Western Digital Technologies, Inc.

Kenneth T Tabacchi

Chun Sei Tsai

Orhan Beker

Carl E Barlow

Kexiu Liu

Ashok K Desai

Charles J Calaway

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks, wherein at least two of the tracks comprise a thermal asperity. Prior to seeking the head from a first track to a second track, for each of at least two of the thermal asperities a minimum seek delay and a maximum seek delay that will cause the head to miss the thermal asperity are computed, and an allowed seek delay range that will cause the head to miss the thermal asperity is computed. When the undelayed seek will cause the head to hit at least one thermal asperity, the seek is delayed by a seek delay determined based on the minimum seek delays, the maximum seek delays, and the allowed seek delay ranges.

Data storage device delaying seek operation to avoid thermal asperities

A disk drive is disclosed comprising a disk, a head coupled to a distal end of an actuator arm, a voice coil motor (VCM) operable to rotate the actuator arm about a pivot in order to actuate the head radially over the disk, and a ramp located near an outer edge of the disk for parking the head. A first back electromotive force (BEMF) voltage of the VCM is measured, and a current is applied to the VCM for a first interval in order to move the actuator arm in a first radial direction. After the first interval, a second BEMF voltage of the VCM is measured, and whether the head is parked is detected in response to the first and second BEMF voltages.

Disk drive detecting when head is parked on ramp

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Irvine, CA, United States of America

Kenneth T Tabacchi