Tamarack Storage Devices

International Business Machines Corporation

Vincent D McCarty

Duane S Dewald

Lindsay Gupton

Randal Housey

Dan Swindler

A spindle for providing precise radial location of a disk includes a spindle having a key that extends from one end thereof. The disk includes a hub having a shape that is similar to that of the spindle with a key notch disposed on the peripheral edge thereof that is shaped similar to that of the key in the spindle. The key has two surfaces that come together at an angle to an apex, which apex extends downward away from the spindle and radially outward. The surfaces of the key notch on the hub are longer than that of the key, such that the surfaces of the key can mate with the surfaces of the key notch and slide therealong, such that the spindle is maintained in the center of the hub.

Disk positioning device for defining precise radial location

A package for a holographic storage media disk (10) is provided that is comprised of a super structure (18) that is operable to hold the disk (10). The disk (10) is comprised of a photopolymer material that is formed in a disk-shaped member having a hub (14) disposed at the center thereof. The disk (10) is disposed in the structure (18) and then a cover (24) disposed thereover, the cover (24) being opaque. An access opening (28) is disposed within the cover (24) to allow access to the surface of the disk (10). A hub opening (26) is provided for allowing access to the hub (14). The hub (14) is disposed such that there is a light tight seal relative to the cover (24). A door (32) is provided for reciprocating over the opening (28) to light seal the package when data is not being recorded to the disk (10) or read therefrom. Additionally, layers of felt (161) and (163) are disposed on the interior surfaces of the cover to dampen any vibrations in the package, and a fiduciary marking opening (30) is provided for allowing access to fiduciary markings (164) disposed on the edge of the disk (10). The door (32) is operable to lock when in a portable mode and unlock when in an access mode.

Holographic storage media package

A print hammer drive circuit is driven by a voltage supply having inherent voltage variations. The driving current is applied to the print hammer coil and the level of the current in the coil detected. After the level of the current in the coil reaches a predetermined maximum level a timing circuit is initiated to control the duration of application of maximum current. Variations in supply voltage on the duration and force of strike of the print hammer have greatly reduced since all timing is based relative to the time that the predetermined drive current level is achieved as distinguished from timing which includes the rise time of the driving current wave form. Also the effects of variations in inductance from coil to coil can be compensated for by adjustment of the timing circuit.

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Austin, TX, United States of America

Vincent D McCarty