Maxtor Corporation

Western Digital Technologies, Inc.

Hgst Netherlands, B.v.

Headway Technologies, Incorporated

International Business Machines Corporation

Seagate Technology Incorporated

Other

Kabushiki Kaisha Toshiba

Tdk Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Erhard Theodor Schreck

Sukumar Rajauria

Barry C Stipe

Yuchen Zhou

Xuhui Jin

Kenichi Takano

Joe Smyth

Shen Ren

Bruce C Schardt

Moris Musa Dovek

John Thomas Contreras

Lidu Huang

Thao Anh Nguyen

Donald Joseph Brunnett

Robert Lee Smith

Don Brunnett

Qing Dai

Brian D Strom

Tobias Maletzky

Duc H Banh

Matteo Staffaroni

Takuya Matsumoto

Michael L Mallary

Bruno Jean Marchon

Oscar Jaime Ruiz

Kowang Liu

Gang Herbert Lin

Francis P Crimi

Kunliang Zhang

Albert John Wallash

Lin Guo

Joey Martin Poss

Rehan Ahmed Zakai

Shaomin Xiong

Hans Juergen Richter

Richard Oswald

Bernhard Hiller

Min Li

Hideaki Fukuzawa

Po-Kang Wang

Shuichi Murakami

Hiromi Yuasa

Yoshihiko Fuji

Michiko Hara

Cyril Guyot

Michael Grobis

Bernhard E Knigge

Yanning Liu

Kenji Kuroki

Hamid Balamane

David E Fowler

Yoshitaka Sasaki

Hironori Araki

Zhigang Bai

David William Abraham

Zvonimir Z Bandic

William Bernard Boyle

Neil Leslie Robertson

Donald Ray Gillis

Luiz M Franca-Neto

Michael M Lee

Guoxiao Guo

Hiroyuki Itoh

Kurt A Rubin

Jordan Asher Katine

Mike Suk

Weldon Mark Hanson

Fu-Ying Huang

Peter Michael Baumgart

Andrew W Vogan

Andrew M Homola

Bernd Lamberts

Remmelt Pit

Weidong Huang

Wei Guo

Mikito Sugiyama

Xiaoping Hu

Takehiro Horinaka

Xing-Cai Guo

Isao Nunokawa

John P Mead

Ian Robson McFadyen

Robert Carl Barrett

John Edward Scura

Kei Yasuna

Thomas Edward Karis

Quinn Jay Haddock

Clinton David Snyder

Wentao Yan

Linden James Crawforth

Ikuya Tagawa

Adam Manzanares

Timothy A Riener

David H Jen

David Hu

Stan Shepherd

Jianhua Li

Naoto Ito

Yong Hu

Robert E Eaton

A data storage device may include a disk, an actuator arm assembly comprising a magnetic recording head, a laser diode, and one or more processing devices configured to: initiate a write operation, wherein the write operation is associated with a first temperature of the laser diode; measure a resistance of the laser diode, wherein the resistance corresponds to a temperature of the laser diode; detect, based at least in part on measuring the resistance, a change in the temperature of the laser diode relative to the first temperature; and in response to detecting the change, adjust the temperature of the laser diode during the write operation.

Measuring laser diode temperature and predicting mode hops using laser diode resistance

Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to receive signals indicative of conditions of a write operation by the selected head. The one or more processing devices are further configured to determine, based on the signals, a verification status indicating whether the write operation was successful. The one or more processing devices are further configured to output the verification status within a selected time limit.

Data storage device with write protection and guaranteed rapid write verification in energy-assisted recording (EAR)

A data storage device includes a laser diode that heats an area of a disk near the read/write head. To mitigate mode hopping, the laser diode is preheated using the laser diode itself, such as by applying a reverse bias to the laser diode, during an interruption in writing of data to the disk. The laser diode is preheated to a temperature that maintains operation of the laser diode within a middle portion of a preselected gain mode and away from abrupt shifts in gain modes.

Temperature control of a laser diode by applying reverse bias in a data storage device configured for heat-assisted magnetic recording

A data storage device may include a media comprising a magnetic recording layer and a heat-assisted magnetic recording (HAMR) head for writing to the magnetic recording layer, the HAMR head comprising: a waveguide, a main pole comprising a main-pole surface facing the magnetic recording layer, a near-field transducer (NFT) situated between the main pole and the waveguide, and a transparent overcoat. The NFT comprises a main body and a micropillar. The micropillar comprises a micropillar surface facing the magnetic recording layer. A first distance between the micropillar surface and the media is less than a second distance between the main-pole surface and the media. The transparent overcoat is situated on the main-pole surface and the micropillar surface.

Near-field transducer (NFT) designs for improved performance of heat-assisted magnetic recording (HAMR)

A data storage device may include one or more disks, an actuator arm assembly comprising one or more magnetic recording heads, a laser diode positioned inside a laser diode cavity, and one or more processing devices configured to initiate a write operation, wherein initiating the write operation comprises activating a magnetic recording head corresponding to the laser diode, and applying a forward bias to the laser diode; apply a first reverse bias to the laser diode during at least one intervening event; and transition from applying the first reverse bias to the at least one laser diode to applying the forward bias to the at least one laser diode.

Managing laser diode cavity thermal transients in HAMR disk drives

A data storage device may include one or more disks, an actuator arm assembly comprising one or more disk heads, at least one laser diode positioned inside a corresponding laser diode cavity, a preamplifier, and one or more processing devices. The one or more processing devices are configured to: generate a reverse bias; apply, using the preamplifier, the reverse bias to the at least one laser diode to preheat a corresponding laser diode cavity to a target temperature prior to a write operation; control transition of the preamplifier from applying the reverse bias to applying a forward bias to the at least one laser diode; and activate the at least one laser diode to begin the write operation.

Preheating laser diodes with reverse bias for HAMR disk drives

Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to: select a sector on the corresponding disk surface to which to write data, wherein the sector is selected in accordance with a data erosion mitigation pattern; and output, while the head is positioned proximate to a preceding sector that precedes the selected sector, a laser pre-bias current to a laser-generating component of the head, wherein the laser pre-bias current is sufficient to induce significant data erosion on the preceding sector.

Data storage device with enhanced management of laser pre-bias and logic block addressing in heat-assisted magnetic recording

The present disclosure generally relate to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, a first reel and a second reel are mounted at stationary positions. One or more of the first reel and/or the second reel includes a hub mounted to a spindle, and a single flange extending relative to the hub. In one or more embodiments, one or more of a first reel and/or a second reel each includes a flangeless hub mounted to a spindle.

Tape assemblies having flangeless reel configurations and single flange reel configurations for magnetic recording devices

The present disclosure generally relates to a tape drive having a regenerative braking system. The tape drive comprises a first reel; a first spindle coupled to the first reel; a first motor coupled to the first spindle, wherein the first motor is configured to rotate the first spindle; a second reel; a second spindle coupled to the second reel; a second motor coupled to the second spindle, wherein the second motor is configured to rotate the second spindle; and a regenerative braking circuit coupled to the first motor and the second motor, wherein during a braking of the motors, the regenerative braking circuit and the motors convert a mechanical energy of the motors to electrical energy for a power storage mechanism, thereby providing resistance to the rotation of the spindles.

Regenerative braking for tape drive

The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Full disk serpentine write path for tamper-proof disk drive

The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Heat treatment of NFT and surrounding material

Example preamplifier circuits, data storage devices, and methods to provide a preamplifier circuit with separate read and write power channels are described. The preamplifier circuit may include a write driver circuit configured to send a write signal to a writer element of a data storage device and a read driver circuit configured to receive a read signal from a reader element of the data storage device. The write driver circuit may receive a write power signal through a write power channel of a bus interface and the read driver circuit may receive a read power signal through a read power channel of the bus interface, where the write power signal and the read power signal are different. In some configurations, the different read and write power signals may be received from a switching regulator on the printed circuit board that mounts other data storage device electronics, such as the drive controller circuit and/or read/write channel circuit.

Preamplifier with read/write power channels

Example systems, data storage devices, and methods to provide long-term spacing compensation for heat assisted magnetic recording are described. The data storage device includes a storage medium with data tracks and a head that can be positioned for reading and writing those tracks. The head includes a laser for heat assisted magnetic recording and a fly height actuator. Based on the operation of the laser, both a short-term fly height compensation parameter and a long-term fly height compensation parameter are determined based on different temperature state models. The operating power of the fly height actuator is determined, at least in part, based on the short-term and long-term height compensation parameters.

Long-term spacing compensation for heat assisted magnetic recording

The present disclosure generally relates to using a data timestamp and/or a read counter to prevent data from being re-read and signal that the data has been accessed. The write assist element in the write head can be utilized to degrade the data or an allocated marker after the data has been read. The degradation functions as a read counter to indicate how many times the data has been read. Additionally and/or alternatively, a timestamp can be utilized. The timestamp is updated each time that the data has been accessed. In so doing, it is possible to determine whether data in a data storage device has been accessed.

Data timestamp and read counter for magnetic recording devices

The present disclosure generally relates to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, one or more of a first reel and/or a second reel is laterally movable relative to a side wall of a casing of the tape assembly. In one or more embodiments, a drive assembly laterally moves the first reel and the second reel substantially simultaneously such that a spindle distance between a first spindle and a second spindle is substantially constant.

Tape assemblies having movable reel configurations for magnetic recording devices

Growing community of inventors

San Jose, CA, United States of America

Erhard Theodor Schreck