PURPOSE: To eliminate an influence of phase characteristics of a reproducing-recording system especially, and to realize a correct copy by differentiating a digital signal reproduced from the first magnetic recording medium, and thereafter, shaping a waveform basing on zero crossing as a reference, and recording this signal in the second magnetic recording medium.
CONSTITUTION: A pulse-like signal A recorded in accordance with a digital signal in a magnetic tape 1 is reproduced by a reproducing head 2, differentiated by a differentiating circuit 4, and a waveform is shaped by a waveform shaping circuit 6 basing on a zero crossing point as a reference, by which an output signal for setting a point corresponding to a rise point and fall point of a signal A as its rise and fall points is obtained. When this output signal D is converted to a current value by a recording amplifying circuit 9 and a resistance 10, and recorded in a magnetic tape 1' for copying by a recording head 11, a digital signal is recorded without being influenced by a phase characteristic of a recording-reproducing system. On the other hand, when the signal A by the reproducing head 2 does not exist, it is detected by a detecting circuit 7, and even if a waveform shaping circuit 6 detects zero crossing by a noise signal and sends out a pulse signal based on the noise signal whose waveform has been shaped, it is cut off by a gate circuit 8.
TANAKA KIYOSHI
KUMAGAI MASAHIKO
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