Patent ID: 7090351

Claim:
A projection type image display apparatus comprising: a light source unit which emits light; three reflective type image display devices as light valve means, which form an optical image corresponding to an image signal; a color separation system, which separates the light from said light source unit into three color light components, including a red color light, a green color light and a blue color light, and which guides each of the color light components to impinge upon a corresponding one of said color reflective type display devices; a color combining system, which combines those three color light components from said reflective type image display devices; a projection lens which projects a color-combined optical image; flat reflective type polarizing plates, each of which transmits a first light polarized into a predetermined polarization direction and reflects a second light polarized into a direction nearly perpendicular to the predetermined polarizing direction, due to diffraction function thereof, as a polarizer and an analyzer for said reflective type image display devices; auxiliary polarizers, each of which transmits said first polarized light, being provided on an entrance side of said flat reflective type polarizing plates; and auxiliary analyzers, each of which transmits said second polarized light, being provided on an entrance side of said flat reflective type polarizing plates, wherein: said color combining system is made up with a color combining prism, and is disposed, so that: each of the color light components, which are separated by said color separation system, penetrates through said auxiliary analyzer and said flat reflective type polarizing plates, to be incident upon each of said reflective type image display devices; and the optical image of reflection light, which is formed by said reflective type image display device, reflects upon said flat reflective type polarizing plate and penetrates through said auxiliary analyzer, to be incident upon said color combining system, and further, a contrast of said auxiliary polarizer for blue color light, which is disposed on an optical path of the blue color light, is made larger than those of said auxiliary polarizers for the other color lights.