Patent ID: 6575578
Filing Date: 2003-06-10
Classification: G03B,H04N

Abstract:
A projector, comprising:three electro-optical devices that form images of three color components; a color-combining optical system that forms a color image by combining the images of the three color components; a projection lens that project the color image formed by the color-combining optical system; a screen, onto which the color image is projected; and first and second mirrors disposed on an optical path ranging from a plane of incidence of the projection lens to a plane of incidence of the screen that sequentially reflect image light representing the color image emitted from the color-combining optical system, wherein, when three axes orthogonal to each other are referred to as an x-axis, a y-axis, and a z-axis, the screen is placed substantially in parallel with a yz-plane, the color-combining optical system, having two kinds of dichroic surfaces arranged substantially in an X-shape, being placed so that a line of intersection between the two kinds of dichroic surfaces is to be substantially parallel to the z-axis, each of the electro-optical devices, having a substantially rectangular image-forming region, being placed so as to face a corresponding plane of incidence out of three planes of incidence parallel to the line of intersection of the color-combining optical system so that a direction of a longer side of the image-forming region agrees with the direction of the line of intersection, a reflection surface of the first mirror being arranged substantially perpendicularly to the yz-plane, and also with an inclination of approximate 45Â° relative to an xy-plane, at least the electro-optical devices, the color combining optical system, and the projection lens being arranged along the xy-plane so that the image light emitted from the color-combining optical system enters the first mirror with an optical-axis parallel to the xy-plane and inclined &agr;Â° with respect to the y-axis, and the second mirror being placed substantially perpendicularly to an xz-plane, and also with an inclination of smaller by &agr;/2Â° than 45Â° approximately with respect to the yz-plane so that the image light reflected from the first mirror is reflected by the second mirror again so as to enter the screen with an optical axis being incident on a substantial center of the screen and substantially perpendicular to the screen.