SLIM WAVEGUIDE COUPLING APPARATUS AND METHOD

• US 20100008628A1
• Filed: 07/10/2009
• Published: 01/14/2010
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Advanced Illumination Solutions Inc.
• Inventors: Shani, Yosi
• Granted Patent: US 8,301,002 B2
• Time in Patent Office: Days
• US Class Current: 385/49
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

In various embodiments, an illumination structure includes a discrete light source disposed proximate a bottom surface of a waveguide. A top mirror may be disposed above the discrete light source to convert modes of light emitted from the discrete light source into trapped modes, thereby increasing the coupling efficiency of the illumination structure.

Claims

1. An illumination structure comprising:

a waveguide;

a discrete light source disposed proximate a bottom surface of the waveguide; and

a top mirror disposed above the discrete light source.

2. The illumination structure of claim 1, further comprising a sub-assembly module disposed proximate a bottom surface of the discrete light source.

3. The illumination structure of claim 2, wherein a portion of a top surface of the sub-assembly module is not covered by the discrete light source.

4. The illumination structure of claim 2, wherein light emitted by the discrete light source is reflected by the top mirror away from a top surface of the sub-assembly module and into a confined mode of the waveguide.

5. The illumination structure of claim 2, wherein the sub-assembly module comprises at least one of printed-circuit board or a carrier plate.

6. The illumination structure of claim 2, wherein the sub-assembly module comprises an index-matching region.

7. The illumination structure of claim 2, wherein the sub-assembly module comprises at least one of an electrical interface with the discrete light source or a mechanical interface with the discrete light source.

8. The illumination structure of claim 1, wherein the top mirror is at least one of a curved mirror, semi-curved mirror, broken-line mirror, or single-line top mirror.

9. The illumination structure of claim 1, wherein the top mirror has a substantially parabolic shape.

10. The illumination structure of claim 1, wherein the top mirror comprises at least one of a cone and pyramid.

11. The illumination structure of claim 1, wherein the top mirror is a specular reflector.

12. The illumination structure of claim 1, wherein the top mirror is positioned such that light from the discrete light source that does not strike the top mirror is within a confined mode of the waveguide.

13. The illumination structure of claim 1, wherein the top mirror is positioned asymmetrically relative to the discrete light source.

14. The illumination structure of claim 1, wherein light emitted by the discrete light source is reflected by the top mirror away from the discrete light source and into a confined mode of the waveguide.

15. The illumination structure of claim 14, wherein the top mirror is positioned such that light from the discrete light source that does not strike the top mirror is within a confined mode of the waveguide.

16. The illumination structure of claim 1, further comprising at least one additional discrete light source.

17. The illumination structure of claim 16, wherein the top mirror is disposed above at least two discrete light sources.

18. The illumination structure of claim 17, wherein the top mirror comprises a prism.

19. The illumination structure of claim 18, wherein the top mirror comprises a triangular prism.

20. The illumination structure of claim 16, wherein the discrete light sources are arranged in a line.

21. The illumination structure of claim 16, wherein the discrete light sources comprise RGB light sources.

22. The illumination structure of claim 1, wherein a thickness of the waveguide is approximately equal to a width of the discrete light source.

23. The illumination structure of claim 1, wherein a thickness of the waveguide is less than a width of the discrete light source.

24. The illumination structure of claim 1, further comprising a flat mirror disposed proximate a top surface of the waveguide and proximate the top mirror.

25. The illumination structure of claim 24, further comprising a diffuse mirror proximate a bottom surface of the waveguide, wherein light emitted by the discrete light source is reflected by the flat mirror toward the diffuse mirror.

26. The illumination structure of claim 1, further comprising a phosphor layer disposed above the discrete light source.

27. The illumination structure of claim 26, wherein the discrete light source and the phosphor layer are disposed within a notch in the bottom surface of the waveguide.

28. The illumination structure of claim 1, further comprising an absorber disposed over the top mirror in a first region of the waveguide.

29. The illumination structure of claim 28, wherein the absorber has an absorbance such that light passing through the top mirror and the absorber has an intensity approximately equal to an intensity of light passing through a top waveguide surface in a second region of the waveguide proximate the first region of the waveguide.

30. A method for coupling light emitted from a discrete light source to a waveguide, the method comprising:

emitting light from a discrete light source disposed proximate a bottom surface of a waveguide; and

reflecting a portion of the emitted light from a top mirror disposed above the discrete light source so as to confine the reflected portion of the emitted light within the waveguide.

31. The method of claim 30, further comprising reflecting a second portion of the emitted light from a diffusive mirror disposed proximate a bottom surface of the waveguide so as to confine the reflected second portion of the emitted light within the waveguide.

32. An illumination structure comprising a plurality of panels, each panel comprising:

an in-coupling region comprising a discrete light source and a horizontal mirror; and

an out-coupling region disposed proximate the in-coupling region,

wherein light emitted by the discrete light source is reflected by the horizontal mirror into the out-coupling region, and the light is emitted over substantially all of a surface of the out-coupling region.

33. The illumination structure of claim 32, wherein the out-coupling region of one panel is disposed over the in-coupling region of another panel, thereby forming a substantially uniform light-emission surface.

34. The illumination structure of claim 32, wherein substantially no light reflected by the horizontal mirror into the out-coupling region reflects back toward the discrete light source.