| 摘要 |
PURPOSE:To improve the waveform reproducibility of a signal recorded on a tape for data and to improve the reliability of the tape as a tape cassette for data, by providing a phase shifting circuit in a reproducing system. CONSTITUTION:Signals on a tape having the phase characteristic shown by the curve (a) by dubbing are converted into voltage in the form which is advanced in phase by 90 deg. by the differential characteristic of a reproducing head 11. The signals amplified by a preamplifier 12 thereafter are flattened in frequency characteristic by a reproducing equivalent circuit 13 and become to have the phase shown by the curve (b). The signals are phase-shifted to have the characteristic shown by the curve (c) by the next phase shifting circuit 14 with no change in amplitude. Therefore, signals returned to the phase of almost flat original waveform as shown by the curve (d) are inputted in a power amplifier 15 and outputted from the amplifier 15 after amplification. Moreover, since the phase shifting quantity can be set smaller in the case of an undubbed tape, a phase shifting characteristic as shown by the curve (e) can be used by means of a phase shifting quantity changing switch 16 so as to bring the phase closer to that of the original waveform. |
