Time base corrector having a velocity error data extracting circuit

Abstract

A time base correcting circuit is provided in which a time base error in a video signal is corrected by converting the video signal to a digital form which is then recorded into a memory with a write-in clock signal synchronized with a horizontal synchronizing signal or a color burst signal carried in the video signal, reading the digital signal with a read-out clock signal generated from a reference clock signal, and converting it into an analog form. In particular, a velocity error data is added to a corresponding horizontal blanking period of the video signal and after processing of the signals having time delays and continuation errors in the time base, the velocity error data is extracted from the horizontal blanking period of the video signal. Then, the read-out clock signal is phase modulated with the velocity error data extracted and used for correction of the velocity error in the video signal of analog form converted from its digital form.