Maxtor Corporation

Seagate Technology Incorporated

Jingbo Yu

Erhard Theodor Schreck

Duc H Banh

Donald Joseph Brunnett

Bruce C Schardt

Scott A Hughes

Kazuhiro Saito

Andrew LeFebvre

Chris Hawks

Michael L Mallary

Thao Anh Nguyen

Don Brunnett

Brian D Strom

Francis P Crimi

Mark Heimbaugh

Joerg Ferber

Suet Teo

Yu Sun

Gang Herbert Lin

Xiaoping Hu

Richard Oswald

Lloyd E Levy

Douglas J Krajnovich

Kezhao Zhang

John Vicars

Anthony R Hurtado

Tim Glassburn

Adrian E Cerda

Duc Bahn

Nick Warner

James McFadyen

Kiem Nguyen

Pang L Tan

Kurt Rusnak

A distance between a head and a storage media is measured. An amount of power applied to a heater element in the head is adaptively adjusted based on a difference between the measured distance and a reference position indicating a desired distance between the head and the storage media. Related circuits and devices are also discussed.

Closed loop fly height control

A disk drive includes a rotatable storage disk, an actuator motor, a slider that magnetically interacts with the storage disk, and a drive circuitry. A portion of the slider moves between a first position wherein the slider does not contact the storage disk and a second position wherein the slider contacts the storage disk. The drive circuitry can detect when the position of the slider changes between these positions. In one embodiment, the drive circuitry monitors off-track movement of the slider to detect when the slider has moved between these positions. The drive circuitry can also current that is directed to the actuator motor that is used to compensate for off-track movement to detect when the slider moves between these positions. In yet another embodiment, the drive circuitry monitors a rotational velocity of the storage disk to detect approximately when the slider moves between these positions.

System for detecting a change in head-to-disk contact status in a disk drive

A disk drive having a drive housing, a storage disk that is rotatably coupled to the drive housing, and a slider assembly that includes a head and a slider mover. The head reads data from the storage disk during a read operation and writes data to the storage disk during a write operation. The slider mover maintains the head at a read HtD spacing during the read operation, at a pre-write HtD spacing during the read operation prior to the write operation, at a write HtD spacing during the write operation, and at an idle HtD spacing when the drive is not performing the read operation or the write operation. The disk drive includes a drive circuitry that directs a read power level to the slider mover to maintain the head at the read HtD spacing, a pre-write power level to maintain the head at the pre-write HtD spacing, a write power level to maintain the head at the write HtD spacing, and a idle power level to maintains the head at the idle HtD spacing.

Disk drive that positions a head at multiple head-to-disk spacings

A disk drive includes a drive housing, a storage disk, a slider and a drive circuitry. The slider magnetically interacts with the storage disk, and includes a read/write head that is positioned to have an actual head-to-disk spacing greater than zero nanometers during rotation of the storage disk. The drive circuitry can determine and/or monitor the actual head-to-disk spacing at any time during the operation of the disk drive based on an amplitude or a change in the amplitude of a signal such as a variable gain amplifier signal. In one embodiment, the slider includes a slider mover that receives current via the drive circuitry and causes a deformation of a portion of the slider to change the head-to-disk spacing based on the amplitude of the signal. In another embodiment, the read/write head moves during substantially consistent rotational velocity of the storage disk from a first actual head-to-disk spacing equal to approximately zero nanometers, to a second actual head-to-disk spacing that is greater than zero nanometers based on a desired amplitude of the signal.

System for monitoring and dynamically adjusting head-to-disk spacing in a disk drive

A method and apparatus for providing a temporary utility zone in a disk drive. A disk surface has a write head associated therewith. The write head is used to write spiral servo information and a propagation state indicator onto the disk surface. The spiral servo information and propagation state indicator are used to perform a self-servo write operation on the disk surface.

Method and apparatus for performing a spiral self-servo write operation in a disk drive using an auto detection scheme

A method of determining side track erasure in a disk drive having a disk and a transducer. A target track and one or more side tracks proximate to the target track on the disk are selected, and recording parameters for recording signals on the target track and each side track with the transducer are selected. Thereafter, signals are recorded on each side track and then signals are recorded on the target track multiple times. A reduction in the integrity of the recorded signals on each side track due to recording signals on the target track multiple times is detected, and the detected reduction in the integrity of the recorded signals on each side track represents the amount of the erasure of the recorded signals on the side track. Recording parameters are changed based on the signal integrity reduction to minimize side track erasure.

Method of determining side track erasure in a disk drive

A PTP test subsystem of a magnetic disk drive identifies an undesired pole tip protrusion (PTP) condition, and takes steps to prevent problems associated with PTP. A PTP stressing mechanism stresses the disk drive during a PTP test mode to induce a PTP condition. A disk contact detection circuit detects when a head of the disk drive contacts the disk. A PTP write current determining circuit is also provided which comprises a write current level detector to ascertain a write current level at which the disk contact detection circuit detects when the head of the disk drive contacts the disk while the disk drive is stressed during the PTP test mode.

Monitoring of phenomena indicative of PTP in a magnetic disk drive

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San Jose, CA, United States of America

Jingbo Yu