ILLUMINATION DEVICES AND METHODS OF FABRICATION THEREOF

• US 20100302218A1
• Filed: 05/27/2010
• Published: 12/02/2010
• Est. Priority Date: 05/29/2009
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Bita, Ion, Ganti, SuryaPrakash, Arbuckle, Brian W., Chan, Clayton Ka Tsun, Patel, Sapna
• Application Number:
  US12/789,412
• Publication Number:
  US 20100302218A1
• Time in Patent Office: Days
• US Class Current: 345/204
• 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, a display device includes a light modulating array and a light guide configured to receive light into at least one edge of the light guide. The display device can also include a light turning layer disposed such that the light guide is at least partially between the turning layer and the array. The turning layer can comprise at least one light turning feature having at least one curved 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 defined between the first end and the second end, the light guide having an x-axis extending parallel to the first surface between the first end and second end, a z-axis extending normal to the first surface and the second surface, and a y-axis extending normal to the x-axis and the z-axis, wherein the light guide is positioned to receive light from the light source into the light guide first end, and wherein light received from the light source propagates through the light guide towards the second end; and

a plurality of light turning features disposed on the first surface and protruding from the first surface into the light guide towards the second surface, each light turning feature having at least one curvilinear turning edge disposed on a plane that is parallel with a plane defined by the x-axis and the z-axis, the at least one turning edge configured to receive at least a portion of the light which is propagating towards the second end of the light guide and reflect at least a portion of the received light out of the second surface of the light guide.

2. The illumination apparatus of claim 1, wherein the turning edge of the light turning feature is configured such that the portion of light reflected by the at least one curvilinear turning edge forms an emission cone of light that has an angular width.

3. The illumination apparatus of claim 2, wherein the at least one turning edge is configured to focus light that is propagating in the light guide and incident on the at least one turning edge.

4. The illumination apparatus of claim 2, wherein the at least one turning edge is configured to disperse light that is propagating in the light guide and incident on the at least one turning edge.

5. The illumination apparatus of claim 1, wherein the at least one turning edge has a convex shaped profile on the x-axis and the z-axis defined plane on which it is disposed.

6. The illumination apparatus of claim 1, wherein the at least one turning has a convex shaped profile on the x-axis and the z-axis defined plane on which it is disposed.

7. The illumination apparatus of claim 1, wherein the surface of at least one turning feature is frustum shaped.

8. The illumination apparatus of claim 7, wherein the frustum comprises concave sides.

9. The illumination apparatus of claim 7, wherein the frustum comprises convex sides.

10. A display device comprising:

an array of light modulating elements;

a light guide disposed over the array, the light guide having at least one edge configured to receive light into the light guide; and

a turning layer disposed such that the light guide is at least partially between the turning layer and the array, the turning layer having a first surface and a second surface opposite the first surface, wherein the second surface is disposed between the first surface and the array, wherein the turning layer further comprises a plurality of light turning features disposed on the first surface and protruding from the first surface into the turning layer towards the second surface, each light turning feature being configured to receive at least a portion of light which is propagating through the turning layer and reflect at least a portion of the received light toward the array, each light turning feature having a light turning surface configured to focus or disperse the portion of light received and reflected toward the array.

11. The device of claim 10, wherein the curved light turning surface of each light turning feature extends from the first surface into the light guide and comprises a depression formed in the first surface.

12. The device of claim 11, wherein the curved light turning surface is frustum shaped.

13. The device of claim 11, wherein each light turning feature has at least one sidewall and wherein at least a portion of the sidewall is curved.

14. The device of claim 13, wherein the curved portion of the sidewall is convex.

15. The device of claim 13, wherein the curved portion of the sidewall is concave.

16. The device of claim 13, wherein each turning feature comprises an optical mask disposed on at least a portion of the sidewall.

17. The device of claim 16, wherein the optical mask comprises a first reflective layer, a second layer, and a third partially reflective layer disposed respectively on the sidewall, wherein the first layer is configured to receive light propagating within the turning layer and reflect at least a portion of the received light toward the array.

18. The device of claim 17, wherein the first, second, and third layers are configured to absorb a portion of light incident on the turning layer.

19. The device of claim 10, further comprising:

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

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

20. The device of claim 19, further comprising a driver circuit configured to send at least one signal to the array of light modulating elements.

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

22. The device of claim 19, further comprising an image source module configured to send the image data to the processor.

23. The device of claim 22, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

24. The device of claim 19, further comprising an input device configured to receive input data and to communicate the input data to the processor.

25. A method of making a light guide including turning features that are configured to focus or disperse light incident thereon, the method comprising:

providing a substrate;

depositing a layer of material over at least a portion of the substrate;

coating the material with a layer of photoresist;

exposing the photoresist to leave a pattern of portions of the photoresist on the layer of material; and

etching the layer of material to produce one or more depressions having curved sidewalls.

26. A method of making a turning film including turning features that are configured to focus or disperse light incident thereon, the method comprising:

providing a substrate;

depositing a layer of material over at least a portion of the substrate;

coating the material with a layer of photoresist;

exposing the photoresist to leave portions of the photoresist on the layer of material;

etching the layer of material to produce one or more depressions having curved sidewalls;

removing the photoresist;

electroplating the surface of the layer of material and the substrate to produce a surface relief; and

using the surface relief to mold a turning film.

27. The method of claim 26, wherein the sidewalls are convex.

28. The method of claim 26, wherein the sidewalls are concave.

29. The method of claim 26, wherein the layer of material and substrate form at least one frustum shaped turning feature.

30. The method of claim 29, wherein the frustum shaped turning feature comprises sidewalls that are convex.

31. The method of claim 29, wherein the frustum shaped turning feature comprises sidewalls that are concave.

32. A display device comprising:

means for modulating light;

means for guiding light disposed over the modulating means, the light guiding means being configured to receive light; and

means for turning light disposed such that the light guiding means is at least partially between the light turning means and the modulating means, wherein the turning means comprises a plurality of light turning features configured to receive at least a portion of light received by the light guiding means and reflect at least a portion of the received light toward the modulating means, wherein each light turning feature is configured to focus or disperse the portion of light received and reflected toward the modulating means, and wherein each light turning feature comprises a depression formed in a surface of the light turning means.