| 摘要 |
PURPOSE:To attain high speed access and minute step feeding by determining the width of a driving pulse to be supplied to a motor, the width of a braking pulse and driving pulse voltage from the distance to a target position of moving of a head and the direction to be moved, and applying these pulses to the motor. CONSTITUTION:When a magnetic head 5 is fed from outer circumference to inner circumference (direction of arrow mark 9), the load of DC motor 1 conforms to the direction of pulling of a spring 17. Accordingly, it becomes lighter compared with the case of opposite direction (arrow mark 18). Consequently, steady speed of the magnetic head 5 is different depending on the direction of feeding. The DC motor and head feeding mechanism can be approximated as a primary delay system. Further, v0 becomes small in the direction (direction of arrow mark 18) in which the load of the DC motor becomes greater. Three kinds of quantity of feeding (5mum, 15mum, 35mum) are provided as correcting feeding according to the amount of positional deviation N', and the DC motor is driven with calculated specified positive and negative pulse signals. |
