Seagate Technology Incorporated

Choon Kiat Lim

Xiong Liu

Joseph Cheng-Tsu Liu

Kevin Arthur Gomez

Wai Onn Chee

MingZhong Ding

Qiang Bi

Michael Joo Chiang Toh

Tak Koon Ooi

Chuen Buan Lee

Lee Ling Tan

Chor Shan Cheng

Hans L Leuthold

Anthony Joseph Aiello

YiRen Hong

Niroot Jierapipatanakul

Kian Keong Ooi

Chris Michael Woldemar

YiChao Ma

Joseph C Liu

Ricky Wei Watt Yeo

Utt Heng Kan

Jack Ming Teng

Kwee Teck Say

Aik Chuan Lim

Wing Kong Chiang

Mui Chong Chai

June Christian Ang

Kok Tong Soh

Long Van Ngo

Than Zaw Myint

Edmun Chian Song Seng

Kay Hee Tang

Jui Jing Lim

Narayanaswamy Pasupathy

Yi Ren Hong

Mike James Darling

Pow-Hing Yong

Michael Joo-Chiang Toh

Niroot Jierapipapatanakul

Yichao Ma

See Jee Johaan Koong

Wai Meng Chan

A data storage device includes a disc, an actuator arm assembly, a servo clock, and a feedback and control system. The disc includes a top and bottom surfaces and a servo wedge. The servo wedge includes a top surface boundary and a bottom surface boundary. The actuator arm assembly supports a head pair configured for interaction with the top and bottom surfaces. The servo clock is configured to determine a top time at which the head pair encounters the top surface boundary and a bottom time at which the head pair encounters the bottom surface boundary during a disc read/write interaction. The feedback and control system is configured to determine an operation time difference; compare the operation time difference to a certification time difference correlating to a target vertical position of the actuator arm assembly relative to the disc; and move the actuator arm assembly to the target vertical position.

Z-height control for disc drive using servo wedge timing

A data storage device includes a stack of discs mounted on a spindle and a pivot block rotatably mounted around a shaft. The data storage device also includes an arm having first and second ends, with the first end supporting a head and the second end movably attached to the pivot block. The data storage device further includes an ultrasonic piezoelectric actuator that moves the arm along the pivot block to enable the head to interact with data storage surfaces of the discs.

Data storage drive with a vertically translatable actuator arm

Systems, apparatuses, and processes having a dependent write fault threshold are disclosed. A first sector may have a first write fault threshold and a second sector, adjacent to the first sector, may have a second write fault threshold, and the write fault thresholds can be variable based on a position error signal value of an adjacent sector. In some embodiments, the adjacent sectors may each be in an adjacent track. In other embodiments, the adjacent sectors may be in the same track. Further, a track may have two write fault thresholds, a positive direction threshold and a negative direction threshold; in some embodiments, only one direction's threshold may be variable based on the position error signal of the adjacent sector, while the opposite direction's threshold may be set to a default (e.g. pre-determined not on a sector by sector basis) value.

Dependent write fault threshold

Systems and methods are disclosed having a write fault threshold for a set of tracks. A set of tracks may have a shared write fault threshold budget, and a write fault threshold for the second track may be selected based on the shared budget reduced by an off-track position error signal value of the first track. In certain embodiments, an apparatus may comprise a processor configured to determine a position error signal value for a first data track, set a write fault threshold for a second data track adjacent to the first data track based on the position error signal, and write data to the second data track based on the write fault threshold.

Write fault threshold for a set of tracks

An apparatus includes a hub, a first disk, a second disk, and a spacer. The hub is supported for relative rotation about a stationary component. The first disk is mounted to the hub with a first dynamic resonance mode associated therewith. The second disk is mounted to the hub with a second dynamic resonance mode associated therewith. The spacer is positioned between the first disk and the second disk, wherein the spacer is operable to cause the first dynamic resonance mode to be different from the second dynamic resonance mode.

Fluid dynamic motor with reduced vibrations

A data storage apparatus and associated method is provided involving a data storage disc that is rotatable around a first axis. An actuator is rotatable around a second axis to operably position a data transfer member between an innermost radial location of the data storage disc and an outermost radial storage location of the data storage disc. A snubber is supported by the actuator and has a distal edge configured as being, in relation to a reference plane including the first axis and the second axis when the actuator is rotated to position the data transfer member at the innermost radial location, arcuate along a first radius on one side of the reference plane and arcuate along a second radius different than the first radius on the other side of the reference plane.

Method and data storage device with a snubber supported on an actuator and having a distal edge configured to have differing arcuate portions

Transducers are oriented differently to address the skew phenomenon. This enables a greater area of the medium to be utilized for data storage, thereby increasing the storage capacity of the device implementing embodiments of the present invention.

Slider having transducers orientated in different directions

Embodiments of the present invention provide for apparatus and methods for performing unload operations, including enabling read/write heads to reach a desired velocity at the ramp. Embodiments of the present invention are particularly beneficial for handheld products where low power consumption and reliability are important requirements.

Ramp unload in disc drives

A method for generating a velocity command for an actuator assembly is provided. The actuator assembly includes an actuator arm, which is to move over a plurality of surfaces. The method begins by providing a compensation torque for each of the plurality of surfaces. A position of the actuator arm is determined so that it may be mapped to one of the plurality of surfaces, which is the present surface over which the actuator arm is moving. A target velocity is then provided for the actuator arm and input to a controller, which generates a velocity command from the target velocity and a selected compensation torque, which is the compensation torque of the present surface.

Velocity control system for an actuator assembly

A method of and apparatus for generating a reader-to-writer offset for a head positioned over a track on a disc in a disc drive having a plurality of tracks is disclosed. A reader and a writer are mounted on the head in a non-overlapping manner with a gap between the reader and the writer, which is known as the reader-to-writer offset. A disc drive controller is operably connected to the reader and the writer. The disc drive controller determines the reader-to-writer offset of the head for each track by computing the difference between a first head position x1 and a second head position x2. The first head position x1 is an optimal head position for writing information on the track and the second head position x2 is a midpoint of an off-track capability (OTC) of the head. The OTC is a portion of a track pitch over which the reader is expected to read information that is free of an incorrigible bit error such that the writer-to-reader track misregistration (TMR) is minimized as the head is radially displaced the reader-to-writer offset to read information written on the track or to write information on the track.

Optimal reader-to-writer offset measurement of a head in a disc drive for reduced track misregistration

A magnetless rotary actuator for carrying one or more read/write heads across a data bearing medium, the rotary actuator comprising: a stator including a plurality of independently controllable flux generating means for directing flux between the stator and a rotor; the rotor including means for presenting discrete regions of low magnetic reluctance to the controllable flux generating means; torque coupling means for transmitting operative torque from the rotor to the read/write head; and pivot means for supporting the torque coupling means.

Magnetless actuator for disc drive

A disc drive is provided which incorporates a rotatable actuator which is mounted to a base of the disc drive through a pivot mechanism. The actuator positioning is controlled by a servo system and during track following operations, the actuator arm is caused to move. In one embodiment, the servo tracks incorporated in the disc drive are distorted when written in by the injection of a sinusoidal signal. In another form, the disc containing the servo information is caused to rotate about an axis which is offset from the disc axis. A method of creating a servo track is also disclosed.

System and method to minimize bearing pivot effect in disc drive actuator

A voice coil motor assembly in a disc drive includes first and second pole pieces held in spaced relationship to one another such that a gap is defined therebetween. A permanent magnet is located on the first pole piece within the gap and a dummy magnet is located on the second pole piece across the gap from the permanent magnet. The first and second pole pieces, together with the magnet and the dummy magnet, form a magnetic circuit conducting lines of magnetic flux within the voice coil motor and across the gap. The dummy magnet acts to encourage magnetic flux to flow across the gap in a manner such that the roll and pitch torque constants of the voice coil motor are reduced.

Voice coil motor dummy magnet

An actuator and a method for using an actuator in a disc drive having a limited range of rotation wherein an actuator arm for providing motion for reading or writing data to or from media engages a shaft or post fixed within the actuator arm for communicating with the actuator arm by means of clips affixed to the shaft. The clips have flexible wings affixed to the actuator arm whereby the shaft and the actuator arm are held in a fixed relationship allowing the arm to rotate with respect to the shaft while movement between the actuator arm and the shaft other than by rotation is prevented by the shape of the flexible wings.

Low cost flexible support actuator

A pivot mechanism is disclosed for mounting a rotatable actuator on a base of a disc drive. The pivot mechanism is made up of a shaft on which a housing is rotatably mounted by a lower ball bearing set and an upper bearing provided by co-acting surfaces of the shaft and the housing.

Growing community of inventors

Singapore, Singapore

Choon Kiat Lim