LED illumination engine using a reflector
View Patent ↗An illumination engine for a projection display using light emitting diodes (LEDs) that includes a reflector having a first and second focal points, a source of electro-luminescence located proximate to the first focal point to emit rays of radiation in a first range of wavelengths that reflect from the reflector and converge substantially at the second focal point, and a light pipe having an first input end and a first output end, the first input end being located proximate to the second focal point to collect substantially all of the radiation and wherein the first output end transmits substantially all of the radiation. The illumination system may further include a substrate having a first side, a platform disposed proximate to the first side of the substrate, and a plurality of reflectors each having a first and second focal points disposed in the platform, each of the first and second focal points disposed proximate to the first side of the substrate, a plurality of sources of electro-luminescence disposed on the first side of the substrate, each of the sources of electro-luminescence disposed substantially coincident with a corresponding one of the first focal points to emit rays of electromagnetic radiation that reflect from a corresponding one of the plurality of reflectors and converges substantially at a corresponding one of the second focal points, a plurality of light pipes disposed in the substrate, each of the light pipes having an input end and an output end, each of the input ends disposed substantially coincident with a corresponding one of the second focal points to collect substantially all of the radiation, wherein each of the output ends transmits substantially all of the radiation emitted by a corresponding one of the plurality of sources.
1. An illumination engine, comprising:
an array of light pipes, each having an input end and an output end; and
an array of light-emitting diodes (LEDs), each LED being associated with an input end of a different light pipe in said array of light pipes and emitting rays of radiation to said input end of said different light pipe;
a plurality of coupling elements between said array of the LEDs and the input ends of said array of light pipes; and
wherein an output end of each light pipe transmits substantially all of said radiation collected by an input end of said each light pipe.
2. The illumination engine of claim 1 , wherein said each light pipe is a tapered light pipe.
3. The illumination engine of claim 1 , further comprising a plurality of waveguides, each waveguide disposed substantially proximate to an output end of said different light pipe.
4. The illumination engine of claim 1 , wherein said output end of said each light pipe is substantially convex.
5. The illumination engine of claim 1 , wherein said output ends of said array of light pipes are closely packed.
6. The illumination engine of claim 1 , wherein said input and output ends of said array of light pipes are hexagonal in shape.
7. The illumination engine of claim 6 , wherein said output ends of said array of light pipes axe closely packed.
8. The illumination engine of claim 1 , wherein said coupling elements are concave reflectors.
9. The illumination engine of claim 1 , wherein each LED of said LED array is placed proximally next to the input end of each light pipe of said array of light pipes.
10. The illumination engine of claim 9 , further comprising a clear epoxy lens packed with said each LED in said array of LEDs.