| 摘要 |
<p>PURPOSE:To miniaturize the circuit scale or to shorten the calculating time by suppressing detecting fluctuations of a tape speed obtained from upper-order and lower-order bit data and a reel rotation period and performing the tape traveling with stable reel drive. CONSTITUTION:Prescribed torque is generated by an S-reel steady torque generating circuit 22 and a T-reel steady torque generating circuit 23 respectively, which are supplied with reel wound diameter data, with each motor in accordance with each reel wound diameter. This prescribed torque is worked in the direction of taking up the S-reel and T-reel respectively to give tension to the tape in order to bring a rotary head into good contact with the tape 1. Then, a high precision wound diameter data Rt drastically reduced in quantize errors at the time of changing the wound diameter by a wound diameter data high precision circuit 24 is supplied to a speed control circuit 25. In this circuit 25, a tape speed is detected from a T-reel rotating frequency obtained from the data Rt and a TFG signal, and a difference from a target tape speed is generated to be negatively fed back to the T-reel motor 9 via an adder circuit 26 and a motor driver 27 so as to control the tape speed.</p> |
