Patent ID: 7961400

Claim:
A projection optical unit for projecting an image on a screen, the projection optical unit comprising: an image display element including a display surface for forming thereon the image; a first optical system including at least one rotationally asymmetrical lens having a concave surface from which a light is emitted, the asymmetrical lens having a shape rotationally asymmetrical with respect to an optical axis of the first optical system; a second optical system having at least one convex mirror including a convex reflection surface for receiving and reflecting the light emitted from the first optical system in such a manner that the light reaches the screen with a predetermined angle relative to a normal line with respect to the screen; and an optical system support unit for supporting the first and second optical systems, wherein: the convex mirror is supported by the optical system support unit to be rotatable on an axis passing a substantial center of the convex reflection surface, and the image display element is movable to adjust an angle of an imaginary straight line extending perpendicularly to the display surface and passing a center of the display surface, with respect to the optical axis of the first optical system.