JP5046730B2 - Electronics - Google Patents

Description

  The present invention relates to a push button switch of an electronic device.

  Since electronic devices such as digital cameras and mobile phones include various functions, many pushbutton switches are required to operate them. For example, there is a push button switch as shown in FIG. In order to send an operation signal for switching the function of the electronic device, the operation surface of the key top 106 is pressed to switch the circuit state.

  A specific mechanism of a push button switch as shown in FIG. 3 that is generally used will be described below.

  By the pressing operation, the key top 106 tilts from the neutral position with the protrusion 106C as a fulcrum, and presses the rubber switch 102. The rubber switch 102 is deformed so that the movable contact 107 provided on the lower surface contacts the fixed contact 103. The contact of the movable contact 107 with the fixed contact 103 can be confirmed by a click feeling. When the finger is released from the operation surface and the pressing force is released, the key top 106 returns to the initial position by the action of the elastic restoring force of the rubber switch 102. As described above, a circuit in which a circuit corresponding to the fixed contact 103 is opened and closed by the movable contact 107 coming into contact with the fixed contact 103 is widely used. There exists patent document 1 as an example.

  In order to press the switch, the key top 106 is protruded to the outside. Therefore, the pushbutton switch has a device case 105 having an opening, a pressing operation unit 106A located outside the key top 106, and a flange portion 106B projecting in the horizontal direction located inside thereof. The collar portion 106B prevents the key top 106 from falling off the device case 105. Further, the opening of the device case 105 and the key top 106 are different in size due to manufacturing accuracy. In order to prevent the displacement due to this, the key top 106 is generally pressed down by the initial pressure (pretension) by the device case 105 and the rubber switch 102.

As the material of the key top 106, a hard resin such as an ABS resin, a polycarbonate resin, or an acrylic resin is generally preferred because it has a good touch feeling with a finger. The circuit board 104 having the switch part is often made of glass epoxy resin, and when it is a flexible board made of polyimide and copper foil, it is made of a metal plate such as stainless steel or aluminum alloy because of strength problems. A substrate fixing unit 108 is used.
Japanese Patent Laying-Open No. 2005-166406

In order to position the key top 106 by urging the key top 106 upward by the rubber switch 102 and bringing the flange 106B into contact with the lower surface of the exterior member 105 , the circuit board 104 having the tip of the protrusion 106C and the switch portion is provided. There is a gap between the two. During the pressing operation, the protrusion 106 </ b> C of the key top 106 comes into contact with the circuit board 104. For this reason, the key top 106 and the substrate 104 made of hard resin collide with each other, so that a hitting sound is generated. Even in a configuration in which a four-way switch is mounted on a circuit board as in Patent Document 1, a hitting sound is generated due to a gap between the four-way switch and the operation member tip. In a quiet use environment such as in a car or music appreciation, and when shooting moving images, this hitting sound is a concern, so improvement is desired. Furthermore, the cross key having a configuration like the four-way switch of Patent Document 1 tilts the key top diagonally when pressed, so a gap is required between the outer wall of the cross key and the device case 105. Due to the gap, the key top is displaced even when the cross key is not operated.

The present invention provides an electronic device that can prevent the displacement of the operation member while reducing the impact sound generated when the operation member of the switch is operated.

An electronic apparatus according to one aspect of the present invention includes an exterior member in which an opening is formed, a circuit board on which a fixed contact is formed, an operation surface protruding from the opening, and an opposite side to the operation surface An operating member having a protruding portion formed thereon, a switch member formed of an elastic material, disposed between the circuit board and the operating member, and having a movable contact formed at a position facing the fixed contact. The switch member is formed with a protrusion receiving portion that contacts the protrusion only when the periphery of the operation surface is pressed toward the circuit board, and the operation member is not operated. In some cases, the switch member biases the operation member so that the protrusion does not contact the protrusion receiver, and the switch member has a wall formed around the protrusion receiver, The operation member is operated. When not, a gap generated between the wall portion and the protrusion, when the operating member is not being operated, and wherein the gap is smaller than that generated between the operating member and the opening To do.

  According to the present invention, it is possible to reduce the hitting sound when the switch is pressed, and to prevent displacement of the exterior member and the operation member when not in use.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a perspective view of an image pickup apparatus (electronic device) incorporating the switch device according to the embodiment of the present invention.

  In the imaging apparatus 1, 9 is an imaging lens, and 10 is an optical viewfinder. When the imaging switch 12 is operated, the subject image formed by the imaging lens 9 is photoelectrically converted by an imaging element (not shown) to generate an image. Reference numeral 11 denotes a monitor display on which a generated image, a menu screen for selecting functions and modes of the imaging apparatus 1 and performing various settings, and the like are displayed. Reference numeral 6 denotes a key top of a switch device that is operated to select or determine an item on the menu screen. The outer surface of the imaging device 1 is covered with an exterior member 5.

  1 and 2 are a longitudinal sectional view and an exploded perspective view of a main part of a switch device according to an embodiment of the present invention.

  The switch device includes a circuit board 4 having four fixed contacts 3, a rubber switch 2 having a plurality of (four in this embodiment) urging portions 2A surrounding the fixed contacts 3, and an operation member. The key top 6 is comprised. In the following description, the top and bottom of FIG.

  A cylindrical pressing protrusion 2B extending downward is formed on the lower surface of the upper portion of the urging portion 2A. The movable contact 7 is made of conductive resin at the tip (lower end) of the pressing protrusion 2B by silk screen printing or the like. Is provided. On the circuit board 4, each fixed contact 3 is installed so as to face each movable contact 7, and the fixed contact 3 and the movable contact 7 constitute a switch unit.

  In FIG. 1, the rubber switch 2 having the truncated cone-shaped urging portion 2A is integrally formed of soft silicone rubber or the like. The inclined outer peripheral wall of the urging portion 2A is a thin portion having flexibility, and an upward urging force is generated by elastic deformation of the thin portion.

  The top surface portion 2C of the elastic portion 2A is formed as a horizontal flat surface on the circuit board 4, and the bottom surface of the key top 6 is in contact with the top surface portion 2C.

  The key top 6 has an operation surface 6A protruding outward from an opening formed in the exterior member 5, a projection 6C provided at a central portion opposite to the operation surface 6A and extending downward, and from the exterior member 5. In order to prevent falling off, it has a flange portion 6B protruding in the horizontal direction.

In order to position the key top 6 by urging the key top 6 upward by the rubber switch 2 and bringing the collar 6B into contact with the lower surface of the exterior member 5, there is a gap between the projection 6C and the circuit board 4. Is formed. The state in which the key top 6 is held horizontally by the contact between the flange portion 6B and the exterior member 5, that is, the non-operating state is referred to as a neutral state of the key top 6, and the position of the key top 6 in this state is It is called a neutral position . When the operation surface 6A is pressed, the key top 6 is tilted from the neutral position with a protrusion 6C supported by the circuit board 4 as a fulcrum by contacting with a protrusion receiving portion 2D described later, and the biasing portion 2A of the rubber switch 2 To switch the state of the switch section.

  The rubber switch 2 is integrally formed with a protrusion receiving portion 2D at the center thereof. The lower surface of the protrusion receiving portion 2D is in contact with the upper surface of the fixed substrate 4. Furthermore, in the neutral state, the tip of the protrusion 6C does not contact the bottom surface (upper surface) of the protrusion receiving portion 2D.

  A gap X is provided between the outer periphery of the key top 6 and the inner periphery of the opening 5a so that the key top 6 can be inclined smoothly.

  Next, the operation when the switch contact is pressed will be described.

  In the neutral state where no external force is applied to the key top 6, the operation surface 6 </ b> A of the key top 6 protrudes from the opening 5 a of the exterior member 5 to the outside as shown in FIG. 1. Therefore, when the user of the imaging device pushes the peripheral portion of the operation surface 6A toward the circuit board 4 with a finger, the key top 6 moves downward. As a result, the protrusion 6C comes into contact with the protrusion receiving part 2D, and tilts from the neutral position toward the side where the key top 6 is pressed with the contact part as a fulcrum. When the key top 6 is tilted, it is elastically deformed below the urging portion 2A provided on the tilted side, so that the movable contact 7 at the tip of the pressing projection 2B contacts the fixed contact 3. Thereby, the state of the switch unit is switched from OFF to ON. When the finger is released from the key top 6, the key top 6 returns to the neutral position by the elastic restoring force of the urging portion 2A.

In the above-described series of operations, the protrusion receiving portion 2D is an elastic member integrally formed with the rubber switch 2, so that even if the protruding portion 6C contacts the protrusion receiving portion 2D on the circuit board 4 (on the substrate) , the impact sound Hardly occurs.

  Further, by using the protrusion receiving portion 2D as a part of the rubber switch 2 (molded integrally), it is possible to achieve a device for reducing the impact sound without increasing the number of parts compared to the conventional case.

  Further, in order for the key top 6 to tilt from the neutral position with the contact portion between the protrusion 6C and the protrusion receiving portion 2D as a fulcrum, it is necessary to provide a gap X between the key top 6 and the device case 5. However, due to the gap X, the key top 6 is displaced in the horizontal direction when pressed and released. Therefore, a wall 2E is formed in the protrusion receiving portion 2D of the rubber switch 2 so as to face (enclose) the outer peripheral surface of the tip portion of the protrusion 6C. The gap Y between the wall 2E and the protrusion 6C (the gap when the protrusion 6C is positioned facing the center of the receiving portion 6D) is configured to be smaller than the gap X.

Thereby, the horizontal displacement of the key top 6 can be prevented ( suppressed in the range of the gap Y ) , and a high-quality switch device with little displacement of the key top 6 at the time of pressing or releasing the pressure can be realized.

  In the embodiment, the case where the switch unit is configured by a movable contact and a fixed contact is shown, but the type of the switch unit is not limited and may be a pressure sensitive switch, a tact switch, or the like.

Sectional drawing of the switch mechanism which is an Example of this invention. The disassembled perspective view of the switch mechanism which is an Example of this invention. The figure explaining the structure of the conventional switch mechanism. The perspective view of the camera which is an Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Imaging device 2, 102 ... Rubber switch 2A, 102A ... Energizing part 2B, 102B ... Pressing protrusion part 2C, 102C ... Top surface part 2D, 102D ... Projection receiving part 2E, 102E ... Wall part 3, 103 ... Fixed contacts 4, 104 ... Circuit boards 5, 105 ... Exterior members 5a, 105a ... Openings 6, 106 ... Key tops 6A, 106A ... Operation surfaces 6B, 106B ... 6C , 106C ... Projection part 7, 107 ... Movable contact 8, 108 ... Substrate fixing part 9 ... Lens 10 ... Finder 11 ... Monitor display 12 ... Shutter

Claims (1)

An exterior member opening mouth portion is formed,
A circuit board on which fixed contacts are formed;
An operation member formed with an operation surface protruding from the opening and a protrusion protruding on the opposite side of the operation surface;
A switch member formed of an elastic material and disposed between the circuit board and the operation member and having a movable contact formed at a position facing the fixed contact ;
The switch member is formed with a protrusion receiving portion with which the protrusion comes into contact only when the periphery of the operation surface is pressed toward the circuit board.
When the operation member is not operated, the switch member urges the operation member so that the protrusion does not contact the protrusion receiving portion,
In the switch member, a wall portion is formed around the protrusion receiving portion,
When the operating member is not being operated, a gap gap formed between said protruding portion and the wall portion, when the operating member is not being operated, that occurs between the operating member and the opening Electronic equipment characterized by being smaller.