JP2010040385A - Switch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch device which can illuminate an operation key after powering off. <P>SOLUTION: The switch device is constituted such that an optical diffusion part 81 which diffuses a part of light from a light source 6 which runs inside a light guiding sheet 8, and illuminates an operation key 91 is formed in a region covering a movable contact 5 on a backside 8b of the light guiding sheet 8 by printing a paint containing a material having a light storing property in a shape of a dot. The operation key 91 is illuminated by light accumulated in the optical diffusion part 81 in luminescence of the light source 6 for a while after quenching of the light source 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a switch device used as an operation switch for an electronic device such as a mobile phone.

  2. Description of the Related Art Conventionally, in electronic devices such as mobile phones and portable game machines, a plurality of light sources such as light emitting diodes (LEDs) are arranged in the vicinity of a plurality of operation keys, and the operation keys are operated by direct light from the light sources. Illumination from inside the electronic equipment.

  There is also known a technique in which a light guide sheet made of a translucent material is arranged below the operation keys, and the light from the light source is guided below the operation keys by this light guide sheet to illuminate the operation keys (for example, , See Patent Document 1).

By illuminating the operation key in this way, the user can perform an operation while visually recognizing the operation key even in a dark place.
JP 2007-324100 A

  However, in the above-described conventional technology, the illumination of the operation key is turned off at the same time when the power is turned off, and it is difficult to visually recognize the operation key in a dark place.

  The present invention has been made in view of the above, and an object thereof is to provide a switch device that can illuminate an operation key even after the power is turned off.

  To achieve the above object, the switch device of the present invention includes a circuit board having a fixed contact disposed on a surface thereof, a dome-shaped movable contact disposed on the fixed contact, and the circuit having the movable contact disposed thereon. A fixed sheet that covers the substrate and holds the movable contact at a predetermined position on the circuit board; a light guide sheet made of a translucent material placed on the fixed sheet; and at least one of the light guide sheets A light source arranged to allow light to be incident on a side surface, an operation key made of a light-transmitting material, arranged above the light guide sheet and pressed, and the movable contact according to a pressing operation of the operation key A key sheet having a pressing portion that presses the light guide, and a phosphorescent paint is printed in a dot shape on a region facing the operation key on at least one of the front and back surfaces of the light guide sheet. Characterized by comprising a light diffusion portion for diffusing light traveling through the light guide sheet.

  According to the switch device of the present invention, the operation keys can be illuminated even after the power is turned off.

  The best mode for carrying out the switch device of the present invention will be described below with reference to the drawings.

  The switch device according to the present embodiment is incorporated in an electronic device such as a mobile phone or a portable game machine, and executes various operations. 1 is an exploded perspective view of a switch device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the switch device according to the present embodiment, and FIG. 3 is a partially enlarged view of FIG.

  As shown in FIGS. 1 to 3, the switch device 1 according to the present embodiment includes a circuit board 2, a plurality of fixed contacts 3, 4, a plurality of movable contacts 5, a light source 6, and a fixed sheet 7. The light guide sheet 8 and the key sheet 9 are provided.

  The circuit board 2 is made of a printed wiring board (PWB) or the like, and a circular fixed contact 3 made of a conductive material is formed on the surface of the circuit board 2 and an annular fixed circuit surrounding the fixed contact 3. A plurality of contacts 4 are arranged.

  The movable contact 5 is made of a dome-shaped elastic body formed by processing a thin plate of stainless steel or the like having flexibility and conductivity, and is arranged so that the edge thereof is connected to the fixed contact 4. . The diameter of the movable contact 5 is, for example, 3.0 to 5.0 mm, and the height is, for example, 0.2 to 0.3 mm. When the apex of the movable contact 5 is pressed downward, the vicinity of the apex is reversed and comes into contact with the fixed contact 3 so that the fixed contact 3 and the fixed contact 4 are electrically connected.

  The light source 6 is mounted on the circuit board 2 and includes a side-emitting LED or the like that emits light in a direction parallel to the mounting surface, and is disposed so that light can be incident on one side surface 8 a of the light guide sheet 8. Has been.

  The fixed sheet 7 is a white sheet made of polyester, olefin, or the like and having a thickness of about 70 μm, for example, and is disposed so as to cover the circuit board 2 on which the movable contact 5 is installed. An adhesive layer (not shown) made of an acrylic adhesive or the like is provided on the surface of the fixed sheet 7 on the circuit board 2 side, whereby the fixed sheet 7 is bonded to the circuit board 2 and the movable contact 5. The movable contact 5 is held at a predetermined position on the circuit board 2.

  Further, the fixed sheet 7 is formed with a recess 71 for adapting to the convex shape of the movable contact 5 in order to position the movable contact 5 more accurately.

  The light guide sheet 8 is made of a material having translucency such as transparent silicone rubber, urethane, polyester, polycarbonate, methacrylic resin, etc., has substantially the same size as the circuit board 2, and has a thickness of about 0.1 mm, for example. It is formed in a sheet shape of ˜0.3 mm and is placed on the fixed sheet 7.

  In the illustrated example, the light guide sheet 8 is deformed by its own weight so as to follow the undulations generated by the movable contact 5 on the circuit board 2, but the light guide sheet 8 has low flexibility such as polycarbonate, methacrylic resin or the like. When the material is used, it is placed on the fixed sheet 7 in a flat plate shape.

  On the back surface 8b that is the surface of the light guide sheet 8 on the fixed sheet 7 side, a light diffusion portion 81 that diffuses part of the light traveling in the light guide sheet 8 is formed in a region covering the movable contact 5. Yes.

  The light diffusing portion 81 is a white paint containing titanium oxide or the like, and a phosphorescent paint which is a paint obtained by adding a material having a phosphorescent property such as ZnS: Cu, ZnS: Ag, ZnS: Mn is printed in dots. Is formed. As a printing technique, a screen printing method, an ink jet printing method, or the like can be used.

  When the density of dots printed on each light diffusing unit 81 is the same, the light diffused by the light diffusing unit 81 located far from the light source 6 is reduced compared to the light diffusing unit 81 close to the light source 6, and the luminance is reduced. There is a tendency to decrease. For this reason, it is preferable to make the luminance of each light diffusion portion 81 uniform by increasing the density of dots to be printed as the light diffusion portion 81 is farther from the light source 6.

  The key sheet 9 is made of a translucent resin or the like and is disposed above the light guide sheet 8. The key sheet 9 protrudes from an opening provided in a housing (not shown) of the electronic device, protrudes in the opposite direction to the operation key 91 pressed by the user, and is pressed by the operation key 91. A pressing portion 92 that presses the movable contact 5 according to the operation is formed.

  The operation key 91 and the pressing portion 92 are disposed immediately above the movable contact 5 and the light diffusion portion 81, and numbers, characters, symbols, and the like indicating input functions are written on the surface of the operation key 91 by printing or the like.

  In the switch device 1 configured as described above, when the operation key 91 of the key sheet 9 is pressed, the key sheet 9 is bent and the pressing portion 92 presses the apex portion of the movable contact 5 downward. Then, the vicinity of the apex portion of the movable contact 5 is reversed to contact the fixed contact 3, and the fixed contact 3 and the fixed contact 4 are brought into conduction through the movable contact 5, whereby an operation input is performed.

  When a power-on operation is performed, the light source 6 emits light. As shown in FIG. 3, the light L emitted from the light source 6 enters the light guide sheet 8 and travels through the light guide sheet 8.

  Of the light traveling in the light guide sheet 8, the light incident on the light diffusing portion 81 is irregularly reflected by the light diffusing portion 81, and the light reflected in the direction of the key sheet 9 passes the operation key 91 on the back side. Illuminate from. The light reflected by the light diffusing unit 81 in the direction of the fixed sheet 7 is reflected by the fixed sheet 7 in the direction of the key sheet 9 and illuminates the operation key 91. As a result, numbers, characters, and the like on the operation keys 91 of the key sheet 9 are displayed in a flashing manner. Further, while the light source 6 emits light, light is accumulated in the luminous paint of the light diffusion portion 81.

  When the power-off operation is performed, the light source 6 is extinguished, but the light diffusing unit 81 continues to emit light for about 10 seconds after the light source 6 is extinguished by the light accumulated in the phosphorescent paint. As a result, the operation key 91 is illuminated.

  As described above, according to the present embodiment, light from the light source 6 traveling in the light guide sheet 8 is diffusely reflected by the light diffusion portion 81 formed by printing the phosphorescent paint, and the key sheet 9 The operation key 91 is illuminated and light is accumulated in the light diffusing unit 81. After the light source 6 is extinguished, the operation key 91 is illuminated by the light accumulated in the light diffusing unit 81. The operation key 91 can be illuminated, and the user can easily confirm the operation key 91 even in a dark place.

  In addition, you may arrange | position the light source 6 so that light may inject not only into the one side surface 8a of the light guide sheet 8, but two or more side surfaces.

  Further, the light diffusion portion 81 may be formed on the surface 8 c of the light guide sheet 8 or may be formed on both surfaces of the light guide sheet 8.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

It is a disassembled perspective view of the switch apparatus which concerns on embodiment of this invention. It is sectional drawing of the switch apparatus which concerns on this Embodiment. It is the elements on larger scale in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Switch apparatus 2 Circuit board 3, 4 Fixed contact 5 Movable contact 6 Light source 7 Fixed sheet 8 Light guide sheet 9 Key sheet 71 Recessed part 81 Light diffusion part 91 Operation key 92 Press part

Claims (1)

A circuit board with fixed contacts on the surface;
A dome-shaped movable contact disposed on the fixed contact;
A fixed sheet that covers the circuit board on which the movable contact is disposed and holds the movable contact at a predetermined position on the circuit board;
A light guide sheet made of a translucent material placed on the fixed sheet;
A light source disposed so that light can be incident on at least one side surface of the light guide sheet;
A key sheet made of a light-transmitting material, disposed above the light guide sheet, and having an operation key that is pressed and a pressing portion that presses the movable contact in response to a pressing operation of the operation key;
A light-storing paint is formed by printing dots in a region facing the operation key on at least one of the front and back surfaces of the light guide sheet, and diffuses light traveling through the light guide sheet And a light diffusion unit.

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