摘要 |
A high efficiency light collection system for a projector such as a light valve projector provides constant tangential magnification for all zones so that the images of the source just fills the pupil of the projection system thereby giving the best source utilization in all zones. The light collection system comprises a reflector (60) behind the source and a correcting refractor (61) in front of the source. The preferred embodiment uses an aconic reflector having continuously changing zonal focus with a single asphere corrector lens that has exactly compensating zonal focus characteristics. It is also possible to use a conic reflector, but this requires two asphere corrector lenses in order to provide the constant tangential magnification characteristics.
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