Illuminator for image projection apparatus, has retro-reflector with specular surface that reflects light back toward concave reflector, where retro-reflector has aperture that is disposed at focal point of light

摘要

The illuminator has a concave reflector (42) that reflects light emitted from a light source e.g. arc lamp, in a predetermined direction. A retro-reflector (45) has a specular surface that reflects the light back toward the concave reflector. The retro-reflector has an aperture that is disposed at a focal point of the light that is reflected by the concave reflector. The aperture transmits part of the reflected light. An independent claim is also included for a method of illuminating light.