Direct current restorer

Abstract

A direct current restorer applied to a pedestal clamp circuit of a television receiver in which an input video signal is compared with a pedestal level setting reference signal for every pedestal period, and, based on difference between the pedestal level of the input video signal and the level of the reference signal, the direct current level of the input video signal is shifted. In this direct current restorer, a direct current according to the level variation of the reference signal may be superposed on the input video signal so that the direct current level of the input video signal is corrected according to the level variation of the reference signal. Accordingly, when adjusting the pedestal level or achieving a liquid crystal display in which the polarity of the input video signal is periodically inverted, a direct current according to the level variation of the reference signal may be superposed on the input video signal. Thus, the pedestal level of the input video signal may quickly follow the level variation of the reference signal and may be controlled to the level of the reference signal with no influence exerted onto the comparison in level of the input video signal with the reference signal.