| 摘要 |
<p>PURPOSE:To control stably a constant tape quantity in a vacuum column when a magnetic tape is stopped by inputting a binary-coded signal from a storage excess state detecting means and a storage deficient state detecting means, counting it and outputting a parameter designation signal from a counter means. CONSTITUTION:A detection signal A from a tape state detector 12 loaded in the vacuum column 6 is inputted to an AND gate 14b via an inverter 14a and a detection signal B from a tape state detector 13 is inputted to an AND gate 14c. Then a running control signal C of a magnetic tape 3 is inputted to output signals A and B to a current setting counter circuit 14d only when the running the stopped, then the signals A, B depending on the state of the magnetic tape 3 in the vacuum column 6 are counted, after the signals are addd or subtracted, a current setting signal E as a parameter varying the motor drive current is sent to a drive motor 11 via a motor drive current amplifier circuit 15. Thus, the quantity of the magnetic tape 3 in the vacuum column 6 is controlled to a constant value.</p> |
