Western Digital Technologies, Inc.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Muratec Automation Co., Ltd.

Kevin Tzou

Tetsuo Semba

Masahito Kobayashi

Matthew Taylor White

Jen-Yuan Chang

Bryan Rowan

Hiroshi Uchida

Mantle Man-Hon Yu

Joseph John Fatula, Jr

Gary Allan Herbst

Hitoshi Shindo

Craig N Fukushima

Robert Carl Reinhart

Hidehiko Numasato

Robert W Carlson

Shrey Khanna

Roumen Iliev Deyanov

Shigenori Takada

Akira Yokozuka

Pablo Gonzalez

Jeffrey J Dobbek

John Brooks Greene

Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: select a seek time model from a plurality of seek time models based at least in part on an operational characteristic of an access command, the operational characteristic relating to an off-track susceptibility of executing the access command; determine an access time for the access command using the selected seek time model; and select a next access command for execution based on the determined access time for the access command and determined access times for other ones of a plurality of access commands.

Data storage device sorting access commands based on performance and off-track mitigation optimization

A data storage device is disclosed comprising a plurality of disks each comprising a top disk surface and a bottom disk surface, and a plurality of actuator arms each comprising a first fine actuator configured to actuate a top head over one of the top disk surfaces and a second fine actuator configured to actuate a bottom head over one of the bottom disk surfaces. A first fine driver controls the fine actuators of an even interleave of the actuator arms, and a second fine driver controls the fine actuators of an odd interleave of the actuator arms.

Data storage device interleave driving secondary actuators

A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk, and a second actuator configured to actuate a second head over a second disk. The first actuator is controlled based on a first feed-forward seek profile to seek the first head over the first disk, and the second actuator is controlled to position the second head over a second data track on the second disk including to process the first feed-forward seek profile to attenuate a coupling disturbance from the first actuator.

Data storage device attenuating multiple actuator coupling disturbance

A data storage device is disclosed comprising a first disk comprising first servo sectors A-Adistributed around a circumference of the first disk, and a second disk comprising second servo sectors B-Bdistributed around a circumference of the second disk, wherein the second servo sectors B-Bare offset circumferentially from the first servo sectors A-A. While the first and second disks are rotating second servo information is transmitted from a second servo channel to a first servo channel. One of the first servo sectors Ai is read to generate first servo information, and a first command value is generated based on the first servo information and the second servo information, wherein a first actuator is controlled based on the first command value.

Data storage device communicating servo information between servo channels of multiple actuators

An integrated lead suspension (ILS) has a constrained layer damper (CLD) that attenuates vibration of the ILS. The CLD may be applied over an already assembled ILS such that the CLD is applied to the cover layer, to the base layer, or to both. Alternatively, the ILS may be encapsulated via a deposition process such that a damping layer is sandwiched between the conductor layer and the cover layer of the ILS, between the conductor layer and the dielectric layer of the ILS, or both.

System and apparatus for vibration damping of integrated lead suspensions in high density magnetic storage devices

A transport mechanism is configured to transport a work piece carrier within a buffer in fabrication facility, comprising: a transporter configured to travel on two rails, wherein the transporter comprises (i) a flat belt hoist mechanism configured to lift and to lower one or more work piece carriers, and (ii) a gripper mechanism configured to capture and to release the one or more work piece carriers.

Buffered storage and transport device for tool utilization

An integrated lead suspension (ILS) has a constrained layer damper (CLD) that attenuates vibration of the ILS. The CLD is applied over an already assembled ILS such that the CLD is applied to the cover layer. The CLD encapsulates the underlying conductors and the cover layer. The damping layer is formed on the cover layer. The width of damping layer is substantially equal to the width of cover layer as it extends over the conductors. The constraining layer extends laterally beyond the width of the damping and cover layers and down to the dielectric layer, which resides on a base layer. The constraining layer has a lateral width equal to that of the dielectric layer.

Integrated lead suspension for vibration damping in magnetic storage device

A disk drive has multiple feedforward controllers for handling external disturbances, such as rotational vibration (RV), that have different external disturbance frequency spectra. Each feedforward controller is designed to be optimal for a canceling a specific associated RV spectrum. The actual RV spectrum acting on the disk drive is determined and the proper feedforward controller is then selected and used to generate a compensation signal for canceling the RV. Each feedforward controller may be tested when the disk drive is experiencing the RV, and the resulting compensation signal and PES measured. The feedforward controller that produces the best external disturbance cancellation is then selected as the feedforward controller. A signal from a RV sensor may be used to detect the peak frequency of the actual RV spectrum. This detected peak frequency is then matched to a peak frequency in a plurality of peak frequencies in a lookup table, and the feedforward controller associated with the matching peak frequency is selected as the feedforward controller.

Magnetic recording disk drive with multiple feedforward controllers for rotational vibration cancellation

A magnetic recording disk drive with rotational vibration (RV) cancellation uses the position error signal (PES) and the signal from a RV sensor to determine when to enable and disable RV cancellation. An RV feedforward compensation signal to be summed with the VCM control signal is 'switchable', meaning that it can be enabled or disabled by the disk drive servo control processor. The determination to enable or disable is made from a comparison of the PES with a threshold PES, which may be an estimate of the off-track position of the head calculated from the RV sensor signal. The estimated off-track is compared to the absolute value of the actual or measured PES. If the estimated off-track is smaller than the actual PES, then the state of the RV cancellation is switched, i.e., if it is enabled it is disabled and if it is disabled it is enabled.

Magnetic recording disk drive with switchable rotational vibration cancellation

A disk drive manufacturing method calibrates the stitching gain of a position error signal (PES) by sampling servo information from a quadrature servo pattern while the head is maintained at the quarter-track positions and then calculating the kurtosis of the distribution of the PES values calculated from the samples. Because the kurtosis is a measure of the deviation from a normal or Gaussian distribution, the kurtosis of a PES distribution is used to optimize the stitching gain value through iteration until the kurtosis is close to zero, indicating that the PES with the optimal stitching gain values has a near-Gaussian distribution. The stitching gain calibration is performed for all heads and for multiple tracks across the surface of the disk for each head. The resulting values of stitching gain, each associated with a head and track, are stored in the disk drive memory and recalled during operation of the disk drive.

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San Jose, CA, United States of America

Kevin Tzou