| 摘要 |
PURPOSE:To automatically detect the generation of crosstalk, by detecting signals other than a modulation signal of a prescribed frequency included in a reproducing signal at a recording section at each prescribed period of a recording track as crosstalk. CONSTITUTION:In the constant line speed system for a video disc for example, a composite video signal A is inputted to a BPF 2 picking up only a beat component appeared as crosstalk and gated at a gate circuit 3. This gate circuit 3 is operated by gating only a specific section (information section of gray level, 8.5 MHz component) in a vertical blanking period of a video signal. Thus, if a suychronizing signal (7.5 MHz) component of adjacent tracks is leaked at this operation, I MHz beat components are outputted and inputted to an envelope detector 5, peak-hold is made at a holding circuit 6, a crosstalk amount D is detected, the polarity is controlled according to the direction of generation of the crosstalk at a polarity changeover device 7 and the amount D becomes a control signal for a rejector 8. |
