JPS6480190A - Convergence device - Google Patents

Abstract

PURPOSE:To attain automatic static convergence correction with high accuracy while a video image is displayed on the screen by using a detector provided on the screen so as to receive a pattern signal and to detect a position deviation and using a correction data from a storage circuit so as to control a convergence correction circuit. CONSTITUTION:When a red pattern signal 54 is deviated, e.g., upward, a photoelectric conversion signal being the result of photoelectric-converting a G pattern signal 16 and an R pattern signal 54 by a detector 14 is fed to a position detection circuit 18, where the position deviation is detected. Then the position deviation is outputted from a position detection circuit 18 and the correction data is stored in a storage circuit 19. The correction data from the storage circuit 19 is fed to an R perpendicular static convergence correction circuit of the convergence correction circuit 21 to move the red pattern signal 54 from X1 to X0 on the screen thereby controlling the static deviation in a way that the signal is at the same position as a green pattern signal 16. Thus, the static convergence is corrected automatically.