Patent ID: 8023222

Claim:
An information storage device, comprising: a recording-reproducing head configured to record data on a recording medium and reproduce the data on the recording medium; a positioning controller configured to position the recording-reproducing head; a position detector configured to detect a position of the recording-reproducing head based on a servo signal on the recording medium; a storage module configured to store a plurality of servo control filters; and a position error detector configured to generate a new position error signal from a target position and the position of the recording-reproducing head detected by the position detector when the positioning controller performs positioning control for the recording-reproducing head with control current obtained by causing a position error signal to pass through each of the servo control filters, wherein, learning to calculate a vibration amount is sequentially performed with respect to each of the servo control filters for a predetermined time when the positioning controller performs the positioning control upon occurrence of a recording error or a reproducing error, the vibration amount being calculated from the position of the recording-reproducing head detected by the position detector, the positioning controller is configured to perform the positioning control with one of the servo control filters where the vibration amount is smallest, the vibration amount calculated with respect to each of the servo control filters is stored in the storage module in association with the servo control filter, and upon occurrence of the recording error or the reproducing error, among the servo control filters each associated with the vibration amount stored in the storage module, the vibration amount is sequentially calculated with respect to the servo control filters in ascending order of the vibration amount stored in the storage module.