| 摘要 |
<p>PURPOSE:To obtain a digital magnetic tape device capable of discriminating the kind of the tape easily based on the difference of the position of a hole, by detecting the hole perforated on the magnetic tape with an optical sensor. CONSTITUTION:On the magnetic tape 13a, the light of a LED21 is inputted to a light receiving part 22 and goes to an (L) and after wards, it goes to an (H) in a transparent part before a time t1, however, an output of (L) is supplied to a CPU9 during a time between t2-t3 when the hole 19a passes through the sensor 10. The CPU measures a time T1 setting the t1 as reference, and decides the tape as the tape 13a if the hole exists within the time T1, and performs reproduction by switching a switch 12 and prohibits recording. On the tape 13b, the position of the hole 19b is different, and a detecting time is set as Ta'<Tb, and the CPU9 measures a time T2 in t2-t5, and decides the presence/absence of the hole within the time T2. The T2 is set behind the T1. The switch is switched based on the decision of the tape 13b, and the reproduction is performed at a circuit 8b. At the time of recording, the recording is started by a circuit 7. In such constitution, it is possible to perform the recording or the reproduction by loading plural magnetic tapes alternatively.</p> |
