Patent ID: 7665849

Claim:
A projection type video display apparatus comprising: a white light source capable of emitting visible light beams; a color separating unit for receiving the visible light beams and emitting a plurality of color light beams; a video display device irradiated with the plurality of color light beams and capable of modulating the color light beams according to image signals corresponding to colors of the plurality of color light beams; a scanning unit for moving color bars formed by the plurality of color light beams on the video display device in a fixed direction; and a projection lens through which a color image formed by the plurality of modulated color light beams is projected; wherein the color separating unit includes: an optical integrator having an entrance aperture plate provided with an entrance aperture through which the visible light beams travel, and a first exit surface through which the uniformed visible light beams emerge; a dichroic mirror having a plurality of color separating surfaces capable of transmitting predetermined color light beams included in the uniformed visible light beams and of reflecting color light beams of wavelengths other than those of the predetermined color light beams and disposed substantially parallel to the first exit surface, the color separating surfaces including a red color separating surface for transmitting red color light, a blue color separating surface for transmitting blue color light, and a green color separating surface for transmitting green color light; and a polarization converting device for converting the uniformed visible light beams falling on the dichroic mirror or the plurality of color light beams emerging from the dichroic mirror into predetermined polarized light beams, the polarization converting device being configured to receive P-polarized white light, wherein P-polarized red light passes through substantially all of the red color separating surface, P-polarized blue light passes through only a first portion of the blue color separating surface, and P-polarized green light is reflected by the red and green color separating surfaces, the polarization converting device further being configured to receive S-polarized white light, wherein S-polarized blue light passes through only a second portion of the blue color separating surface, S-polarized green light passes through substantially all of the green color separating surface, and S-polarized red light is reflected by the blue and green color separation surfaces.