Patent ID: 7532407
Filing Date: 2009-05-12
Classification: H04N

Abstract:
1. A projection-type image display apparatus, comprising: a light source; first and second multi-lenses for equalizing intensities of lights from said light source; a polarized-light conversion element for unifying polarization directions of the lights from said first and second multi-lenses; a color separation portion for separating the lights from said polarized-light conversion element into a plural number of colors; a plurality of transmission-type image display elements, each being disposed corresponding to each of said plural number of light colors; an optical synthesizing portion, for synthesizing the lights from said plurality of transmission-type image display elements, each different surface thereof being attached with one of said plurality of transmission-type image display elements, respectively in such a manner that the transmission-type image display elements can be freely attached and detached; a seat portion, including a plurality of projection frame portions, on which one face of the optical synthesizing portion is mounted to permit accurate positioning of the optical synthesizing portion; a projection lens for projecting light from said optical synthesizing portion; a supporting portion for supporting said optical synthesizing portion thereon; and a housing for disposing said first and second multi-lenses, said polarized-light conversion element and said color separation portion therein, wherein said housing is sealed by said first multi-lens, said housing including a recessed portion in an outer wall of the housing, said recessed portion being located adjacent to said projection lens and including collimator lens being located in said recessed portion, wherein said plurality of transmission-type image display elements and said optical synthesizing portion are located in said recessed portion, outside of said housing to facilitate easy access for accurately attaching the transmission-type image display elements and for easily detaching the transmission-type image display elements, as desired for repair or replacement, wherein said optical synthesizing portion includes cross dichroic prisms, wherein said cross dichroic prisms include jigs, disposed corresponding to each of said plurality of transmission-type image display elements, each of which is comprised of a metal plate and include a projection, and wherein said plurality of transmission-type image display elements are attached on said jigs, wherein, on one surface of the seat portion a projecting portion is formed for positioning said cross dichroic prisms, and on another surface thereof being mounted said cross dichroic prisms abutting on a surface different from a surface on which said plurality of transmission-type image display elements are attached, further comprising a member for absorbing reflection light upon said projection lens between said cross dichroic prisms and said projection lens, and wherein said member for absorbing reflection light is comprised of a reflection-type polarization plate and an absorption-type polarization plate located substantially parallel to one another between the cross dichroic prisms and the projection lens.