Circuit for generating a signal for correcting registration in a color

Abstract

A digital registration circuit for a multi-tube television camera wherein correction quantities corresponding to positions on a target of an image pickup tube are stored in a digital memory. The digital signal for the correction quantity read out from the digital memory is converted into an analog signal which is supplied to a low-pass filter and smoothed. The smoothed signal is sampled at a sampling frequency higher than the frequency at which the correction quantities stored in the digital memory are read out and the sampled signal is converted into a digital signal. The digital signals sequentially produced are applied to a shift register, and four sequential sample values supplied from the shift register are added together in an adder. The shift register operates in such a manner that four samples are shifted one by one every adding time. An output signal from the adder is used for correcting registration, so that the generation of shading can be prevented.