Abstract
This paper classifies schlieren projection systems for light valves (LV's) into three groups according to the type of illumination. The requirements for uniform illumination and the tradeoffs between brightness, contrast, and resolution are discussed for different systems. Consideration is given to transmissive versus reflective LV's, black-on-white versus white-on-black, image overlay, color, and luminous efficiency. Copyright © 1977 by The Institute of Electrical and Electronics Engineers, Inc.