Integral Peripherals, Inc.

Mobile Storage Technology, Inc.

Seagate Technology Incorporated

Conner Peripherals, Inc.

Thomas L Andrews

Gary E Counts

James H Morehouse

John H Blagaila

H Ross Chessman

Terry G Johnson

David M Furay

Steven Bernard Volk

Robert A Alt

Michael R Utenick

Stephen R Cowen

Richard K Thompson

Ronald J Loomis

Steven J Mertens

David H Furay

An adaptive servo system for a disk drive compensates for a track being off center or distorted by analyzing the spectral content of the radial variation of the centerline of a track relative to a rotation axis, generating multiple component signals having frequencies that are harmonics of the rotation frequency, and combining the component signals in a positioning signal for an actuator. Analyzing the spectral content of the radial variation can be accomplished by a discrete Fourier transform of a position error signal while generating a correction signal that cancels all or part of previously determined components of the position error signal. The system converges to generating a periodic signal that compensates for multiple harmonics in the radial variation in the position of the track.

Multi-harmonic compensator for track following in disk drives

A disk drive apparatus is disclosed for primary use with portable, laptop or other information storage systems. The disk drive apparatus includes one or more about 2.5 inch hard disks. The disk drive apparatus also has electronics, including hardware and software, for detecting a lapse of first and second predetermined time intervals since a last disk access. The disk drive apparatus also includes power conservation means which power down a first portion of disk drive components after a first predetermined time interval has elapsed and for powering down a second portion of disk drive components after a second predetermined time interval has elapsed.

Disk drive apparatus with power conservation capability

Disclosed is a rigid disk drive information storage device which includes a rigid disk having an outside diameter in the range of about 33-34 mm., with a housing having a footprint that includes a width of about 35 mm. and utilizing a rotary actuator for positioning read/write recording elements across the surface of the disk. The disk storage devices further includes a footprint with length of about 50.8 mm., and includes in one embodiment dynamic head loading apparatus for loading the read/write recording elements into operative relationship with the disk. In another embodiment the rigid disk drive utilizes contact start stop loading and unloading of the read/write recording elements. An inertial latch is also provided for preventing rotation of the actuator when the drive is subjected to a rotational force.

Microminiature hard disk drive with adaptive runout compensation

A secondary servo compensator, in a miniature disk drive having at least one disk and a servo system to position an actuator driven read/write head over any one of a number of tracks on the disk, provides on-line real-time compensation for disk runout that occurs during operation of the miniature disk drive. The servo system includes a servo compensator that has a gain and that generates an actuator position signal for positioning the read/write head over the track in response to a position error signal. The secondary servo compensator functions independently of the servo compensator. Specifically, the secondary servo compensator receives the position error signal and analyzes the disk runout and simultaneously generates a runout compensation signal during operation of the disk drive, i.e., while the disk drive is idle, reading, or writing. An actuator signal generator combines the actuator adjustment signal that is generated using the position error signal from sector 'i' and the runout compensation signal that is generated using the position error signal for sector 'i-1' to create a runout compensated actuator signal for sector 'i'. Hence, the runout compensation is fed forward. The servo system, using the information from the servo compensator and the secondary servo compensator, continuously maintains the read/write head over the desired track centerline independent of the offset of the center of the disk from true center of rotation.

Adaptive runout compensation for miniature disk drives

A silent seek servo controller is used in a low profile miniature disk drive to minimize acoustic noise and the problems associated therewith. The silent seek servo controller of this invention reduces acoustic noise generation at the expense of seek performance. Since the silent seek servo controller of this invention minimizes acoustic noise, the controller helps to eliminate vibrations within the computer. The silent seek servo controller is a one mode continuous position servo seek controller that accelerates and decelerates the actuator using a smooth, continuous and completely symmetric acceleration trajectory. Specifically, for a seek time t, the disk drive actuator is accelerated for one-half the seek time, i.e, time t/2, and decelerated for the other half of seek time t. The peak acceleration occurs at time t/4 and the peak deceleration occurs at time 3t/4. The symmetry of each acceleration phase assures that any acoustic noise generated by uneven acceleration is eliminated.

Low acoustic noise seeking method and apparatus

Disk drive apparatus with cam and follower for unloading heads

Growing community of inventors

Ward, CO, United States of America

Thomas L Andrews