(12) United States Patent ao) Patent No.: Us 7,182,466 B2
Sunaga (45) Date of Patent: Feb. 27,2007
A projection optical system includes an optical modulation unit which outputs modulated light for displaying an image, an optical scanning unit on which the modulated light output from the optical modulation unit is incident, the optical scanning unit scanning the light from the optical modulation unit to obtain a two-dimensional image, and a plurality of curved reflecting surfaces on which the light scanned by the optical scanning means is sequentially incident, the plurality of curved reflecting surfaces sequentially reflecting the light scanned by the optical scanning means and projecting the light on a projected surface, wherein when an optical path of a ray connecting a center of a pupil of the projection optical system and a center of a projected image is set as a reference axis, the reference axis is inclined with respect to a normal to the projected surface.
12 Claims, 16 Drawing Sheets