Patent ID: 6966658

Claim:
A projection type display apparatus comprising: an illumination optical system for collecting light radiated from a light source to form illumination light; a reflection type light valve for reflecting the illumination light to output modulated light forming an optical image; a projection lens system for projecting the optical image formed by the reflection type light valve; and a lens element with a positive power, wherein the lens element is composed of one plano-convex lens, and is placed between the reflection type light valve and the projection lens system with a convex surface directed to the projection lens system, in such a manner that the illumination light passes through the lens element to illuminate the reflection type light valve, and the modulated light output from the reflection type light valve passes through the lens element to be incident upon the projection lens system, an output of the illumination optical system and an entrance pupil of the projection lens system have a substantially conjugate relationship with respect to the lens element, and 80% or more of a luminous flux reflected from a display region of the reflection type light valve among luminous fluxes passing through the output pupil of the illumination optical system passes through the lens element to be incident upon an effective region of the entrance pupil of the protection lens system.