive sensor body. The housing combined switch according to claim 1 or 2, wherein the back plate is fixed by a claw portion protruding from the inner surface of the housing. The housing has a flat box shape and has a flat box shape.
The housing combined switch according to any one of claims 1 to 3, wherein the recess is formed on a side surface of the housing. The housing-combined switch according to any one of claims 1 to 4, wherein the pressure-sensitive sensor body is a resistance-changing pressure-sensitive sensor whose resistance value changes when the pressing force changes. The housing-combined switch according to claim 5 and
The voltage source that drives the pressure sensor body and
An input device including a pressure detection control unit having an amplifier circuit including a filter that uses a voltage generated in the pressure-sensitive sensor body as an input signal and removes a DC component from the input signal.