Patent ID: 6213606
Filing Date: 2001-04-10
Classification: G03B

Abstract:
An illuminating system, comprising:an output screen including a liquid crystal display (LCD),means for generating polarized white light;a polarized light source system for illuminating said output screen such that light of a first polarization state from the means for generating polarized light is converted to polarized light of a second polarization state for display on said screen, said polarized light source system including:(a) a first set of polarization selective light processing elements including a conicoidal reflecting element whose vertex contains a small inlet that receives light from the means for generating polarized white light and passes a focused high numerical aperture white light of first circular polarization state and also whose surface converts the white light of a first circular polarization state into reflected light of a second circular polarization state, the second circular polarization state being orthogonal to that of said first circular polarization state;(b) a second set of polarization selective light processing elements including a first element which reflects light of a first linear polarization state and also transmits light of a second linear polarization state and further including a second optical element for converting light of said first circular polarization state into light of said first linear polarization state and for converting light of said second circular polarization state into light of said second linear polarization state, thereby enabling output of light of the second linear polarization state onto the output screen; andsaid output screen including at least one of a Fresnel lens, a diffuser for converting the light of the second linear polarization state passed through said Fresnel lens into output beams of specific angular extent, a polarizer for at least one of absorbing and reflecting the light of said first linear polarization state and transmitting the light of said second linear polarization state, and said LCD screen receiving output light.