Thin Key Sheet

• US 20080277253A1
• Filed: 02/07/2006
• Published: 11/13/2008
• Est. Priority Date: 02/07/2005
• Status: Active Grant

• Current Assignee: Sunarrow Ltd.
• Original Assignee: Sunarrow Ltd.
• Inventors: Kenmochi, Yoshio
• Granted Patent: US 7,705,256 B2
• Time in Patent Office: Days
• US Class Current: 200/314
• CPC Class Codes: H01H 13/7006 comprising a separate movable contact element for each switch site, all other elements being integrated in layers
• CPC Class Codes: H01H 13/83 characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements
• CPC Class Codes: H01H 2207/014 Plated through holes
• CPC Class Codes: H01H 2209/07 metallic
• CPC Class Codes: H01H 2219/018 Electroluminescent panel
• CPC Class Codes: H01H 2219/03 in transparent keyboard
• CPC Class Codes: H01H 2221/006 Adhesive
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: H01H 2227/004 Membrane

Abstract

Mobile phones are in a trend of having thinner configuration due to emphasis on the design. Thus, in order to meet this demand, the present invention aims to thin the key sheet portion as much as possible. The present invention provides a thin key sheet 1 comprising a key top 2 made of a metal or a resin having on the front surface or the back surface indications such as letters, symbols, graphics or the like indicating the functions of keys, a key pad 3 made of a material having rubber elasticity such as a silicone rubber or various elastomers for supporting/fixing the key top, an EL element 8 formed on the back surface of the key top by means of printing, and a printed circuit board 5 on which a switch element is provided at its surface for turning ON/OFF of an electric circuit by the pressing of the key top 2 and on which a circuit pattern involved therewith is formed.

Claims

1. A thin key sheet comprising a key top made of a metal or a resin having on the front surface or the back surface indications such as letters, symbols, graphics or the like indicating the functions of keys, a key pad made of a material having rubber elasticity such as a silicone rubber or various elastomers for supporting/fixing the key tops, and an EL element for illuminating the key top, wherein the EL element is formed on the back surface of the key top by means of printing.

5. The thin key sheet according to claim 1, wherein, when the key top is made of a metal, perforated openings in the shape of letters or symbols are perforated on the key top by means of laser etching or chemical etching in order to obtain an illumination type key top.

2. A thin key sheet comprising a key top made of a metal or a resin having on the front surface or the back surface indications such as letters, symbols, graphics or the like indicating the functions of keys, a key pad made of a material having rubber elasticity such as a silicone rubber or various elastomers for supporting/fixing the key tops, and an EL element for illuminating the key top, wherein the EL element is formed on the back surface of the key top by means of printing, and a wiring to the EL element is formed on the key pad of a silicone rubber by means of any one of printing, deposition, and sputtering.

4. The thin key sheet according to claim 2, wherein, when the wiring to the EL element is provided not only on the top surface but also on the back surface of the key pad, the front surface and the back surface thereof are connected via a through hole, and the through hole after the connection is filled by means of conductive printing or rubber filling.

3. A thin key sheet comprising a key top made of a metal or a resin having on the front surface or the back surface indications such as letters, symbols, graphics or the like indicating the functions of keys, a key pad made of a material having rubber elasticity such as a silicone rubber or various elastomers for supporting/fixing the key top, an EL element for illuminating the key top, and a printed circuit board on which a switch element is provided at its surface for turning ON/OFF of an electric circuit by the pressing of the key top and on which a circuit pattern involved therewith is formed, wherein the EL element is formed on the back surface of the key top by means of printing, a wiring to the EL element is formed on the top surface or the undersurface of the key pad of a silicone rubber by means of a film-forming method for metal thin films such as deposition, sputtering or the like, and, when forming by means of the film-forming method, film-forming is conducted in such a state that a material having rubber elasticity is stretched.