Patent ID: 7232228

Claim:
A light recovery apparatus for a projection display comprising: a reflector having a first and a second focal points; a source of electro-magnetic radiation disposed proximate to said first focal point of said reflector to emit rays of radiation that reflect from said reflector and converge substantially at said second focal point; a retro-reflector disposed opposite said reflector to reflect at least a portion of the electromagnetic radiation that does not impinge directly on said reflector toward said reflector through the first focal point of said reflector to increase the flux intensity of the converging rays; a light pipe having an input surface and an output surface, said input surface of said light pipe disposed proximate to said second focal point to collect and transmit substantially all of said radiation; a PBS disposed proximate said output surface, said PBS collecting and polarizing substantially all of said radiation into a first polarization and a second polarization; wherein said radiation of said first polarization is transmitted; radiation of said second polarization is reflected toward said output surface; and a wave plate is disposed in a path of said radiation of said second polarization.