Western Digital Technologies, Inc.

Timothy D Bouwkamp

David Malcolm Hannon

Michael John Shea

Jodie Ann Christner

Gary L Dunbar

James Weispfenning

The present invention may be regarded as a disk drive with protection against damage due to a thermal asperity. The disk drive comprises a disk having a surface with an asperity, and a magneto-resistive head actuated radially over the surface of the disk for generating a read signal comprising a thermal asperity component caused by the magneto-resistive head contacting the asperity on the surface of the disk. A bias generator is provided for generating an electrical bias applied to the magneto-resistive head, and a thermal asperity detector detects the thermal asperity component in the read signal. When the thermal asperity component is detected, the electrical bias is reduced for a time interval, thereby protecting the magneto-resistive head.

Disk drive comprising thermal asperity protection by reducing an electrical bias supplied to a magneto-resistive head

A disk drive having a rotary actuator, an embedded servo system for controlling the rotary actuator, a rotating disk surface for recording and reproducing data, and a dual element head supported by the actuator comprising a read element and a write element. The disk surface has a plurality of repeating servo track patterns defining radially spaced-apart servo tracks. The disk surface further includes a user data band having a plurality of radially spaced-apart data tracks for storing user data. Each data track is written with an offset from a corresponding servo track centerline depending on a skew introduced by the dual element head. A reserved band is located outside the user data portion including a reserved data track for storing drive specific data wherein the reserved data track is centrally aligned with a corresponding servo track centerline. The reserved data track can be read reliably by the read element when the servo system is tracking on the servo track centerline. A method for making the disk drive includes writing the reserved data track in central alignment with a corresponding servo track centerline.

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Rochester, MN, United States of America

Timothy D Bouwkamp