Patent ID: 7436476

Claim:
An optical projection system having a projection light path and comprising: a light source for providing a projection light, the light source being positioned at the beginning of the projection light path; a projection lens positioned at the ending of the projection light path; and a compensating optical component positioned in the projection light path, the compensating optical component being exposed to high-intensity light at its position in the projection light path, wherein the compensating optical component comprises: a retarder film characterized by a retardance, the retarder film being susceptible to undergoing a photochemical reaction when exposed to the high-intensity light, wherein the photochemical reaction would alter the retardance of the retarder film; and a sealing element at least partially surrounding the retarder film, whereby the sealing element, by itself or with another element, is operable to provide a hermetic seal that encloses the retarder film and substantially limits the photochemical reaction that would have otherwise altered the retardance of the retarder film.