AUTOMATIC RANGING AND FOCUSING PROJECTOR

摘要

A projector having an optical ranging system for automatically optically sensing the screen-to-lens distance and in response thereto establishing a predetermined film-to-lens distance for placing a projected film image in focus. The projector further has an optical focusing system operative in conjunction with the optical ranging system for sensing the established predetermined film-to-lens distance in the projector, and if any change occurs therein to automatically move the projection lens and/or film to refocus the projected film image.