Illumination system and method for recycling light to increase the brightness of the light source

• US 7,976,204 B2
• Filed: 06/13/2007
• Issued: 07/12/2011
• Est. Priority Date: 06/13/2006
• Status: Active Grant

• Current Assignee: Wavien, Inc.
• Original Assignee: Wavien, Inc.
• Inventors: Inatsugu, Seiji, Li, Kenneth K.
• Primary Examiner(s): MAY, ROBERT J
• Application Number:
  US11/818,308
• Publication Number:
  US 20070291491A1
• Time in Patent Office: 1,490 Days
• Field of Search: 362/551, 362/555, 362/19, 362/800, 362297-308, 362309-310, 36229601-29608, 385/146, 385/11
• US Class Current: 362/555
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An illumination system for increasing the brightness of a light source comprises an optical recycling device coupled to the light source, preferably light emitting diode (LED), for spatially and/or angularly recycling light. The optical recycling device spatially recycles a portion of rays of light emitted by the LED back to the light source using a reflector or mirror and/or angularly recycles high angle rays of light and transmits small angle rays of light, thereby increasing the brightness of the light source'"'"'s output.

Claims

1. An illumination system for increasing the brightness of a light source, comprising:

a light source for emitting a plurality of rays of light; and

an optical recycling device for transmitting said plurality of rays of light from said light source, said optical recycling device comprising a single solid optical component having reflective concave surfaces and a lens surface; and

wherein said lens surface of said single solid optical component forms a predetermined cone angle with said light source such that said reflective concave surfaces of said single solid optical component angularly recycles a portion of said plurality of rays of light by reflecting rays of light emitted from said light source outside said predetermined cone angle back to said light source which re-emits said rays of light emitted outside said predetermined cone angle to said angular optical recycling device, thereby increasing the brightness of said light source'"'"'s output;

wherein said lens surface of said single solid optical component transmits rays of light emitted from said light source within said predetermined cone angle from said optical recycling device; and

wherein all of said light rays outside of said predetermined cone angle impact said concave surface before impacting any other surface.

2. The illumination system of claim 1, wherein said light source comprises a plurality of LED chips.

3. The illumination system of claim 2, wherein said plurality of LED chips are closed packed in a single dimension or in a two-dimensional array.

4. The illumination system of claim 1, wherein said light source comprises a plurality of colored LED chips, each colored LED chip emitting light having different wavelength.

5. The illumination system of claim 1, wherein said reflective concave surfaces form dual paraboloid reflective surfaces to reflect said rays of light emitted from said light source outside said predetermined cone angle twice before being focused back onto said light source.

6. The illumination system of claim 1, wherein said reflective concave surface being spherical, parabolic or elliptical in shape.

7. The illumination system of claim 1, wherein said reflective concave surface surrounds said aperture.

8. The illumination system of claim 1, wherein said light source comprises a light emitting diode (LED) or LED chip.

9. The illumination system of claim 8, wherein said LED chip is mounted on a substrate having a reflective surface coating.

10. The illumination system of claim 8, wherein said LED chip comprises integrated optics for extracting light from said LED chip.

11. The illumination system of claim 1, wherein said reflective concave surfaces of said solid optical component are spherical, parabolic or elliptical in shape.

12. The illumination system of claim 1, wherein said reflective concave surfaces of said solid optical component surrounds said lens surface of said solid optical component.

13. An illumination system for increasing the brightness of a light source and a method for increasing the method of increasing the brightness, comprising:

a light source for emitting a plurality of rays of light; and

an angular optical recycling device for transmitting said plurality of rays of light from said light source, said angular optical recycling device comprising a single hollow optical component having an aperture and reflective concave surfaces that are in the shape of a dual paraboloid; and

wherein said aperture of said single hollow optical component forms a predetermined cone angle with said light source such that said reflective concave surfaces of said hollow optical component angularly recycles a portion of said plurality of rays of light by reflecting rays of light emitted from said light source outside said predetermined cone angle back to said light source which re-emits said of rays of light emitted outside said predetermined cone angle to said angular optical recycling device, thereby increasing the brightness of said light source'"'"'s output; and

wherein said aperture of said single hollow optical component transmits rays of light emitted from said light source within said predetermined cone angle from said angular optical recycling device; and

wherein all of said light rays outside of said predetermined cone angle impact one of said dual paraboloid reflective surfaces before impacting any other surface.

14. The illumination system of claim 13, wherein said dual paraboloid reflective surfaces reflect said rays of light emitted from said light source outside said predetermined cone angle twice before being focused back onto said light source.

15. The illumination system of claim 13, wherein said reflective concave surface being spherical, parabolic or elliptical in shape.

16. The illumination system of claim 13, wherein said reflective concave surface surrounds said aperture.

17. The illumination system of claim 13, wherein said light source comprises a light emitting diode (LED) or LED chip.

18. The illumination system of claim 17, wherein said LED chip is mounted on a substrate having a reflective surface coating.

19. The illumination system of claim 17, wherein said LED chip comprises integrated optics for extracting light from said LED chip.

20. The illumination system of claim 13, wherein said light source comprises a plurality of light emitting diode (LED) chips closed packed in a single dimension or in a two-dimensional array.

21. The illumination system of claim 13, wherein said light source comprises a plurality of colored light emitting diode (LED) chips, each colored LED chip emitting light having a different wavelength.

22. A method for increasing the brightness of a light source, comprising the steps of:

coupling an optical recycling device to a light source to receive a plurality of rays of light from said light source and to recycle a portion of said plurality of rays of light, said optical recycling device comprising a single solid optical component having reflective concave surfaces and lens surface forming a predetermined cone angle with said light source;

angularly recycling a portion of said plurality of rays of light by reflecting rays of light emitted from said light source outside said predetermined cone angle back to said light source by said reflective concave surfaces of said optical component;

transmitting rays of light emitted from said light source within said predetermined cone angle from said optical recycling device through said lens surface;

re-emitting said rays of light emitted outside said predetermined cone angle to said optical recycling device by said light source, thereby increasing the brightness of said light source'"'"'s output; and

wherein all of said light rays outside of said predetermined cone angle impact one of said concave surface before impacting any other surface.

23. The method of claim 22, further comprising the step of reflecting said rays of light emitted from light source outside said predetermined cone angle twice before being focused back onto said light source by said reflective concave surface forming dual paraboloid reflective surfaces.

24. The method of claim 22, further comprising the step of receiving said plurality of rays of light from a light emitting diode (LED) or LED chip.

25. The method of claim 24, further comprising the step of mounting said LED chip on a substrate having a reflective coating.

26. The method of claim 24, further comprising the steps of receiving said plurality of rays of light from said plurality of colored LED chips, each colored LED chip emitting light having a different wavelength.

27. The method of claim 24, further comprising the step of extracting light from said LED chip using integrated optics on said LED chip.

28. The method of claim 22, further comprising the step of receiving said plurality of rays of light from a plurality of LED chips closed packed in a single dimension or in a two-dimensional array on a substrate.

29. A method for increasing the brightness of a light source, comprising the steps of:

coupling an optical recycling device to a light source to receive a plurality of rays of light from said light source and to recycle a portion of said plurality of rays of light, said optical recycling device comprising a single hollow optical component having a reflective concave surface and an aperture forming a predetermined cone angle with said light source;

recycling a portion of said plurality of rays of light by reflecting rays of light emitted from said light source outside said predetermined cone angle back to said light source by said reflective concave surface of said single hollow optical component;

transmitting rays of light emitted from said light source within said predetermined cone angle from said optical recycling device through said aperture; and

re-emitting said rays of light emitted outside said predetermined cone angle to said optical recycling device by said light source, thereby increasing the brightness of said light source'"'"'s output; and

wherein all of said light rays outside of said predetermined cone angle impact said concave surface before impacting any other surface.

30. The method of claim 29, further comprising the step of reflecting said rays of light emitted from light source outside said predetermined cone angle twice before being focused back onto said light source by said reflective concave surface forming dual paraboloid reflective surfaces.

31. The method of claim 29, further comprising the step of receiving said plurality of rays of light from a light emitting diode (LED) or LED chip.

32. The method of claim 31, further comprising the step of mounting said LED chip on a substrate having a reflective surface coating.

33. The method of claim 31, further comprising the step of extracting light from said LED chip using integrated optics on said LED chip.

34. The method of claim 29, further comprising the step of receiving said plurality of rays of light from a plurality of light emitting diode (LED) chips closed packed in a single dimension or in a two-dimensional array.

35. The method of claim 29, further comprising the steps of receiving said plurality of rays of light from a plurality of colored LED chips, each colored LED chip emitting light having a different wavelength.