| 摘要 |
PURPOSE:To output an accurate read pulse even if there is considerable variation in the magnetic inversion time of digital data recorded on a magnetic medium by generating the read pulse by the 1st edge detecting circuit and the 2nd edge detecting circuit. CONSTITUTION:A circuit 3 which differentiates a playback waveform reproduced from a magnetic medium where digital data are recorded, a zero-cross comparator 5 which detects zero-cross points of the signal obtained from the differentiating circuit 3, and a hysteresis comparator 4 which has its threshold level almost at the zero level of the playback waveform are provided. Further, the 1st edge detecting circuit 6 which outputs the 1st signal when the output of the hysteresis comparator 4 is inverted and the 2nd edge detecting circuit 7 which outputs the 2nd signal when the output of the zero-cross comparator 5 is inverted are provided; and the 2nd edge detecting circuit is released from being reset with the 1st signal and the 1st edge detecting circuit is reset with the 2nd signal.
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