Illuminated keyboard

• US 9,142,370 B2
• Filed: 03/13/2013
• Issued: 09/22/2015
• Est. Priority Date: 11/21/2012
• Status: Active Grant

• Current Assignee: Primax Electronics Limited
• Original Assignee: Primax Electronics Limited
• Inventors: Chen, Chung-Yuan
• Primary Examiner(s): Leon, Edwin A.
• Assistant Examiner(s): Jimenez, Anthony R.
• Application Number:
  US13/801,542
• Publication Number:
  US 20140138230A1
• Time in Patent Office: 923 Days
• Field of Search: 200/324, 200/5.A, 200/5.R, 200/402, 200/512, 200310-314, 200/341
• US Class Current: 1/1
• 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 2219/06 Reflector
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H01H 2221/028 Telescopic guiding
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H03K 17/98 having a plurality of control members, e.g. keyboard
• CPC Class Codes: H03K 2217/9653 with illumination

Abstract

An illuminated keyboard includes a keycap, a keycap guiding frame, a light guide plate and a sensing circuit layer, which are sequentially arranged from top to bottom. The keycap guiding frame is used for fixing the keycap and guiding movement of the keycap. The light guide plate is used for fixing the keycap guiding frame and transferring the light beam from a light-emitting element. As the keycap is depressed by the user, the approaching keycap is sensed by the sensing circuit layer, and thus the sensing circuit layer generates a corresponding non-contact key signal.

Claims

1. An illuminated keyboard, comprising:

at least one keycap including a conductive structure;

at least one light-emitting element for providing a light beam to said keycap;

a light guide plate for transferring said light beam from said light-emitting element;

a sensing circuit layer disposed under said light guide plate and including at least one pair of first electrode layer and second electrode layer, between which an electric field is generated; and

at least one keycap guiding frame disposed on said light guide plate for connecting said keycap and said light guide plate, wherein said keycap guiding frame is disposed and in contact with said keycap for guiding a movement of said keycap,

wherein said pair of first and second electrode layers of said sensing layer aligns with said conductive structure of said keycap, and in response to said movement of said keycap along said keycap guiding frame toward said sensing circuit layer, said electric field changes so as to have a non-contact key signal generated from said sensing circuit layer.

2. The illuminated keyboard according to claim 1, wherein said first electrode layer and said second electrode layer are formed on the same substrate.

3. The illuminated keyboard according to claim 2, wherein said first electrode layer comprises plural first electrode patterns, and said second electrode layer comprises plural second electrode patters, wherein when said sensing circuit layer is electrically conducted, plural electric fields between said plural first electrode patterns and said plural second electrode patterns are generated, wherein as said keycap is moved to a position near a corresponding electric field, said corresponding electric fields is changed, so that said non-contact key signal is generated by said sensing circuit layer.

4. The illuminated keyboard according to claim 1, wherein said first electrode layer and said second electrode layer are formed on different substrates.

5. The illuminated keyboard according to claim 4, wherein said first electrode layer comprises plural first electrode patterns, and said second electrode layer comprises plural second electrode patterns, wherein when said sensing circuit layer is electrically conducted, plural electric fields between said plural first electrode patterns and said plural second electrode patterns are generated, wherein as said keycap is moved to a position near a corresponding electric field, said corresponding electric field is changed, so that said non-contact key signal is generated by said sensing circuit layer.

6. The illuminated keyboard according to claim 1, further comprising a reflective plate, wherein said reflective plate is arranged between said light guide plate and said sensing circuit layer, or said reflective plate is disposed under said sensing circuit layer.

7. The illuminated keyboard according to claim 1, further comprising a reflective layer, wherein said reflective layer is disposed over or under said sensing circuit layer.

8. The illuminated keyboard according to claim 1, further comprising a metallic base plate, wherein said metallic base plate is disposed under said sensing circuit layer.

9. The illuminated keyboard according to claim 1, further comprising a buffer layer, wherein said buffer layer is formed on said light guide plate.

10. The illuminated keyboard according to claim 9, wherein a refractive index of said buffer layer is in a range between 1 and a refractive index of said guide plate.

11. The illuminated keyboard according to claim 9, further comprising a light-shading layer, wherein said light-shading layer is disposed over said buffer layer.

12. The illuminated keyboard according to claim 1, wherein said light-emitting element is located at a side of said light guide plate.

13. The illuminated keyboard according to claim 1, further comprising plural light-guiding structures, wherein said plural light-guiding structures are formed on said light guide plate corresponding to said keycap, wherein said light beam from said light-emitting element is guided by said plural light-guiding structures to be projected onto said keycap.

14. The illuminated keyboard according to claim 1, wherein said keycap comprises a light-outputting region.

15. The illuminated keyboard according to claim 1, further comprising an elastic element, wherein said elastic element is arranged between said keycap and said light guide plate for providing an elastic force to said keycap, wherein said elastic element is light-transmissible.

16. The illuminated keyboard according to claim 1, wherein said conductive structure is formed on an inner surface of said keycap.

17. The illuminated keyboard according to claim 16, wherein said conductive structure is a metallic paint film or a conductive foam structure.

18. The illuminated keyboard according to claim 1, wherein said keycap guiding frame comprises at least one hollow portion, wherein said keycap is movable within said hollow portion.

19. The illuminated keyboard according to claim 1, wherein said sensing circuit layer is a capacitive sensing circuit layer.