device for the correction of zeitbasisfehler a videosignals.

摘要

In order to correct a time base error of a video signal reproduced from a video signal recording/reproducing apparatus such as a VTR or the like, when the reproduced video signal is sequentially written into or read out from a memory, a signal which is obtained by frequency multiplying an output of an oscillator for generating a signal of a constant frequency whose phase is momentarily synchronized by a burst signal extracted from the reproduced video signal is used as a write clock. The signal based on the output of the oscillator and the signal based on the output of a reference signal generator for generating a read clock for the memory are phase compared for the vertical blanking period of the reproduced video signal, and a phase difference signal is generated. The oscillating frequency of the oscillator is controlled in a negative feedback manner using this phase difference signal, thereby assuring the stable oscillating frequency which does not cause any frequency deviation. To prevent that erroneous horizontal sync information is used when the burst signal is extracted, the write clock whose phase is synchronized with the reproduced video signal is counted until a predetermined count value and only the normal horizontal sync signal is separated, and also the dropout horizontal sync signal is corrected.