| 摘要 |
<p>PURPOSE:To obtain stable tape tension without providing a tension lever. CONSTITUTION:A tape state medium 101 is sent by a tape transferring means 1 with fixed speed. A wound diameter detecting circuit 40 obtains wound diameter information of the tape state medium 101 wound on a reel 2. A back torque operation circuit 5 outputs a signal proportional to an output of the wound diameter detecting circuit 40. A sine wave pattern generating circuit 9 outputs a signal having a sine wave pattern synchronized with an output of a pulse generator 8. A speed control circuit 13 outputs a signal so as to remove an output of a speed error detecting circuit 12. An adder circuit 10 outputs a synthetic signal of output signals of a back torque operation circuit 5, a sine wave torque generating circuit 9 and a speed control circuit 13. A driving circuit 6 generates torque in a motor 7 based on an output of the adder circuit 10, and gives tension to the tape state medium 101. At the time, variation of tension of the tape state medium 101 is suppressed by setting a phase and amplitude of variation pattern of the sine wave pattern generating circuit 9 so as to cancel intrinsic torque variation of the motor 7.</p> |
