JP2010049812A - Key switch structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a key switch structure with light leak reduced and capable of improving in designing and aesthetic properties as well as operability. <P>SOLUTION: An elastic low rubber layer 10 is made opposed to a metal dome layer 2 incorporated into a portable phone 1, a click part 11 for operating each of a plurality of metal domes 3 of the metal dome layer 2 is formed at the low rubber layer 10 with its surface adhered to a transmissive key top 13, and the low rubber layer 10 is molded of a light-guiding silicone rubber, with a part of its peripheral face opposed to an ultraviolet LED 20. Then, fluorescent diffusion light-emitting pattern 30 for dispersing and irradiating visible light toward each key top 13 is screen-printed on the surface of each click part 11 of the low rubber layer 10 by transmission of near ultraviolet rays from the ultraviolet LED 20 to the click part 11. <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. In addition, the plurality of LEDs has a number corresponding to the number of key tops, and is arranged in the vicinity of the click portion to emit visible light (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 that irradiate visible light are merely interposed between the contact layer and the light-transmitting low rubber layer. There is a problem that the design, aesthetics, and operability of mobile phones are impaired.

  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 reduce light leakage and can improve design, aesthetics, and operability.

In the present invention, in order to solve the above problems, the contact layer and the elastic key mat layer are made to face 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 is transparent. Of key tops,
The key mat layer is formed of a light-guiding silicone rubber, and the peripheral surface thereof is opposed to the ultraviolet LED. Between the click part of the key mat layer and the key top, by transmission of ultraviolet light from the ultraviolet LED to the click part, It is characterized by the formation of a fluorescent diffuse light emission pattern that diffuses visible light toward the key top.

A plurality of click portions are arranged in the key mat layer, and an interference restriction wall is formed between adjacent click portions and the click portions. The interference restriction wall surrounds the click portions and is adjacent thereto. It is possible to prevent an erroneous operation on the click part.
Further, the click part of the key mat layer can be formed in a substantially hollow frustum shape, and the pusher facing the contact part of the contact layer can be protruded from the inside thereof.
Moreover, the fluorescence diffusion light-emitting pattern can be formed by screen printing a fluorescent paint on the surface of the click part.

  Here, the ultraviolet LED in the claims does not specifically refer to the plural number. The fluorescent diffuse light emission pattern can be formed on either the front surface of the click portion or the back surface of the key top. 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 the ultraviolet LED emits light, the ultraviolet light, which is an invisible light of the ultraviolet LED, enters the inner direction from the peripheral surface of the silicone rubber key mat layer, is guided and transmitted, and the click portion diffuses the fluorescence. The luminous pattern is excited to emit visible light, and this visible light illuminates the key tops of various electronic devices.

  According to the present invention, light leakage can be reduced, and there is an effect that designability, aesthetics, and operability can be improved.

  In addition, if the fluorescent diffusion light-emitting pattern is formed by screen printing a fluorescent paint on the surface of the click part, the fluorescent diffuse light-emitting pattern can be easily formed on a complex surface made up of irregularities in addition to a flat surface. The manufacturing process can be smoothed and speeded up. Further, the fluorescent paint layer can be thickened to increase the concealing power of the fluorescent diffusing light emitting pattern, and since the printing pressure during screen printing is small, it can be expected to prevent damage to the click part.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. A key switch structure in the present embodiment includes a metal dome layer 2 built in a mobile phone 1 as shown in FIG. 1 and FIG. A low rubber layer 10 facing the metal dome layer 2, the low rubber layer 10 is formed of silicone rubber, and a part of the peripheral surface thereof is opposed to a plurality of long-lived ultraviolet LEDs 20. A fluorescent diffuse light emission pattern 30 is screen-printed between the click part 11 and the key top 13 and used as a key switch of the mobile phone 1.

  As shown in FIG. 2, the metal dome layer 2 has a plurality of metal domes 3 that are pressed and operated from above in an XY direction on the surface of the substrate mounted on the printed wiring board. It is electrically connected to a circuit board (not shown), its circuit elements, and the like, and a plurality of metal domes 3 are selectively pressed to turn on and off the electronic circuit. Realize sending and receiving functions and mail functions. Each metal dome 3 is not particularly limited, and is formed in a hemispherical shape that swells in a deformable manner toward the low rubber layer 10, for example.

  As shown in FIG. 2, the low rubber layer 10 covers the metal dome layer 2 using a molding material containing silicone rubber having excellent light guiding properties, transparency, temperature characteristics, environmental characteristics, electrical characteristics, etc., for example. It is formed into a thin sheet that can be elastically deformed, and is bonded to the peripheral edge of the metal dome layer 2 via an adhesive sheet or an adhesive, and is laminated on the surface of the metal dome layer 2 with a slight gap.

  In the low rubber layer 10, a plurality of click portions 11 facing the plurality of metal domes 3 are arranged and a plurality of interference regulating walls 12 positioned between the adjacent click portions 11 and the click portions 11 are upward. The plurality of interference regulating walls 12 surround each click portion 11 and function to prevent an erroneous operation with respect to the other click portions 11 adjacent to each other.

  Each click portion 11 bulges into a hollow frustum shape that swells in the direction of the key top 13, and a light-transmitting key top 13 that is pressed is bonded to a flat surface. From the flat inner back surface of the click portion 11, a tapered pusher 14 which faces the surface of the metal dome 3 so as to be able to come into contact with and separate from is formed to project downward, and the pusher 14 directly turns the metal dome 3 on and off. Make it work.

  The key top 13 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 erroneous operation is prevented by the interference regulating wall 12. The key top 13 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.

  As shown in FIG. 2, a plurality of ultraviolet LEDs 20 are arranged in a small number (for example, two or three) at the peripheral corners of the metal dome layer 2 and the low rubber layer 10, and close to the peripheral surface of the low rubber layer 10. It functions to irradiate invisible near-ultraviolet rays (wavelength 380 to 200 nm) close to visible light in the internal XY direction.

  As shown in the figure, the fluorescent diffuse light emission pattern 30 is a screen using a fluorescent paint having a high ultraviolet sensitivity on the surface of each click portion 11 between the click portions 11 and the key tops 13 in other words. Dot printing is performed by a printing method, and near-ultraviolet rays are incident and transmitted from the plurality of ultraviolet LEDs 20 to the respective click portions 11 to excite and emit fluorescence, and radiate and emit visible light toward the surface of the key top 13 diffusingly. It works as follows.

  In the above configuration, when the plurality of ultraviolet LEDs 20 emit light when using the transmission / reception function of the mobile phone 1, the near ultraviolet rays of the ultraviolet LEDs 20 are incident from the peripheral surface of the low rubber layer 10 in the internal XY directions and are guided and transmitted. The fluorescence diffusion light emission pattern 30 of each click portion 11 is excited to diffuse visible light and illuminate the key top 13. Thus, when the key top 13 emits light and is pressed, the click part 11 of the low rubber layer 10 descends and directly presses the metal dome 3 of the opposing metal dome layer 2. By pressing the metal dome 3, A predetermined function of the mobile phone 1 is executed.

  According to the above configuration, the low rubber layer 10 made of silicone rubber having excellent transmittance of ultraviolet light and ultraviolet light are combined to excite the fluorescence diffusing light emitting pattern 30 so that visible light is emitted from the click part 11. Light leakage from other than the key top 13 can be suppressed and prevented very effectively, and the design, aesthetics, color rendering, and operability of the mobile phone 1 can be remarkably improved. Further, since the ultraviolet LED 20 is located at the peripheral corner of the low rubber layer 10, the key switch structure can be thinned. 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.

  Further, since the pusher 14 of the click part 11 does not indirectly turn on and off the metal dome 3 through a sheet or the like, but directly turns it on and off, it can obtain a good click feeling without a sense of incongruity. It becomes possible. Furthermore, since the fluorescent diffusion light emitting pattern 30 is printed on the surface of the click part 11 by the screen printing method, various kinds of fluorescent paints can be used.

  Note that there are UV-A, UV-B, and UV-C types of near-ultraviolet rays of the ultraviolet LED 20 in the above-described embodiment, and any of them may be selected as long as no particular problem occurs.

It is a perspective explanatory view showing typically a cellular phone and its key switch in an embodiment of a 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.

Explanation of symbols

1 Mobile phone 2 Metal dome layer (contact layer)
3 Metal dome (contact point)
10 Low rubber layer (key mat layer)
11 Click part 13 Key top 20 UV LED
30 Fluorescent diffuse light emission pattern

Claims (2)

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 transparent key top is provided on the surface thereof. Because
The key mat layer is formed of a light-guiding silicone rubber, and the peripheral surface thereof is opposed to the ultraviolet LED. Between the click part of the key mat layer and the key top, by transmission of ultraviolet light from the ultraviolet LED to the click part, A key switch structure characterized in that a fluorescent diffused light emission pattern is formed that diffuses visible light toward a key top.   The key switch structure according to claim 1, wherein the fluorescent diffuse light emission pattern is formed by screen printing a fluorescent paint on the surface of the click part.

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