Patent ID: 8154821

Claim:
A magnetic head-positioning servo system for positioning a magnetic head on a predetermined track of a magnetic disk in response to a servo signal read from the track of the magnetic disk, the magnetic head-positioning servo system comprising: a first fine actuator, supported directly on a fixed base or a coarse actuator, or supported through an intermediary; and a second fine actuator, supported directly on the first fine actuator, or supported through an intermediary; wherein the second fine actuator is configured to support the magnetic head through a head-suspension, and configured to move the head-suspension; wherein the second fine actuator is configured to let the magnetic head follow the maximum repeatable-eccentricity of a target track written in the magnetic disk; wherein the first fine actuator is configured to let the magnetic head follow the target track whose maximum repeatable-eccentricity has been compensated by the second fine actuator; and wherein the second fine actuator is configured to generate a larger generating displacement than a generating displacement generated by the first fine actuator.