Quantum Corporation

Western Digital Technologies, Inc.

Richard T Curran

Richard M Ehrlich

Stanley H Shepherd

William R Akin, Jr

James V Wiseman

Lloyd E Levy

Bruce C Schardt

Daniel J Gunderson

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks. Data is read from a target track, and an off-track read capability (OTRC) is generated for a plurality of segments of the target track. For example, an OTRC may be generated for a plurality of data sectors, wherein the combined OTRCs may be evaluated to compute an average track center, or an average track width, or a repeatable runout (RRO).

Disk drive generating off-track read capability for a plurality of track segments

Embedded servo sectors within a data track of a hard disk drive including a rotating data storage disk and a closed loop rotary actuator structure for positioning a data transducer head relative to the data track are written by a method including the steps of positioning the rotary actuator structure relative to the data track with a laser-interferometer-based servo writer and writing a pattern of circumferentially sequential, radially offset fine position bursts within each servo sector with the data transducer head, this step including writing-in undetermined position errors within each pattern being written, moving the disk drive to a self scan environment away from the servo writer, operating the rotary actuator structure in closed loop for following the data track by reference to the servo burst pattern, extracting the undetermined position error from each pattern thereby to iteratively determine written-in position errors, generating burst correction values from the determined written-in position errors, and writing the burst correction values to the data track for later use by the closed loop rotary actuator structure during following of the data track to remove the written-in position errors.

In-drive correction of servo pattern errors

In drive correction of servo pattern errors

Growing community of inventors

Los Altos, CA, United States of America

Richard T Curran