LARGE AREA LIGHT PANEL AND SCREEN

• US 20100177533A1
• Filed: 06/10/2009
• Published: 07/15/2010
• Est. Priority Date: 01/13/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Webster, James R., Sethi, Gaurav, Griffiths, Jonathan C.
• Granted Patent: US 8,231,257 B2
• Time in Patent Office: Days
• US Class Current: 362/605
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Embodiments of a panel lighting apparatus and methods of its manufacture are described. In one embodiment, the apparatus can include a light source, an at least partially transparent panel comprising a planar front surface and a planar back surface, the panel disposed in conjunction with the light source such that light from the light source is input into at least one edge of the panel and guided therein, and a plurality of light extraction dots disposed on the planar back surface, the plurality of light extraction dots configured to reflect light incident on the planar back surface and extract light from the light source propagating in the panel through the planar front surface.

Claims

1. A privacy screen, comprising:

a light source;

a panel comprising a planar first surface and a planar second surface, the panel configured to be at least partially transparent and positioned relative to the light source to receive light from the light source on at least one edge of the panel, the panel further configured such that the received light enters the panel and propagates therein; and

a plurality of light extraction dots disposed on the planar first surface, the plurality of light extraction dots is configured to extract light, propagating within the panel, uniformly across at least one of the planar first surface and the planar second surface.

2. The privacy screen of claim 1, wherein the plurality of light extraction dots is further configured to reflect ambient light incident on the panel first surface.

3. The privacy screen of claim 1, wherein the plurality of light extraction dots is configured to extract light propagating in the panel through both the first surface and the second surface.

4. The privacy screen of claim 3, wherein the plurality of light extraction dots are configured to extract, through the first surface, light of a different color than light extracted through the second surface.

5. The privacy screen of claim 1, wherein at least one of the plurality of light extraction dots comprises an inner layer disposed proximate to the first surface and an outer layer disposed at least partially on the inner layer.

6. The privacy screen of claim 5, wherein a portion of the outer layer is disposed on the first surface.

7. The privacy screen of claim 5, wherein the outer layer comprises a first colored material that reflects ambient light of a first color and the inner layer comprises a second colored material that reflects light, propagating within the panel, of a second color, wherein the first color is different than the second color.

8. The privacy screen of claim 7, wherein the first color is white.

9. The privacy screen of claim 5, wherein the outer layer comprises a first colored material that extracts light propagating within the panel of a first color and the inner layer comprises a second colored material that reflects light, propagating within the panel, or a second color, wherein the first color is different than the second color.

10. The privacy screen of claim 1, wherein the plurality of light extraction dots are configured to extract light through at least one of the first surface and the second surface of a different color than the light provided by the light source.

11. The privacy screen of claim 1, further comprising a reflector disposed adjacent to the first surface.

12. The privacy screen of claim 1, further comprising a diffuser disposed adjacent to the first or second surface.

13. The privacy screen of claim 1, further comprising an isolation layer disposed between at least one of the plurality of light extraction dots and the first surface.

14. The privacy screen of claim 13, wherein the isolation layer comprises a refractive index less than the refractive index of the panel.

15. The privacy screen of claim 1, further comprising an isolation layer disposed between at least a portion of one of the plurality of light extraction dots and the first surface.

16. The privacy screen of claim 1, further comprising:

a plurality of non-extraction features; and

an isolation layer disposed between the plurality of non-extraction features and the first surface, the plurality of non-extraction features and the plurality of light extraction dots disposed together in a uniform pattern.

17. The privacy screen of claim 16, wherein the plurality of non-extraction features comprises one or more dots.

18. The privacy screen of claim 1, further comprising an isolation layer, wherein a portion of the isolation layer is disposed between at least a portion of at least one of the plurality of light extraction dots and the first surface, and wherein the isolation layer is not disposed between another portion of the at least one of the plurality of light extraction dots and the first surface.

19. The privacy screen of claim 1, wherein the plurality of light extraction dots comprises material that can be printed or painted onto the first surface.

20. The privacy screen of claim 1, further comprising one or more secondary dots disposed on the first surface, wherein each secondary dot is configured to extract less light than one of the light extraction dots.

21. The privacy screen of claim 20, wherein the plurality of light extraction dots and the one or more secondary dots are disposed together in a pattern.

22. The privacy screen of claim 21, wherein the pattern comprises uniform spacing between the center of each of the dots.

23. The privacy screen of claim 1, further comprising a plurality of light extraction dots disposed on the second surface.

24. The privacy screen of claim 23, wherein the plurality of light extraction dots disposed on the second surface is configured to extract light of a first color and the plurality of light extraction dots disposed on the first surface is configured to extract light of a second color, wherein the first color is different than the second color.

25. The privacy screen of claim 23, wherein the plurality of light extraction dots disposed on the second surface is configured to extract light of a first color through the second surface and to extract light of a second color through the first surface, and the plurality of light extraction dots disposed on the first surface is configured to extract light of the first color through the second surface and to extract light of the second color through the first surface, wherein the first color is different than the second color.

26. The privacy screen of claim 1, wherein the plurality of light extraction dots are disposed in a uniform pattern across the first surface.

27. The privacy screen of claim 1, wherein the plurality of light extraction dots are disposed in a non-uniform pattern.

28. The privacy screen of claim 1, wherein the plurality of light extraction dots comprises light extraction dots of differing sizes.

29. A lighting apparatus, comprising:

a light source configured to switch between at least a first mode and a second mode, the light source emitting more light in the second mode than in the first mode;

an at least partially transparent panel comprising a planar first surface and a planar second surface, the panel configured to receive light from the light source through an edge of the panel and propagate the light in the panel; and

a plurality of light extraction features disposed on at least one of the first surface and the second surface, the plurality of light extraction features configured to extract light that propagates within the panel through one of the first surface and the second surface,

the plurality of light extraction features extracting more light in the second mode than in the first mode such that visibility through the transparent panel is greater in the first mode than in the second mode.

30. The lighting apparatus of claim 29, wherein at least one light extraction feature is disposed on the second surface.

31. The lighting apparatus of claim 30, wherein the at least one light extraction feature disposed on the second surface is configured to extract light through the second surface.

32. The lighting apparatus of claim 30, wherein the at least one light extraction feature disposed on the second surface is configured to extract light through the first surface.

33. The lighting apparatus of claim 30, wherein the at least one light extraction feature disposed on the second surface is configured to extract light through the first surface and the second surface.

34. The lighting apparatus of claim 29, wherein at least one light extraction feature is disposed on the first surface.

35. The lighting apparatus of claim 34, wherein the at least one light extraction feature disposed on the first surface is configured to extract light through the second surface.

36. The lighting apparatus of claim 34, wherein the at least one light extraction feature disposed on the first surface is configured to extract light through the first surface.

37. The lighting apparatus of claim 34, wherein the at least one light extraction feature disposed on the first surface is configured to extract light through the first surface and the second surface.

38. The lighting apparatus of claim 29, wherein at least one light extraction feature is disposed on the first surface and at least one light extraction feature is disposed on the second surface.

39. The lighting apparatus of claim 38, wherein the plurality of light extraction features are configured to extract light through the first surface.

40. The lighting apparatus of claim 38, wherein the plurality of light extraction features are configured to extract light through the second surface.

41. The lighting apparatus of claim 38, wherein the plurality of light extraction features are configured to extract light through the first surface and the second surface.

42. The lighting apparatus of claim 29, wherein plurality of light extraction features comprises a feature selected from the group consisting of dots, grooves, pits, and prismatic features.

43. A method of manufacturing a lighting apparatus, comprising:

optically coupling a light source to an at least partially transparent panel comprising a planar back surface and a planar front surface such that light from the light source is input into at least one edge of the panel and guided therein; and

placing a plurality of light extraction features on the back surface, the plurality of light extraction features configured extract light from the light source through the front surface.

44. The method of claim 43, wherein the plurality of light extraction dots are further configured to reflect ambient light incident on the back surface.

45. The method of claim 43, wherein placing the plurality of light extraction features comprises printing the plurality of light extraction features onto the panel using an ink jet printer.

46. The method of claim 43, wherein placing the plurality of light extraction features on the back surface comprises screen printing.

47. The method of claim 43, wherein the plurality of light extraction features comprises one or more light extraction dots.

48. A lighting apparatus, comprising:

an at least partially transparent panel comprising a planar front surface and a planar back surface, the panel configured to receive light provided from a light source through an edge of the panel and propagate the light within the panel; and

a film positioned on the back surface, the film having a plurality of light extraction dots disposed thereon, the plurality of light extraction dots configured to extract light propagating in the panel through the front surface.

49. The apparatus of claim 48, further comprising a light source.

50. The apparatus of claim 48, further comprising an adhesive disposed between the film and the panel for bonding the film to the panel.

51. The apparatus of claim 50, wherein the adhesive is a pressure sensitive adhesive.

52. A method of manufacturing a lighting apparatus, comprising:

printing a plurality of light extraction dots onto a sheet; and

bonding the sheet to a surface of an at least partially transparent light panel having a front and back surface.

53. The method of claim 52, wherein the bonding comprises attaching the sheet to the panel using an adhesive having an equal or lower refractive index than the refractive index of the panel.

54. The method of claim 52, wherein the bonding comprises attaching the sheet to the panel using heat and/or pressure.

55. The method of claim 52, further comprising at least one light source, the light source optically coupled to the light panel, the light source configured to switch between at least a first mode and a second mode, the light source emitting more light in the second mode than in the first mode.

57. The privacy screen of claim 55, wherein the means for producing light comprises a light source.

58. The privacy screen of claim 55, wherein the means for guiding light comprises an at least partially transparent panel comprising a back surface and a front surface.

59. The privacy screen of claim 55, wherein the means for extracting light comprises a plurality of light extraction dots.

56. A privacy screen, comprising:

means for producing light;

means for guiding light, the means for guiding light positioned relative to the means for producing light to receive light from the means for producing light on at least a portion of the means for guiding light, the means for guiding light configured such that the received light enters the means for guiding light and propagates therein; and

means for extracting light from the means for guiding light, the means for extracting light disposed on the means for guiding light and configured to reflect light incident on the means for guiding light and extract light, propagating within the means for guiding light, uniformly across the means for guiding light.

60. A lighting apparatus, comprising:

means for producing light, the means for producing light configured to switch between a first mode and a second mode, the means for producing light emitting more light in the second mode than in the first mode;

means for guiding light, the means for guiding light configured to receive light provided from the means for producing light through a surface of the means for guiding light and propagate the light therein; and

means for extracting light, the plurality of means for extracting light disposed on at least one surface of the means for guiding light, the means for extracting light configured to extract light that propagates within the means for guiding light through a surface on the means for guiding light.

61. The lighting apparatus of claim 60, wherein the means for producing light comprises a light source.

62. The lighting apparatus of claim 60, wherein the means for guiding light comprises an at least partially transparent panel comprising a back surface and a front surface.

63. The lighting apparatus of claim 60, wherein the means for extracting light comprises a plurality of light extraction dots.

64. A method of screening by decreasing the visibility through a panel, comprising:

positioning an at least partially transparent panel comprising a planar first surface and a planar second surface in a location to screen an object or an area, the panel comprising a plurality of light extraction dots disposed on the panel, the light extraction dots configured to extract light propagating within the panel through the first surface of the panel;

providing light into the panel at a first illumination level; and

providing light into the panel at a second illumination level, the second illumination level being greater than the first illumination level such that more light is extracted through the first surface of the panel at the second illumination level than at first illumination level lowering the visibility through the panel as viewed through the first surface of the panel.