| 摘要 |
<p>PURPOSE:To securely retract the unlocking of a cylinder revolution follow-up servo by sweeping the number of revolutions of a cylinder up and down from the center of such a number of revolutions of the cylinder as conformed with a prescribed tape speed when the servo lock is tripped out. CONSTITUTION:A 1st cylinder revolution control means 11 is driven by a control signal of a state discriminating means 10 to accelerate or decelerate a cylinder motor 16 so as to enable the cylinder 1 to sweep up and down in a prescribed range with the center of the number of revolutions conformed with the prescribed tape speed, while the number of revolutions of the cylinder is controlled to a prescribed value by a 2nd cylinder revolution control means 13. When a control signal indicating the unlocking of the cylinder revolution follow-up servo is received by a control means 15 from the state discriminating means 10, a changeover means 14 is changed in its connection from the side of a cylinder revolution follow-up control means over to the side of the 1st cylinder revolution means 11, and moreover after receiving a control signal from a detecting means 12, the changeover means 14 is changed in its connection over to the side of the 2nd cylinder revolution control means 13. By this method, even when the cylinder servo lock is tripped out, the cylinder revolution follow-up servo can be retracted.</p> |
