| 摘要 |
PURPOSE:To detect in advance an unerased remainder of a data by setting a data by a data write signal or a start signal, setting a val level to a low level, also resetting it by an input of a write data, and setting it to a high level again. CONSTITUTION:An AND gate 7, a monostable circuit 8 and a latching circuit 9 are provided on a circuit consisting of a read head 1, a pre-amplifier 2, an amplifier 3, a phase equalizing circuit 4, a comparator 5 and a pulse sense circuit 6. Regenerative voltage read out of a magnetic tape by a head is applied as a signal D to a comparator 5. It is converted to a pulse by the circuit 8 by a write signal WRT or a start signal, and stored by the circuit 9. The circuit 9 is reset by a signal C by which write is started. In this way, even if an erasion effect of an erasing head is incomplete and an unerased remainder of a data exists, it can be detected in advance by a data write operation, and a loss time of reprocessing can be eliminated. |
