Seagate Technology Incorporated

International Business Machines Corporation

Capella Photonics, Inc.

Jp Morgan Chase Bank

Iolon, Inc.

Seagate Tech. LLC

U.S. Philips Corporation

Karl Arnold Belser

Terry Wayne McDaniel

John H Jerman

Edward Charles Gage

Gabor Szita

Lawrence Matthias Bryant

Alan A Fennema

Jeffrey P Wilde

Jerry E Hurst, Jr

Alexei Hiram Sacks

Stephen J Hrinya

James E Durnin

John Edward Kulakowski

Joseph Eugene Davis

Robert Dale Murphy

Wayne Leung Cheung

Christina L Hutchinson

Ju-Hi John Hong

Lori Grace Swanson

Aihua E Li

Max T Artusy

Ga-Lane Chen

Glen Alan Jaquette

Louis Joseph Serrano

Mohamad Towfik Krounbi

Mario Blaum

Kurt A Rubin

Rodney Jerome Means

Satoshi Yamamoto

Li-Ping Wang

Mark H Garrett

Timothy Francis Ellis

Neil Deeman

Tarek Makansi

Gayle L Noble

Johannus Leopoldus Bakx

Ronald Evan Gerber

Joseph D Drake

Michael Paul Salo

Ian L Sanders

Charles Frederick Brucker

Craig N Fukushima

Pavel G Polynkin

Judson A McDowell

Masud Mansuripur

Scott Arthur Thomas

Jill D Berger

Patrick J Korkowski

Tai Seng Chen

Randall Harry Victora

Ian E Henderson

Spencer D Roberts

Ronald J Kadlec

ChiapHeok Ang

Howard S Lee

John H Richards

Paul J Dounn

Rodney J Whitefield

Michael R Madison

Gabor Sz&iuml;ta

Dave Anthony Freitas

Gabor G Szita

Paulus G Weijenbergh

Philip B Metz

The present invention provides for the enhancement of the storage capacity of a data disk drive while reducing optical path optics, electronics and/or the mass and complexity of associated read/write heads. The system utilizes light transmitted by optical elements to servo track a data disk and to heat the data disk during reading and writing of data, and magnetic elements for actual reading and writing.

Laser assisted track width definition and radial control with magnetic recording

A novel wavelength routing apparatus is disclosed, which uses a diffraction grating to separate a multi-wavelength optical signal from an input port into multiple spectral channels; a channel-interleaving assembly (e.g., an array of prisms) to interleave the spectral channels into two channel groups; and an 'augmented relay system' to relay the interleaved channel groups onto two separate arrays of channel micromirrors, respectively. The channel micromirrors are individually controllable and pivotable to reflect the spectral channels into multiple output ports. As such, the inventive wavelength routing apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. Further, the channel-interleaving scheme thus devised effectively 'enlarges' the channel spacing and thereby allows the channel micromirrors in each array to be made considerably larger and more reliable, thereby significantly improving the channel filtering characteristics and ensuring more robust performance.

Free-space dynamic wavelength routing systems with interleaved channels for enhanced performance

The invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into multiple output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values. The WSR apparatus of the present invention can be used to construct a novel class of dynamically reconfigurable optical add-drop multiplexers (OADMs) for WDM optical networking applications.

Reconfigurable all-optical multiplexers with simultaneous add-drop capability

A system and method for replicating magnetic patterns on hard disk media includes a mask located over or above a magnetic recording layer. The recording layer may include a single, dual, or multi-layer recording layer. A pattern is or has been formed in the mask, where the pattern defines the recordable regions and the non-recordable regions to be created in one or more layers within the recording layer. Portions of the recording layer are then exposed. An etch may then be performed to create grooves within one or more layers in the exposed regions of the recording layer. The magnetic properties of at least one layer in the exposed portions of the recording layer are then altered in order to create recordable or non-recordable regions. The mask is then removed from the recording layer.

Method for replicating magnetic patterns on hard disk media

Embodiments of a data storage system having thermally activated readout are provided, in one embodiment, a data storage system includes a source of heat, a substrate, a write layer disposed above the substrate, a copy layer disposed above the write layer, a flying head disposed above the layers and carrying the source of heat for heating a selected spot on the copy and write layers, wherein the write layer comprises a ferromagnetic material selected to have an extremely high coercivity at room temperature and a very high write temperature T, and the copy layer comprises a ferromagnetic material selected to have a coercivity always less than coercivity of the write layer at the same temperature and a copy temperature Tsubstantially less than the write temperature of the write layer.

Data storage system having thermally activated readout

A transducer position sensing system in a disc drive to take frequent data measurements from micro-servo sectors on the disc and to interpret the information to predict recording failures. The disc drive is formatted with many small or micro-servo sectors containing, among other things, a servo address mark, encoded disc location information, and radial track position information. The sensing system frequently retrieves this information through the transducer, compares the measurements to expected values, and given unexpected measurements predicts errors. The time elapsed between the passing of servo address marks can be used to predict adjacent sector overwrites. The radial track position information can be used to predict off-track write errors. The radial track position signal amplitude can be used to predict the transducer moving too far from the disc, resulting in skip write errors.

Position sensing system for a disc drive using micro-servo sectors and side-by-side R/W recording elements

Fabrication of an MO disc, the formation of a master pattern of servo and track information, and the subsequent transfer of that pattern to a series of pits and grooves on a substrate. On top of that substrate, at least one sacrificial layer is provided atop a relatively hard layer. The recording stack may be provided with both silicon nitride and silicon dioxide top layers, with the silicon dioxide layer acting as a sacrificial layer to ensure that the hard layer, of silicon nitride, remains at the end of the process. A layer of aluminum or aluminum alloy may be deposited, with the aluminum plugs filling the grooves and pits (created by the embossed servo information) to a level higher than any of the adjacent layers of silicon dioxide, silicon nitride, or similar dielectric layer. Since the polishing rate of aluminum can be far faster than that of the silicon dioxide, then the aluminum can be etched or otherwise removed down to a level equal to or slightly below a planar surface with the silicon dioxide, with the silicon dioxide layer allowing for some small level of over polishing. The silicon nitride layer is protected completely; the silicon dioxide layer partially remains and is partially removed; and the aluminum metal which fills the grooves and pits would rise only to a level substantially equal the very flat top surface of the silicon dioxide.

Method for providing track position and identification information for data storage devices

A disc drive with an information portion previously written on a rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing a reference mark to the rotatable disc surface in substantial time alignment and phase and frequency coherent with the information portion previously written to the rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing the reference mark, a pulse detector circuit for creating logic level signals from the reference mark, a pattern generator for generating reference mark write signals from the logic level signals, a memory buffer for storing radial position correction tables and values for writing the reference mark, and a self-servo control and sequencing circuit synchronizing timing signals for writing the reference mark to rotatable disc surface of disc drive.

Self-writing servo and clock fields on a recording medium

Marks with curved edges are used in data patterns and sensed with proximity recording. Circular, elliptical, and oval marks are examples of marks with curved edges that can be used in the present invention. The marks with curved edges are used to define data patterns (e.g. position error signal patterns) as a function of radius. If the marks with curved edges have been recorded longitudinally, an amplitude of a read back signal, such as a peak amplitude, is determined in order to generate a position error signal. If the marks with curved edges have been recorded vertically, an area under the curve of the read back signal is determined in order to generate a position error signal.

Method and system for utilizing circular marks in position error signal patterns

A propagating method is provided in which timing and servo sector information is propagated throughout a data storage media that initially contains only a guide pattern. The method uses an offset between the write element and the read element in a read/write head to position and propagate the timing information. In addition, a method for circumferentially aligning timing and servo sector information is disclosed that utilizes a time delay to position the propagated timing and servo sector information. Another method for attenuating timing errors during timing and servo sector propagation to a data storage media is disclosed. Timing errors are attenuated through the use of phase locked loop circuit and measurement of the phase error detected between different tracks on the data storage media. Apparatuses implementing the methods including a storage device readable by a computer system that implements the methods are provided.

Circumferential positioning of servo sectors for servo track writing

Radial correction factors are calculated for each ruler on a patterned media in a data storage system. A ruler is a position-sensing pattern that defines the radial position of a recording head. Rulers are patterned onto each disk before the disks are assembled into a storage system. The radial correction factors are then added to the measured position information during read and/or write operations of the data storage system. The radial correction factors correct for any radial misalignment created by disturbances in the data storage system. Circumferential correction factors are calculated for each patterned media in the data storage system. A corrected sector number is then determined by redefining the original sector numbers using the circumferential correction factors.

Method and system for radial and circumferential alignment of data tracks on patterned media

A patterned media having recordable and non-recordable regions is initialized by first erasing (e.g. DC magnetizing) at least a portion of the recordable regions. At least one offset may then be determined. The at least one offset may compensate for a read to write delay in the electronics and/or at least one delay caused by the space separation between a read and a write head. A plurality of position error signal (PES) bursts may then be written on at least a portion of the recordable regions. During the write process, the previously written PES bursts are read and used to determine PES signals (e.g. servo signals) in order to guide the write head while writing new PES bursts. Magnetically written gray code may then be written on the media. The magnetically written gray code may be used to define a track number for the data tracks with no eccentricity.

Method and system for initializing patterned media

A method for self-servo writing begins by calibrating at least one ruler formed on at least one storage disk. A ruler is a position-sensing pattern that defines the radial position of a recording head. The calibration process determines at least one correction factor for the at least one ruler on the disk. A servo system is then activated and the correction factors are used when writing the final servo pattern. During the process of writing the final servo patterns, the correction factors are modified to account for variations in any repeatable disturbances and for errors caused by any non-repeatable disturbances.

Writing servo data patterns on a data storage disk to account for repeatable and non-repeatable disturbances and thereby provide concentric data tracks

A patterned recording media is comprised of a combination of raised features and depressed features in or on the surface of the recording disk. A depressed feature is known as a pit, while a raised feature is known as an island. The islands form areas where one or more data bits can be written. The recording head is synchronized to the discrete bit pattern by determining the correct clock cycle (phase) and clock count within the clock cycle.

Method for synchronizing the write current for magnetic recording with the bit islands on discrete bit patterned media

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San Jose, CA, United States of America

Karl Arnold Belser