Etendue efficient combination of multiple light sources

Abstract

A multi-colored illumination system comprising a beam combiner. The beam combiner comprises two triangular prisms and a filter for transmitting a first light and reflecting a second light, each light having a different wavelength. The beam combiner combines the transmitted first light and the reflected light to provide a combined beam. The six surfaces of each of the triangular prism of the beam combiner is polished, thereby combining the lights without increasing etendue of the multi-colored illumination system.

1 . A multi-colored illumination system comprising a beam combiner comprising two triangular prisms and a filter for transmitting a first light and reflecting a second light, each light having a different wavelength; and wherein said beam combiner is operable to combine said transmitted first light and said reflected light to provide a combined beam; and wherein each surface said two triangular prisms being polished, thereby combining said lights without increasing etendue of said multi-colored illumination system. 
   
   
       2 . The system of  claim 1 , further comprising:
 n beam combiners for combining n+1 lights, each light having different wavelengths, where n is greater than 2, each beam combiner comprising two triangular prisms, each surface of said two triangular prisms being polished, and a filter for transmitting said combined beam received from a previous beam combiner and reflecting a new light from said n+1 lights which has not been previously transmitted or reflected, said each beam combiner combining said transmitted combined beam and said reflected new light to provide a new combined beam to a next beam combiner if said each beam combiner is not the last beam combiner or output said new combined beam if said each beam combiner is the last beam combiner; and   a low index glue or air gap being provided between each of said beam combiners, thereby combining all of said lights without increasing etendue of said multi-colored illumination system.   
   
   
       3 . The system of  claim 2 , further comprising n light sources for generating n lights, each with different wavelength. 
   
   
       4 . The system of  claim 3 , wherein each light source is an LED or an array of LED. 
   
   
       5 . The system of  claim 1 , further comprising an output light pipe positioned to receive a substantial portion of said combined beam. 
   
   
       6 . The system of  claim 5 , wherein said output light pipe is one of the following: a straight light pipe, a tapered up light pipe or a tapered down light pipe. 
   
   
       7 . The system of  claim 5 , further comprising a low index glue or air gap between said output light pipe and said beam combiner. 
   
   
       8 . The system of  claim 4 , further comprising a light pipe associated with each LED or array of LED. 
   
   
       9 . The system of  claim 8 , wherein said light pipe is one of the following: a straight light pipe, a tapered up light pipe or a tapered down light pipe. 
   
   
       10 . The system of  claim 1 , further comprising:
 n beam combiners for combining n lights, each light having different wavelengths, where n is greater than 2, each beam combiner comprising two triangular prisms, each surface of said two triangular prisms being polished, and a filter for transmitting said combined beam received from a previous beam combiner and reflecting a new light from said n lights which has not been previously transmitted or reflected, said each beam combiner combining said transmitted combined beam and said reflected new light to provide a new combined beam to a next beam combiner if said each beam combiner is not the last beam combiner or output said new combined beam if said each beam combiner is the last beam combiner, and wherein each light has a different wavelength; and   a low index glue or air gap being provided between each of said beam combiners, thereby combining all of said lights without increasing etendue of said multi-colored illumination system.   
   
   
       11 . A light engine for a projection display system comprising the multi-colored illumination system of  claim 2 . 
   
   
       12 . The light engine of  claim 11 , wherein said light engine is one of the following: digital light processing (DLP), liquid crystal on silicon (LCOS) or high temperature poly-silicon (HTP). 
   
   
       13 . A projection display system comprising the light engine for a projection display system of  claim 11 ; at least one light modulator panel for modulating light in accordance with a display signal; and a projection lens for projecting the modulated light onto a display screen. 
   
   
       14 . A light engine for a projection display system comprising the multi-colored illumination system of  claim 1 . 
   
   
       15 . A multi-colored illumination system, comprising:
 at least two LEDs or arrays of LEDs providing two lights having two different wavelengths;   a light pipe associated with each LED or array of LEDs;   an X-cube for combining lights received from each light pipe associated with a LED to provide an output beam; and   a low index glue or air gap between each of said light pipe and said X-cube, thereby combining said lights without increasing etendue of said multi-colored illumination system.   
   
   
       16 . The system of  claim 15 , further comprising n LEDs or arrays of LED, where n is greater than two, for providing n lights, each light having different wavelengths 
   
   
       17 . The system of  claim 15 , further comprising an output light pipe positioned to receive a substantial portion of the output beam. 
   
   
       18 . The system of  claim 17 , wherein said output light pipe is one of the following: a straight light pipe, a tapered up light pipe or a tapered down light pipe. 
   
   
       19 . The system of  claim 18 , further comprising a low index glue or air gap between said output light pipe and said X-cube. 
   
   
       20 . The system of  claim 15 , wherein each of said light pipe is one of the following: a straight light pipe, a tapered up light pipe or a tapered down light pipe. 
   
   
       21 . A light engine for a projection display system comprising the multi-colored illumination system of  claim 16 . 
   
   
       22 . The light engine of  claim 21 , wherein said light engine is one of the following:
 digital light processing (DLP), liquid crystal on silicon (LCOS) or high temperature poly-silicon (HTP).   
   
   
       23 . A projection display system comprising the light engine for a projection display system of  claim 22 ; at least one light modulator panel for modulating light in accordance with a display signal; and a projection lens for projecting the modulated light onto a display screen. 
   
   
       24 . A light engine for a projection display system comprising the multi-colored illumination system of  claim 15 . 
   
   
       25 . A method for multi-colored illumination, comprising the steps of:
 combining by a first beam combiner a first light transmitted by a first filter and a second light reflected by said first filter to provide a combined beam;   combining by a second beam combiner said combined beam transmitted by a second filter and a third light reflected by said second filter to provide an output beam, each light having a different wavelength; and   providing a low index glue or air gap between said first and second beam combiners, thereby combining said lights without increasing etendue.   
   
   
       26 . A method for multi-colored illumination, comprising the steps of:
 combining by an X-cube at least two lights having two different wavelengths received from corresponding two light pipes; and   providing a low index glue or air gap between each light pipe and said X-cube, thereby combining said lights without increasing etendue.