| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a disk drive that prevents acoustic noise caused by a voltage pulse when the head is retracted using a speed control method using voltage obtained by rectifying a back electromotive force after the power source has been cut off from the rotation of a spindle motor. <P>SOLUTION: Retraction control circuit 63 is used to control the on and off modes of transistors Tr31-34 in accordance with the speed of VCM 39. The voltage across VCM 39 becomes a voltage that can be regulated by a current value of a current circuit 82, using VCM voltage control circuit 80. At this time, voltage is supplied to the terminals based on the voltage of ISO5V that is the rectified voltage of the back electromotive force of the spindle motor and the pulsating voltage is synchronized and produced at both terminals. As a result, the potential difference across VCM 39 is such that the pulsating voltage is negated and acoustic noise is inhibited. <P>COPYRIGHT: (C)2011,JPO&INPIT |
