Patent ID: 6698895
Filing Date: 2004-03-02
Classification: G02B,H04N

Abstract:
A projection-type image display apparatus, comprising:a light source portion for emitting a white light beam; a first optical system comprising a white illumination optical system that the white light beam from the light source portion enters and that emits a uniform white illumination light beam having a rectangular cross-section, a color separation optical system for separating the white illumination light beam into respective light beams of red, green and blue, and a relay lens system that the respective light beams obtained by a color separation enter; a rotating polygon mirror that the respective light beams having left the relay lens system enter and that scans the respective light beams while reflecting the respective light beams; a second optical system for leading the respective light beams reflected by the rotating polygon mirror to an illumination position; an image display panel that is arranged at the illumination position and provided with many pixels for modulating an incident light according to a color signal of red, green or blue; an image display panel driving circuit for driving each of the pixels of the image display panel by a signal corresponding to a color of light entering this pixel; and a projection optical system for magnifying and projecting an image of the image display panel; wherein the color separation optical system comprises first and second red-reflecting mirrors that reflect at least the red light beam, first and second green-reflecting mirrors that reflect at least the green light beam, and first and second blue-reflecting mirrors that reflect at least the blue light beam, and the mirrors are arranged so that optical paths of the respective light beams have equal lengths from the light source portion to the rotating polygon mirror.