Patent ID: 7564643

Claim:
A medium storage device, comprising: a plurality of heads for at least reading data on each surface of rotating storage media; an actuator for positioning the plurality of heads at a predetermined position of the storage media; and a control unit configured as a two degree of freedom control system which corrects an eccentricity of the actuator by eccentricity correction current on a disk surface facing a specified head, and executes seek control according to a position error between a target position of the head and a current position acquired from the head, wherein when the control unit switches one head to another head and seeks the another head, the control unit calculates an initial value of a correction locus to cancel a current step difference of the output current due to the head switching from an output current supplied to the actuator before the switching and the eccentricity correction current and initial velocity of the another head after the switching, and supplies a correction locus according to the initial value to the two degree of freedom control system where seek locus is input.