Illumination device with built-in light coupler

• US 8,061,882 B2
• Filed: 04/01/2009
• Issued: 11/22/2011
• Est. Priority Date: 10/06/2006
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Gruhlke, Russell W., Mienko, Marek, Xu, Gang, Bita, Ion
• Primary Examiner(s): Ward; John A
• Application Number:
  US12/416,886
• Publication Number:
  US 20090190373A1
• Time in Patent Office: 965 Days
• Field of Search: 362/600, 362/606, 362/610, 362/612, 362/613, 362/621, 362/623, 362/615
• US Class Current: 362/623
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12107 Grating
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• 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 6/0036 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 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/1226 involving surface plasmon interaction
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence

Abstract

The invention comprises devices and methods for coupling a light source to a display illumination device. In one embodiment, an illumination device includes a light guide comprising a front surface, a back surface, a light coupling section configured to receive optical energy from a light source in to the light guide through said front surface or said back surface at an angle about normal to the optical energy receiving surface, and further configured to direct light through said light guide, and a light turning section configured to redirect out of the light guide at least a portion of the light received from said light coupling section, said redirected light at an angle about normal to the optical energy receiving surface.

Claims

1. An illumination device comprising:

a light guide including;

a front surface exposed to ambient light;

a back surface;

a light coupling section including a diffraction grating, said light coupling section disposed at least partially between said front surface and said back surface, said light coupling section configured to receive optical energy through said back surface at an angle about normal to said back surface, said diffraction grating configured to direct light through said light guide; and

a light turning section configured to redirect at least a portion of the light received from said light coupling section out of said back surface, said redirected light being emitted from said back surface at an angle about normal to said back surface; and

a light source disposed to provide optical energy to said back surface of said light coupling section at an angle about normal to said back surface,

wherein said light guide is a film stack or said light guide has a film applied directly thereto.

2. The device of claim 1, wherein said light source is disposed adjacent to said back surface of the said light coupling section.

3. The device of claim 1, wherein said diffraction grating includes surface diffractive features.

4. The device of claim 1, wherein said diffraction grating includes volume diffractive features.

5. The device of claim 1, wherein said diffraction grating is disposed on said front surface.

6. The device of claim 1, wherein said diffraction grating is disposed on said back surface.

7. The device of claim 1, wherein said diffraction grating is a transmissive diffraction grating.

8. The device of claim 1, wherein said diffraction grating is a reflective diffraction grating.

9. The device of claim 1, wherein said diffraction grating includes a blazed grating.

10. The device of claim 1, wherein said light coupling section further includes a light emissive material and a metal surface disposed adjacent to said light emissive material, said coupling section configured such that surface plasmon excitation occurs in said metal surface when said light emissive material is illuminated with said optical energy.

11. The device of claim 1, wherein said light turning section includes a plurality of turning features disposed on said front surface of the light guide.

12. The device of claim 1, wherein said light turning section includes a plurality of turning features disposed on said back surface of the light guide.

13. The device of claim 1, wherein said light turning section includes a plurality of turning features within said light guide.

14. The device of claim 1, wherein said light turning section includes prismatic features configured to direct light out of the back surface of the light guide.

15. The device of claim 1, further comprising a reflector disposed adjacent to the light coupling section to reflect at least a portion of light emitted from said light coupling section back into said light coupling section.

16. The device of claim 1, further comprising a display disposed substantially parallel to said back surface and adjacent to at least a portion of said light turning section.

17. The device of claim 16, wherein said display includes a plurality of interferometric modulators.

18. The device of claim 16, further comprising:

a processor that is configured to communicate with said display, said processor being configured to process image data; and

a memory device that is configured to communicate with said processor.

19. The device of claim 18, further comprising a driver circuit configured to send at least one signal to said display.

20. The device of claim 19, further comprising a controller configured to send at least a section of the image data to said driver circuit.

21. The device of claim 18, further comprising an image source module configured to send said image data to said processor.

22. The device of claim 21, wherein the image source module includes at least one of a receiver, transceiver, and transmitter.

23. The device of claim 18, further comprising an input device configured to receive input data and to communicate said input data to said processor.

24. The device of claim 1, wherein said light coupling section is configured to direct at least a portion of said light through said light guide via total internal reflection.

25. The device of claim 1, further comprising a reflector disposed with respect to said light coupling section so as to reflect at least a portion of light emitted from said light coupling section back into said light coupling section.

26. The device of claim 1, further comprising a display disposed substantially parallel to said back surface and disposed with respect to at least a portion of said light turning section so as to receive at least some of said redirected light.

27. The device of claim 1, wherein said diffraction grating is embossed or etched on said light guide.

28. The device of claim 1, wherein said light turning section includes a plurality of turning features that are embossed or etched on said light guide.

29. The device of claim 1, wherein the film stack or the film includes an adhesive.

30. The device of claim 1, wherein the light source has a width that is greater than a thickness of the light coupling section of the light guide.

41. The device of claim 1, wherein said diffraction grating is disposed on a surface of said light coupling section.

42. The device of claim 1, wherein said diffraction grating is disposed inside said light coupling section.

31. An illumination device comprising:

means for guiding light, said light guiding means having a front surface disposed towards ambient light and a back surface, said light guiding means including;

means for coupling optical energy, disposed at least partially between said front surface and said back surface, and configured to receive optical energy through said back surface at an angle about normal to said back surface, said coupling means including a diffraction grating configured to direct light through said light guiding means; and

means for turning light to redirect at least a portion of the light received from said coupling means out of said back surface, said redirected light being emitted from said back surface at an angle about normal to said back surface; and

means for providing optical energy to said coupling means by illuminating said back surface with optical energy at an angle about normal to said back surface,

wherein said light guiding means is a film stack or said light guiding means has a film applied directly thereto.

32. The device of claim 31, wherein said coupling means is configured to direct at least a portion of said light through said light guiding means via total internal reflection.

33. The device of claim 31, further comprising means for modulating light, said light modulating means disposed substantially parallel to said back surface and disposed with respect to at least a portion of said light turning means so as to receive at least some of said redirected light.

34. The device of claim 33, wherein said modulating means includes a reflective spatial light modulator.

35. The device of claim 34, wherein said reflective spatial light modulator includes a plurality of interferometric modulators.

36. The device of claim 31, wherein said light guiding means includes a light guide.

37. The device of claim 31, wherein said optical energy coupling means includes a light coupler section.

38. The device of claim 31, wherein said light turning means includes a light turning section including a plurality of turning features disposed on said front surface of said light guiding means.

39. The device of claim 38, wherein said plurality of turning features includes a plurality of prismatic features configured to direct light out of the back surface of said light guiding means.

40. The device of claim 31, further comprising means for reflecting light, said light reflecting means disposed with respect to said coupling means to reflect at least a portion of light emitted from said coupling means back into said coupling means.

43. The device of claim 31, wherein said diffraction grating is disposed on a surface of said coupling means.

44. The device of claim 31, wherein said diffraction grating is disposed inside said coupling means.

45. The device of claim 31, wherein said diffraction grating is embossed or etched on said light guide.

46. The device of claim 31, wherein said light turning means includes a light turning section comprising a plurality of turning features that are embossed or etched on said light guiding means.

47. The device of claim 31, wherein the film stack or the film includes an adhesive.

48. The device of claim 31, wherein the optical energy providing means has a width that is greater than a thickness of the optical energy coupling means of the light guiding means.