Automatic convergence and gray scale correction for television _receivers and projection television systems

摘要: A system for the automatic correction of convergence and gray scale in color television employs light sensors, either singly or an array, on beam landing face a cathode ray tube screen projection receiver. The sensors can be placed overscanned area raster, such that they are outside normal viewing area, if made sufficiently small. In vicinity sensor, two three tubes electron guns blanked. As beam, case system, crosses output is produced. This processed to obtain accurate timing characteristics. Since position sensor known terms counts both vertical horizontal directions, error signals developed by comparing with proper count. These used develop correct one gun. process then repeated remaining guns. also amplified gated amplifiers each sequential order, outputs these compared preset value signals. set gun drives scale.