RESIDUAL CLAMP ERROR COMPENSATION CIRCUIT

摘要

RESIDUAL CLAMP ERROR COMPENSATION CIRCUIT of the disclosure An apparatus for matching the blanking levels of two television video signals is disclosed. When the vertical interval reference signal or any other signal (e.g., sync) is inserted on a program video signal their blanking levels should be matched. The apparatus described accomplishes this by matching the blanking level of the signal being inserted to that of the program video. The match is produced by sampling the residual clamping error of a slow clamp on the program channel and adding it to the signal being inserted. Therefore, the noise which would have been added to the program video is added to the inserted signal instead and therefore will not be visible in the television picture.