| 摘要 |
<p>PURPOSE:To enable the setting of tension for a magnetic tape without providing a tension arm by detecting a driving current for a driving motor, which varies in accordance with a rotary load of a rotary head device, and giving braking force to a motor for driving a supply side reel base in response to this variation. CONSTITUTION:Contact frictional resistance between a rotary drum of the rotary head device 5 and the magnetic tape T is changed by varying the tape tension, etc., and when the contact frictional resistance is increased, a load of the drum motor Mc is increased, and its motor driving current is increased, and then this motor driving current is converted by an I/V converter 22 into voltage to be given to a reel motor control circuit 23. A current to be given to a reel motor Ma from a motor driving circuit 24 is lowered by the reel motor control circuit 23 in accordance with a rise of a voltage given to this circuit, and hence driving force in the reverse direction by the reel motor Ma is lowered to carry out a control for diminishing the tension. By this method, the tension control is feasible without using any tension arm.</p> |
