Head positioning device and disk drive using same

A head positioning device comprising:

• a fine actuator having a head mounted thereto for reading and/or writing data on a recording medium of discoidal shape, said fine actuator for making fine positioning of said head;
• a coarse actuator for making rough positioning of said head by moving a head support mechanism provided with said fine actuator;
• and
• a control unit for controlling a displacement of said fine actuator and a movement of said head with said coarse actuator,
• wherein said control unit further comprises:
• a fine motion controller for receiving, as an input of position error signal, a difference between a target position signal for positioning said head into a target position and a present position signal derived from a servo data on said recording medium read by said head, and generating a fine motion control signal to control a magnitude of displacement of said fine actuator according to said position error signal;
• a coarse motion controller for receiving a relative displacement signal corresponding to a displacement distance of said fine actuator, and generating a coarse motion control signal to control a movement of said head by said coarse actuator based on said relative displacement signal;
• a vibration detector for receiving said relative displacement signal, extracting a high frequency component contained in said relative displacement signal, and using said extracted high frequency component as a vibration detection signal to produce and output a fine motion correction signal and a coarse motion correction signal by amplifying said vibration detection signal with a predetermined amplification factor;
• a fine motion corrector for producing a signal by combining together said fine motion control signal and said fine motion correction signal, and outputting said signal as a fine motion composite signal;
• and
• a coarse motion corrector for producing another signal by combining together said coarse motion control signal and said coarse motion correction signal, and outputting said another signal as a coarse motion composite signal,
• wherein said control unit drives said fine actuator according to said fine motion composite signal, and said coarse actuator according to said coarse motion composite signal.

A disk drive unit provided with a head positioning device, said head positioning device comprising:

• head moving means defining an actuator provided with a coarse actuator and a fine actuator;
• and
• control means for positioning control by operating said actuator cooperatively to move a head to a target position in a manner that an absolute value of a displacement distance of said fine actuator is reduced to a minimum,
• wherein said control means further comprises:
• positioning control means for generating a control signal used to control positioning of said coarse actuator and said fine actuator;
• vibration detection means for extracting only a high frequency component contained in a signal corresponding to said displacement distance of said fine actuator;
• and
• disturbance correction means for combining said high frequency component with said control signal.

A disk drive unit provided with a head positioning device, said head positioning device comprising:

• head moving means defining an actuator provided with a coarse actuator and a fine actuator;
• and
• control means for positioning control by operating said actuator cooperatively to move a head to a target position in a manner that an absolute value of a displacement distance of said fine actuator is reduced to a minimum,
• wherein said control means further comprises:
• positioning control means for generating a control signal used to control positioning of said coarse actuator and said fine actuator;
• vibration detection means for extracting only a high frequency component contained in a signal corresponding to said displacement distance of said fine actuator;
• and
• disturbance correction means for combining said high frequency component with said control signal.