Seagate Technology Incorporated

Jianbo He

Hai Thanh Ho

Kevin Arthur Gomez

Reed David Hanson

Joseph Cheng-Tsu Liu

Brent Jay Harmer

Margot Ann LaPanse

Sandeep Dominic Sequeira

Gregory Christopher Labbe

Khalil B Dizaji

Tao Zhang

Avanindra Annu Gupta

Charles Leon McHenry

A system and method for improving write integrity of a magnetic storage system. A settling algorithm counter is reset if a position error signal of the write head indicates the head is vibrating with mechanical oscillations outside a predetermined threshold.

Peak to peak detect method to protect seek/settle induced encroachment

Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A 'measured' subset of the tracks is selected so as to be interspersed with an 'unmeasured' subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

Efficient feedforward compensation for repeatable runout in a disc drive

An actuator control system for a two-stage actuator system of a disc drive has a first, or primary, stage actuator consisting of a voice coil motor that positions the head relative to a disc and a microactuator that alters the actuator system without operation of the voice coil motor. A control loop includes a controller responsive to seek commands to operate the voice coil motor, thereby moving the head relative to the disc. An active damping circuit is coupled to the head to operate the microactuator to damp resonance modes of the actuator system.

Active damping of two-stage actuator system in a disc drive

A system for positioning a read/write head having a voice coil suitable for coarse control and a piezoelectric transducer (PZT) suitable for fine control. A voice coil control signal and a PZT control signal are generated from a position-indicative signal, both receiving power via a shared supply having a nominal rectified voltage V In a preferred method, control signals are both applied to the voice coil and PZT when amplified so that each has a saturation voltage smaller than &verbar;V

Dual stage positioning system using a shared voltage source

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Longmont, CO, United States of America

Jianbo He