International Business Machines Corporation

Rudolf W Lissner

Edwin Ralph Childers

John Alexander Koski

Spencer D Roberts

Richard A Bargerhuff

Richard B Mulvany

A rotary actuator utilizing a magnetically biased bearing. A magnetized rotor is held in close proximity to a ferromagnetic mount. The magnetic flux created by the magnetic rotor through the ferromagnetic mount creates a magnetic bias force on the rotor bearing surface. The rotary actuator with the magnetically biased bearing rotates a mounted mirror to direct a reading laser beam to act as a fine tracking actuator within an optical data storage system.

Rotary actuator with a magnetic bias bearing configuration for rotating

A reel-to-reel web (tape) transport apparatus which has no tape length buffering between the supply and take-up reels. The tape follows a fixed length path from the supply reel, past a read/write head and guides, to a take-up reel. A two motor control mechanism is employed in which one motor drives the take-up reel and one motor drives the supply reel to maintain the appropriate tension and tape motion at the read/write head. The control mechanism is adaptive to dynamic changes as the tape is moved from the supply reel to the take-up reel. Three quantities are monitored: lineal tape position and the angular reel displacement of the supply and take-up reel. From these quantities reel radii are derived, tape inertia calculated and the velocity or position error is determined. A motor current algorithm is utilized to generate the appropriate torque for each reel to drive the control error to zero along a predetermined profile with negligible tape tension disturbances. The result is a reel-to-reel tape drive with static and dynamic performance characteristics which are independent of reel radius and inertia changes resulting from tape motion.

Adaptive reel-to-reel tape control system

A data storage apparatus includes an interchangeable sealed cartridge, enclosing magnetic disks, accessing magnetic head arm assemblies, a movable carriage to which the head arms are mounted, and a drive spindle on which the disks are seated. This portion of the storage apparatus is referred to as a data module. For accessing the heads to selected data tracks, coupling means are provided to engage the carriage and head arm assemblies with an external actuator, such as a linear D.C. motor or voice coil motor, disposed in a disk file housing. The file housing includes a drive motor coupled by pulley means, for example, to the enclosed spindle to provide rotary motion to the disks. This latter portion of the storage apparatus is referred to as the data module drive. The data module drive operates as a data storage apparatus when combined with one of many interchangeable data modules.

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San Jose, CA, United States of America

Rudolf W Lissner