A projection display which includes reflective light valves such as liquid crystal spatial light modulators, and a 1.times. optical relay lens system. The 1.times. optical relay lens system eliminates the requirement for a projection lens having a large retrofocus distance. Projection displays based...http://www.google.de/patents/US5597222?utm_source=gb-gplus-sharePatent US5597222 - Optical relay lens system for projection displays
