Patent ID: 6963459

Claim:
A disk drive comprising: a disk medium in which a plurality of data areas with data recorded therein are constituted in a radial direction, the data areas being recording areas corresponding to a plurality of zones into which a track group constituted in the radial direction on the disk medium is formed; a read head configured to execute a read operation of the data with respect to the respective data areas; an AGC amplifier configured to control an amplitude of a read signal generated by the read operation by the read head; a memory that stores a plurality of initial gain value data to set a gain of the AGC amplifier so as to be adapted for recording frequency characteristics for each of the respective zones, the initial gain value data being data that controls the gain of the AGC amplifier during an initial time of the read operation for each respective zone; and a controller configured to read the initial gain value data corresponding to the respective zones as read objects from the memory and to set the initial gain value data of the AGC amplifier at a start of gain control of the AGC amplifier during the initial time of the read operation by the read head, wherein the gain of the AGC amplifier can be varied after the initial gain value data is set in the AGC amplifier during the initial time of the read operation.