Light emitting device with light mixing within a film

• US 8,950,902 B2
• Filed: 05/06/2013
• Issued: 02/10/2015
• Est. Priority Date: 10/09/2007
• Status: Active Grant

• Current Assignee: FLEx Lighting II, LLC
• Original Assignee: FLEx Lighting II, LLC
• Inventors: Nichol, Anthony J., Coleman, Zane A.
• Primary Examiner(s): Hines, Anne
• Application Number:
  US13/888,139
• Publication Number:
  US 20130250618A1
• Time in Patent Office: 645 Days
• Field of Search: 362/296.01, 36231101-31103, 362/257, 362/317, 362/362, 362/623, 362/247, 362/600, 362/612, 362/92, 362/812, 362546-547
• US Class Current: 362/296.01
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/002 by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: Y10T 156/1051 by folding

Abstract

In one embodiment, a light emitting device comprises an array of legs extending from a body of film with the bounding edges of the legs stacked, a first light source emitting light of a first color and a second light source emitting light of a second color into the stacked bounding edges where the light emitting region defined within the body is configured to extract light of a third color. In another embodiment, a light emitting device comprises three light sources positioned to direct light into a stacked array of bounding edges. In one embodiment, a method of generating light of adjustable color exiting a surface of a film is disclosed.

Claims

1. A lightguide comprising:

a light transmitting film having a body with opposing faces with a thickness not greater than 0.5 millimeters therebetween;

a first array of legs formed along a first side of the body of the film wherein;

each leg of the first array of legs comprises a first bounding edge at an end thereof;

the first bounding edges defining a first light input surface; and

each leg of the first array of legs is folded over 90 degrees and stacked to form a first bundle of the first array of legs; and

a second array of legs formed along the body of the film wherein;

each leg of the second array of legs comprises a second bounding edge at an end thereof;

the second bounding edges defining a second light input surface; and

each leg of the second array of legs is folded over 90 degrees and stacked to form a second bundle of the second array of legs different from the first bundle.

2. The lightguide of claim 1 wherein the first array of legs are sequentially stacked and the second array of legs are sequentially stacked.

3. The lightguide of claim 1 wherein the first light input surface and the second light input surfaces are positioned to receive light from different light sources.

4. The lightguide of claim 1 wherein the second array extends from a second side of the body of the film different from the first side.

5. The lightguide of claim 4 wherein one or more sides are disposed between the first side and the second side of the body.

6. The lightguide of claim 4 wherein the second side is opposite the body from the first side.

7. The lightguide of claim 4 wherein the second side of the body is adjacent the first side of the body.

8. The lightguide of claim 1 wherein the second array of legs extend from the first side of the body.

9. The lightguide of claim 8 wherein the first light input surface is positioned side by side with the second light input surface.

10. The lightguide of claim 8 wherein the first light input surface is separated from the second light input surface.

11. The lightguide of claim 8 wherein the each leg of the first array of legs is adjacent a leg of the second array of legs and the first light input surface is above the second light input surface.

12. The lightguide of claim 1 wherein the first light input surface and the second light input surface are positioned to receive light from a light source directly or indirectly via one or more common optical elements.

13. A light emitting device comprising the lightguide of claim 1 and a light source.

14. A reflective display comprising the light emitting device of claim 13 and reflective spatial light modulator.

15. A transmissive display comprising the light emitting device of claim 13 and transmissive spatial light modulator.

16. A lightguide comprising:

a first light input coupler comprising a first bundle of flexible strips with first ends extending from a first side of a region of material with opposing faces with a thickness not greater than 0.5 millimeters therebetween, the first bundle of strips are bent, folded, and stacked such that the first ends define a first light input surface; and

a second light input coupler comprising a second bundle of flexible strips with second ends extending from the region of material, the second bundle of strips are bent, folded, and stacked such that the second ends define a second light input surface different from the first light input surface.

17. The lightguide of claim 16 wherein the second bundle extends from a second side of the region of material different from the first side.

18. The lightguide of claim 16 wherein the second bundle extends from the first side of the region of material.

19. The lightguide of claim 18 wherein the first light input surface and the second light input surface are positioned to receive light from different light sources and the first light input coupler is positioned adjacent the second light input coupler.

20. The lightguide of claim 16 wherein the first light input surface and the second light input surface are positioned to receive light from different light sources.

21. The lightguide of claim 16 wherein the first light input surface and the second light input surface are positioned to receive light from the same light source.

22. The lightguide of claim 16 wherein the second bundle of flexible strips is positioned between the first light input surface and the second light input surface.

23. A light emitting device comprising the lightguide of claim 16 and a light source.

24. A method of manufacturing a lightguide comprising:

forming a first array flexible strips with first ends and a second array of flexible strips with second ends extending from a body of light transmitting material;

bending and folding the first array of flexible strips over itself;

bending and folding the second array of flexible strips over itself;

stacking the first array of flexible strips such that the first ends define a first light input surface; and

stacking the second array of flexible strips such that the second ends define a second light input surface different that the first light input surface.

25. The method of claim 24 wherein the first array of flexible strips is formed on a first side of the body of light transmitting material and the second array of flexible strips is formed on a second side of the body of light transmitting material different from the first side.

26. The method of claim 24 wherein the first array of flexible strips is formed on a first side of the body of light transmitting material and the second array of flexible strips is formed on the first side of the body of light transmitting material.