| 摘要 |
PURPOSE:To obtain the error signals of small disturbance by forming envelope signals having amplitude information from burst signals, thereby taking out the burst signals from carrier signals and making necessary weighting. CONSTITUTION:Burst flag pulse Pf obtained from an LPF 2 is supplied to a voltage comparator circuit 5 and wide gate pulse Pg is taken out from the comparator circuit 5. Burst signals Sb are taken out from carrier chrominance signals Sc by a gate circuit 6, and supplied to an amplitude detector circuit 7. The amplitude detector circuit 7 outputs detecting signals Sd that show envelope and supplies to a non-linear circuit 8. The signals are made to the pulse of sharp waveform without changing the center position by the non-linear circuit 8, and multiplied to carrier chrominance signals Sc by a multiplier circuit 3. The burst signals Sb weighted in the central part are obtained from the multiplier circuit 3 and supplied to a phase detector circuit 4. Thus, the error signals Se of small disturbance are taken out.
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