ILLUMINATION DEVICE WITH BUILT-IN LIGHT COUPLER

• US 20090190373A1
• Filed: 04/01/2009
• Published: 07/30/2009
• Est. Priority Date: 10/06/2006
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mienko, Marek, Xu, Gang, Bita, Ion, Gruhlke, Russell Wayne
• Granted Patent: US 8,061,882 B2
• Time in Patent Office: Days
• US Class Current: 362/620
• 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 comprising

a front surface exposed to ambient light;

a back surface;

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

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.

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 light guide comprises a film stack.

4. The device of claim 1, wherein said light coupling section comprises a diffractive optical element.

5. The device of claim 4, wherein said diffractive optical element comprises a diffraction grating.

6. The device of claim 4, wherein said diffractive optical element comprises surface diffractive features.

7. The device of claim 4, wherein said diffractive optical element comprises volume diffractive features.

8. The device of claim 4, wherein said diffractive optical element is disposed on said front surface.

9. The device of claim 4, wherein said diffractive optical element is disposed on said back surface.

10. The device of claim 5, wherein said diffraction grating is a transmissive diffraction grating.

11. The device of claim 5, wherein said diffraction grating is a reflective diffraction grating.

12. The device of claim 5, wherein said diffraction grating comprises a blazed grating.

13. The device of claim 1, wherein said light coupling section further comprises 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.

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

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

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

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

18. 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.

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

20. The device of claim 19, wherein said display comprises a plurality of interferometric modulators.

21. The device of claim 19, 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.

22. The device of claim 21, further comprising a driver circuit configured to send at least one signal to said display.

23. The device of claim 22, further comprising a controller configured to send at least a section of the image data to said driver circuit.

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

25. The device of claim 24, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

26. The device of claim 21, further comprising an input device configured to receive input data and to communicate said input data to said processor.

27. An illumination device comprising:

a light guide comprising

a front surface exposed to ambient light;

a back surface;

a light coupling section comprising a photoluminescent material, wherein said light coupling section is disposed at least partially between said front surface and said back surface, configured to receive optical energy through said back surface at an angle about normal to said back surface, and further configured to direct light through said light guide;

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 UV light source disposed with respect to said light coupling section to provide UV light to said back surface of said light coupling section such that at least a portion of UV light emitted from the light source can enter said light coupling section and propagate to said photoluminescent material.

28. The device of claim 27, wherein the light coupling section further comprises a reflector disposed adjacent to said photoluminescent material to redirect light emitted therefrom into said light coupling section such that at least a portion of the redirected light propagates to said light turning section of said light guide.

29. The device of claim 27, wherein said photoluminescent material is selected to match the emitted light spectrum from the light source.

30. The device of claim 28, wherein said reflector comprises at least one metallic film.