| 摘要 |
<p>PURPOSE:To prevent a tape from being damaged by forcibly stopping the head of a rotary cylinder so that a magnetic tape may not abut on the head even if the tension of the magnetic tape drastically changes at the time of loading or unloading the magnetic tape. CONSTITUTION:In a rotation angle detection circuit 14, the stop angle of a cylinder 3 is detected on the basis of the signal of a monostable-multivibrator 6 and the signal of a rotation speed detection circuit 9 and the cylinder 3 is controlled so as to be stopped at the angle corresponding to a target value. In the circuit 14, the cylinder 3 is rotated for a fixed time by operating a cylinder control circuit 10 and a cylinder motor driving circuit 11 on the basis of the control signal from a controller 12 at the time of loading or unloading. At this time, the control signal is generated from the rotation speed signal FG8 from the cylinder motor, the signal of the rotation speed detection circuit 9, the rotation phase signal PG5 and the signal of the monostable-multivibrator 6 and added to the circuit 10, a brake signal and a stop signal are transferred to the circuit 11, so that the cylinder 3 may be forcibly stopped at a a trget position.</p> |
