Western Digital Technologies, Inc.

James B French, Jr

Gary Allan Herbst

David Timothy Flynn

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of data tracks, wherein each servo sector comprises a track ID followed by a sync mark followed by at least one servo burst, and a first servo sector does not include a preamble. During a read operation, a servo gate is opened in order to read the track ID, the sync mark, and the servo burst of the first servo sector. During a write operation, the servo gate is opened in order to miss reading at least part of the track ID of the first servo sector so as to reduce a write gap preceding the first servo sector.

Data storage device eliminating preamble from servo sectors

A data storage device is disclosed comprising a first head actuated over a first disk surface comprising a first spiral track written from an outer diameter (OD) of the first disk surface to an inner diameter (ID) of the first disk surface, and a second head actuated over a second disk surface comprising a second spiral track written from an ID of the second disk surface to an OD of the second disk surface. A seek operation of the first head over the first disk surface is performed in order to access the first disk surface by reading the second spiral track from the second disk surface, seeking the second head over the second disk surface based on reading the second spiral track, and after seeking the second head over the second disk surface, accessing the first disk surface using the first head.

Data storage device switching disk surfaces to perform seek using spiral track

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks and a plurality of data tracks defined by the servo tracks. Each servo track is defined by a first set of servo sectors interleaved with a second set of servo sectors, wherein each servo sector comprises a servo burst field. The servo burst field of the first set of servo sectors has a first length and the servo burst field of the second set of servo sectors has a second length longer than the first length. Data is written to a first data track by reading at least one of the second set of servo sectors and skipping the read of at least part of one of the first set of servo sectors, and servoing the head over the first data track in response to reading the second set servo sector.

Data storage device extending servo burst field by alternating servo field processing during writes

A data storage device is disclosed comprising a head actuated over a disk surface comprising a plurality of servo sectors, wherein each servo sector comprises a servo burst field. Across a first radial band of servo tracks, the servo burst field comprises a first length, and across a second radial band of servo tracks, the servo burst field comprises a second length longer than the first length. When the head is over the first radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a first servo sector and the second read element concurrently reading a second servo sector different from the first servo sector. When the head is over the second radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a third servo sector.

Data storage device comprising extended servo burst field over part of a disk surface

A data storage device is disclosed comprising a head actuated over a disk surface comprising a plurality of servo tracks, wherein the head comprises at least two read elements including a first read element and a second read element, and at least two of the read elements are offset radially relative to a center of the two read elements by at least a width of a servo track at all radial locations of the head over the disk surface. First servo data recorded in a first servo track is read using the first read element to generate a first read signal, and second servo data recorded in a second servo track is read using the second read element to generate a second read signal. The head is servoed over the disk surface based on at least the first read signal and the second read signal.

Data storage device with two read elements offset radially by at least one servo track at all radial locations

A data storage device is disclosed comprising a first disk surface comprising a plurality of servo tracks, a first head actuated over the first disk surface, wherein the first head comprises a first read element, and a second read element. During a write operation first servo data in a first servo track is read using the first read element to generate a first read signal, and the first head is servoed over the first servo track based on the first read signal while writing data to the first disk surface. Second servo data is read using the second read element to generate a second read signal, and the write operation is aborted when the first read signal indicates a shock event is affecting the servoing of the first head and the second read signal confirms the shock event.

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Whitefish, MT, United States of America

James B French, Jr