Push-button switch member and manufacturing method of same

• US 20040129542A1
• Filed: 06/26/2003
• Published: 07/08/2004
• Est. Priority Date: 05/25/2001
• Status: Active Grant

• Current Assignee: Shin-Etsu Polymer Company Limited (Shin-Etsu Chemical Company Limited)
• Original Assignee: Shin-Etsu Polymer Company Limited (Shin-Etsu Chemical Company Limited)
• Inventors: Kawaguchi, Toshiyuki, Takahashi, Masayuki, Hotta, Shinji
• Granted Patent: US 6,936,783 B2
• Time in Patent Office: Days
• US Class Current: 200/61.1
• CPC Class Codes: B29C 43/18 incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles B29C43/206 takes precedence
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: H01H 13/14 Operating parts, e.g. push-button
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2001/0005 Redundant contact pairs in one switch for safety reasons
• CPC Class Codes: H01H 2009/186 using an electroluminiscent panel
• CPC Class Codes: H01H 2207/00 Connections
• CPC Class Codes: H01H 2207/002 Conductive rubber; Zebra
• CPC Class Codes: H01H 2219/018 Electroluminescent panel
• CPC Class Codes: H01H 2219/03 in transparent keyboard
• CPC Class Codes: H01H 2219/034 Coloured areas
• CPC Class Codes: H01H 9/182 Illumination of the symbols or distinguishing marks H01H9/181 takes precedence
• CPC Class Codes: H05B 33/28 of translucent electrodes
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

It is an object to provide a push-button switch member (1), by utilizing light energy with out any loss for back-lightening on a display section, capable of realizing the back-lightening to the display section with even luminance while suppressing power consumption and having high visibility and thin thickness, the push-button switch member comprising a key-top portion (3) and a cover base member provided with the key top portion at a predetermined portion; thereof and adapted to be mounted to the circuit board (5), the key-top portion (3) being provided with a display section (2) displaying a switching function and an area emitter (4) integrally formed with the display section, wherein the area emitter member (4) is provided with a light emitting layer (13) disposed between a base electrode (14), and a transparent electrode (10) disposed so as to oppose to the base electrode (14) and the transparent electrode (10) arranged to be contacted to the display section (2) is formed of a transparent conductive polymer.

Claims

1. A push-button switch member comprising a key-top portion for pressing a movable contact point disposed so as to oppose to a stationary contact point on a circuit board against said stationary contact point, and a cover base member provided with the key top portion at a predetermined portion thereof and adapted to be mounted to the circuit board, said key-top portion being provided with a display section displaying a switching function and an area emitter member integrally formed with the display section, wherein said area emitter member is provided with an light emitting layer disposed between a base electrode and a transparent electrode disposed so as to oppose to the base electrode and said transparent electrode is arranged to be contacted to the display section and formed of a transparent conductive polymer.

2. The push-button switch member according to claim 1, wherein said transparent electrode has a surface resistance of not less than 10 Ω

/□ and

light transmittance of not more than 90%.

3. The push-button switch member according to claim 1 or 2, wherein said transparent electrode has an electroconductive fiber having a diameter of not more than 0.5 μ

m and an aspect ratio of not less than 20.

4. The push-button switch member according to any one of claims 1 to 3, wherein said transparent electrode is colored.

5. The push-button switch member according to any one of claims 1 to 4, wherein said transparent conductive polymer is composed of a dielectric member formed from either one of derivatives of polypyrrole, polythiophen and polyaniline.

6. The push-button switch member according to any one of claims 1 to 5, wherein elongatable conductive members are connected to said base electrode and said transparent electrode, respectively, and said conductive members having elongating portions to which tensile force is applied at a molding process, are covered with elongatable insulating thin films.

7. The push-button switch member according to claim 6, wherein said conductive members connected respectively to the base electrode and the transparent electrode are arranged so as not to be overlapped with each other.

8. The push-button switch member according to claim 6 or 7, wherein said insulating thin film has a storage modulus, at molding temperature thereof, which is larger than a storage modulus of the conductive members connected to the base electrode and the transparent electrode at molding temperature thereof.

9. The push-button switch member according to any one of claims 6 to 8, wherein said base electrode and said conductive member connected to the base electrode are comprised of a conductive layer containing organic polymer and conductive filler and said filler has a side length not more than ⅓

of thickness of the conductive layer.

10. The push-button switch according to claim 9, wherein a conductive layer has the conductive polymer layer.

11. The push-button switch member according to claim 9 or 10, wherein said conductive filler is composed of a fiber material having a diameter of not more than 1 μ

m.

12. The push-button switch member according to any one of claims 6 to 11, wherein said base electrode and said conductive member connected to the base electrode are formed of conductive polymer.

13. The push-button switch member according to any one of claims 1 to 12, wherein said key-top portion includes key-top body in shape of key-top formed to a rear surface of said base electrode, and a push projection is formed to the rear surface of the key-top body for contacting the movable electrode to the stationary electrode.

14. The push-button switch member according to any one of claims 1 to 12, wherein said key-top portion has a transparent first resin molded form having a key-top shape to the surface of the transparent electrode through transparent insulating film and a second resin molded form formed with a push projection to the rear surface of the base electrode for contacting the movable electrode to the stationary electrode.

15. The push-button switch member according to any one of claims 1 to 12, wherein a plurality of switch circuits composed of a plurality of key-top portions and base electrodes and transparent electrodes corresponding to the key-top portions, respectively, are integrally formed to said cover base member.

16. A method of manufacturing a push-button switch member according to any one of claims 1 to 15, wherein, at a time when a transparent insulating film, having one surface on which said transparent electrode is formed, is subjected to a drawing process so as to be formed in a predetermined key-top shape, the transparent electrode of the elongating portion at which tensile force is applied at the drawing process, is formed from elongatable conductive polymer.

17. The method of manufacturing a push-button switch member according to claim 16, wherein at least said elongating portion of the transparent electrode before the drawing process is thickened.

18. A method of manufacturing a push-button switch member according to any one of claims 6 to 15, comprising the steps of forming a transparent electrode at a portion corresponding to a key-top portion formed to one surface of a transparent insulating film covering an outer surface of the key-top portion, forming an light emitting layer on the transparent electrode, forming a base electrode on the light emitting layer, preparing a printed sheet before a drawing process for forming elongatable conductive members connected to the base electrode and the transparent electrode, and drawing the printed sheet so as to provide a predetermined key top shape, wherein the elongating portion constituting a portion of the conductive member to which tensile force is applied at the drawing process is covered with an insulating thin film.