Overhead type projector e.g. LCD device - has projection head mounted on carrier arm and comprising objective and deflection mirror with light source

摘要

The projector includes a base plate accommodating the writing plate, fresnel lens and a mirror and mounting a carrier arm with projection head comprising an objective (5) and deflection mirror (6) and light source (7-9) with lamp (7), reflector (8) and condenser (9). The cone of light leaving the lamp (7) passes through the Fresnel lens (2) and is reflected on to the mirror (3), with the light re-emerging from the Fresnel lens (2) absorbed by the objective (5) and then projected via the deflection mirror (6) onto a vertical projection wall. A liquid-crystal display (LCD) device (14) is arranged above that part of the Fresnel lens (2) which lies on the side of an imaginary plane (17) facing the light source (7, 8). ADVANTAGE - Has light source and projection optics on one side of Fresnel lens.