JP6261270B2 - Metal dome switch and electronic equipment - Google Patents

Description

  The present invention relates to a metal dome switch and an electronic device, and particularly to an electronic device including a metal dome switch.

  An imaging device such as a digital camera, which is an example of an electronic device, is provided with operation buttons such as a power button, a release button, a zoom lever, a display unit, and a cross key. Here, a metal dome switch is used to detect the pressing operation of the power button or the operation button.

  The metal dome switch is, for example, a switch in which a conductive metal dome is disposed on two electrode portions formed on a substrate, and the two electrode portions are made conductive by deformation of the metal dome.

  In the technique described in Patent Document 1, in order to fix the metal dome on the substrate, in the adhesive sheet attached to the substrate, the adhesive layer between at least two adjacent metal domes is removed, and the air escape portion is removed. Forming.

Japanese Patent No. 4417588

  In a metal dome switch in which a plurality of metal domes are arranged on one substrate, when the metal dome is deformed, the air between the metal dome and the substrate passes through the above-described air escape portion and the other metal domes. It is discharged between the substrates.

  However, in a metal dome switch in which one metal dome is arranged on one substrate, the adhesive layer at the peripheral edge of the adhesive sheet is removed, and when the metal dome is deformed, the air between the metal dome and the substrate is removed. It will be discharged outside. Therefore, in a metal dome switch in which one metal dome is disposed on one substrate, the space between the metal dome and the substrate cannot be sealed with an adhesive sheet.

  On the other hand, a user of an electronic device may be charged with static electricity. In that case, when the electronic device is used, static electricity may be applied to the electronic device. Static electricity is generally a charge having a high voltage of several thousand to several tens of thousands of volts. Therefore, when static electricity is applied to an electronic device, there is a risk of causing fatal damage to an internal circuit of the electronic device.

  Static electricity often enters the electronic device from the user's fingertip through a gap between the operation button and the exterior cover. Therefore, in a metal dome switch in which one metal dome is disposed on one substrate, static electricity may enter the space between the metal dome and the substrate from the vent. If static electricity enters the inside of the metal dome switch, that is, the space between the metal dome and the substrate, the electronic circuit may malfunction through the wiring pattern formed on the substrate, or the electronic component may be damaged. There is.

  The present invention provides a metal dome switch and an electronic device that can reduce the possibility of static electricity entering between the metal dome and the substrate even when the space between the metal dome and the substrate is not sealed. The purpose is to provide.

The electronic device according to the present invention has a substrate in which the first wiring portion and the second wiring portion are provided on the same surface, and has conductivity, and a part of the first wiring portion and the second wiring portion A dome-shaped elastic member disposed so as to cover a part of the wiring part, and the substrate formed of an insulating material so as to cover the elastic member, the first wiring part, and the second wiring part. A sheet member affixed to the elastic member and an operation member that elastically deforms the elastic member, and the elastic member is elastically deformed by operation of the operation member, whereby the first wiring portion and the first member are The wiring member is an electronic device electrically connected to the sheet member, and the sheet member includes a ventilation opening provided in a peripheral portion of the sheet member, and a peripheral portion of the elastic member to the ventilation opening. It has a path for air to escape, and the substrate The surface on which the first wiring portion and the second wiring portion is provided have, at least partially ground wiring portion serving as a ground potential is further provided so as to be exposed from the periphery of the sheet member, wherein Of the ground wiring portion, the exposed portion exposed from the peripheral edge portion of the sheet member has a wide exposed area along the path for escaping the air in the vicinity of the ventilation opening of the sheet member. And

  According to the present invention, even when the space between the metal dome and the substrate is not sealed, the metal dome switch and the electronic device that reduce the possibility of static electricity entering between the metal dome and the substrate are provided. Can be provided.

1 is an external perspective view of a digital camera according to an embodiment of the present invention. It is a disassembled perspective view of the digital camera of FIG. It is a figure which shows the structure of the 2nd metal dome sheet | seat with which the digital camera of FIG. 1 is provided. It is a figure which shows the structure of the 1st metal dome sheet | seat with which the digital camera of FIG. 1 is provided. It is a figure which shows arrangement | positioning and structure of 1 metal dome sheet | seat and power button with which the digital camera of FIG. 1 is equipped.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, a compact digital camera is taken up as an electronic apparatus according to the present invention.

  FIG. 1 is an external perspective view of a digital camera 100 according to an embodiment of the present invention, FIG. 1A is a perspective view of the digital camera 100 viewed from the front side, and FIG. It is the perspective view which looked at the camera 100 from the back side.

  The digital camera 100 includes a front cover 109 and a rear cover 110 that constitute an external appearance part. The front cover 109 and the rear cover 110 are fixed to each other by locking claws and fixed to an internal structure such as a battery box 300 (see FIG. 2) by screws or the like.

  A collapsible lens barrel 200 and a strobe 400 are disposed in front of the digital camera 100. The lens barrel 200 includes a focus lens and a zoom lens, and forms an imaging light flux on an image sensor such as a CCD sensor or a CMOS sensor that photoelectrically converts a subject image to generate image data. The strobe 400 emits light according to the shooting scene, such as when there is insufficient light during shooting, and irradiates the subject with flash.

  On the top surface of the digital camera 100, a power button 101, a release button 102, and a zoom lever 103, which are a part of operation members, are provided. When the power button 101 is pressed, the digital camera 100 becomes ready for photographing. The release button 102 is composed of a two-stage switch. When the release button 102 is half-pressed, an AF operation, an AE operation, or the like is performed. By changing the zoom lever 103, the shooting angle of view can be changed.

  A liquid crystal display 500 and an operation button group 105 are provided on the back surface of the digital camera 100, and a strap attachment member 106 and a connector lid 107 are provided on the side surface of the digital camera 100. The liquid crystal display 500 displays a subject image to be photographed, a photographed image, various setting menus and icons of the digital camera 100, and the like. The operation button group 105 is used for selecting an image to be displayed on the liquid crystal display 500 and displaying and selecting various setting menus and icons. A strap can be attached to the strap attachment member 106. The connector lid 107 can be opened and closed. When the connector lid 107 is opened, a connector (not shown) for attaching an external output cable appears.

  2 is an exploded perspective view of the digital camera 100, FIG. 2A is an exploded perspective view of the entire digital camera 100 as viewed from the back side, and FIG. It is a disassembled perspective view of the 1st metal dome sheet | seat 601 as a sheet | seat member arrange | positioned.

  When the digital camera 100 is viewed from the back side, a battery box 300 for inserting a main battery serving as a power source is disposed on the right side of the lens barrel 200, and a warning is provided on the upper side of the lens barrel 200. A speaker 301 that emits sound and the like is arranged. The power button 101, the release button 102, and the zoom lever 103 are unitized as a top unit 108. The top unit 108 is fixed to the battery box 300 from the upper part of the digital camera 100 by a locking claw (not shown).

  An operation board 600 is disposed on the right side of the liquid crystal display 500 when the digital camera 100 is viewed from the back side. The operation board 600 is a single-sided flexible board having flexibility, and a wiring pattern made of copper foil is sandwiched between a base film using a film such as polyimide having insulation properties and a coverlay film, and a thermosetting adhesive is used. Used and bonded structure. In addition, since the wiring pattern is formed only on one surface of the single-sided flexible substrate, the degree of freedom of wiring is limited, but there is an advantage that the manufacturing cost is lower than that of the multilayer flexible substrate.

  The operation board 600 is bent and arranged on the upper surface and the back surface. The upper surface side of the operation board 600 is held by the battery box 300, and the back surface side of the operation board 600 is held by the sub chassis 302. A first metal dome sheet 601 for detecting an operation when the power button 101 is operated is fixed to the operation board 600. The first metal dome switch includes an operation board 600 and a first metal dome sheet 601.

  In addition, a second metal dome sheet 604 for detecting an operation when the operation button group 105 is operated is fixed to the operation board 600. The second metal dome switch includes an operation board 600 and a second metal dome sheet 604. A release switch 602 that detects an operation when the release button 102 is operated is mounted on the operation board 600 by soldering. A zoom pattern 603 for detecting an operation when the zoom lever 103 is operated is formed on the operation board 600. The first metal dome sheet 601 and the second metal dome sheet 604 are each adhesively fixed to the operation substrate 600 with an adhesive sheet.

  A main board 605 is fixed to the back side of the battery box 300 with screws or the like, and the main board 605 is further fixed to the main chassis 303. The main chassis 303 holds the lens barrel 200, the strobe 400, the sub chassis 302, and the liquid crystal display 500 using screws or double-sided tape. On the main board 605, a control circuit (not shown) for controlling the operation of the digital camera 100 and a connector (not shown) used for electrical connection with the operation board 600 are mounted. The operation board 600 is provided with a terminal portion (not shown) for electrical connection with the connector of the main board 605. By connecting these connector and the terminal part, the operation board 600 and the operation board 600 are operated. Electric signals can be exchanged with the substrate 600.

  FIG. 3 is a view showing the structure of the second metal dome sheet 604. 3A is a plan perspective view of the second metal dome sheet 604, and FIG. 3B is a cross-sectional view taken along line AA in FIG. 3A. The second metal dome sheet 604 includes a plurality of metal domes 604a, an adhesive sheet 604b, and a PET (polyethylene terephthalate) film 604c.

  A plurality of metal domes 604a are adhesively fixed to the PET film 604c by the adhesive sheet 604b. The adhesive sheet 604b has an air path 604d for releasing air when the metal dome 604a is pressed. In general, since adjacent switches are hardly pressed at the same time, when a plurality of metal domes 604 are provided, an air path 604d is provided so that air can pass between at least two metal domes. Thereby, the escape of air can be performed smoothly. Even if adjacent switches are pressed at the same time, if the air path 604d is provided so that air can flow between all the metal domes, the air can be released smoothly and a good operation feeling can be obtained. Can be obtained.

  FIG. 4 is a view showing the structure of the first metal dome sheet 601. Fig.4 (a) is a plane perspective view of the 1st metal dome sheet | seat 601, FIG.4 (b) is a partially expanded view of the arrow BB cross section in Fig.4 (a). The first metal dome sheet 601 includes a metal dome 601a, a first adhesive sheet 601b1, a spacer sheet 601h, a second adhesive sheet 601b2, and a PET film 601c (see FIG. 2 (b) as appropriate). The first adhesive sheet 601b1, the spacer sheet 601h, the second adhesive sheet 601b2, and the PET film 601c are each formed of an insulating material.

  The metal dome 601a is a conductive elastic member having a dome shape and generally made of metal, and is adhesively fixed to the PET film 601c by a second adhesive sheet 601b2. The spacer sheet 601h is adhesively fixed to the operation substrate 600 by the first adhesive sheet 601b1. On the operation substrate 600, a ground wiring portion 609 serving as a ground potential is formed along the peripheral portion 600k of the operation substrate 600. The first metal dome sheet 601 is affixed to the operation substrate 600 so that a part of the ground wiring portion 609 (exposed portion 609k) is exposed along the peripheral edge portion 601k of the first metal dome sheet 601. That is, the ground wiring portion 609 is wired along the peripheral edge portion 600 k of the operation board 600, and the exposed portion 609 k of the ground wiring portion 609 is exposed from the peripheral edge portion 601 k of the first metal dome sheet 601.

  The spacer sheet 601h and the first adhesive sheet 601b1 are partially removed to form an air path 601g for allowing air to escape when the metal dome 601a is pressed. Generally, in a metal dome switch in which one metal dome is arranged on one substrate, it is necessary to discharge the air between the metal dome and the substrate to the outside of the metal dome sheet when the metal dome is deformed. . The first metal dome sheet 601 is provided with a metal dome sheet ventilation opening 601e communicating with the air path 601g in a proximity region between the peripheral edge portion 601k of the first metal dome sheet 601 and the peripheral edge portion 600k of the operation substrate 600. It has been. The exposed portion 609k of the ground wiring portion 609 is widened by an exposed region 609m exposed along the air path 601g in the vicinity of the metal dome sheet ventilation opening 601e.

  FIG. 5 is a diagram showing the arrangement and structure of the first metal dome sheet 601 and the power button 101. FIG. 5A is a perspective view of the first metal dome sheet 601 and the power button as viewed from the upper surface side of the digital camera 100, and FIG. FIG. 3 is a view of a first metal dome sheet 601 and a power button as viewed from the back side of the digital camera 100.

  A first switch wiring unit 606 and a second switch wiring unit 607 are provided on the operation board 600 (see FIG. 2B as appropriate). The second switch wiring portion 607 is always in contact with and electrically coupled to the peripheral edge of the metal dome 601a, but the first switch wiring portion 606 is not in contact with the metal dome 601a. When the power button 101 which is a pressing member for pressing the metal dome 601a is pressed and the metal dome 601a is pressed, the metal dome 601a is elastically deformed so that the dome shape is reversed and contacts the first switch wiring portion 606. To do. Thereby, the 1st switch wiring part 606 and the 2nd switch wiring part 607 are conduct | electrically_connected through the metal dome 601a. By detecting continuity between the first switch wiring portion 606 and the second switch wiring portion 607, it is possible to detect that the metal dome 601a is pressed.

  The power button 101 has a pressure receiving portion 101 a that restricts the pressing operation by contacting the first metal dome sheet 601, and the air path 601 g corresponds to the pressure receiving portion 101 a of the power button 101. It is provided at a position to avoid. In addition, the metal dome 601a has a substantially oval shape in which two opposite sides are cut out (see FIG. 2B as appropriate), and the second switch wiring portion 607 is also formed of the metal dome 601a. It has a substantially oval shape in which portions corresponding to the two cutout sides are cut out. The air path 601g is formed so as to extend from the peripheral area 601f corresponding to the cut-out side of the metal dome 601a to the metal dome sheet ventilation opening 601e. Further, the signal lines of the first switch wiring portion 606 and the second switch wiring portion 607 are drawn out in a region corresponding to the other side facing the peripheral region 601f where the air path 601 extends.

  Usually, the first switch wiring unit 606 is allocated to the signal line, and the second switch wiring unit 607 is allocated to the ground. Therefore, even if static electricity enters from the metal dome sheet ventilation opening 601e through the air path 601g, the second switch wiring portion 607 serving as the ground serves as a lightning rod, and the first switch wiring portion 606 serving as the signal line is connected to the first switch wiring portion 606 serving as the signal line. Static electricity can be prevented from being applied. Thereby, damage to the electronic circuit can be prevented.

  When the first metal dome sheet 601 is adhesively fixed to the operation board 600, the positioning hole 601i (see FIG. 4 (a)) and the positioning hole 600i (see FIG. 2 (b)) formed respectively. To fix the fixed position. At this time, it is preferable that the positioning holes 601i and 600i are separated from each other, and thereby it is possible to suppress a positional shift during the fixing operation.

  According to the above configuration, in the first metal dome sheet 601 provided with the metal dome sheet ventilation opening 601e, the air path is not blocked by the power button 101 or the like, and smooth air escape is ensured, which is good. You can get a good feeling of operation. In addition, since the exposed portion 609k of the ground wiring portion 609 serves as a lightning rod, static electricity can be prevented from entering the signal line, and damage or malfunction of the electronic circuit can be prevented.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. In the above embodiment, the compact digital camera 100 is taken up as an electronic device, but the present invention is not limited to this. For example, examples of the electronic apparatus to which the present invention can be applied include a digital single-lens reflex camera, a digital video camera, a portable game machine, a mobile phone, and a printer.

DESCRIPTION OF SYMBOLS 101 Power button 101a Pressure receiving part 600 Operation board 600k Operation board peripheral part 601 1st metal dome sheet 601a Metal dome 601b1, 601b2 Adhesive sheet 601c PET film 601e Metal dome sheet ventilation opening 601f Peripheral area 601g Air path 601h Spacer sheet 601k peripheral edge of metal dome sheet 606 first switch wiring portion 607 second switch wiring portion 609 ground wiring portion 609k exposed portion of ground wiring portion 609m exposed region of ground wiring portion

Claims (8)

A substrate in which the first wiring portion and the second wiring portion are provided on the same surface;
A dome-shaped elastic member having conductivity and disposed so as to cover a part of the first wiring part and a part of the second wiring part;
A sheet member formed of an insulating material and attached to the substrate so as to cover the elastic member, the first wiring portion, and the second wiring portion;
An operation member that elastically deforms the elastic member,
An electronic device in which the first wiring portion and the second wiring portion are electrically connected by the elastic member by elastically deforming the elastic member by operating the operation member,
The sheet member has a ventilation opening provided in a peripheral portion of the sheet member, and a path for escaping air from the peripheral portion of the elastic member to the ventilation opening,
On the surface of the substrate on which the first wiring portion and the second wiring portion are provided, a ground wiring portion that becomes a ground potential is further provided so that at least a part is exposed from the peripheral portion of the sheet member. ,
Of the ground wiring portion, the exposed portion exposed from the peripheral edge portion of the sheet member has a wide exposed area along the path for releasing the air in the vicinity of the vent opening of the sheet member. Features electronic equipment. The elastic member has a substantially oval shape having an arcuate side in which a part of two opposite sides of a rectangle is cut out in plan view;
Path for releasing the air, according to claim 1, characterized in that it is formed so as to extend from a peripheral region corresponding to the arcuate one side of the elastic member to the vent opening of the sheet member The electronic device as described in. Of the peripheral portion of the elastic member, in the region facing the region corresponding to one of the arcuate sides of the elastic member where the path for escaping the air extends, the first wiring portion and the second wiring portion The electronic device according to claim 2 , wherein a signal line is drawn from at least one of the wiring portions. The second wiring portion is an electronic device according to claim 2 or 3, characterized in that it has the elastic arcuate shape cut away at its portion corresponding to the two sides of the member. The sheet member is attached to the substrate via an adhesive sheet,
Path for releasing the air, the electronic device according to any one of claims 1 to 4, characterized in that it is formed by removing the adhesive sheet partially. The sheet member further includes a spacer sheet attached to the substrate by the adhesive sheet,
The electronic device according to claim 5 , wherein the path for releasing the air is formed by partially removing the adhesive sheet and the spacer sheet. The first wiring portion to the signal line, the electronic device according to any one of claims 1 to 6 wherein the second wiring portion and wherein the assigned respectively to ground. A substrate in which the first wiring portion and the second wiring portion are provided on the same surface;
A dome-shaped elastic member having conductivity and disposed so as to cover a part of the first wiring part and a part of the second wiring part;
Is formed of an insulating material, and a pasted sheet member to the substrate so as to cover said elastic member and the first wiring portion and the second wiring portion,
A metal dome switch in which the first wiring portion and the second wiring portion are electrically connected via the elastic member by the elastic member by elastically deforming the elastic member;
The sheet member has a ventilation opening provided in a peripheral portion of the sheet member, and a path for escaping air from the peripheral portion of the elastic member to the ventilation opening,
On the surface of the substrate on which the first wiring portion and the second wiring portion are provided, a ground wiring portion that becomes a ground potential is formed so that at least a part is exposed from a peripheral portion of the sheet member ,
Of the ground wiring portion, the exposed portion exposed from the peripheral edge portion of the sheet member has a wide exposed area along the path for releasing the air in the vicinity of the vent opening of the sheet member. Features a metal dome switch.

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