THIN LIGHT BAR AND METHOD OF MANUFACTURING

• US 20090231877A1
• Filed: 09/28/2007
• Published: 09/17/2009
• Est. Priority Date: 10/06/2006
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mienko, Marek, Xu, Gang, Bita, Ion, Gruhlke, Russell Wayne
• Application Number:
  US12/444,389
• Publication Number:
  US 20090231877A1
• Time in Patent Office: Days
• US Class Current: 362/552
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• 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 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer

Abstract

Various embodiments disclosed herein comprise a display device comprising a plurality of spatial light modulators and an illumination apparatus. The illumination apparatus comprising a light bar that guides light along a length thereof and turning microstructure disposed on top or bottom of the light bar. The turning microstructure directs the light out a side of the light bar. The illumination apparatus further comprises a light guide panel disposed with respect to the side of the light bar such that the light from the light bar is coupled to the light guide panel. The light guide panel is configured to direct the light coupled therein out of the light guide panel. The plurality of light modulators disposed with respect to the light guide panel to receive the light directed out of the light guide panel.

Claims

1. A display device comprising:

a light bar, having two or more distinct layers, that guides light along a length thereof;

a turning microstructure disposed on at least one of a top and a bottom of the light bar, the turning microstructure configured to direct said light out a side of the light bar;

a light guide panel disposed with respect to said side of the light bar such that said light from said light bar is coupled to said light guide panel, said light guide panel configured to direct said light coupled therein out of said light guide panel; and

a plurality of light modulators disposed with respect to the light guide panel to receive said light directed out of said light guide panel.

2. The device of claim 1, wherein the turning microstructure comprises a plurality of faceted features that are embossed on a film layer.

3. The device of claim 2, wherein the film layer is one of the two or more distinct layers

4. The device of claim 2, wherein the film layer has a thickness in the range of about 25 to 350 microns.

5. The device of claim 2, wherein the film layer has a thickness in the range of about 50 to 60 microns.

6. The device of claim 1, further comprising a light source disposed at an input end of the light bar to inject light therein.

7. The device of claim 6, wherein the light source comprises a light emitting diode.

8. The device of claim 1, wherein the turning microstructure is disposed on both the top and the bottom of the light bar.

9. The device of claim 7, wherein the turning microstructure comprises a plurality of faceted features that are embossed on a first film layer on the top of the light bar and on a second film layer on the bottom of the light bar.

10. The device of claim 8, wherein the two or more distinct layers comprise the first film layer and the second film layer.

11. The device of claim 1, wherein the turning microstructure comprises a plurality of faceted features in said light bar.

12. The device of claim 1, wherein the turning microstructure comprises a plurality of elongated grooves.

13. The device of claim 1, wherein the turning microstructure comprises a plurality of triangular grooves having substantially triangular cross-sections.

14. The device of claim 6, wherein the turning microstructure increases in density with distance from the input end of said light bar.

15. The device of claim 6, wherein the turning microstructure increases in depth with distance from the input end of said light bar.

16. The device of claim 6, wherein the turning microstructure changes in spacing or angle with distance from the input end of said light bar.

17. The device of claim 1, wherein said turning microstructure is disposed in a film on said light bar.

18. The device of claim 1, wherein said light bar comprises a film disposed on a carrier, said film having said turning microstructures disposed therein.

19. The device of claim 18, wherein said carrier comprises an optical element.

20. The device of claim 19, wherein said optical element comprises a polarizer or a filter.

21. The device of claim 1, wherein said light bar comprises first and second films disposed on opposite sides of a carrier, said light turning microstructures being disposed in said first and second films.

22. The device of claim 1, wherein said light guide panel includes turning features that turn said light coupled into said light guide panel and direct said light out thereof.

23. The device of claim 22, wherein said turning features comprise grooves disposed in a film.

24. The device of claim 22, wherein said light guide panel is configured to direct said light out a bottom surface of the light guide panel onto said plurality of light modulators.

25. The device of claim 1, wherein the plurality of light modulators comprises a reflective light modulator array.

26. The device of claim 1, wherein the plurality of light modulators comprises a plurality of MEMS.

27. The device of claim 1, wherein the plurality of light modulators comprises a plurality of interferometric modulators.

28. The display of claim 1, further comprising:

a processor that is in electrical communication with at least one of said a plurality of light modulators, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

29. The display of claim 28, further comprising:

a driver circuit configured to send at least one signal to said at least one of said plurality of light modulators.

30. The display of claim 29, further comprising:

a controller configured to send at least a portion of said image data to said driver circuit.

31. The display of claim 28, further comprising:

an image source module configured to send said image data to said processor.

32. The display of claim 31, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

33. The display of claim 28, further comprising:

an input device configured to receive input data and to communicate said input data to said processor.

34. The display of claim 1, further comprising:

an optical coupling element between the light bar and the light guide panel.

35. The display of claim 33, wherein the optical coupling element is a collimator.

36. The display of claim 33, wherein the optical coupling element is tapered.

37. The display of claim 1, wherein the light bar is tapered.

38. A display device comprising:

a first means for guiding light along a length thereof;

means for turning said light guided in said first light guiding means and directing said light out a side of the first light guiding means, said light turning means disposed on at least one of a top and a bottom of the first light guiding means;

a second means for guiding said light disposed with respect to said side of the first light guiding means such that said light from said first light guiding means is coupled therein, said second light guiding means configured to direct said light coupled therein out of said second light guiding means; and

means for modulating said light disposed with respect to the second light guiding means to receive said light directed out of said second light guiding means.

39. The device of claim 38, wherein said first light guiding means comprises a light bar.

40. The device of claim 39, wherein said light turning means comprises a light turning microstructure.

41. The device of claim 40, wherein said second light guiding means comprises a light guide panel.

42. The device of claim 41, wherein the modulating means comprises a plurality of light modulators.

43. The device of claim 42, wherein the plurality of light modulators comprises an array of interferometric modulators.

44. A method of manufacturing a display device comprising:

providing a light bar that guides light along a length thereof, said light bar having a turning microstructure disposed on a top or bottom thereof, the turning microstructure configured to direct said light out a side of the light bar;

disposing a light guide panel with respect to the side of the light bar such that light from said light bar is coupled to said light guide panel, said light guide panel configured to direct said light coupled therein out of said light panel; and

disposing a plurality of light modulators with respect to the light guide panel to receive said light directed out of said light guide panel.

45. The method of claim 44, wherein said plurality of light modulators comprises a plurality of MEMS.

46. The method of claim 45, wherein said plurality of light modulators comprises a plurality of interferometric modulators.

47. An illumination apparatus fabricate using the method of claim 44.

48. A light bar having a front surface in optical communication with a display device, the light bar being configured to guide light along a length thereof, the light bar comprising:

a first film layer having a plurality of faceted features thereon;

a second film layer having a plurality of faceted features thereon;

an optical coupling layer positioned between and coupling the first and second film layers, the optical coupling layer configured to propagate light, wherein the faceted features on the first and second film layers are configured to direct light out of the front surface of the light bar towards the display device.

49. The light bar of claim 48, wherein the first and second film layers each have a thickness of less than about 350 micrometers.

50. The light bar of claim 48, wherein at least some of the faceted features are formed by embossing.

51. A method of manufacturing a light bar material for delivering light to a display device, the method comprising:

embossing a first plurality of faceted features on a first film layer;

embossing a second plurality of faceted features on a second film layer;

coupling the first and second film layers to form a composite film, wherein the faceted features on the first and second film layers are configured to direct light out of the light bar material.

52. The method of claim 51, wherein the first and second film layers are coupled with an optical coupling layer.

53. The method of claim 51, wherein the first and second film layers are coupled with an adhesive.

54. The method of claim 51, further comprising cutting the composite film into rectangular segments for use as light bars with respective display devices.

55. An illumination apparatus comprising:

a light bar, having two or more distinct layers, that guides light along a length thereof; and

a turning microstructure disposed on at least one of a top and a bottom of the light bar, the turning microstructure configured to direct said light out a side of the light bar.

56. The apparatus of claim 55, wherein the turning microstructure comprises a plurality of faceted features that are embossed on a first film layer on the top of the light bar and on a second film layer on the bottom of the light bar.

57. The device of claim 56, wherein the two or more distinct layers comprise the first film layer and the second film layer.