Maxtor Corporation

Seagate Technology Incorporated

Rickmer Kose

Erhard Theodor Schreck

Brian D Strom

Bruce C Schardt

Davide Guarisco

Frank Obregon

A disk drive includes a drive circuitry, a suspension, a slider assembly that includes a read/write head, and a pressure compensator. The pressure compensator is electrically decoupled from the drive circuitry. A portion of the pressure compensator has a volume that passively changes when an ambient pressure near the pressure compensator changes. The pressure compensator at least partially offsets a change in a head-to-disk spacing that occurs when an ambient pressure near the pressure compensator changes. The pressure compensator can exert a force on the slider assembly to change a pivot angle between the suspension and the slider assembly, and/or to change a pitch angle between the slider assembly and the storage disk. In alternate embodiments, the pressure compensator can include a piston that moves or a resilient membranous material that changes shape based on changes in ambient pressure.

Passive fly height adjustment to compensate for ambient pressure changes in a disk drive

A microactuator incorporated within an actuator assembly of a disk drive is used as a detection element for rapid off track events that may occur. Preferably, the microactuator employs one or more piezoelectric elements used for purposes of secondary actuation. Uncontrolled movement of the actuator across the disk results in the piezoelectric elements generating a voltage spike or signal that is analyzed to determine whether a rapid off track event has occurred. Rapid off track events are distinguished from other possible events, such as shock events. If a rapid off track event is detected, then remedial actions are taken to restore data integrity, to include executing restore commands such as rewriting selected data tracks. Dedicated piezoelectric elements may also be provided for detecting rapid off track events wherein these elements are not incorporated in the servo loop that controls positioning of the actuator.

Rapid off track detection using in-drive microactuator

In one example, a method is provided and includes comparing a measured change in spacing between a transducer element and a storage element in response to a fly height control signal with an expected change in spacing for the applied fly height control signal. The method also includes detecting an event condition based on the comparison between the measured change in spacing and the expected change in spacing.

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San Francisco, CA, United States of America

Rickmer Kose