| 摘要 |
PURPOSE:To enable the reproduction of striped index parts when the index parts can not be reproduced by a magnetic tape device which uses a rotary head, by performing logical operation between a read head position indication signal and an index read output signal. CONSTITUTION:A read head position indication signal 12 which indicates that a read head 1 is at an index N part showing a track number (n) and a read output signal 14 outputted by reading an index N by the read head 1 are operated logically to detect the reproduction of the index N being disabled owing to a dropout. For example, the position indication signal 12 obtained through a head position detector 3 and a monostable multivibrator 4 and the read output signal 14 obtained through an amplifier 5 and a level comparing circuit 6 are inputted to an AND circuit 7 and an exclusive OR circuit 8 to output a detection signal 15 indicating that the index N can not be reproduced when so. |
