Mobile Storage Technology, Inc.

Integral Peripherals, Inc.

Seagate Technology Incorporated

Maxtor Corporation

Esgw Holdings Limited

Mobile Storage Technology, Inv.

Bruce D Emo

Brian D Wilson

James H Morehouse

Robert A Alt

David M Furay

Nelson Chenkin

James A Dunckley

Steven Bernard Volk

Gary Frank Kelsic

Peter S Harllee, Iii

Patricia M Vincent

Timothy Richard Feldman

Jonathan Williams Haines

James M Jones

Edwin Scott Olds

James Joseph Touchton

John H Blagaila

Quinn Jay Haddock

John P Squires

Mai Ghaly

Michael R Utenick

Jason Matthew Feist

Dale Thomas Riley

Gary E Counts

Jerry Moline

Michael Jay Hassel

Sailaja Venkata Chilaka

Paul J Poisson

Dan Joseph Coonen

Wenjuan Wang

Noureddine Kermiche

Wayne T Weber, Deceased

Ken R Burns

Satya V Allumallu

Nicholas Scott Eggert

Neil Darragh

Glen Catalano

Method and apparatus for predicting data storage device failures using adaptive failure prediction modeling. In some embodiments, monitored parameters are used to predict a potential imminent failure of a first data storage device using a first copy of a first failure prediction model (FPM). Data associated with the predicted potential imminent failure are transferred by the device across a computer network to a host device. The host device generates an updated, second FPM responsive to the transferred data as well as from data from at least a second data storage device transmitted across the computer network having a second copy of the first FPM. A first copy of the updated, second FPM is transferred, via the network, for use by the second data storage device.

Adaptive failure prediction modeling for detection of data storage device failures

An adaptive search scheme leads to threshold voltages that have lower bit error rates over initial values. An initial reference voltage is used and data is measured for set steps in voltage about the initial value sufficient to fit a polynomial curve. A minimum is used to determine the lowest bit error rate and corresponding optimum threshold voltage. This voltage is adopted as the new threshold voltage for reading the given data.

Determination of optimum threshold voltage to read data values in memory cells

Systems and methods are disclosed for recording density variation of data tracks. In some embodiments, an apparatus may comprise a circuit configured to record data to a first track of a data zone at a first recording density, and record data to a second track of the data zone at second recording density different from the first recording density. Recording density may be measured as a bits per inch (BPI) value for a data track. Different recording densities may be applied based on a width of the target track. In some embodiments, such as for shingled magnetic recording (SMR), data may be recorded to partially overlapped tracks at a first density, and to non-overlapped tracks at a second density.

Recording density variation of data tracks

A data storage system having a read channel configured to function in a normal operation mode and a test mode. In the normal operation mode, the read channel is configured to decode a readback signal to obtain data bits. In the test mode, the read channel is configured to extract gain control loop data and/or timing control loop data from the readback signal.

Collection of readback signal modulation data

Apparatus and method for writing data to a data storage medium using shingled magnetic recording (SMR). In accordance with some embodiments, a transducer is positioned adjacent a recording medium. The transducer is used to write data to the medium in the form of partially overlapping tracks grouped together into bands so that a first track and a last track in a selected band are wider than remaining tracks in the selected band.

Shingled magnetic recording with variable track spacing

A predictive failure control circuit and associated method are provided in a data storing and retrieving apparatus. The circuit is configured to schedule a data integrity operation on data associated with a subportion of a data storage space, in relation to a comparison of an accumulated plurality of executed host access commands associated with the subportion. The subportion can comprise a sector or a single track or a band of tracks. A table preferably stores accumulated number of host access commands for each of a plurality of subportions of the data storage space. The data integrity operation can comprise reading the data on to detect degradation and restoring the recovered data to the same or to new, different tracks. The data subportions can also be reallocated to a new location.

Preventive recovery from adjacent track interference

A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the data track pitch established, a track location formula for data tracks on the surface is defined. For a disk drive with a plurality of read/write transducer-media surface combinations, a track location formula for data tracks is established for each combination. Disclosed is a method of measuring a track width performance of a read/write transducer which includes the steps of writing a first test pattern having a first waveform with the read/write transducer at location t on the surface of a magnetic medium, reading the first test pattern and measuring an error rate of the signal, followed by moving the read/write transducer in a first direction a predetermined distance from location t and writing a second test pattern comprised of a waveform different than the first waveform, moving the read/write transducer in a second direction to a position distance d from location t and writing a third test pattern comprised of a waveform different to the first test pattern. The first test pattern is read at location t and the error rate of the signal is measured. A disk drive including a disk having a first magnetic surface, a first read/write transducer associated with the first magnetic surface for reading and writing data in tracks in a plurality of zones each zone having a read/write frequency, a first load beam for supporting and positioning the first read/write transducer at a plurality of locations above the surface of the magnetic media as disclosed and the drives produced utilizing the steps of writing servo information in tracks on the surface at a track pitch, followed by measuring a track width performance of the read/write transducer and establishing a track pitch for data tracks as a function of the measured track width performance.

Disk drive with variable track density

Method and apparatus for off-track write error recovery. A storage medium is provided with at least first and second tracks, and a write protected status is assigned to the second track to inhibit subsequent writing of data thereto in relation to a position error detected during writing of data to the first track. Preferably, a third track is disposed between the first and second tracks. The position error is preferably characterized as a first position error, and a write fault condition is declared during the writing of data to the first track in relation to a second position error different from the first position error. Data write operations are preferably performed on additional tracks while the write protected status of the second track is maintained. In this way, dual-sided encroachment or other track squeezing effects are reduced.

Off-track write error recovery

A preamplifier that includes an input configured to receive a preamplifier control signal and a fault detection circuit configured to monitor the preamplifier control signal received at the input is provided. The fault detection circuit is further configured to identify a fault condition triggered by an improper temperature control signal provided by the preamplifier.

Preamplifier for use in data storage devices

A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the established track pitch, a track location formula for data tracks on the disk surface is defined. For a disk drive having a plurality of read/write transducers, a track location formula is established for each transducer. A method for measuring track width performance of a read/write head is also disclosed.

In a disk drive, a contact write current that causes head-disk contact due to pole tip protrusion is detected using a variance of a position error signal (PES). A method of determining the contact write current includes generating PES's in response to the head reading servo sectors on the disk, calculating PES variances wherein each PES variance is a statistical measure of a different group of the PES's, calculating a change in the PES variances, and selecting the contact write current in response to the change in the PES variances.

Determining contact write current in disk drive using position error signal variance

A method and apparatus for generating an index location from a spin motor of a disk drive are disclosed. A disk drive includes a motor having a plurality of commutation states, wherein changes in commutation states are controlled by an FCOM signal having FCOM pulses. Ideally, when the motor is spinning at a constant speed, the time between FCOM pulses is constant. However, the inventor of the present invention has recognized that, in practice, the time between FCOM pulses, when measured more closely, is not constant due to mechanical tolerances in the motor. Accordingly, the inventor has determined that the non-constant times between FCOM pulses can be advantageously used to generate a spin motor index in a disk drive. Once obtained, the spin motor index may advantageously be used for a number of purposes.

Method and apparatus for generating an index location from a spin motor of a disk drive

A method and apparatus to control the amount by which thermal expansion causes a write head to extend toward a disk is provided. In one aspect, a single write operation uses two or more different write currents. A first write current is initially used, and is large enough to achieve desired magnetic flux at the disk. After the write current heats and expands the arm tip, and extends it toward the disk surface, the write current is reduced, to avoid or postpone the time at which thermal expansion might cause the tip to contact the disk, or cause other undesirable effects.

Method and apparatus to control pole tip protrusion

The present invention provides a method and apparatus for recovering data in a disk drive following a read error. At least a portion of the actuator arm tip is heated. Thermal expansion reduces the read-head-to-disk spacing, increasing the likelihood of success when a re-read of the data is attempted. In one approach, a heater is operatively coupled to the tip. In one aspect, a write head is provided with write current in order to heat the tip. Data which may be modified or overwritten when providing write current to the write head is preferably read and buffered prior to the write operation, for later re-writing to the disk.

Read error recovery method and apparatus

A method for assembling and operating a fixed media hard disk drive using a disk or a stack of disks on which servo information is pre-written off the drive spindle. The disks are subsequently mounted on the drive spindle and a set of rotationally concentric &ldquo;virtual tracks&rdquo; for seeking and following in terms of said pre-written servo tracks are defined. The use of the concentric virtual tracks assures minimal actuator motion during drive operation and increases acceptable offtrack tolerances. The off-spindle, pre-writing of the servo information increases the efficiency of the assembly operation and reduces the clean room burden.

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Niwot, CO, United States of America

Bruce D Emo