ILLUMINATION DEVICES AND METHODS OF FABRICATION THEREOF

• US 20100302803A1
• Filed: 05/27/2010
• Published: 12/02/2010
• Est. Priority Date: 05/29/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Ganti, SuryaPrakash, Arbuckle, Brian W., Chan, Clayton Ka Tsun, Patel, Sapna, Bita, Ion
• Granted Patent: US 8,979,349 B2
• Time in Patent Office: Days
• US Class Current: 362/606
• 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 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133616 Front illuminating devices

Abstract

Illumination devices and methods of making same are disclosed. In one embodiment, an illumination apparatus includes a light source, a light guide having a planar first surface, a first end and a second end, and a length therebetween, the light guide positioned to receive light from the light source into the light guide first end, and the light guide configured such that light from the light source provided into the first end of the light guide propagates towards the second end, and a plurality of light turning features that are configured to reflect light propagating towards the second end of the light guide out of the planar first surface of the light guide, each light turning feature having a turning surface and an interferometric stack formed on the turning surface.

Claims

1. An illumination apparatus comprising:

a light source;

a light guide having a generally planar first surface, a generally planar second surface opposite the first surface, a first end and a second end, and a length therebetween, wherein the light guide is positioned to receive light from the light source into the light guide first end, and wherein the light guide is configured such that light from the light source provided into the first end of the light guide propagates generally towards the second end; and

a plurality of light turning features, each light turning feature having a turning surface configured to receive at least a portion of the light which is propagating generally towards the second end of the light guide and reflect at least a portion of the received light out of the first surface of the light guide, each light turning feature comprising an interferometric stack formed on at least a portion of the turning surface.

2. The apparatus of claim 1, wherein each light turning feature comprises a depression formed in the first surface or second surface of the light guide.

3. The apparatus of claim 1, wherein the light guide is disposed with respect to a plurality of spatial light modulators such that light reflected out of the light guide first surface illuminates the plurality of spatial light modulators.

4. The apparatus of claim 1, wherein the interferometric stack comprises a reflective layer disposed on the turning surface, a spacer layer disposed on the reflective layer, and a partially reflective absorber layer disposed on the spacer layer.

5. The apparatus of claim 4, wherein the reflective layer comprises aluminum.

6. The apparatus of claim 4, wherein the absorber layer comprises chromium.

7. The apparatus of claim 4, wherein the spacer layer comprises silicon oxide.

8. The apparatus of claim 1, further comprising a turning film having a generally planar first portion and a generally planar second portion, wherein the second portion is disposed between the first portion and the light guide.

9. The apparatus of claim 8, wherein the turning film comprises the plurality of light turning features.

10. The apparatus of claim 9, wherein the plurality of light turning features are disposed in a uniform pattern on the turning film.

11. The apparatus of claim 9, wherein the plurality of light turning features are disposed in a non-uniform pattern on the turning film.

12. The apparatus of claim 8, wherein the first portion and the second portion of the turning film include at least a portion of a light turning feature.

13. The apparatus of claim 8, wherein at least one of the plurality of light turning features runs through both the first portion and the second portion.

14. The apparatus of claim 8, wherein the turning film comprises at least one light turning feature in the first portion and at least one light turning feature in the second portion.

15. The apparatus of claim 14, wherein the at least one light turning feature in the first portion is laterally offset from the at least one light turning feature disposed in the second portion.

16. The apparatus of claim 1, further comprising a turning film disposed on the light guide and having first and second ends, wherein the turning film comprises the light turning features.

17. The apparatus of claim 16, wherein the turning film and the light guide are configured such that at least one of the first and second ends of the turning film and at least one of the first and second ends of the light guide are curved.

18. The apparatus of claim 1, wherein at least two of the plurality of light turning features are configured with a different depth.

19. The apparatus of claim 1, wherein at least two of the plurality of light turning features are configured in a different shape.

20. The apparatus of claim 1, wherein the plurality of light turning features are disposed in a non-uniform pattern on the light guide second surface.

21. The apparatus of claim 1, wherein the plurality of light turning features are disposed in a uniform pattern on the light guide second surface.

22. The apparatus of claim 1, wherein the plurality of light turning features are disposed in a non-uniform pattern on the light guide first surface.

23. The apparatus of claim 1, wherein the plurality of light turning features are disposed in a uniform pattern on the light guide first surface.

24. The apparatus of claim 1, wherein the turning surface of at least one of the plurality of light turning features is curved.

25. The apparatus of claim 1, wherein at least one of the plurality of light turning features is frustum-shaped.

26. The apparatus of claim 1, wherein at least one of the plurality of light turning features is cone-shaped.

27. The apparatus of claim 1, wherein the plurality of light turning features are rotationally symmetrical.

28. The apparatus of claim 1, further comprising:

an array of light modulating elements positioned to receive light reflected out of the first surface of the light guide;

a processor that is configured to communicate with the an array of light modulating elements, said processor being configured to process image data; and

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

29. The apparatus of claim 28, further comprising a driver circuit configured to send at least one signal to the array of light modulating elements.

30. The apparatus of claim 29, further comprising a controller configured to send at least a portion of the image data to said driver circuit.

31. The apparatus of claim 28, further comprising an image source module configured to send the image data to the processor.

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

33. The apparatus of claim 28, further comprising an input device configured to receive input data and to communicate said input data to said processor.

34. The apparatus of claim 1, further comprising a turning film disposed on the light guide, the turning film having a first end and a second end, wherein the light source is further configured to provide light into the turning film first end such that the light propagates through the turning film towards the turning film second end, wherein the turning film comprises the plurality of light turning features.

35. An illumination apparatus comprising:

means for providing light;

means for guiding light, wherein the light guiding means has a planar first surface, a first end and a second end, and a length therebetween, wherein the light guiding means is configured such that light from the light providing means provided into the light guiding means first end propagates generally towards the light guiding means second end; and

a plurality of means for turning light, each means for turning light having a turning surface configured to receive light propagating towards the second end of the light guiding means and reflect at least a portion of the received light out of the light guiding means first surface, each means for turning light comprising an interferometric stack formed on the turning surface.

36. The apparatus of claim 35, wherein the light providing means comprises a light emitting diode.

37. The apparatus of claim 35, wherein the light guiding means comprises a light guide.

38. The apparatus of claim 35, wherein the plurality of light turning means comprises frustum-shaped light turning features.

39. An illumination apparatus comprising:

a light source;

a light guide having a generally planar first surface, a first end and a second end, and a length therebetween, the light guide positioned to receive light from the light source into the light guide first end, and the light guide configured such that light from the light source provided into the first end of the light guide propagates generally towards the second end; and

a plurality of light turning features, each light turning feature having a turning surface configured to receive at least a portion of the light which is propagating generally towards the second end of the light guide and reflect at least a portion of the received light out of the planar first surface of the light guide, each light turning feature comprising a reflective layer disposed over at least a portion of each turning surface; and

a plurality of optical masks, each optical mask formed on a reflective layer.

40. The illumination apparatus of claim 39, wherein the optical masks comprise a dark coating.

41. The illumination apparatus of claim 39, wherein the optical masks comprise an absorber layer that forms an interferometric stack with the reflective layer.

42. A method of manufacturing an illumination apparatus, the comprising:

providing a light guide;

forming a turning film on the light guide;

forming a plurality of light turning features on the turning film, each light turning feature comprising a light turning surface; and

forming an interferometric stack on each light turning surface.

43. The method of claim 42, wherein forming the interferometric stack comprises electroplating at least one layer of the interferometric stack.

44. The method of claim 42, wherein forming the interferometric stack comprises etching the light turning film to form light turning features and depositing the layers of the interferometric stack on each light turning surface.