Video signal transmission systems

摘要

A video signal transmission system wherein a television video signal is subjected to a waveform conversion in a video processing unit on a transmission side, then sent to a receiving side and restored in a restoring processing unit on the receiving side. The video processing unit comprises partly polarity inverts a composite video signal containing a horizontal synchronizing signal in accordance with a pseudo-random code utilizing a horizontal scanning frequency as a clock pulse such that the while level of an inverted video signal portion will not be smaller than a peak level of a non-inverted horizontal synchronizing signal portion. The restoring processing unit on the receiving side inverts again the polarity of the polarity inverted composite video signal portion in accordance with the pseudo-random code to obtain a restored composite video signal portion having the same polarity as the original composite video signal. A difference between the peak level of the horizontal synchronizing signal of the inverted and restored composite video signal portion and the peak level of the horizontal synchronizing signal of the non-inverted composite video signal portion is detected and feedback to the input of the restoring processing unit so as to control these peak levels to the same level.