Patent ID: 6345895
Filing Date: 2002-02-12
Classification: G02B,H04N

Abstract:
A projection type image display apparatus comprising:a housing; an analyzing-synthesizing optical system unit for projection image display apparatus in which beams of the three primary colors of R, G, and B are modulated by respective, dedicated polarization beam splitters and light valves, the modulated beams are extracted, and a synthesizing optical system synthesizes the modulated beams of the three colors to output synthetic light, wherein said light valves and said polarization beam splitters are fixed as integrated with said synthesizing optical system and wherein optical path lengths of optical paths of the respective color beams, each optical path being established by said light valve, said polarization beam splitter, and said synthesizing optical system, are approximately equal to each other, wherein only a portion of said synthesizing optical system is fixed to said housing; a color separation optical system for generating the beams of the respective colors of R, G, and B and guiding the beams to said analyzing-synthesizing optical system unit, said color separation optical system being held in said housing; and a projection lens for magnifying and projecting the synthetic light emerging from the analyzing-synthesizing optical system unit, said projection lens being held in said housing; wherein each of said polarization beam splitters is fixed in a constituent member to which said synthesizing optical system is also fixed.