ILLUMINATION ASSEMBLY INCLUDING WAVELENGTH CONVERTING MATERIAL

• US 20090034292A1
• Filed: 07/31/2007
• Published: 02/05/2009
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Inventors: Doyle, David, Taraschi, Gianni, Nemchuk, Nikolay I., Lim, Michael, Pokrovskiy, Alexander L., Erchak, Alexei A.
• Granted Patent: US 8,585,273 B2
• Time in Patent Office: Days
• US Class Current: 362/617
• 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 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

Illumination assemblies, components, and related methods are described. An illumination assembly can include at least one solid state light-emitting device, and at least one light guide including a light homogenization region configured to receive light emitted by the solid state light-emitting device and including a light output boundary. The light homogenization region substantially uniformly distributes light outputted over the light output boundary. A wavelength converting material can be disposed within at least a portion of the light homogenization region. In some assemblies, a light extraction region can be configured to receive light from the light output boundary of the light homogenization region, and can have a length along which received light propagates and an emission surface through which light is emitted. The light extraction region can include a wavelength converting material disposed within at least a portion of the light extraction region.

Claims

1. An illumination assembly comprising:

at least one solid state light-emitting device; and

at least one light guide including

a light homogenization region configured to receive light emitted by the solid state light-emitting device and including a light output boundary, the light homogenization region substantially uniformly distributing light outputted over the light output boundary, the light homogenization region including a wavelength converting material disposed within at least a portion of the light homogenization region.

2. The illumination assembly of claim 1, wherein the at least one light guide further comprises a light extraction region configured to receive light from the light homogenization region, the light extraction region having a length along which received light propagates and an emission surface through which light is emitted.

3. The illumination assembly of claim 1, wherein the wavelength converting material is disposed throughout the light homogenization region.

4. The illumination assembly of claim 1, wherein the wavelength converting material has a varying density for at least two locations in the homogenization region.

5. The illumination assembly of claim 4, wherein the density of wavelength converting material is highest at the light output boundary.

6. The illumination assembly of claim 4, wherein the density of wavelength converting material is lowest at the light output boundary.

7. The illumination assembly of claim 1, wherein the wavelength converting material includes a first and a second wavelength converting material, and wherein the first wavelength converting material is configured to emit a first dominant wavelength and the second wavelength converting material is configured to emit a second dominant wavelength different from the first dominant wavelength, and wherein first wavelength converting material is disposed in the optical path between the solid state light-emitting device and the second wavelength converting material.

8. The illumination assembly of claim 7, wherein the first dominant wavelength is larger than the second dominant wavelength.

9. The illumination assembly of claim 7, wherein the first dominant wavelength is smaller than the second dominant wavelength.

10. The illumination assembly of claim 7, further comprising a wavelength filter disposed in the optical path between the first and the second wavelength converting materials, and configured to reflect light emitted by the second wavelength converting material and transmit light emitted by the first wavelength material and the solid state light-emitting device.

11. The illumination assembly of claim 1, wherein the at least one light guide includes a rectangular guide and the light output boundary is a rectangular cross-section of the rectangular guide.

12. The illumination assembly of claim 1, wherein the wavelength converting material comprises a phosphor.

13. An illumination assembly comprising:

at least one solid state light-emitting device; and

at least one light guide comprising

a light homogenization region configured to receive light emitted by the solid state light-emitting device and including a light output boundary, the light homogenization region substantially uniformly distributing light outputted over the light output boundary, and

a light extraction region configured to receive light from the light output boundary of the light homogenization region, the light extraction region including a wavelength converting material disposed within at least a portion of the light extraction region, the light extraction region having a length along which received light propagates and an emission surface through which light is emitted.

14. A liquid crystal display system, comprising:

a liquid crystal display panel having an illumination area;

at least one sold state light-emitting device associated with the liquid crystal display panel such that light emitted from the solid state light-emitting device illuminates the liquid crystal display panel; and

a wavelength converting material disposed remotely from the at least one solid state light-emitting device,

wherein the number of solid state light-emitting device per m² of the illumination area is less than 100.

15. An illumination assembly comprising:

at least one solid state light-emitting device;

a light guide configured to receive light emitted by the solid state light-emitting device, the light guide having a length along which received light propagates and an emission surface through which light is emitted;

a wavelength converting material disposed in the optical path between the solid state light-emitting device and the emission surface of the light guide; and

a wavelength filter disposed in the optical path between the solid sate light-emitting device and the wavelength converting material.

16. The illumination assembly of claim 15, further comprising a light homogenization region disposed in the optical path between the solid state light-emitting device and the emission surface of the light guide.

17. The illumination assembly of claim 16, wherein the wavelength converting material is disposed within the light homogenization region.

18. The illumination assembly of claim 16, wherein the wavelength converting material is disposed on one or more light input or light output sides of the light homogenization region.

19. The illumination assembly of claim 16, wherein the wavelength filter comprises a first short pass wavelength filter on a light input side of the light homogenization region, wherein the short pass wavelength filter is configured to transmit light from the solid state light-emitting device and reflect wavelength converted light from the wavelength converting material.

20. The illumination assembly of claim 19, further comprising a long pass wavelength filter on a light output side of the light homogenization region, wherein the long pass wavelength filter is configured to transmit the wavelength converted light from the wavelength converting material and reflect light from the solid state light-emitting device.

21. The illumination assembly of claim 19, further comprising a second short pass wavelength filter and a second wavelength converting material different from the first wavelength converting material, wherein the second short pass filter is disposed in the optical path between the wavelength converting material and the second wavelength converting material, and wherein the second short pass wavelength filter is configured to transmit light from the solid state light-emitting device, transmit wavelength converted light from the wavelength converting material, and reflect wavelength converted light from the second wavelength converting material.

22. The illumination assembly of claim 16, further comprising one or more reflective surfaces on one or more surfaces of the light homogenization region.

23. The illumination assembly of claim 15, wherein the wavelength converting material comprises a phosphor.

24. A method of making an illumination assembly, the method comprising:

providing at least one solid state light-emitting device; and

providing at least one light guide including

a light homogenization region configured to receive light emitted by the solid state light-emitting device and including a light output boundary, the light homogenization region substantially uniformly distributing light outputted over the light output boundary, the light homogenization region including a wavelength converting material disposed within at least a portion of the light homogenization region.