Light-guiding method of light-guiding plate and key pad assembly using the light-guiding plate

• US 7,534,001 B2
• Filed: 03/07/2007
• Issued: 05/19/2009
• Est. Priority Date: 03/07/2007
• Status: Expired due to Fees

• Current Assignee: Ichia Technologies Incorporated
• Original Assignee: Ichia Technologies Incorporated
• Inventors: Liu, Chang-Li
• Primary Examiner(s): Lee; Y My Quach
• Application Number:
  US11/683,085
• Publication Number:
  US 20080218991A1
• Time in Patent Office: 804 Days
• Field of Search: 362/24, 362/26, 362/27, 362/85, 362/86, 362/88, 362/612, 362/613, 362/619, 362/627, 200/310, 200/313, 200/314, 345/170, 345/176
• US Class Current: 362/24
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: H01H 13/83 characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements
• CPC Class Codes: H01H 2219/044 Edge lighting of layer
• CPC Class Codes: H01H 2219/056 Diffuser; Uneven surface
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials

Abstract

A key pad assembly includes a printed circuit board, a first elastic layer, a second elastic layer, a light-shielding layer, a keycap group, a light-emitting element and a light-shielding piece. The second elastic layer has a light-guiding plate thereon. The light-guiding plate has a chain-like light-shielding structure. The light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively and divides the light-guiding plate into two light-guiding sections. When the lights with different colors are introduced from the outside of the two light-guiding sections into the light-guiding plate, and the light of either light-guiding section passes through the light-shielding structure, the intensity of the light passing through the penetrating hole is so reduced that it cannot achieve the other light-guiding section, thereby to avoid the mutual interference and mixing of the lights of the two light-guiding sections.

Claims

1. A light-guiding plate assembly within a keycap, having a carrier, the carrier having block-like light-guiding portions, frame-like light-guiding portions and stripe-like light-guiding portions, a light-shielding structure provided among the block-like light-guiding portion, the frame-like light-guiding portion and the stripe-like light-guiding portion to divide the carrier into two light-guiding sections,

wherein the carrier is made of a transparent PC film or TPU film.

2. The light-guiding plate assembly within a keycap according to claim 1, wherein the block-like light-guiding portion directs the light to a corresponding keycap.

3. The light-guiding plate assembly within a keycap according to claim 1, wherein the frame-like light-guiding portion directs the light to a specific keycap group.

4. The light-guiding plate assembly within a keycap according to claim 1, wherein the strip-like light-guiding portion directs the light to a side edge of the carrier.

5. The light-guiding plate assembly within a keycap according to claim 1, wherein each of the block-like, the frame-like and the stripe-like light-guiding portions is constituted of a plurality of light-guiding microstructures.

6. The light-guiding plate assembly within a keycap according to claim 5, wherein the light-guiding microstructure is a semicircular pit or a bump projecting from a surface of the carrier.

7. The light-guiding plate assembly within a keycap according to claim 1, wherein one side and two corners of the carrier are each provided with a notch thereon.

8. The light-guiding plate assembly within a keycap according to claim 7, wherein the notch is provided therein with a stepped light-refracting portion.

9. The light-guiding plate assembly within a keycap according to claim 7, wherein the notch is disposed a light-emitting element thereon.

10. A light-guiding plate assembly within a keycap, having a carrier, the carrier having block-like light-guiding portions, frame-like light-guiding portions and stripe-like light-guiding portions, a light-shielding structure provided among the block-like light-guiding portion, the frame-like light-guiding portion and the stripe-like light-guiding portion to divide the carrier into two light-guiding sections, wherein the light-shielding structure is formed into a chain.

11. The light-guiding plate assembly within a keycap according to claim 10, wherein the chain-like light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively.

12. A key pad assembly, comprising:

a printed circuit board;

a first elastic layer disposed on the printed circuit board and having a thin film elastic piece and a metal dome adhered on the thin film elastic piece and disposed to correspond to the printed circuit board;

a second elastic layer disposed on the first elastic layer and constituted of a light-guiding plate and an elastic body, the light-guiding plate having a carrier thereon, the carrier having block-like light-guiding portions, frame-like light-guiding portions and stripe-like light-guiding portions, a light-shielding structure provided among the block-like light-guiding portion, the frame-like light-guiding portion and the stripe-like light-guiding portion to divide the carrier into two light-guiding sections;

the elastic body formed with a plurality of protrusion bodies disposed to correspond to the metal dome;

a light-shielding layer provided on the second elastic layer, the light-shielding layer formed into a hollowed hole at the position corresponding to the block-like light-guiding portion; and

a keycap group, provided on the light-shielding layer, constituted of a plurality of keycaps, a surface of the keycap having a light-transmitting numeral, character or symbol.

13. The key pad assembly according to claim 12, wherein the printed circuit board is a thin film printed circuit board.

14. The key pad assembly according to claim 12, wherein the thin film elastic piece is made of a hard PC material.

15. The key pad assembly according to claim 12, wherein the carrier is made of a transparent PC film or TPU film.

16. The key pad assembly according to claim 12, wherein the block-like light-guiding portion directs the light to a corresponding keycap.

17. The key pad assembly according to claim 12, wherein the frame-like light-guiding portion directs the light to a specific keycap group.

18. The key pad assembly according to claim 12, wherein the strip-like light-guiding portion directs the light to a side edge of the carrier.

19. The key pad assembly according to claim 12, wherein each of the block-like, the frame-like and the stripe-like light-guiding portions is constituted of a plurality of light-guiding microstructures.

20. The key pad assembly according to claim 19, wherein the light-guiding microstructure is a semicircular pit or a bump projecting from a surface of the carrier.

21. The key pad assembly according to claim 12, wherein the light-shielding structure is formed into a chain.

22. The key pad assembly according to claim 21, wherein the chain-like light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively.

23. The key pad assembly according to claim 12, wherein one side and two corners of the carrier are each provided with a notch thereon.

24. The key pad assembly according to claim 23, wherein the notch is provided therein with a stepped light-refracting portion.

25. The key pad assembly according to claim 12, wherein the elastic body is made of a soft PC material.

26. The key pad assembly according to claim 12, wherein the keycap is made of materials having a light-transmitting effect.

27. The key pad assembly according to claim 12, wherein a bottom of the keycap is provided with an adhesive layer, and the adhesive layer allows the keycap to be adhered on the light-shielding layer.

28. The key pad assembly according to claim 12, further comprising a light-emitting element disposed at one side of the second elastic layer.

29. The key pad assembly according to claim 12, further comprising a light-shielding piece disposed above the light-emitting element and the second elastic layer.