Maxtor Corporation

Matsushita Electric Industrial Co., Ltd.

Other

Kabushiki Kaisha Toshiba

Toshiba Corporation

Optical Devices, LLC

Fred R Hansen

Brian Kenneth Tanner

Charles R Watt

Thorsten Schmidt

Fernando Anibal Zayas

Tim K Emami

Joseph R Hagan

Kim DeVormer

Unkyong Hand

Kerry Mellor

Methods and systems are described for correcting repeatable runout. In one aspect, an open loop tracking signal is received and squared. A discrete Fourier transform (DFT) of the squared open loop tracking signal is obtained. A velocity magnitude and an absolute value of the phase of the open loop tracking signal is determined. A RRO correction signal is iteratively constructed by performing a partial correction based on an initial phase selected and an initial velocity amplitude, measuring a relative velocity amplitude, performing a partial control correction using the initial phase and relative velocity amplitude if the amplitude is smaller than an initial amplitude or using the initial phase rotated by one hundred eighty degrees and the relative velocity amplitude if the amplitude is larger than an initial amplitude, and repeating the above steps until a tracking controller can perform closed loop control of the track to optical pickup unit velocity.

Methods, systems, and computer program products for correcting repeatable runout

A method of determining a correction factor for a voice coil motor of a disk drive device is performed by driving a relatively low current through the voice coil motor during a seek operation. Actuator velocity is then measured. A correction factor is calculated as a function of the actuator velocity to allow estimation of velocity as a function of back EMF.

Voice coil motor effective resistance determination

A method and device for parking heads of a disk drive device involves receiving a command to immediately park the heads. A first pulse is provided to a voice coil motor causing the heads to move toward a parked position. After the first pulse, the VCM current is reduced substantially (e.g., close to zero) and back EMF in the voice coil motor is measured to determine speed of the heads. The voice coil motor is iteratively pulsed, and back EMF is measured between pulses to track a desired velocity profile to park the heads.

Current pulsing for unloading

A method and apparatus for reducing seek acoustics in a disk drive using feedback during large current transitions is provided. A desired transition profile, which uses feedback, is followed in order to smoothen transitions of a commanded current profile that is supplied to a VCM for moving a head relative to a disk surface during a seek operation. Linear interpolation is used to provide feedback for following the desired transition profile.

Method and apparatus for reducing seek acoustics in a disk drive using feedback during large current transitions

Improved deceleration control for a disk drive is provided. A deceleration profile is selected based on a present velocity (v), a present position (x) and a BEMF constant associated with a voice coil motor (VCM), wherein the deceleration profile is useful for moving the read/write head to a point in phase space (defined by a target velocity and a target position) where it is efficient to hand-off control of a seek operation from a deceleration controller to a seek controller. A control signal is supplied to a VCM driver in an attempt to have a read/write head follow the selected deceleration profile. As new present velocities and new present positions are obtained, these steps are repeated until the seek operation transitions from the deceleration phase to a settle phase. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Methods and systems for moving a read/write head to a velocity and position where it is useful to switch from a deceleration phase to a settling phase of a seek operation

Improved deceleration control for a disk drive is provided. A deceleration profile is selected based on a present velocity (v), a present position (x) and a BEMF constant associated with a voice coil motor (VCM). A control signal is supplied to a VCM driver in an attempt to have a read/write head follow the selected deceleration profile. As new present velocities and new present positions are obtained, these steps are repeated until the seek operation transitions from the deceleration phase to a settle phase. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Methods and systems for improved deceleration control for a disk drive

A method for improving disk drive performance by reducing the overhead associated with the command processing code requesting a seek. As multiple commands are queued up in a command queue, a next command is identified and immediately stored in a servo position queue, as soon as the next command location is determined. Therefore, as the drive electronics are prepared for read and write operations, the servo system initiates the actuator to move the read/write head to the next command location. By the time the read/write head arrives at the next command location, the drive electronics are ready for the read/write operation. As a subsequent command is determined, its location is again entered into the position queue, overwriting the previous command location.

Seek queue for improved disk drive performance

Methods and apparatus for processing a seek request on a disk drive apparatus having a disk drive head is disclosed. The seek request is processed. During the seek request, the disk drive head is traversed across an actual distance. At least one expected seek time associated with the actual distance is obtained from a set of seek time data. One or more measurements are performed on the disk drive apparatus to obtain an update value. At least one expected seek time is then updated such that at least part of the update value is included in the at least one expected seek time.

Adaptive update of seek time prediction data

A drainage track useful in combination with exterior insulation and finish systems including a clog-resistant drainage channel so that water collecting behind the exterior insulation and finish may drain from the structure. The drainage track, in a preferred form, is extruded from PVC and defines a substantially L-shaped configuration in cross-section. An elongated, relatively tall flashing leg is provided for attachment of the drainage track to the structure such that all water resistant material and insulation laps over the flashing leg to direct water into the drainage channel. Finish apertures are provided through a portion of the drainage track so that exterior finish such as, for example, stucco, will readily adhere and bond to the drainage track.

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Boulder, CO, United States of America

Fred R Hansen