| 摘要 |
PURPOSE:To enable improvement in SN ratio or band compression by recording a synchronizing signal together with a pilot signal after inverting at a pedestal level and by reproducing a picture by obtaining a false synchronizing signal from a demodulate pilot signal. CONSTITUTION:Synchronizing signal removal circuit 6 removes a synchronizing signal from the composite output signal of clamping circuit 4 on the basis of a pedestal level. Synchronizing video synthesizer circuit 7 synthesizes an input synchronizing signal by inverting to the input video signal side and inputs this signal to FM modulation circuit 9 via pre-emphasis circuit 8. Modulation circuit 10 AM- modulates a pilot signal by the synchronizing signal. Mixer circuit 11 mixes the outputs of circuit 9 and 10 together and then supplies the signal to magnetic head 13 via recording amplifier 12. A pilot signal obtained by separating the regenerated signal of magnetic head 13 by separator circuit 16 is spplied to demodulation circuit 19, and synchronizing video separator circuit 20 and synchronizing video synthesizer circuit 21 regenerate a normal composite video signal by using a false synchronizing signal. Consequently, equalizing the SN ratio makes it possible to narrow the recording band. |
