Western Digital Technologies, Inc.

Maxtor Corporation

Seagate Technology Incorporated

Other

Xiaokun L Chew

Thao Anh Nguyen

Sukumar Rajauria

Gang Herbert Lin

Bruce C Schardt

Steven B Marshall

Robert McKenzie

Jack Tsai

Erhard Theodor Schreck

Guoxiao Guo

Lin Guo

Roberto Alini

Qing Dai

Wei Guo

John Edward Scura

Tehri S Lee

Teik Ee Yeo

Axel Alegre De La Soujeole

Jung-Seo Park

Yunfeng Li

Mark Heimbaugh

Bac V Pham

Oliver W Northrup

William Flynn

Yun Hong

Tim Glassburn

Ruihua Li

Mehdi Habibollahzadeh

Mark R McCornack

Lin Mei

Dongying Li

G Herbert Lin

Don Brunnet

Gilles Denoyer

Dan Wang

Davidc Guarisco

Llyod Levy

David Joseph Bezinque

Quocdzung T Lam

Su Dang Le

Yixiang Zhang

A data storage device may include a container comprising a gas-permeable membrane and a temperature-sensitive gas-releasing substance inside of the container. The temperature-sensitive gas-releasing substance is characterized by a gas-release profile wherein, below a critical temperature, the temperature-sensitive gas-releasing substance releases essentially none of a particular gas, and above the critical temperature, and within a range of expected operating temperatures of the data storage device, the temperature-sensitive gas-releasing substance releases the particular gas in quantities that generally increase with increasing temperature.

Passive and active gas compensation techniques for data storage devices

A heat-assisted magnetic recording apparatus may include a slider body, a submount, a laser diode assembly, and a first heat sink. The laser diode assembly comprises a plurality of lateral surfaces and a waveguide-facing surface. The submount is attached to the slider body by a first connector material. A first lateral surface of the laser diode assembly is in contact with the submount, and a second lateral surface of the laser diode assembly is in contact with the first heat sink. The first heat sink is in contact with a second connector material, which is in contact with the slider body to provide a heat flow path from the laser diode assembly to the slider body.

Reducing laser diode temperature swings in heat-assisted magnetic recording (HAMR) using a slider-mounted heat sink

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 apply a pre-bias current to the assistive energy emitter at a first value while the selected head is positioned proximate to one or more spiral patterns on the corresponding disk surface. The one or more processing devices are further configured to apply the pre-bias current to the assistive energy emitter at a boosted value while the selected head is not positioned proximate to the one or more spiral patterns, wherein the boosted value is greater than the first value.

Energy-assisted magnetic recording data storage device with assistive energy pre-heating for writing servo patterns

A method and apparatus for providing an early warning of thermal decay in magnetic storage media are provided. In accordance with an embodiment of the present invention, a test pattern that is particularly susceptible to thermal decay is written to a disk. The test pattern is then read, and the amplitude of the signal produced by the test pattern is stored. When testing for thermal decay is desired, the test pattern is again read, and the amplitude of the signal produced in the channel is compared to the stored amplitude. If the later amplitude is less than the stored amplitude by at least a predetermined amount, a thermal decay warning signal is generated. In accordance with another embodiment of the present invention, a test pattern is written to a portion of a disk that has been identified as being particularly susceptible to thermal decay. The amplitude produced by the test pattern is then stored so that it can later be compared to an observed amplitude when testing for thermal decay. The present invention allows remedial measures to ensure the integrity of data to be taken before data loss due to thermal decay can occur.

Method and apparatus for providing an early warning of thermal decay in magnetic storage devices

A disk drive is disclosed comprising a disk and a head actuated radially over the disk. The head is positioned over a first radial location, and a first data tracks per inch (TPI) is selected for data tracks recorded near the first radial location. The head is positioned over a second radial location, and a second data tracks per inch (TPI) is selected for data tracks recorded near the second radial location. The head is positioned over a third radial location, and a third data tracks per inch (TPI) is selected for data tracks recorded near the third radial location. A geometry of the head is estimated in response to TPI, TPIand TPI

Disk drive selecting TPI profile by estimating head geometry

A disk drive includes a slider assembly and a controller that directs current to the slider assembly to dynamically adjust the head-to-disk spacing. In one embodiment, the slider assembly includes a write element having a first end, a second end and an intermediate section, a conductor that is connected to the intermediate section. In this embodiment, the controller directs electrical current through the conductor to heat the write element without writing data to a storage disk. The electrical current can be directed through the conductor at any time prior to data transfer or during data transfer. Heating the write element causes a deformation of the slider assembly to decrease the head-to-disk spacing. In another embodiment, the slider assembly includes a separate slider deformer. Electrical current is selectively directed to the slider deformer to cause a deformation of the slider assembly to obtain a desired head-to-disk spacing. The slider deformer can include electrically conductive material or can be a piezoelectric element. Further, the slider deformer can be serpentine-shaped or substantially planar in shape.

Dynamically adjustable head disk spacing slider using thermal expansion

A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.

Mobile hard disk drive free fall detection and protection

Circuitry for detecting and recording latches in read bias current may include circuitry for generating a reference voltage, a pair of current to voltage converters to convert the bias and reference currents to voltage signals, a comparator to compare those two voltages, a latch to latch the compared signal, and a counter/register to count and store the number of glitches that have been detected. It may be possible to read from the register the number of detected glitches to be used in diagnosing faults in the disk drive system. In addition, it may be possible to provide a reset input to the register to zero the counter.

Technique for recording bias current glitches in magnetoresistive heads

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. Similarly, a write condition can involve a combination of a write threshold and a radial transducer velocity. Other write criteria are also possible.

Variable write fault protection window

A method is disclosed for controlling the write head of a magnetic disk storage device. The method includes sinking current from the first terminal of the write head and sourcing current to the second terminal of the write head substantially simultaneously with sinking current from the first terminal so that a first steady state voltage level appears on the first terminal of the write head and a second steady state voltage level appears on the second terminal thereof that are approximately at a midpoint between a high reference voltage level and a low reference voltage level. The common mode voltage of the write head is substantially constant over time.

Method for differentially writing to a memory disk

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San Juan Capistrano, CA, United States of America

Xiaokun L Chew