| 摘要 |
PURPOSE:To detect the clogging state in the early stage by comparing the level of the reproduced signal or its demodulated signal of a head, which is obtained at the time of starting or terminating contacting between a magnetic type and the head, with one or plural reference levels on the basis of a timing signal. CONSTITUTION:A timing generating circuit 9 which outputs the timing signal of the start or the end of contacting between the magnetic tape and the head on the basis of a head switching signal and a detecting circuit 17 which compares the level of the reproduced signal or its demodulated signal at the time of starting or terminating this contacting with one or plural reference levels on the basis of said timing signal and outputs the signal of the comparison result as a clogging state detection signal are provided. Thus, the clogging state due to dirt of the magnetic head is detected in the early stage by the level of the reproduced signal or its demodulated signal of the magnetic head obtained at the timing when dirt of the magnetic head apt to have an influence on the signal, namely, at the timing when contacting strength between the magnetic tape and the magnetic head is weakest at the time of starting or terminating this contacting. |
