Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Douglas Michael Zuercher

Kris Victor Schouterden

David H Jen

Indukumar Kalahasthi

Bernd Lamberts

Quan-chiu Harry Lam

Donald Earl Vosberg

Christopher David Wiederholt

Hoan Andrew Au

Masayoshi Shimokoshi

Joseph Silva

Theofilos George Fkiaras

Lakshmi Ramamoorthy

Guo Mian

David Livingston Smith

Approaches for adjusting the recording density of a recording medium in a circumferential direction are disclosed. A hard-disk drive includes one or more electronic components configured to divide a track, of a plurality of concentric tracks on a magnetic-recording disk, into a plurality of portions, and write data to each of the plurality of portions at a recording density that is independent of the recording density used for any of the other portions. Data may be written to a first portion of a track at a different frequency than to a second portion of the same track. The frequency at which data is written may be adjusted for different portions of the same track to allow the frequency to be reduced at certain portions shown to have relatively higher soft error rate while increasing the frequency for other portions to achieve a desired average error rate for the track.

Adjusting recording density in a circumferential direction

Approaches for improving the write quality of a hard-disk drive (HDD) head experiencing temporary fly-height problem. When the hard-disk drive is idle and heads are parked on the ramp, fluid, such as a lubricant or the condensation of vapor, may collect between the surface of a platter and the head or a slider, thereby causing the head to temporarily fly higher than normal. An HDD may include electronic component(s) configured to (a) determine whether it is likely that fluid is interposed between the surface of a magnetic-recording disk and the slider or the head, and (b) temporarily adjust one or more of (i) a thermal fly height control setting of the head and (ii) a write parameter of the head to compensate for the head flying higher than normal as a result of the fluid being interposed between the surface of the disk and the slider or the head.

Write quality of HDD heads experiencing temporary fly-height problems

Data recovery information characterizes data recovery procedure (DRP) steps to be performed within a hard disk drive (HDD) in response to a miss. Particular data recovery information corresponds to a radial position of the actuator and, therefore, the position of the magnetic recording read/write head relative to the associated storage media at the location at which the miss occurred. The data recovery information is based on the physical shape of a write pole and on how the physical shape of the pole inherently affects operational data error associated with the head. Because of the foregoing characteristics of such data recovery information, a more efficient and performant data recovery procedure is performed based thereon.

Adaptive data recovery procedure based on radial positioning

A method is presented for writing data to a surface of a magnetic disk in a disk drive. The method includes determining a number of sector groups into which sectors of the data to be written will be grouped, loading registers with current values, kick-latching values, and precompensation values for each of said sector groups, and applying the current values, kick-latching values, and precompensation values for each of the sector groups to the write head while writing data to the sector groups of the recording media.

Method for precompensation/write-current latching to improve error rate

An apparatus, program product and method of mapping defects on a data storage medium analyze one or more previously-identified defects on a storage medium to detect any growth in those defects over time, such that any detected growth of a previously-identified defect can be accommodated for through the dynamic remapping of additional surface area adjacent the defect to one or more replacement regions located elsewhere on the storage medium. As such, any buffer regions defined around pre-existing defects are effectively maintained as those defects grow over time, thus maintaining suitable protection from data loss that would otherwise result from an attempt to store information in a region that has been impinged upon as a result of the growth of an adjacent defect.

Accommodation of media defect growth on a data storage medium through dynamic remapping

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Byron, MN, United States of America

Douglas Michael Zuercher