LIGHT-GUIDING METHOD OF LIGHT-GUIDING PLATE AND KEY PAD ASSEMBLY USING THE LIGHT-GUIDING PLATE

• US 20080218991A1
• Filed: 03/07/2007
• Published: 09/11/2008
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: Ichia Technologies Incorporated
• Original Assignee: Ichia Technologies Incorporated
• Inventors: LIU, Chang-Li
• Granted Patent: US 7,534,001 B2
• Time in Patent Office: Days
• US Class Current: 362/26
• 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 method of a backlight source within a keycap, comprising the steps of:

a) preparing a light-guiding plate;

b) forming on the light-guiding plate with a light-shielding structure for dividing the light-guiding plate into two light-guiding sections; and

c) after at least two lights are introduced via the two light-guiding sections of the light-guiding plate, and when the optical paths of the two lights pass through the light-shielding structure, reducing the light entering the light-shielding structure an thus unable to pass through the light-shielding structure, thereby to form lights with different colors on the two light-guiding sections and project the light on the keycap.

2. The method according to claim 1, wherein the light-guiding plate prepared in step a) has a carrier.

3. The method according to claim 1, wherein the light-shielding structure in step a) is formed into a chain.

4. The method according to claim 3, wherein the chain-like light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively.

5. The method according to claim 1, wherein the carrier of the light-guiding plate prepared in step a) has block-like light-guiding portions, frame-like light-guiding portions, and stripe-like light-guiding portions.

6. The method according to claim 5, wherein the light-guiding portion is constituted of a plurality of light-guiding microstructures.

7. The method according to claim 6, wherein the light-guiding microstructure is a semicircular pit or a bump projecting from the surface of the carrier.

8. 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.

9. The light-guiding plate assembly within a keycap according to claim 8, wherein the carrier is made of a transparent PC film or TPU film.

10. The light-guiding plate assembly within a keycap according to claim 8, wherein the block-like light-guiding portion directs the light to a corresponding keycap.

11. The light-guiding plate assembly within a keycap according to claim 8, wherein the frame-like light-guiding portion directs the light to the specific keycap group.

12. The light-guiding plate assembly within a keycap according to claim 8, wherein the strip-like light-guiding portion directs the light to the side edge of the carrier.

13. The light-guiding plate assembly within a keycap according to claim 8, wherein the light-guiding portion is constituted of a plurality of light-guiding microstructures.

14. The light-guiding plate assembly within a keycap according to claim 13, wherein the light-guiding microstructure is a semicircular pit or a bump projecting from the surface of the carrier

15. The light-guiding plate assembly within a keycap according to claim 8, wherein the light-shielding structure is formed into a chain.

16. The light-guiding plate assembly within a keycap according to claim 15, wherein the chain-like light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively.

17. The light-guiding plate assembly within a keycap according to claim 8, wherein one side and two corners of the carrier are each provided with a notch thereon.

18. The light-guiding plate assembly within a keycap according to claim 17, wherein the notch is provided therein with a stepped light-refracting portion.

19. The light-guiding plate assembly within a keycap according to claim 17, wherein the notch is disposed a light-emitting element thereon.

20. 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 light-guiding microstructure; and

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

21. The key pad assembly according to claim 20, wherein the printed circuit board is a thin film printed circuit board.

22. The key pad assembly according to claim 20, wherein the thin film elastic piece is made of a hard PC material.

23. The key pad assembly according to claim 20, wherein the carrier is made of a transparent PC film or TPU film.

24. The key pad assembly according to claim 20, wherein the block-like light-guiding portion directs the light to a corresponding keycap.

25. The key pad assembly according to claim 20, wherein the frame-like light-guiding portion directs the light to the specific keycap group.

26. The key pad assembly according to claim 20, wherein the strip-like light-guiding portion directs the light to the side edge of the carrier.

27. The key pad assembly according to claim 20, wherein the light-guiding portion is constituted of a plurality of light-guiding microstructures.

28. The key pad assembly according to claim 27, wherein the light-guiding microstructure is a semicircular pit or a bump projecting from the surface of the carrier

29. The key pad assembly according to claim 20, wherein the light-shielding structure is formed into a chain.

30. The key pad assembly according to claim 29, wherein the chain-like light-shielding structure is constituted of a plurality of penetrating holes with neighboring ones arranged alternatively.

31. The key pad assembly according to claim 20, wherein one side and two corners of the carrier are each provided with a notch thereon.

32. The key pad assembly according to claim 31, wherein the notch is provided therein with a stepped light-refracting portion.

33. The key pad assembly according to claim 20, wherein the elastic body is made of a soft PC material.

34. The key pad assembly according to claim 20, wherein the keycap is made of materials having a light-transmitting effect.

35. The key pad assembly according to claim 20, wherein the 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.

36. The key pad assembly according to claim 20, further comprising a light-emitting element disposed at one side of the second elastic layer.

37. The key pad assembly according to claim 20, further comprising a light-shielding piece disposed above the light-emitting element and the second elastic layer.