| 摘要 |
<p>PURPOSE:To ensure the accurate working despite a change of the tape traveling speed, by generating a detecting signal from a comparator when the output of a counter circuit is larger than the output signal of a reference signal generating circuit. CONSTITUTION:A counter circuit 11 counts the pulse signals delivered from a waveform shaping circuit 3 while a signal of H level is delivered to the output terminal of a timer circuit 8 and then delivers a counted output NS. The output of an inverter 13 is set at H level when the output of the circuit 8 is set at L level. As a result, a comparator 14 is actuated to compare the signal NSO sent from a reference signal generating circuit 12 with the signal SN. The revolving number of a supply reel shaft 1 increases as a magnetic tape is taken up. When the tape is taken up to a prescribed position before the tape termination, the output NS becomes larger than the signal NSO. Then a detecting signal of H level is delivered to an output terminal 14 of the comparator 14. As a result, an informing circuit 17 is actuated to inform that the tape has drawn to an end.</p> |
