Western Digital Technologies, Inc.

Steven C Smith

Siri S Weerasooriya

Brian P Rigney

Guoxiao Guo

Wei Guo

Charles A Park

Jenghung Chen

Yakov M Lifchits

Boworn Panyavoravaj

A disk drive is disclosed comprising a head actuated over a disk, the disk comprising a plurality of servo sectors defining a plurality of servo tracks, wherein the servo tracks form a plurality of servo zones. A servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo sectors in a second servo zone. A boundary of a first servo zone overlaps with a boundary of a second servo zone over a transition zone. The servo sectors of the first servo zone are interleaved with the servo sectors of the second servo zone within the transition zone. At least one servo parameter is adjusted when the head is over the transition zone in order to transition between the first servo zone and the second servo zone.

Disk drive employing overlapping servo zones to facilitate servo zone crossing

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral tracks. During a seek operation, a demodulation window is opened in response to a window offset during a first revolution of the disk, wherein the demodulation window corresponds to the head approaching a spiral track. A window position error signal (PES) is generated representing a difference between a target framing of the demodulation window around the spiral track crossing and a detected framing of the demodulation window around the spiral track crossing. The window offset is adjusted in response to the first window PES, and the demodulation window is opened in response to the adjusted window offset during a second revolution of the disk.

Disk drive centering demodulation windows on spiral tracks during a seek operation

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral tracks. A first sync frame is first opened in response to a first frame offset during a first revolution of the disk, wherein the first sync frame corresponds to the head approaching a first sync mark in a first spiral track crossing. A first sync frame position error signal (PES) is generated representing a difference between a target framing of the first sync frame around the first sync mark and a detected framing of the first sync frame around the first sync mark. The first frame offset is adjusted in response to the first sync frame PES, and during a second revolution of the disk the first sync frame is second opened in response to the adjusted first frame offset.

Disk drive centering sync frames on sync marks of a spiral track

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San Jose, CA, United States of America

Steven C Smith