Motion signal detecting circuit

摘要

A motion signal detecting circuit is adapted to an image reproducing system having a frequency unfolding circuit for generating an unfolded luminance signal by unfolding a high frequency component folded into low-frequency component into an original frequency band in order to reproduce a full bandwidth image signal in which the high frequency component has been folded into the low frequency component and recorded on a recording medium having a limited bandwidth. The detecting circuit comprises a prefilter (100) for eliminating the folding carrier contained in the unfolded luminance signal and sidebands thereof and a comb filter (110) for detecting a motion signal which is the difference component between frames in the unfolded luminance signal by filtering the output of the prefilter (100).