| 摘要 |
<p>PURPOSE:To detect a tape mark in a normal way without having such a case where a pit shift produced within a special data pattern is transmitted to the subsequent special data patterns, by setting a resynchronized pull-in pattern between the special data patterns within a tape mark. CONSTITUTION:The read signal for the mark read out of a read head 21 is supplied to a window generating circuit 23, a block detecting circuit 28 and a data production circuit 24 respectively via a preamplifier 22. The circuit 23 starts the synchronization by a block detecting signal 31 sent from the circuit 28 and transmits a signal to the circuit 24 for synchronization. The circuit 24 produces the shaped read data. A special data pattern detecting circuit 25 detects a special data pattern out of the shaped read data and transmits a special data pattern detecting signal 31 to a special data pattern counter circuit 26. While the circuit 25 detects a pattern for resynchronization and delivers a resynchronization signal 29 to make the circuit 23 perform the resynchronization.</p> |
