RETRACTION OF DISK DRIVE HEAD SPEED-CONTROLLED TO REDUCE AUDIBLE NOISE

摘要

PROBLEM TO BE SOLVED: To provide a control circuit for controlling a current through a voice coil motor (VCM) when a conversion head is retracted from the surface of a recordable medium.;SOLUTION: A conversion head is conveyed on a movable member operated by a VCM. The control circuit is provided with a measurement circuit for measuring a reverse electromotive force (reverse EMF) from a VCM. This control is further provided with a driver circuit connected to the terminal of the VCM to supply a driving current of a size based on the reverse EMF from the VCM to the VCM. The control circuit is yet further provided with a chip clock for alternately executing measuring of the reverse EMF from the VCM and supplying of the driving current of a random frequency within a frequency range centering on a median frequency to the VCM.;COPYRIGHT: (C)2006,JPO&NCIPI