Overhead projector with LCD plates - has fresnel lens plate in hinged frame enabling projection of LCD images and computer generated text

摘要

A reflection overhead projector has a light source, projection lens and deflection mirror, a liquid crystal display or LCD in the image window plane above a plane mirror and a computer interface. The LCD has upper and lower LCD plates below a Fresnel lens plate in a common hinged frame (34). With the frame hinged inwards the upper LCD plate forms a controllable projection pattern and the lower plate is transparent. With the frame out the lower plate forms a matt plate back illuminate to show the text etc. on the upper plate. USE/ADVANTAGE - For projecting liquid crystal images and computer generated text.