Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hgst Netherlands, B.v.

Western Digital Technologies, Inc.

Kris Victor Schouterden

Donald Ray Gillis

Bernd Lamberts

David H Jen

Douglas Michael Zuercher

Mike Suk

Remmelt Pit

Vedantham Raman

Reinhard Ferdinand Wolter

Walton Fong

Jorge F Escobar

Masayoshi Shimokoshi

Indukumar Kalahasthi

Lakshmi Ramamoorthy

David Robison Hall

Ullal Vasant Nayak

Quan-chiu Harry Lam

Shad Henry Thorstenson

Christopher David Wiederholt

Cory J Peterson

Nelson Cheng

Thomas Nguyen

Hoan Andrew Au

Joseph Silva

Steven Nowlen Guilliams

Theofilos George Fkiaras

Guo Mian

Scott McCoy

Ryoheita Hattori

Annamica Bhan

Andy Larson

A Data Storage Device (DSD) includes a memory for storing data, and a controller configured to execute firmware or code to perform a task. While performing the task, the controller is further configured to assign unique identifiers to respective firmware or code portions that are executed to perform the task, and create a list or data structure including the unique identifier assigned to the firmware or code portion that created the task. A unique identifier is added to the list or data structure for each firmware or code portion executed for the task. The list or data structure indicates the order in which the firmware or code portions are executed.

Exception analysis for data storage devices

Cleaning a recording head slider in-drive during operation is accomplished by periodically performing a series of full stroke seek operations, whereby liquid contaminants that may have migrated to the head slider are flung from the slider and liquid from the disk surface may be adsorbed onto the slider for removal by way of flinging. Consequently, head-disk spacing may be stabilized and data write operations improved. Furthermore, the series of full stroke seek operations may be performed at predetermined intervals, and for a predetermined period of time. However, the series may be interrupted by a client request, and continued thereafter, so as not to affect the operational status of the recording system.

Self-cleaning recording heads based on actuator seek profile

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

A hard disk drive (HDD) comprising a magnetic disk that includes a data storage surface and an external magnetic field parallel to the data storage surface for suppressing track interference.

Suppressing adjacent track interference/far track interference (ATI/FTI) in a hard disk drive (HDD) by an external magnetic field

A data formatting system and method to improve data efficiency and integrity in a hard disk are disclosed. One embodiment provides a disk drive system having a plurality of lookup tables which store a plurality of randomizer seeds which may be dynamically encoded into the preamble field of a customer data block if the customer data is deemed marginal. Encoding the randomizer seed into the preamble field prevents adjacent data track mis-writes and mis-reads.

Method and system for dynamically allocating read and write sequence randomizer

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 for increasing reliability of a hard disk drive (HDD) is disclosed. One of a plurality of magnetic read/write heads in a hard disk drive (HDD) is determined to be disabled, and a fly-height associated with the disabled read/write head is increased with respect to a fly-height associated with the plurality of read/write heads.

Adjusting a fly-height in hard disk drives

A method for controlling a burnish cycle to minimize cycle time is disclosed. MR sensor resistance measurements are used to monitor interference with the recording surface and when clearance is not detected, steps are taken to fine tune the interference signal.

Method for controlling a burnish cycle to minimize cycle time

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

A slider burnishing method is introduced, in which the slider is brought into a predetermined surface contact with the rotating disk for a specified period. The predetermined surface contact end the specified time period are selected together with the surface condition of the rotating hard disk, such that smoothened slider surface is abrasively formed. The smoothened slider surface is substantially parallel to the disk surface and thus provides reduced contact pressure during eventual operational contacting. In addition, the smoothened slider surface creates a constant gap together with the disk surface, which enhances the aerodynamic properties of the air bearing surface and stabilizes a small fly height.

Magnetic recording head burnishing method

A method for burnishing a slider in a disk drive in which the disk is rotated in the opposite or reverse direction from that used to develop the air-bearing and to read and write data is described. Rotating the disk in the reverse direction results in no air-bearing being formed and the slider being in contact with the disk surface. The burnishing removes material over the magnetic transducers in the slider which separate the transducers from the disk resulting in greater sensitivity. Optionally the stopping point for burnishing can be determined by monitoring measurable parameters such as the change in the MR resistance (MRR), i.e., &#x394;MRR/MRR until a selected range is achieved. The invention can be used to remove an overcoat from the air-bearing surface of the slider, remove protruding areas from the slider and to remove debris from the disk surface.

Method and apparatus using reverse disk rotation to achieve slider contact with a disk surface

A disk drive controller controls a vacuum pump to establish a vacuum within a disk drive housing to conserve power while ensuring that the head of the drive does not crash into the disk. The controller compares actual spindle power to a predetermined maximum power threshold and actual fly height to a calibration fly height to control the pump. The calibration values are derived by comparing no-load and loaded values for a parameter, e.g., error rate, disk temperature, and so on.

Method for controlling air pressure in an evacuated disk drive

A method for controlling the velocity of an actuator arm in a hard disk drive includes moving the actuator arm to an inner limit or outer limit of motion. Then the power to the actuator coil, which drives the actuator arm, is reduced to zero and the actuator arm is released. Bends in the flexible cable connected to the actuator arm can cause the actuator arm to move toward the outer limit of motion. As the actuator arm moves due to the flexible cable, the velocity contribution of the flexible cable is measured and stored. Thereafter, the velocity of the actuator arm, during emergency power shut off, normal unload of the disk drive, or normal load of the disk drive, is decreased or increased by an amount equal to the cable-induced velocity to compensate for the velocity contribution of the flexible cable.

Method for controlling the velocity of an actuator arm in a hard disk drive

A disk drive having an actuator-activated pumping mechanism is disclosed. The pumping mechanism creates a low pressure operating environment for the disk drive in order to enhance the performance of the drive at higher rotational operating speeds. Through the use of an engaging element, the actuator motor acts to drive a pumping element. This design does not use a separate electrical motor to evacuate the disk drive housing. Instead, the natural motion of the actuator provides the necessary power to drive the pumping element.

Growing community of inventors

Los Gatos, CA, United States of America

Kris Victor Schouterden