Illumination system for an LCD display system.

摘要

An illumination system for an LCD projection display system to increase the brightness of the system. The system includes a polarizing beam splitter (26) which splits a beam of light (24) from a light source (20) into two orthogonally polarized beams (28,30). The beam of the desired polarization direction (28) is directed through a first face (A) of a prism (10) so that it reflects off of a second face (B) of the prism and exists through a third face (C) . The other beam (30) of the non-desired polarization direction is passed through a device (36) for rotating its polarization 90 DEG and towards the underside of the second face (B) of the prism (10) at an angle such that it is refracted into the prism. Both beams (28,30) then exit the prism (10) through its third face (C) , have the same polarization direction, and are only slightly divergent. The recombined beam may be thereafter directed towards the light modulation system. The illumination system minimizes the number of air-glass interfaces and the number of reflecting surfaces.