Overlap and overscan exposure control system

Abstract

In an optical scanning exposure system for manufacturing cathode ray tubes having a faceplate with an inner surface layer of photosensitive material and an adjacent apertured mask wherein the exposure system includes a light source providing a light beam, an angle of incidence deflector means for deflecting the light beam at an angle related to the angle of incidence of an electron beam, means for imaging the light beam, and a means for scanning the light beam in a predetermined fashion over the apertured mask to expose the photosensitive material, a control system having a means for storing information representative of the angle of incidence of a light beam and the rate of scanning of a light beam between a matrix of positional locations on the faceplate, a scan rate means for controlling the rate of horizontal and vertical light beam scanning, an encoder means providing light beam positional information to the storage means, and an angle of incidence control means for activating the angle of incidence deflector means in accordance with angular information of the storage means. Other aspects of the invention include controlling the integral with respect to time of the light beam intensity to effect uniform photosensitive material exposure, controlling movement of the effective light beam source to control the size and shape of the exposure area, and controlling the overlapping and overscanning of the light beam scanning to minimize stripes of unexposed photosensitive material and to provide uniform exposure at the edges of the faceplate.