Digital convergence correcting apparatus.

摘要

A convergence correcting apparatus is used in a projection television receiver including a CRT (1010) having an aspherical fluorescent screen (P1) and a projection lens apparatus which is attached to the display screen of the CRT and has aspherical plastic lenses (101, 103, 104). In the digital convergence correcting apparatus, a digital memory (8) stores digital correction data corresponding to correction values of convergence adjustment points (201) indicative of a plurality of points on the display screens divided in the horizontal and vertical directions. A multiplexer (15) reads out predetermined digital correction data from the digital memory (8) and time sharingly multiplexes. At least one digital/analog converter (19) receives the time sharingly multiplexed data from the multiplexer (15) and generates an analog signal. Sample and hold circuits (26, 26 min ) extract a predetermined correction signal from the analog output of the digital/analog converter (19) and sample and hold them. The convergence correcting apparatus is driven in accordance with the respective correction signals held by the sample and hold circuits (26, 26 min ).