ILLUMINATION OPTICAL SYSTEM AND PROJECTION-TYPE DISPLAY DEVICE

摘要

The objective of the present invention is to provide an easily manufactured, compact illumination optical system. The illumination optical system is provided with: a parabolic reflector provided with a reflecting unit in the shape of a parabolic of revolution; a flat base plate on which is formed a window allowing light to pass through on the rotational axis of the parabolic reflector; a plurality of fixed light sources for emitting light parallel to the rotational axis, the light sources being disposed on the base plate around the window, and the light-emitting point of the fixed light sources being disposed closer to the parabolic reflector than the focal point of the reflecting unit; and an optical system disposed on the opposite side of the parabolic reflector relative to the window, the optical system configured so that the angle of convergence or divergence of light passing through the window is less than the angle of convergence or divergence of light reflected by the parabolic reflector.