| 摘要 |
PROBLEM TO BE SOLVED: To provide a loading and unloading device for a magnetic disk device realizing unloading by speed control by using back electromotive volt without the contact of a magnetic head and a disk though a floating quantity is reduced. SOLUTION: A target speed generator 25 for generating the target speed of a head in seeking generates a target speed and a speed controller 24 controls a head ed to follow the target speed. At this time, a corrector 20 measures the resistance fluctuating portion of a motor from the current value of the motor outputted from a current sense amplifier 11, a speed estimated value outputted from a speed estimation device 22 and the output of the back electromotive voltage of a back electromotive voltage detector 21 and from the measuring result of the fluctuating portion of coil resistance, the corrector 20 adds correction equivalent to this fluctuating portion to the output of the back electromotive voltage detector of the detector 21. A correct back electromotive voltage value without including a current component error is obtained by this correction. Based on this back electromotive voltage value, the speed of unloading is controlled.
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