This paper describes a diascopic projection system that efficiently combines and integrates the output from multiple light sources. The images of these light sources are superposed at a common focus in the projection lens, resulting in a projected screen brightness considerably greater than that produced by a single lamp of equivalent wattage. The illumination system consists of a series of collimating and converging plastic Fresnel lenses, and a linear beam- integrating micro-prismatic element. Glass anamorphic condenser optics are also used. The optics can be cascaded, and the design requirements of a four-lamp system is described. The experimental results from a laboratory developed overhead projection system using dual tungsten-halogen lamps is discussed.

Date Published: 29 March 1996
PDF: 9 pages
Proc. SPIE 2650, Projection Displays II, (29 March 1996); doi: 10.1117/12.237018

Published in SPIE Proceedings Vol. 2650:
Projection Displays II
Ming Hsien Wu, Editor(s)