Seagate Technology Incorporated

Pu-Ling Lu

Edward Charles Gage

Wenzhong Zhu

Tim Rausch

Alfredo Sam Chu

Minjie Ma

Kaizhong Gao

Riyan Alex Mendonsa

Nurul Amin

Patrick Joseph Ryan

Jason Wayne Riddering

Jason Charles Jury

John West Dykes

Huazhou Lou

Drew Michael Mader

Ned Tabat

Johannes Van Ek

Franklin P Martens

James H McGlennen

Andrzej Adam Stankiewicz

Taras Grigoryevich Pokhil

Steven Paul Bozeman

Steven Kalderon

Janusz Jozef Nowak

Douglas A Saunders

An error is determined in a target track of a heat-assisted recording medium. The error triggers an error recovery procedure. The error recovery procedure involves storing data from at least part of an adjacent track that is immediately proximate the target track to another data storage location. The error recovery procedure also involves, for two or more iterations in which a laser power is incrementally changed from a lower power to a higher power, erasing at least part of the adjacent track at the laser power and attempting to recover the target track.

Heat-assisted magnetic recording error-recovery by erasing adjacent tracks using laser

An apparatus and method provide for performing, using a heat-assisted magnetic recording head, multiple sequential writes to a recording medium, and recording a metric of write performance for each of the writes. The apparatus and method further provide for calculating fluctuations in the metric, detecting whether the head has a laser mode hopping problem using the metric fluctuations, and categorizing a severity of the laser mode hopping problem.

Laser mode hopping detection method and apparatus for a heat-assisted magnetic recording device

A method comprises performing a write operation using a heat-assisted magnetic recording (HAMR) drive operating at a plurality of temperatures. The method involves measuring a metric of write performance subsequent to the write operation at each of the operating temperatures. The method also involves detecting one or more laser mode hops using the metrics, and determining a temperature at which each of the detected mode hops occurred. The method further involves storing the temperature for each detected mode hop in a non-volatile memory of the drive. The method may involve mitigating laser mode hopping, such as by the drive avoiding the stored temperature(s).

Laser mode hopping detection in a heat-assisted magnetic recording drive

Bits are written to a track of a heat-assisted magnetic recording medium via a write transducer at a first skew angle. The track is read via a read transducer oriented at a second skew angle different from the first skew angle. The second skew angle causes the read transducer be more closely aligned with boundaries of the bits than if oriented at the first skew angle.

Reading and writing to a HAMR recording medium at different skew angles

Based on thermal time constant of a head-to-media spacing of a write head, a write parameter is determined that includes at least one of: a modified laser power boost used at a beginning of writing; and a time adjustment affecting the beginning of the writing. The write parameter is applied to writing operations affecting a heat-assisted magnetic recording medium, the write parameter ensuring accurate phase lock during reading of the heat-assisted magnetic recording medium.

Write parameters used to ensure accurate phase lock during reading of a heat-assisted magnetic recording medium

A method includes setting a heat assisted magnetic recording (HAMR) device located in a data storage system having a laser to an operating temperature. A threshold laser current is determined. An optimal laser current is determined. The threshold laser current and the optimal laser current are stored in memory. The steps of determining a threshold laser current, determining an optimal laser current and storing the threshold laser current and the optimal laser current into the calibration table are repeated until acceptable device performance is achieved at more than one operating temperature.

Laser temperature calibration in a HAMR device

The present invention relates to a head having an air bearing surface for confronting the surface of a storage medium. The head includes a first pole that is spaced apart from a second pole. At least one non-magnetic spacer is positioned between the first pole and the second pole such that the first pole is magnetically decoupled from the second pole. In a further aspect, one or both of the first pole and the second pole can be elliptical in shape.

Recording head for reducing side track erasure

Growing community of inventors

Rosemount, MN, United States of America

Pu-Ling Lu