Patent ID: 8169708

Claim:
An optical projection unit for projecting an image onto a screen, comprising: an image source including three image display elements for forming respective image elements, and a cross-dichroic prism for combining the image elements into the image; a projection lens unit including a plurality of lenses to enlarge the image formed by the image source, at least one of the lenses having a shape rotationally asymmetrical with respect to an optical axis of the projection lens unit, the optical axis of the projection lens unit at the locations where it intersects the display elements being oblique with respect to normal lines of the image display elements; a reflection mirror for enlarging the image and emitting the image in a reflecting direction so that the image reaches the screen with a predetermined angle with respect to a normal line of the screen, a reflection surface of the reflection mirror having a shape rotationally asymmetrical with respect to an optical axis of the reflection mirror; and a support unit for adjusting the reflecting direction of the mirror with respect to the optical axis of the projection lens unit.