Cover member for illuminated pushbutton switch

• US 20030116414A1
• Filed: 12/17/2002
• Published: 06/26/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Polymatech Company Limited
• Original Assignee: Polymatech Company Limited
• Inventors: Nishimura, Takeshi, Maeda, Junya
• Granted Patent: US 7,005,596 B2
• Time in Patent Office: Days
• US Class Current: 200/56R
• CPC Class Codes: H01H 2009/183 Provisions for enhancing the contrast between the illuminated symbol and the background or between juxtaposed symbols
• CPC Class Codes: H01H 2009/187 having symbols engraved or printed by laser
• CPC Class Codes: H01H 2221/002 integral with membrane
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: H01H 2229/046 Multi-colour or double shot injection moulding
• CPC Class Codes: H01H 2233/07 Cap or button on actuator part
• CPC Class Codes: H01H 25/041 having a generally flat operating member depressible at different locations to operate different controls
• CPC Class Codes: H01H 9/182 Illumination of the symbols or distinguishing marks H01H9/181 takes precedence

Abstract

An illuminated pushbutton switch cover member has a key seat and a resin key top. An indicator portion provided in the resin key top is illuminated with light from an internal light source provided below the key seat, and the light is emitted from the inside to the outside of the cover member through the indicator portion. The cover member is constructed by joining the resin key top to the key seat. The key seat is formed of a thermoplastic elastomer that prevents leakage of light, and an opening for passage of light is formed in the key seat to expose the bottom side of the resin key top to the internal light source. Thus, light from the internal light source can reach the bottom side of the resin key top directly without being attenuated. The indicator portion of the resin key top can therefore be illuminated with high luminance.

Claims

1. An illuminated pushbutton switch cover member, comprising:

a key seat; and

a resin key top jointed to the key seat, said resin key top having an indicator portion provided therein that emits light from inside upon receiving light from an internal light source provided below the key seat;

wherein the key seat is formed of a thermoplastic elastomer and is capable of blocking light, and an opening for passage of light is formed in the key seat to expose the bottom side of the resin key top to the internal light source.

2. The illuminated pushbutton switch cover member according to claim 1, wherein the resin key top is formed of a transparent member covered by a light-blocking layer to make a portion of the resin key top capable of blocking light.

3. The illuminated pushbutton switch cover member according to claim 2, wherein the indicator portion is formed in the light-blocking layer with which the resin key top is covered, and a resin film is further provided as a protective layer covering the light-blocking layer.

4. The illuminated pushbutton switch cover member according to claim 2, wherein the transparent member is formed in a substantially hat-like shape as viewed in section such that the resin key top has a top-side portion and a peripheral-side portion extending from a peripheral end of the top side portion and has a cavity surrounded by the top-side and peripheral-side portions.

5. The illuminated pushbutton switch cover member according to claim 4, wherein a shape of an open end of the resin key top and a shape of an open end of the key seat coincide substantially with each other.

6. The illuminated pushbutton switch cover member according to claim 5, wherein the key seat is formed from a thermoplastic elastomer capable of blocking light.

7. The illuminated pushbutton switch cover member according to claim 5, wherein a light-blocking layer is formed on the key seat.

8. The illuminated pushbutton switch cover member according to claim 1, wherein the resin key top is formed of a resin capable of blocking light.

9. The illuminated pushbutton switch cover member according to claim 8, wherein the transparent member is formed in a substantially hat-like shape as viewed in section such that the resin key top has a top-side portion and a peripheral-side portion extending from a peripheral end of the top side portion and has a cavity surrounded by the top-side and peripheral-side portions.

10. The illuminated pushbutton switch cover member according to claim 9, wherein a shape of an open end of the resin key top and a shape of an open end of the key seat coincide substantially with each other.

11. The illuminated pushbutton switch cover member according to claim 10, wherein the key seat is formed from a thermoplastic elastomer capable of blocking light.

12. The illuminated pushbutton switch cover member according to claim 10, wherein a light-blocking layer is formed on the key seat.

13. The illuminated pushbutton switch cover member according to claim 1, wherein the key seat is formed from a thermoplastic elastomer capable of blocking light.

14. The illuminated pushbutton switch cover member according to claim 13, further comprising a pressing projection for pressing against a contact on a circuit board, said pressing projection being formed on a back side of a portion of the key seat joined to the resin key top.

15. The illuminated pushbutton switch cover member according to claim 1, wherein a light-blocking layer is formed on the key seat.

16. The illuminated pushbutton switch cover member according to claim 15, further comprising a pressing projection for pressing against a contact on a circuit board, said pressing projection being formed on a back side of a portion of the key seat joined to the resin key top.

17. The illuminated pushbutton switch cover member according to claim 1, wherein the resin key top has a flange portion extending outward, and a cover portion for covering the flange portion is provided on the key seat.

18. The illuminated pushbutton switch cover member according to claim 1, wherein the key seat comprises:

a key top supporting portion having a portion to be jointed to the resin key top and the opening for passage of light;

a base portion placed on a circuit board; and

a skirt portion connecting the key top supporting portion and the base portion, wherein said skirt portion is thin and flexible and broadens toward its end.

19. The illuminated pushbutton switch cover member according to claim 1, further comprising a pressing projection for pressing against a contact on a circuit board, said pressing projection being formed on a back side of a portion of the key seat joined to the resin key top.

20. The illuminated pushbutton switch cover member according to claim 1, wherein the key top and the key seat are integrally combined by being welded to each other.

21. An illuminated pushbutton switch cover member, comprising:

a resin key top and a key seat which are integrally combined by heat welding to each other;

said key seat being formed of a thermoplastic elastomer and having a key top supporting portion attached to the key top, a base portion placed on a circuit board, and a skirt portion connecting the key top supporting portion and the base portion, said key seat having a pressing projection formed thereon for pressing against a contact on the circuit board, and said key seat being impervious to light except for an opening extending therethrough for passing light from an internal light source to the key top; and

said resin key top having a hat-like shape defined by a top-side portion and a peripheral-side portion extending from the top-side portion, an indicator portion provided in the top-side portion, and a cavity surrounded by said top-side and peripheral-side portions through which light passes unobstructed from the internal light source to the indicator portion.