Digital Equipment Corporation

Other

Maxtor Corporation

Peter R Svendsen

Charles M Riggle

Steven W Meeks

Frank W Bernett

John D Read

David Scott McMurtrey

Richard LeSage

W Craig Tomalty

A magneto-optical clock head is disclosed. The magneto-optical clock head allows a longitudinally recorded clock track to be read from a disk surface from a position outside of a head-disk assembly (HDA). The clock track has sections of alternating magnetization which define transitions. Importantly, the magneto-optical clock head is used to sense the transitions using the transverse Kerr effect, as opposed to the longitudinal Kerr effect as used in one prior technique. In one embodiment, the magneto-optical clock head includes a light source for generating a p-polarized beam which is aligned in such a manner that it strikes the clock track. A reflected beam is then produced which has an intensity that varies based upon the direction of the magnetization of the sections of alternating magnetization of the clock track due to the transverse Kerr effect. A detector is provided to detect the intensity variations in the reflected beam and to ultimately generate a clock signal which is provided to transducers to allow them to appropriately write servo information onto their respective disk surfaces. A method for optically reading a clock signal stored within a clock track which is written onto a disk surface that is located within a head disk assembly of a disk drive is also provided.

Method and apparatus for reading a clock track with a magneto-optical clock head using the transverse Kerr effect

A disk drive system which has a plurality of disks and a plurality of transducing head positioning across. The arms are mounted about common shaft for independent notation to desired radial position on the disk.

Multiple-disk storage system

A balance-moment head positioner includes a rotor assembly which rotates about a central shaft. The rotor assembly supports at the same axial location a current-carrying coil, arms for the heads, and a counterweight such that the positioner is dynamically balanced with its center of gravity at the center of rotation. The coils are arranged with legs parallel to the central shaft on diametrically opposite sides of the assembly. In addition, the positioner includes magnets and an elongated U-shaped magnetic pole member with ends facing the coils at the same axial location at the arms. Thus the torque developed when current flows through the coil, and a reactive counter-torque developed by the rotating mass coincide, substantially eliminating all torsion in the shaft, and there is no net force on the shaft.

Integral balanced-moment head positioner

A housing assembly (1-10) for multiple disks (1-12) used in a disk mass information storage unit in a data processing system. The housing includes fixed baffles (2-84, 86) proximate the outer disk surfaces in the housing to substantially reduce temperature differentials among the disk surfaces.

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Colorado Springs, CO, United States of America

Peter R Svendsen