Maxtor Corporation

Wd Media, LLC

Komag Corporation

Michael McNeil

Harlan P Mathews

Quinn Jay Haddock

Thomas O Melrose

David E Wachenschwanz

John Vicars

Larry J Koudele

Roger G Bailey

Carolyn R Girvin

Andrew W Davis

Moris Musa Dovek

Keith W Malang

Michael A Blatchley

Ross Chessman

G Herbert Lin

William G Haines

A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.

Patterned medium and recording head

The invention is generally directed to a slider that is particularly suited for dynamic load/unload disk drive designs. This slider desirably addresses potential disk damage associated with contact between sharp edges of the slider of the disk drive and the data storage surface of a corresponding disk. Any appropriate type/configuration of a disk drive may benefit from performing read/write operations utilizing the slider of the present invention. Generally, this slider includes at least one air bearing surface which enables the slider to 'fly' above the read/write surface of the disk, and at least one self-blending contact pad disposed on the lower surface of the slider to reduce the potential for contact between any portion of the slider other than the self-blending contact pad(s) and the corresponding read/write surface of the disk.

Flying-type disk drive slider with self-blending contact pad

The present invention provides a flux-guided head for use in a magnetic recording system, such as a disk drive. The head includes a write element that is capable of writing magnetic polarity transitions into the surface of a magnetic media, such as a magnetic disk, using vertical/perpendicular recording techniques. Further, a read element is provided that includes a magnetoresistive element that, when reading perpendicularly-recorded magnetic transitions from the surface of the magnetic media, produces a readback pulse signal having a substantially Lorentzian pulse shape.

Magnetic storage device with flux-guided magnetoresistive head using a perpendicular recording media

A disk drive utilizes a unique write condition for each of the transducers within the drive. Each write condition is determined based upon the specific properties of the corresponding transducer. The write condition information is preferably stored within a memory within the disk drive. When a write operation is performed, the appropriate write condition for the corresponding transducer is used to determine when to write data to the disk. A write condition will typically include one or more individual write criteria. For example, a write condition can specify a write threshold value to be used during a write operation. A write fault threshold value is selected for each transducer by determining a position error distribution corresponding to that transducer wherein the position error distribution is essentially a function of random noise associated with the disk drive, and by using that distribution to determine allowable off-track threshold value (WFL), will protect the drive from encroachments.

Method to accurately predict hard error rates resulting from encroachment

A disk drive utilizes a track dependent variable write fault gate for each of the transducers within the drive. By deriving a 3 sigma distribution across the repeatable run out (RRO) and the non-repeatable run out (NRRO), a position error signal (PES) is derived which varies in magnitude across the stroke of the transducers and which has a slope used to derive variable write fault gate thresholds for the tracks associated with each transducer. As the stroke of the transducer moves from the outer diameter (OD) to the inner diameter (ID), the magnitude of the write fault gate thresholds may be decreased relative to the PES, and track density and capacity may increase where PES and write fault gate thresholds are low. The invention thus maintains a constant hard error recovery margin across the stroke.

Method and apparatus for increasing track density by adapting write fault gate to position error signal as it varies from ID to OD

Adaptive channel optimization in a disk drive is achieved by selecting a track of the recording medium and then writing a first data pattern to opposite sides of the selected track. The first data pattern is written a certain percentage off-track in relation to the centerline of the selected track. A second data pattern is then written directly on the selected data track and the off-track margin is determined as a function of how far the recording head can be positioned away from the center of the selected track during reading of the second data pattern while meeting a specified error rate. The off-track margin test is repeated iteratively using a combination of channel variable settings in order to find a set of variable settings which provides an optimal performance criterion for the drive.

Disk drive with adaptive channel optimization

The present invention relates to circuitry for processing an analog read signal, such as a signal produced by a magnetoresistive head, in a magnetic data storage system. The circuitry processes the analog signal before the signal reaches the detector which converts the analog signal into a digital signal representative of the data originally stored on the magnetic medium. In one embodiment, the invention comprises circuitry for equalizing the amplitudes of the positive and negative pulses in the analog read signal. In another embodiment, the invention comprises circuitry for reducing the baseline shift of the analog read signal. The invention may be used in magnetic data storage systems using any conventional data detection method.

Mr head read signal preconditioning circuitry

A method for fabricating a dual element head is disclosed. One embodiment includes first depositing a first head element upon a substrate and second depositing a second head element upon the first head element. Each of the depositing steps includes a tolerance that is independent of the other. In the second depositing step, the functional width of the second head element (i.e., the write width if the second head element is a write element) is made wider than a desired functional width for the second head element. The second head element is then trimmed to substantially achieve the desired functional width while using a portion of the first head element as a reference to reduce errors associated with the independent nature of the first and second tolerances. For instance, the portion of the first head element used as a reference can be an edge of a magnetoresistive (MR) read element that defines the read width of the read element. Preferably, the trimming step includes creating erase notches on a portion of the write element that are capable of erasing data from a recording medium. Thereafter, second notches that are deeper than the erase notches and hence less capable of erasing data than the erase notches are created next to the erase notches to adjust the width of the erase notches. It is also preferred that the first head element and the second head element include an air bearing surface that resides substantially in the x-z plane, and that the second head element is trimmed by a focussed ion beam from a direction that includes a y-component to adjust the width of the second head element in the z-direction.

Method for fabricating a dual element head

Adaptive channel optimization in a disk drive is achieved by selecting a track of the recording medium and then writing a first data pattern to opposite sides of the selected track. The first data pattern is written a certain percentage off-track in relation to the centerline of the selected track. A second data pattern is then written directly on the selected data track and the off-track margin is determined as a function of how far the recording head can be positioned away from the center of the selected track during reading of the second data pattern while meeting a specified error rate. The off-track margin test is repeated iteratively using a combination of channel variable settings in order to find a set of variable settings which provides an optimal performance criteria for the drive.

Disk drive using off-track margin to obtain optimal performance

MR head read signal preconditioning circuitry for reducing pulse

A dual element head is provided that includes a read element and a separate write element, wherein the read width of the read element is greater than the write width of the write element. The head also includes an erase notch for creating an erase strip along the edge of data written by the write element during a write operation. The width of the erase strip is optimized so that undesired data on the track, that could otherwise be read by the wider read element during a subsequent read operation, is removed during the write operation.

Disk drive head having a read wide/write narrow architecture

The present invention is directed to a disk drive that employs a proximity recording interface in which a slider that carries a head is designed to remain in contact with the disk during data transfer operations to achieve a high data density. In particular, the present invention is directed to cleaning debris from a pad on the slider that carries the head. The debris, if allowed to accumulate, can reach a depth at which the head is spaced from the disk at a distance which adversely affects the transfer of data with the disk. In one embodiment, the spin motor of the disk drive is caused to rotate at a lower angular velocity than during normal data transfer operations while the actuator of the disk drive is used to radially displace the slider and associated head. For a constant angular velocity of the disk, the change in radial position causes different areas of the pad to be contacted and cleaned by the disk. Additionally, the disk is cleaned of debris that could also affect the ability to transfer data with the disk. Further, the lubricant on the disk surface that facilitates the proximity recording interface and may have migrated is redistributed.

Self-cleaning proximity recording interface

A resonant frequency control circuit communicates with a head of a disk drive and the preamplifier of a read channel. The resonant frequency control circuit is useful in achieving peaking of a readback signal generated by reading data from a magnetic disk. The read channel also includes an equalizer circuit for enhancing equalization of the readback signal. A controller communicates with the read channel and the resonant frequency control circuit for, in one embodiment, selectively adding capacitance to that capacitance which is present in the read element of the head and the preamplifier. By controlling the resonant frequency, this desired signal peaking can be achieved, which is related to the frequencies of the coded data on the disk.

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Nederland, CO, United States of America

Michael McNeil