Hybrid fiber optic framing projector

Abstract

This invention provides a hybrid fiber optic framing projector of high optical efficiency that emits no UV (ultraviolet) or IR (infrared) energy in the projected beam. A preferred embodiment includes a light source on an optical axis at the primary focus of an ellipsoidal cold mirror reflector. The ellipsoidal reflector focuses visible light from the light source to a conjugate focus through a dichroic hot mirror and then into a heat-absorbing, UV-absorbing glass rod. The glass rod transmits light by total internal reflection as an optical fiber from the conjugate focus to the focal plane of a collimating lens. A confocal reflector has a spherical radius about the light source, that radius being equal to the distance from the primary focus to the conjugate focus. The proximal end of the glass rod is positioned on the optical axis in a hole through the confocal reflector at the conjugate focus, whereby light rays from the light source that fall outside the glass rod in are reflected by the spherical confocal reflector back to the light source to be re-reflected or re-radiated as additional light focussed back to the conjugate focus, through the glass rod and to a collimating lens. The foregoing optical components are enclosed in a housing having heat flow paths from the optical elements to the housing exterior.