PURPOSE:To make easy the adjustment of delay time, by automatically adjusting the amplitude and the polarity, and by displaying the adjusting state due to the delay time of the delay circuit. CONSTITUTION:The composite video signal including the ghost gignal from the input terminal 1 is inputted via the synthesis circuit 2 and the delay circuit 3 delays the signal by the time equal to the delay time of ghost, and the differentiation circuits 6 and 7 differentiate the respective output of the circuits 2 and 3 are provided. Further, the phase detection circuit 8 which performs phase detection for the output of the circuits 6 and 7 and the DC conversion circuit 9 converting two outputs of the circuit 8 into DC are provided, and the output of the circuit 3 is fed to the amplitude and polarity adjustment circuit 4 with the output difference of the circuit 8, and the output of the circuit 4 is synthesized with the composite video signal in the circuit 2. Moreover, saw tooth wave is generated with the saw tooth wave generator 11 by means of the horizontal synchronizing signal at the terminal 10, the output of the generator 11 is fed to the slice and amplifier 12 and 13, slicing it with the DC output of the circuit 9. Logical sum is taken with the exclusive logical sum circuit 14 for the output and the state of adjustment is displayed by adding it to the blanking circuit 16.
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