Reflection type overhead projector

摘要

A reflection type overhead projector employs a Fresnel concave mirror adapted for allowing a transparency to be put on the mirror surface thereof. The beam of light emitted from a light source lamp is reflected by the Fresnel concave mirror, enters a projecting lens and then is projected on a screen. A reflecting mirror is interposed in an optical path between the Fresnel concave mirror and the projecting lens to thereby bend the optical path. The Fresnel concave mirror, the light source lamp and the projecting lens are all mounted to a single case.