Computer keyboard backlighting

• US 20020114153A1
• Filed: 11/27/2001
• Published: 08/22/2002
• Est. Priority Date: 11/13/1998
• Status: Active Grant

• Current Assignee: Firefly International, Inc.
• Original Assignee: Lightwave technologies Inc.
• Inventors: Chan, Sam E. J., Church, W. Edward, Chu, King Sum, Krafft, Randall
• Granted Patent: US 6,871,978 B2
• Time in Patent Office: Days
• US Class Current: 362/85
• CPC Class Codes: G05G 1/105 comprising arrangements for illumination
• 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 2219/018 Electroluminescent panel
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: H01H 2223/0345 with keys positioned directly next to each other without an intermediate bezel or frame

Abstract

Embodiments of a peripheral backlighting system for keyboards are shown and described, which include one or more light-emitting panels exterior to the keyswitches of the keyboard. The panels are preferably electroluminescent material and surround at least two sides, and preferably all sides, of the stem of a keyswitch or the space in which the stem slides up and down during use. Alternatively, the electroluminescent panel(s) may extend substantially continuously between and underneath a plurality of keyswitches. The panels extend closely adjacent to the stem or stem path, or under the keyswitch, to be as far under the key cap as possible without extending into the stem or cap of the keyswitch. The EL panels are preferably powered by the computer keyboard port, via voltage inverters. Preferably, the keyswitch is translucent or partially translucent, and the base plate over the EL panels, if any, is at least partially translucent or transparent. This way, the light from the light-emitting panels radiates upward through, and preferably around the outer surface of, the translucent keycaps, rather than up through an aperture or lightpipe in the center of the keycaps.

Claims

1. A backlit keyboard for use with a computer or internet television, the keyboard comprising:

a plurality of keyswitches, each having a cap and a stem extending downwardly from the cap, wherein at least a portion of the cap is transparent or translucent;

wherein said caps are spaced apart to provide gaps between the caps;

a substantially planar panel of light-emitting electroluminescent material extending beneath said caps; and

wherein said panel emits light directly up through said keyswitches by passing through said portion of each cap that is translucent or transparent; and

wherein said panel emits light up between the caps through said gaps to be visible by a user.

2. A backlit keyboard as in claim 1, further comprising a base plate received between said plurality of keyswitches, below the caps, and above said panel of light-emitting electroluminescent material, wherein at least a portion of the base plate is transparent or translucent so that the light emitted by said panel up through said gaps passes through said transparent or translucent portion of the base plate.

3. A backlit keyboard as in claim 1, wherein the keyboard does not include any base plate above the panel of light-emitting electroluminescent material.

4. A backlit keyboard as in claim 1, wherein the keyboard further comprises hinges located underneath the caps, wherein at least one of said hinges is substantially translucent or transparent.

5. A backlit keyboard as in claim 1, wherein the keyboard further comprises hinges located underneath the caps, wherein at least one of said hinges is substantially translucent or transparent nylon.

6. A backlit keyboard as in claim 1, wherein the panel of light-emitting electroluminescent material is powered by a computer power source with voltage increased by means of a voltage inverter.

7. A backlit keyboard as in claim 1 wherein the panel is an electroluminescent membrane.

8. A backlit keyboard as in claim 1, wherein the caps are substantially opaque with transparent or translucent indicia.

9. A backlit keyboard as in claim 1, wherein the stems are substantially translucent or transparent.

10. A backlit keyboard as in claim 1, wherein the keyswitches are substantially translucent or transparent.

11. A backlit keyboard as in claim 1, further comprising a control device to vary intensity of light emitted by said panel.

12. A backlit keyboard as in claim 1, further comprising a control device that automatically turns off the light emitted by said panel after a period of inactivity of the keyboard.

13. A backlit keyboard as in claim 1, further comprising a touch pad, a frame near the touch pad having at least a portion that is transparent or translucent, and electroluminescent material beneath at least said portion of the frame for illuminating the frame.

14. A backlit keyboard as in claim 1, further comprising right and left controls, a frame near the right and left controls having at least a portion that is transparent or translucent, and electroluminescent material beneath at least said portion of the frame for illuminating the frame.

15. A backlit keyboard as in claim 1, wherein the panel emits light up between the caps substantially all the way between the caps.

16. A backlit keyboard as in claim 1, wherein the caps each have an outer perimeter and the panel emits light up between the caps near said outer perimeters.

17. A backlit keyboard as in claim 1, wherein the caps each have an outer perimeter and wherein said panel comprises non-light-emitting areas directly below the gaps so that the panel radiates light from near the outer perimeters up through the gaps at an angle to said panel but so that the panel does not radiate light straight up from below the centers of the gaps.

18. A backlit keyboard as in claim 2, wherein the caps each have an outer perimeter and wherein said base plate comprises opaque areas generally centered below the gaps and wherein said base plate further comprises translucent or transparent areas near said outer perimeters, so that the panel emits light from near the outer perimeters of the caps through the base plate translucent or transparent areas and through the gaps at an angle to said panel, but the base plate opaque areas block light from being emitted straight up through centers of the gaps.

19. A backlit keyboard as in claim 18, wherein said base plate comprises opaque areas comprise masking on the base plate.

20. A backlit keyboard as in claim 3, wherein the caps each have an outer perimeter and said panel comprises areas of non-light-emitting material and areas that emit light, wherein said areas of non-light-emitting material are generally centered below the gaps and said areas that emit light are nearer said outer perimeters, so that the panel emits light up through the gap near the cap outer perimeters but the non-light-emitting areas block light from passing directly up through centers of the gap.

21. A backlit keyboard as in claim 1, comprising masking on said panel below the gap to inhibit a user from directly viewing areas of said panel that emit light.

22. A backlit keyboard as in claim 1, wherein the caps each have an outer perimeter and said panel comprises light-emitting areas near said outer perimeters and non-light-emitting areas below the gap to inhibit a user from directly viewing said light-emitting areas.

23. A backlit keyboard of claim 2, comprising masking on said base plate to inhibit a user from directly viewing said panel.

24. A backlit keyboard as in claim 1, wherein the panel is continuous between and underneath said plurality of keyswitches and has no perforations for keyswitches.

25. A backlit keyboard as in claim 1, wherein the stems each have an outer side surface, and the panel has one or more perforations and a perforation edge defining each perforation, wherein the panel receives the stems in the perforations and the perforation edge extends near to the stem outer side surface for emitting light through the keyswitches.

26. A backlit keyboard as in claim 1, wherein:

the keyboard further comprises a circuit board or membrane generally parallel to and below said panel;

the stems have bottom ends;

the panel is continuous and is located between the keyswitches and the circuit board or membrane so that, when the keyswitch is depressed, the keyswitch contacts the panel to apply pressure to the circuit board or membrane.

28. A backlit keyboard as in claim 27, further comprising partial masking on the electroluminescent material.

29. A backlit keyboard as in claim 27, further comprising a control device to vary intensity of light emitted by said panel.

30. A backlit keyboard as in claim 27, further comprising a control device that automatically turns off the light emitted by said panel after a period of inactivity of the keyboard.

31. A backlit keyboard as in claim 27, further comprising a touch pad, a frame near the touch pad having at least a portion that is transparent or translucent, and electroluminescent material beneath said frame for illuminating said portion of the frame.

32. A backlit keyboard as in claim 27, further comprising right and left controls, a frame near the right and left controls having at least a portion that is transparent or translucent, and electroluminescent material beneath the frame for illuminating said portion of the frame.

27. A backlit keyboard for use with a computer or internet television, the keyboard comprising:

a plurality of keyswitches each comprising a cap and a stem extending downwardly from the cap, wherein each cap has a translucent or transparent portion and an outer perimeter;

light-emitting electroluminescent material positioned below the caps and illuminating said translucent or transparent portions of the caps, and positioned at least partially between the keyswitches and emitting light up between the caps to illuminate said outer perimeters of the caps;

a base plate below the caps and above the light-emitting electroluminescent material, the base plate comprising a transparent or translucent area to transmit light from said electroluminescent material up through the base plate between the caps for said illumination of the outer perimeters.

33. A backlit keyboard for use with a computer or internet television, the keyboard comprising:

a plurality of keyswitches each comprising a cap and a stem extending downwardly from the cap, wherein each cap has a translucent or transparent portion and an outer perimeter;

light-emitting electroluminescent material positioned below the caps and illuminating said translucent or transparent portions of the caps, and positioned at least partially between the keyswitches and emitting light up between the caps to illuminate said outer perimeters of the caps;

wherein the keyboard does not include any baseplate above the electroluminescent material, so that light emitted up between the caps is visible by a user.

34. A backlit keyboard as in claim 33, further comprising partial masking on the electroluminescent material.

35. A backlit keyboard as in claim 33, further comprising a control device to vary intensity of light emitted by said panel.

36. A backlit keyboard as in claim 33, further comprising a control device that automatically turns off the light emitted by said panel after a period of inactivity of the keyboard.

37. A backlit keyboard as in claim 33, further comprising a touch pad, a frame near the touch pad having at least a portion that is transparent or translucent, and electroluminescent material beneath the frame for illuminating said portion of the frame.

38. A backlit keyboard as in claim 33, further comprising right and left controls, a frame near the right and left controls having at least a portion that is transparent or translucent, and electroluminescent material beneath the frame for illuminating said portion of the frame.