Verfahren für die automatische Bildgrößensteuerung halbbreiter Fernsehempfänger

摘要

An automatic picture size control method for a semiwide-screen television receiver. According to the method, levels of left and right edge portions in all active period of one horizontal scanning line of a received television signal are sampled, and how many times a sampled level becomes a black level for a predetermined time is detected and counted. Thereafter, a size of a displayed picture is designated as a plus picture size or a normal picture if a counted value is larger than a predetermined first value, or smaller than a predetermined second value, respectively.