JP2010027568A - Key switch structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a key switch structure capable of making the profile thin, and helping support of an electronic device trend of thin-profile and miniaturization. <P>SOLUTION: A metal dome layer 10 and an elastic lower rubber layer 20 are arranged face to face, and a click part 21 is formed on the lower rubber layer 20 for a direct On-Off operation of a metal dome 11 located on the metal dome layer 10, with a keytop 24 which is of light transmission nature arranged on the front surface of the same. further, the key switch structure is equipped with an LED 30 located in a fringe portion of the metal dome layer 10 and the lower rubber layer 20, as well as a light guide layer 40 guiding light from the LED 30 and laminated in one piece with the lower rubber layer 20 and located between the click part 21 and the keytop 24. A solid-formed light diffusion pattern 42, diffusion irradiating the light emitted and guided from the LED 30 toward the keytop 24, is formed in the laminated portion 41 where the light guide layer 40 and the click part 21 are laid down together in piles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a key switch structure used for a mobile phone, a game machine, and the like.

  Although not shown, a conventional key switch structure used for a mobile phone or the like includes a contact layer built in the mobile phone, a light-transmitting low rubber layer laminated on the surface of the contact layer, and these contact layers. And a plurality of LEDs interposed between the low rubber layers.

The low rubber layer is formed to be thick using a predetermined molding material, and a plurality of click portions that respectively turn on and off the plurality of contact portions of the contact layer are integrally formed. A light-transmitting key top that transmits light from the LED is bonded. The plurality of LEDs is a number corresponding to the number of key tops, and is arranged in the vicinity of the click part (see Patent Documents 1, 2, 3, 4, 5, 6, and 7).
JP 2001-67973 A JP 2003-7161 A JP 2007-27115 A JP 2006-318905 A JP 2008-60058 A JP 2007-280810 A JP 2005-268165 A

  The conventional key switch structure is configured as described above, and a plurality of LEDs are interposed between the contact layer and the low rubber layer, and since the low rubber layer is thick, it cannot be thinned. As a result, there is a problem that the recent demand for reduction in thickness, size, and weight of mobile phones is hindered.

  The present invention has been made in view of the above, and an object of the present invention is to provide a key switch structure that can be thinned and can contribute to thinning and downsizing of electronic devices.

In the present invention, in order to solve the above-mentioned problem, the contact layer and the elastic key mat layer are opposed to each other, and a click portion for operating the contact portion of the contact layer is formed on the key mat layer, and the surface thereof transmits light. With a sex key top,
A light source located at least at the peripheral edge of the key mat layer of the contact layer and the key mat layer, and laminated integrally with the key mat layer and interposed between the click portion and the key top, and guides light from the light source. And a light diffusion pattern for diffusing and irradiating the light beam guided from the light source toward the key top is formed in the laminated portion overlapping the click portion of the light guide layer.

The key mat layer can be made of silicone rubber and the light guide layer can be made of polyurethane.
In addition, a three-dimensional light diffusing pattern can be formed on the back surface overlapping the click portion of the stacked portion.

  Here, the light source in the claims includes at least a small-sized high-brightness LED or EL. The light diffusion pattern can be formed on either the front surface or the back surface of the laminated portion. Furthermore, the key switch structure according to the present invention is used as a component of at least various electronic devices, specifically, mobile phones, PDAs, notebook computers, game machines, video cameras, audio devices, remote controllers and the like.

  According to the present invention, when a light source located at least at the periphery of the key mat layer emits light, the light from the light source is incident on the inner surface from the peripheral surface of the light guide layer integrated with the key mat layer and guided. Then, the light diffusing pattern is emitted through the light diffusing pattern of the laminated portion, and the key top on the laminated portion is illuminated.

According to the present invention, the key switch structure can be thinned, and there is an effect that the electronic device can be reduced in thickness and size.
If the key mat layer is made of silicone rubber, excellent weather resistance, temperature characteristics, environmental characteristics, electrical characteristics, and the like can be obtained. In addition, if the light guide layer is made of polyurethane, excellent stretchability, strength characteristics, and light weight can be obtained, and the same hardness as the key mat layer or an approximate hardness can be easily obtained. A good click feeling can be obtained with respect to the switch.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. A key switch structure according to the present embodiment includes a metal dome layer 10 built in a mobile phone 1 as shown in FIGS. The elastic low rubber layer 20 laminated on the metal dome layer 10, the plurality of LEDs 30 positioned on the peripheral edge of the metal dome layer 10 and the low rubber layer 20, and the plurality of LEDs 30 integrated with the low rubber layer 20. And a light guide layer 40 that guides the rays of light, and is used as a key switch of the mobile phone 1.

  The metal dome layer 10 is formed by arranging a plurality of metal domes 11 to be pressed from above in the XY directions on the surface of a substrate mounted on a printed wiring board (not shown) at predetermined intervals. A predetermined function of the cellular phone 1, such as a transmission / reception function or a mail function, is electrically connected to the circuit element or the like, and a plurality of metal domes 11 are selectively pressed to turn on and off the electronic circuit. And so on. Each metal dome 11 is not particularly limited. For example, each metal dome 11 is formed in a hemispherical shape that swells in a deformable manner toward the low rubber layer 20.

  The low rubber layer 20 is formed into an elastically deformable thin sheet that covers the metal dome layer 10 using a molding material containing silicone rubber having excellent temperature characteristics, environmental characteristics, electrical characteristics, and the like. The metal dome layer 10 is laminated with a slight gap on the surface of the metal dome layer 10.

  A plurality of click portions 21 facing the plurality of metal domes 11 are formed in the low rubber layer 20, and a plurality of interference regulating walls 22 positioned between the adjacent click portions 21 and the click portions 21 are upward. The plurality of interference restriction walls 22 surround each click portion 21 and function to prevent an erroneous operation with respect to the other click portions 21 adjacent to each other.

  Each click portion 21 bulges into a hollow frustum shape that bulges in the direction of the key top 24, and a light transmissive key top 24 that is pressed is bonded to a flat surface via a light guide layer 40. From the flat inner back surface of the click portion 21, a tapered pusher 23 that faces the surface of the metal dome 11 so as to be able to come into contact with and separate from is formed to project downward, and the pusher 23 directly turns the metal dome 11 on and off. Make it work.

  The key top 24 is formed as a part of a flexible key top layer (not shown) as necessary, or is formed in a small cross-sectional plate shape, and is positioned at the same height as the interference regulation wall 22. An erroneous operation is prevented by the interference regulating wall 22. The key top 24 is formed using a predetermined resin or metal, and a pattern made of telephone numbers, letters, symbols, and the like is screen-printed on the surface.

  A plurality of LEDs 30 are arranged in a small number (for example, two or three) at the peripheral corners of the metal dome layer 10 and the low rubber layer 20, and are adjacent to the peripheral surface of the light guide layer 40 and have a chromatic color in the inner XY direction. It functions to irradiate light rays (for example, red and blue light rays).

  The light guide layer 40 is formed into an elastically deformable sheet that covers the low rubber layer 20 using a predetermined material, and is integrally laminated thinly on the surface of the low rubber layer 20 including the interference regulating wall 22. Are interposed between the plurality of click portions 21 and the key tops 24, and guide light beams from the plurality of LEDs 30 in the XY directions and reinforce the low rubber layer 20. As the predetermined material of the light guide layer 40, various thermoplastic elastomers are used. Preferably, the same hardness as the low rubber layer 20 or a hardness similar to that of the low rubber layer 20 can be easily obtained. Polyurethane having excellent permeability and the like is preferable.

  In the light guide layer 40, a plurality of laminated portions 41 that respectively overlap the surfaces of the plurality of click portions 21 are formed to bulge in a cross-sectional shape, and the key tops 24 are horizontally bonded to the flat surface of each laminated portion 41. In addition, a light diffusion pattern 42 is formed on the back surface of each laminated portion 41 that contacts the click portion 21 to guide the light beam guided from the LED 30 to the upper key top 24 and diffusely irradiate it. The light diffusing pattern 42 is transferred and formed into a three-dimensional shape composed of a plurality of irregularities, for example, by embossing a fine frustum-shaped die.

  In the above configuration, when the plurality of LEDs 30 emit light when using the transmission / reception function of the mobile phone 1, the light rays of the LEDs 30 are incident and guided / transmitted in the internal XY directions from the peripheral surface of the light guide layer 40, and are stacked The three-dimensional light diffusing pattern 42 is surface-emitted through the light diffusing pattern 42 of 41, and the key top 24 on the laminated portion 41 is illuminated. Thus, when the key top 24 emits light and is pressed, the click portion 21 of the low rubber layer 20 descends and directly presses the metal dome 11 of the opposing metal dome layer 10. By pressing the metal dome 11, A predetermined function of the mobile phone 1 is executed.

  According to the above configuration, the LED 30 is positioned not at the periphery of the metal dome layer 10 and the low rubber layer 20 but at the peripheral corner, and since the low rubber layer 20 and the light guide layer 40 are integrated and thin, the key switch structure. Thinning of the body can be achieved. Therefore, it is possible to contribute to the realization of demands for reduction in thickness, size, and weight of the cellular phone 1 and the like in recent years. Moreover, since the light-diffusion pattern 42 is formed not on the surface of the lamination | stacking part 41 but on the back surface which overlaps with the click part 21, the appearance can be arranged and the design property can be improved.

  Further, since the pusher 23 of the click portion 21 does not indirectly turn on and off the metal dome 11 through a sheet or the like, but directly turns on and off, it can obtain a good click feeling without a sense of incongruity. It becomes possible. In addition, since the low rubber layer 20 having low mechanical strength is reinforced by the light guide layer 40 having excellent stretchability, it is possible to make it difficult to tear even if used for a long time. Furthermore, since the light diffusion pattern 42 is formed on the back surface of the polyurethane laminate 41, it can be manufactured only by heating and cooling, and the manufacturing cycle can be greatly shortened.

  In addition, you may abbreviate | omit the interference control wall 22 of the said embodiment. In the above embodiment, the light diffusing pattern 42 is formed on the back surface of the laminated portion 41 that overlaps the click portion 21, but the light diffusing pattern 42 may be formed on the surface of the laminated portion 41 by printing or the like. Furthermore, although the key switch structure is used as the key switch of the mobile phone 1, the present invention is not limited to this. For example, the key switch structure may be used as a key switch of the PDA 2 shown in FIG.

It is a perspective explanatory view showing typically the cellular phone in the embodiment of the key switch structure according to the present invention. It is a section explanatory view showing typically an embodiment of a key switch structure concerning the present invention. It is a perspective explanatory view showing other embodiments of the key switch structure concerning the present invention typically.

Explanation of symbols

1 Mobile phone 10 Metal dome layer (contact layer)
11 Metal dome (contact part)
20 Low rubber layer (key mat layer)
21 Click part 24 Key top 30 LED (light source)
40 Light guide layer 41 Laminating part 42 Light diffusion pattern

Claims (3)

A key switch structure in which a contact layer and an elastic key mat layer are opposed to each other, a click portion for operating the contact portion of the contact layer is formed on the key mat layer, and a light transmissive key top is provided on the surface. Because
A light source located at least at the peripheral edge of the key mat layer of the contact layer and the key mat layer, and laminated integrally with the key mat layer and interposed between the click portion and the key top, and guides light from the light source. A light guide layer, and a light diffusion pattern for diffusing and irradiating a light beam guided from a light source toward a key top is formed on a laminated portion overlapping a click portion of the light guide layer. body.   The key switch structure according to claim 1, wherein the key mat layer is made of silicone rubber and the light guide layer is made of polyurethane.   The key switch structure according to claim 1 or 2, wherein a three-dimensional light diffusing pattern is formed on the back surface overlapping the click portion of the laminated portion.

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