Lighting system using multiple colored light emitting sources and diffuser element

• US 7,837,348 B2
• Filed: 12/20/2006
• Issued: 11/23/2010
• Est. Priority Date: 05/05/2004
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Gu, Yimin, Narendran, Nadarajah
• Primary Examiner(s): Payne; Sharon E
• Application Number:
  US11/642,089
• Publication Number:
  US 20080094829A1
• Time in Patent Office: 1,434 Days
• Field of Search: 362/231, 362/555, 362/558, 362/235, 362/293, 362/355, 362/84, 313/512, 313/498, 313/501
• US Class Current: 362/231
• CPC Class Codes: F21K 2/00 Non-electric light sources using luminescence using excitation by radioactivity G21H3/02, H01J65/06, H01J65/08; using excitation by an external electromagnetic field or by external corpuscular radiation H01J65/04; Light sources using electrochemiluminescence
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 5/004 using microlenses
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21V 9/45 by adjustment of photoluminescent elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting apparatus has a radiation source for emitting multi-colored radiation. A diffuser material receives at least a portion of the multi-colored radiation emitted by the radiation source and converts the multi-colored radiation into forward transferred radiation and back transferred radiation. An optic device is coupled to the diffuser material and is adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device.

Claims

1. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material coupled to a down conversion material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device having a first end proximal the radiation source and a second end distal the radiation source, the proximal end of the optic device having a width smaller that a width of the distal end, the optic device disposed between (i) the radiation source and (ii) the diffuser material and the down conversion material, having at least one substantially transparent side wall absent the down conversion material, coupled to the diffuser material and the down conversion material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device through the at least one substantially transparent side wall.

2. The light emitting apparatus of claim 1, wherein the radiation source comprises a plurality of light emitting sources, each of the light emitting sources exhibiting a spectrum different than a spectrum of at least one of the other light emitting sources.

3. The light emitting apparatus of claim 2, wherein the plurality of light sources comprises at least one of one of light emitting diodes (LEDs), laser diodes (LDs), and resonant cavity light emitting diodes (RCLEDs).

5. The light emitting device of claim 2, wherein the optic device is substantially transparent and the plurality of light emitting sources is disposed between substantially transparent walls of the substantially transparent optic device at a first end portion of the substantially transparent optic device.

6. The light emitting device of claim 5, wherein the diffuser material and the down conversion material are disposed adjacent a second end portion of the substantially transparent optic device.

7. The light emitting device of claim 5, wherein the diffuser material and the down conversion material are disposed on one of a portion of a second end portion of the optic device or on substantially all of the second end portion of the optic device.

8. The light emitting apparatus of claim 2, further comprising a light pipe, wherein the plurality of light emitting sources are disposed about at least a portion of a circumference of the light pipe for directing the light into the light pipe.

9. The light emitting apparatus of claim 8, further comprising a microlens layer disposed on a side of the light pipe.

10. The light emitting apparatus of claim 1, wherein the diffuser material for receiving the multi-colored radiation is at least one of a diffuser, a down conversion material, and a microlens.

11. The light emitting apparatus of claim 10, wherein the down conversion material includes at least one material for absorbing radiation of a first wavelength in a spectral region and emitting radiation of a second wavelength longer than the first wavelength in the spectral region.

12. The light emitting apparatus of claim 10, wherein the down conversion material comprises one of a layer having substantially uniformly dispersed material, a layer having a plurality of materials each of the plurality of materials exhibiting a respective density, or material dispersed within the optic device.

13. The light emitting apparatus of claim 10, wherein the diffuser material comprises at least one layer of down conversion material adjacent the diffuser.

14. The light emitting apparatus of claim 10, wherein the diffuser material comprises at least one layer of down conversion material positioned away from a second diffuser.

15. The light emitting apparatus of claim 1, wherein the down conversion material for receiving the multi-colored radiation comprises a plurality of down conversion materials for absorbing radiation of a first wavelength in a spectral region and emitting radiation of at least a second wavelength in the spectral region longer than the first wavelength.

16. The light emitting apparatus of claim 1, wherein the diffuser material and the down conversion material for receiving the multi-colored radiation comprises respectively at least one of i) a plurality of diffuser layers and ii) a plurality of down conversion material layers.

17. The light emitting apparatus of claim 1, further comprising a collecting device for collecting at least a portion of the back transferred radiation that has been extracted from the optic device.

18. The light emitting apparatus of claim 17, wherein the collecting device includes a reflector disposed around at least a portion of the optic device.

19. The light emitting apparatus of claim 18, wherein a shape of the reflector is one of a cone, sphere, hyperbola, parabola, ellipse, pyramid, and box.

20. The light emitting apparatus of claim 17, wherein the optic device is disposed one of on the collecting device or at a distance away from the collecting device.

21. The light emitting apparatus of claim 20, wherein the collecting device is disposed adjacent at least two sides of the optic device.

22. The light emitting apparatus of claim 1, further comprising additional diffuser material dispersed within the optic device.

23. The light emitting apparatus of claim 1, further comprising a heat dissipation device coupled to the radiation source.

24. The light emitting apparatus of claim 1, further comprising a collecting device positioned outside the optic device for collecting at least a portion of the back transferred radiation that has been extracted from the optic device.

25. The light emitting apparatus of claim 1, wherein the diffuser material comprises a diffuser material layer, the down conversion material comprises a down conversion material layer, the diffuser material layer is separate from the down conversion material layer, and the optic device is coupled to the diffuser material layer and the separate down conversion material layer.

4. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation, the radiation source comprising a plurality of light emitting sources, each of the light emitting sources exhibiting a spectrum different than a spectrum of at least one of the other light emitting sources;

a diffuser material coupled to a down conversion material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device coupled to the diffuser material and the down conversion material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device,

wherein the down conversion material is disposed between a first diffuser layer and a second diffuser layer, a first plurality of the plurality of light emitting sources is disposed adjacent the first diffuser layer, and a second plurality of the plurality of light emitting sources is disposed adjacent the second diffuser layer.

26. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device havin a first end roximal the radiation source and a second end distal the radiation source the roximal end of the otic device having a width smaller that a width of the distal end, and having at least one substantially transparent side wall, coupled to the diffuser material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device through the at least one substantially transparent side wall,

wherein the radiation source is disposed between the collecting device and the diffuser material, and

wherein the optic device is disposed between the radiation source and the diffuser material, and the at least one substantially transparent side wall absent the down conversion material.

27. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a substantially transparent optic device havinci a first end proximal the radiation source and a second end distal the radiation source, the proximal end of the optic device having a width smaller that a width of the distal end, and having at least one substantially transparent side wall, configured to receive radiation emitted from the radiation source, the radiation source being disposed within a first end portion of the substantially transparent optic device;

a diffuser material coupled to a down conversion material disposed on a second end portion of the optic device receiving at least a portion of the multi-colored radiation received by the substantially transparent optic device and converting the portion of the multi-colored radiation into forward transferred light and back transferred light,

wherein the substantially transparent optic device is disposed between (i) the radiation source and (ii) the diffuser material and the down conversion material and configured to extract a portion of the back transferred light through the at least one substantially transparent side wall, the at least one substantially transparent side wall absent the down conversion material.

28. The light emitting apparatus of claim 27, wherein the radiation source comprises a plurality of light emitting sources, each of the light emitting sources exhibiting a spectrum different than a spectrum of at least one other of the other light emitting sources.

29. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the portion of the multi-colored radiation into forward transferred radiation and back transferred radiation; and

a substantially transparent optic device havin a first end proximal the radiation source and a second end distal the radiation source, the proximal end of the optic device having a width smaller that a width of the distal end, the optic device disposed between the radiation source and the diffuser material, having at least one substantially transparent side wall, coupled to the diffuser material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device through the at least one substantially transparent side wall,

wherein the least one substantially transparent side wall is absent the diffuser material.

30. The light emitting apparatus of claim 29, wherein the portion of the back transferred radiation is extracted through a side of the substantially transparent optic device.

31. The light emitting apparatus of claim 30, wherein the multi-colored radiation is forward facing multi-colored radiation.

32. A light emitting apparatus comprising:

a substantially transparent optic device having i) a first end proximal the radiation source, ii) a second end distal the radiation source the roximal end of the optic device having a width smaller that a width of the distal end, and iii) a substantially transparent side wall coupling the first end to the second end, the optic device being configured to guide radiation from the first end to the second end of the optic device;

a diffuser layer disposed on the second end of the optic device;

a down conversion layer disposed on the diffuser layer;

a plurality of radiation sources for emitting multi-colored radiation disposed at the first end of the optic device for transmitting multi-colored radiation from the first end of the optic device, through the optic device, to the diffuser layer and the down conversion layer at the second end of the optic device,

wherein the optic device is further configured to receive back transferred radiation from the diffuser layer and the down conversion layer and to extract at least a portion of the back transferred radiation through the substantially transparent side wall of the optic device, and

wherein the optic device is disposed between (i) the radiation source and (ii) the diffuser material and the down conversion material, and the at least one substantially transparent side wall is absent the down conversion material.

33. The light emitting apparatus of claim 32, wherein a width of the first end of the substantially transparent optic device is different than a width of the second end of the substantially transparent optic device.

34. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation, the radiation source comprising at least a first light emitting source and at least a second light emitting source;

a diffuser material coupled to a down conversion material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device coupled to the diffuser material and the down conversion material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device,

wherein the down conversion material is disposed between a first diffuser layer and a second diffuser layer, the at least first light emitting source is disposed adjacent the first diffuser layer, and the at least second light emitting source is disposed adjacent the second diffuser layer.

35. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material coupled to a down conversion material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device coupled to the diffuser material and the down conversion material, the optic device adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device,

wherein the down conversion material is disposed between a first diffuser layer and a second diffuser layer and the radiation source is disposed adjacent the first diffuser layer and the second diffuser layer.

36. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material coupled to a down conversion material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device having a first end proximal the radiation source and a second end distal the radiation source, the proximal end of the optic device having a width smaller that a width of the distal end and disposed between (i) the radiation source and (ii) the diffuser material and the down conversion material, having at least one substantially transparent side wall extending between the distal and proximal ends, the at least one substantially transparent sidewall absent the down conversion material, the distal end coupled to the diffuser material and the down conversion material, the optic device adapted to receive the back transferred radiation from the distal end and pass at least a portion of the back transferred radiation from the optic device through the at least one substantially transparent side wall.