Polarization recycler
First Claim
1. A polarization recovery system, comprising:
- a light channel;
said light channel having a light injection aperture for receiving light from a source of illumination radiating light with first and second polarizations (e.g., p and s);
said light channel having a reflecting polarizer that transmits said injected light having said first polarization and that reflects said injected light having said second polarization;
at least one reflective surface for further reflecting said reflected light back toward said reflecting polarizer; and
, means positioned in said light channel for transforming said light reflected by said reflecting polarizer into light having said first polarization, said transformed light also being transmitted by said reflecting polarizer.
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Accused Products
Abstract
A method for recovering polarization comprises the steps of: guiding light having first and second polarizations in a forward direction along a light path; passing the guided light having the first polarization out of the path; reflecting the light having the second polarization backwardly and forwardly along the light path; transforming the reflected light during the reflecting step to have the first polarization; and, passing the light transformed to the first polarization out of the path, enabling more of the light having the first polarization to be passed out of the path. The method can be implemented with a light integrator, a reflecting polarizer, at least one reflective surface that further reflects the reflected light back toward the reflecting polarizer and a quarter wave plate positioned in the light path. The method and apparatus can be used in an illumination system for a liquid crystal display imager.
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Citations
25 Claims
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1. A polarization recovery system, comprising:
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a light channel;
said light channel having a light injection aperture for receiving light from a source of illumination radiating light with first and second polarizations (e.g., p and s);
said light channel having a reflecting polarizer that transmits said injected light having said first polarization and that reflects said injected light having said second polarization;
at least one reflective surface for further reflecting said reflected light back toward said reflecting polarizer; and
,means positioned in said light channel for transforming said light reflected by said reflecting polarizer into light having said first polarization, said transformed light also being transmitted by said reflecting polarizer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for recovering polarization in an illumination system for a liquid crystal display imager, comprising the steps of:
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guiding light having first and second polarizations in a forward direction along a light path;
passing said guided light having said first polarization out of said path;
reflecting said light having said second polarization backwardly and forwardly along said light path;
transforming said reflected light during said reflecting step to have said first polarization; and
,passing said light transformed to said first polarization out of said path, enabling more of said light having said first polarization to be passed out of said path. - View Dependent Claims (19, 20)
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21. An illumination system for a liquid crystal imager, comprising:
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a source of randomly polarized light;
a light integrator having an aperture at one end for receiving said randomly polarized light and having reflective surfaces defining an internal light path;
a reflecting polarizer disposed at an opposite end of said light path that transmits light having a first polarization and that reflects light having a second polarization, said light having said second polarization being reflected back and forth along said light path; and
,means positioned in said light path for transforming said back and forth reflected light into light having said first polarization, said transformed light also being transmitted by said reflecting polarizer. - View Dependent Claims (22, 23, 24, 25)
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Specification