| 摘要 |
PURPOSE:To quantitatively measure edge noise by reproducing a luminance signal of a rectangular wave shape recorded on a recording medium, and taking out detecting a noise component lower than the repeating frequency of the luminance signal of the rectangular wave shape from this signal. CONSTITUTION:The luminance signal of the rectangular shape recorded on the recording medium is reproduced through a recording and reproducing system and this reproduced signal is supplied to a low pass filter LPF 2 and to a synchronization separating circuit 3, respectively through a terminal 1. Then, from the LPF2, the luminance signal component of the rectangular wave shape is removed and in the circuit 3, a synchronizing signal is taken out and according thereto, a gate pulse is generated by a gate pulse generator 4. Then, by this pulse, a gate circuit 5 is controlled and from the output of the LPF2, the synchronizing signal component is removed. Namely, by the LPF2 and the circuit 5, the noise component of the frequency lower than the repeating frequency of the luminance signal is taken out, detected in a detecting circuit 6, thereafter, fed to a voltmeter 7 and the noise is measured. Thereby, the edge noise can be measured quantitatively.
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