International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

University of Minnesota

Other

Hitachi Global Storage Technologies

Hitachi Global Technologies

Hal Hjalmar Ottesen

Gordon James Smith

Earl Albert Cunningham

Zine-Eddine Boutaghou

George Willard VanLeeuwen

Dana H Brown

Kevin Jack Erickson

George Willard Van Leeuwen

Richard Greenberg

Muthuthamby Sri-Jayantha

David William Abraham

Sri Muthuthamby Sri-Jayantha

Arun Sharma

Timothy C Reiley

Long-Sheng Fan

James Hammond Brannon

Nathaniel C Anderson

Michael Joseph Ross

Karl Gong

Daniel L Good

Mohammed Amine Hajji

James P Licari

Donald R Tobie

George Willard Vanleeuwen

Timothy Joseph Chainer

Hemantha Kumar Wickramasinghe

Dallas W Meyer

Mark David Hagen

Lowell James Berg

John Jeffrey Stephenson

Anthony Paul Praino

Mark E Re

Michael Charles Stich

Jerry Lee Neubauer

Thomas W Glaser

Peter M Herman

Thomas S Larson

Koichi Arai

Karl-Friedrich Etzold

Molly Smith

Richard H Estry

Russell A Billings

Jeffrey E Mason

Jay Michael Mosbrucker

Dean C Palmer

Gregory G Floryance

David Eugene Iverson

Gary T Egbert

Jim Walters

Dana Henry Brown

Russell Allen Billings

Method, apparatus and signal bearing medium for processing multimedia data which improve server performance in rendering multimedia data. In one aspect, a method is provided for processing multimedia data without requiring utilization of the hard disk drive's data recovery procedure when soft or hard errors are encountered in connection with reading of the multimedia data from the hard disk drive. The method for processing multimedia data comprises: indexing the multimedia data to an i by j matrix; storing the i by j matrix in a data storage device utilizing odd/even index sequencing of the i by j matrix; retrieving data from the data storage device; and reconstructing the i by j matrix utilizing odd/even index sequencing of retrieved data.

Location predicative restoration of compressed images stored on a hard disk drive with soft and hard errors

An original image or other data sequence is modified with an internal marker value, and is communicated (stored and/or transmitted) as one component of a transform having multiple complementary components. The image is restored in a closed form, without iteration, and in some cases without any loss of precision from the original image. The original image may have complex element values. Multiple original images may be combined, and separated after restoration. Several types of maps may be embedded in or packaged with the communicated component. Communicated component elements may be stored with variable lengths.

Non-iterative method to restore image from transformed component data

A hybrid energy system heats or cools a plant with a geothermal unit powered at least partly by a fuel cell, which may also power other devices. The thermal fluid for the geothermal unit also cools the fuel cell via a heat exchanger. A digital controller bypasses a variable portion of the thermal fluid around the heat exchanger to regulate the fuel-cell temperature.

Hybrid geothermal and fuel-cell system

A method and apparatus for estimating the flyheight of an airbearing slider in a storage device. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a rated storage disk velocity. For each of the washboard-sections, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured. A determination is made of which washboard-section caused the largest measured flyheight modulation. The washboard-section having a pitch that provides an excitation frequency (when the disk is rotated at the rated storage disk velocity) that is closest to the actual airbearing resonance frequency of the slider will produce the largest flyheight modulation. The result of this determination is used to estimate the flyheight of the slider. For example, the flyheight may be estimated using an empirical formula that relates the flyheight and the resonance frequency. Once the flyheight is estimated, a determination may be made of whether the flyheight is unsatisfactory, e.g., below a minimum flyheight or decreasing. Appropriate action may be taken when the flyheight is unsatisfactory, such as notifying the user and/or scrubbing the slider. Accordingly, catastrophic head-crash may be avoided and the useful life of the storage device extended.

Method of manufacturing an apparatus and a method for estimating the flyheight of an airbearing slider in a storage device

A slider having leading and trailing edges is configured to fly on an airbearing above a data storage disk rotating from the leading edge to the trailing edge. Read and write heads are mounted on the slider proximate the trailing edge. An auxiliary thermal sensor is mounted on the slider, but preferably nearer the leading edge. Forward placement of the sensor allows it to sense mechanical defects before they reach the heads, thereby permitting a write inhibit operation, for example. The sensor may also be used to detect airbearing modulation. Appropriate action may be taken when unacceptable airbearing modulation is detected, such as notifying the user and/or scrubbing the slider. The sensor is preferably wider than the heads. This allows, for example, an in-situ glide test to be performed faster using the sensor. An arm electronics module is preferably configured to permit concurrent operation of the sensor and heads.

Apparatus for look-ahead thermal sensing in a data storage device

A slider having leading and trailing edges is configured to fly on an airbearing adjacent a data storage disk rotating from the leading edge to the trailing edge. Read and write heads are mounted on the slider proximate the trailing edge. An auxiliary thermal sensor is mounted on the slider, but preferably nearer the leading edge. Forward placement of the sensor allows it to sense mechanical defects before they reach the heads, thereby permitting a write inhibit operation, for example. The sensor may also be used to detect airbearing modulation. Appropriate action may be taken when unacceptable airbearing modulation is detected, such as notifying the user and/or scrubbing the slider. The sensor is preferably wider than the heads. This allows, for example, an in-situ glide test to be performed faster using the sensor. An arm electronics module is preferably configured to permit concurrent operation of the sensor and heads.

Method for look-ahead thermal sensing in a data storage device

A position error signal amplitude indicative of the distance between an expected position of a magnetic head relative to the track centerline of a magnetic data storage and retrieval system and an actual position of the magnetic head relative to the track centerline is detected and filtered. The signal is filtered to generate a sway mode signal amplitude indicative of an oscillation of the actual position of the magnetic head relative to the track centerline in the frequency range of the filter. The absolute value of the sway mode signal amplitude is then determined. If the absolute value of the sway mode signal exceeds a predetermined threshold value that correlates to a high probability of impending a head-disk crash, a warning signal is propagated. Alternative embodiments similarly predict the possibility of head-disk crash on the basis of the maximum value of several samples of the position error signal and on the basis of the maximum value of several samples of the square of the position error signal amplitude

Method and apparatus for controlling data read/write between a hard disk and a hard disk controller

An image in a base domain (e.g., spatial) is restored from only one component (e.g., magnitude) of a transform-domain (e.g., Fourier) image by combining this component with a complementary component (e.g., phase) of a transformed previous iteration. Every iteration is converted to the base domain, and predefined known marker and padding data is reapplied to the iteration during every iteration, for convergence purposes. The restored image can be scaled and trimmed, and the marker position interpolated. The original image to be restored is modified to contain the known marker and known padding at known locations. These may be inserted in the base domain or in the transform domain.

Image restoration from transformed component data

A disk for a disk drive data storage device contains embedded track identifying fields which identify a track within a range of tracks, the range being less than the full range of tracks on the disk surface. The full identity of a track during a track seek operation is determined by iteratively assuming a track identity and estimating acceleration of the transducer based on the assumed track identity, until a track identity is found for which estimated acceleration meets some pre-determined threshold. Preferably, embedded servo fields are recorded at angularly spaced intervals on the disk surface, and every Nth servo field contains a Gray code full track identifier, while all servo fields in between contain abbreviated Gray code fields which identify a track within a range of tracks.

Method and apparatus for determining track identity from abbreviated track identifying data in a disk drive data storage device

Method and apparatus for estimating the flyheight of an airbearing slider in a storage device

A recording disk contains at least two types of servo sector format, including a first type having a relatively larger track identifying field containing the track number, and a second type having an abbreviated track identifying field identifying a track within a range of tracks, the range being less than the full range of tracks on the disk surface. Preferably, Gray code encodings are used, the first type of track field contains sufficient Gray code bits to identify the ful track number, every Nth servo sector is of the first type, and all servo sectors in between are of the second type, N being at least 2. As a result, the disk area required for track identification is reduced, and the additional disk space available can be used to expand the PES field.

Servo format for disk drive data storage devices

A disk drive comprises an actuator servo control system including at least one disk, an actuator structure comprising at least transducer head for writing and/or reading data from the disk and providing a transducer head position error signal (PES), and a servo compensator applying a servo control algorithm to the PES to produce a servo control signal. An adaptive elliptic notch filter controller is adapted to analyze the PES for a transducer head at a disk track radii, identify resonant disturbances present in the PES, select two adjacent resonant disturbances having first and second frequencies, ascertain coefficients of at least a fourth-order elliptic notch filter transfer function having first and second zero-notches with frequencies substantially at the first and second resonant frequencies, apply the at least fourth-order elliptic notch filter transfer function with the ascertained coefficients in the servo system to thereby substantially attenuate the selected adjacent resonant disturbances.

Adaptive dual-frequency notch filter

A method and apparatus are provided for in situ detection of high-flying sliders over customer data. A sampled and digitized readback sequence x(n) from a logical data block of customer data is received. Bandpass filtered data of the readback sequence x(n) is generated and processed for generating a predefined harmonic ratio. The generated predefined harmonic ratio is compared with a predefined threshold value to identify a high-flying slider. Bandpass filtered data of the readback sequence x(n) is generated with a digital comb filter and a digital resonator. The bandpass filtered data of the readback sequence x(n) is either squared or the absolute value is taken for a predefined number of samples and then accumulatively summed for the predefined number of samples and the harmonic ratio is calculated. The generated predefined harmonic ratio is compared with a predefined threshold value that is determined as a function of head and disk parameters. During a read operation, an equalizer high-frequency boost is generated responsive to identifying a high-flying slider. During a write operation to a selected write location, the write operation is aborted responsive to identifying a high-flying slider near the selected write location.

Method and apparatus for in situ detection of high-flying sliders over customer data

A method and apparatus for estimating the flyheight of an airbearing slider in a storage device using variable spindle velocity. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a plurality of discrete velocities. For each of the washboard-sections and at each of the velocities, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured as the storage disk rotates at that velocity. A determination is made of the velocity/washboard-section combination that caused the largest measured flyheight modulation. The combination that provides an excitation frequency closest to the actual airbearing resonance frequency of the slider will produce the largest flyheight modulation. The result of this determination is used to estimate the flyheight of the slider. For example, the flyheight may be estimated using an empirical formula that relates the flyheight and the resonance frequency. Once the flyheight is estimated, a determination may be made of whether the flyheight is unsatisfactory, e.g., below a minimum flyheight or decreasing. Appropriate action may be taken when the flyheight is unsatisfactory, such as notifying the user and/or scrubbing the slider. Accordingly, catastrophic head-crash may be avoided and the useful life of the storage device extended.

Method and apparatus for estimating the flyheight of an airbearing slider in a storage device using variable spindle velocity

A method and apparatus are provided for implementing enhanced, high speed updating and storing of electronic-commerce orders in a server computer system. A received electronic-commerce order is stored in a predetermined temporary read/write cylinder of a disk drive. Responsive to identifying that the predetermined temporary read/write cylinder is full, the stored electronic-commerce order is read. A customer type for the electronic-commerce order is identified. Responsive to identifying a predefined first customer type for the electronic-commerce order, the electronic-commerce order is transferred from the predetermined temporary read/write cylinder to a selected cylinder within a set number of cylinders from the predetermined temporary read/write cylinder. Responsive to identifying a predefined second customer type for the electronic-commerce order, the electronic-commerce order is transferred from the predetermined temporary read/write cylinder to a selected cylinder more than the set number of cylinders from the predetermined temporary read/write cylinder.

Method and apparatus for enhanced, high speed updating and storing of E-commerce orders in a server

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Rochester, MN, United States of America

Hal Hjalmar Ottesen