Patent ID: 6364489
Filing Date: 2002-04-02
Classification: G03B

Abstract:
An image projection apparatus comprising:a display device which has a plurality of pixel apertures and displays image information; an illumination optical unit for illuminating said display device; a projection optical unit for projecting the image information displayed on said display device onto a predetermined surface; and a blower for blowing air to an atmosphere in said display device, wherein letting 2A be a pixel aperture width of said display device, &agr; be an effective illumination angle of a projection optical system including said illumination optical unit and projection optical unit in a medium defining a dust-attaching surface of said display device, t be a thickness of the medium defining the dust-attaching surface, and 2&dgr; be a dust diameter, a dustproof filter for preventing passage of dust having a size given by &dgr;&gE;{square root over ({D+L Â·(A+t+L Â·tan &agr;)2+L })} (for 0.030.3)â€ƒâ€ƒ(1) is arranged on an inlet side of said blower.