JPS6434090A - Convergence device - Google Patents

Abstract

PURPOSE:To reduce a convergence dislocation by light-receiving a pattern signal with a detector provided on a screen, detecting a dislocating quantity, writing alternately the detected signal at a storing circuit and controlling a convergence correcting circuit with an adding output to add the correcting data of a fine adjustment and a coarse adjustment. CONSTITUTION:After a convergence adjustment, when a static convergence dislocation is generated owing to a temperature or the like, the pattern signal is light-received by detectors 14 and 15 provided on the screen, the dislocating quantity is detected, and the detecting signal is controlled so as to make the writing actions of (n) number of storing circuits 20 and 21 to be opposite to each other. A convergence correcting circuit 24 is controlled by the adding output to add fine adjustment data from the storing circuits 20 and 21 and (n) number of the correcting data of coarse adjustment data. Thus, an accurate automatic static convergence correction can be executed in a condition in which a video is projected on the screen.