| 20110075105 | MULTIPLEXING LIGHT PIPE HAVING ENHANCED BRIGHTNESS - Multi-color light sources are mixed in a recycling housing to achieve high light output. In one embodiment, the light from each color light source, such as from red, green and blue LEDs, is multiplexed together and a portion of the mixed light passes through an output aperture in the light pipe. A portion of each colored light is recycled back, for example, by a shaped reflective surface and/or a reflective coating adjacent the aperture. The shape of the reflective surface is such as to direct each color of light back to a specific location to maximize the ultimate output light. In one embodiment, the light is directed back from the output side of the housing to an input light source having the same color. In another embodiment, the light is directed back from the output side of the housing to a coating designed to reflect that color light. The reflected light is then reflected back toward the output aperture and a portion of that reflected light is again reflected toward the input and impacts the original source for that color light. In this way, the light (at least in theory) recycles infinitely, thereby increasing the total light output of the housing. In some embodiments, the light is recycled using polarization and in some embodiments the input light is collimated. | 03-31-2011 |
