| 摘要 |
PURPOSE:To find out objectively the cleaning period by comparing a level of a reproducing output signal of a magnetic head with a reference signal level and displaying a cleaning period detecting signal when its reproducing output signal level is larger than no signal level and smaller than the reference signal level consecutively for a prescribed time. CONSTITUTION:Comparators 9, 10 compare the reproduced output signal level A of magnetic heads 2, 3 with the reference signal level B to output the cleaning period detecting signal to a sample and hold circuit 12 when the reproduced output signal level A is larger than a non-signal level C where no information is recorded on a magnetic tape 1 and smaller than the reference signal level B consecutively for a prescribed time T. The sample and hold circuit 12 gives an output toward a display circuit 13 based on the cleaning period detecting signal to display the cleaning period. Thus, the user knows objectively the cleaning period of the magnetic heads 2, 3 respectively. |
