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US 5,636,091 AGranted
Magnetic disk apparatus
AssigneeKabushiki Kaisha Toshiba
InventorTakahiro Asano
Life of this patent
Estimating the term…
Abstract
A hard disk drive includes a casing and a cover closing a top opening of the casing. In the casing are arranged a magnetic disk, magnetic heads for recording and reproducing information on and from the disk, a carriage supporting the magnetic heads, and a voice coil motor having a magnet, for driving the carriage. The cover is formed of a material with a high magnetic permeability and constitutes a magnetically permeable section which faces the magnet and allows a magnetic flux from the magnet to flow in the permeable section.
Claims8
A magnetic disk apparatus comprising:
- a casing having a bottom wall, a plurality of sidewalls, and an open top;
- a magnetic disk arranged in the casing;
- means for rotating the magnetic disk, the rotating means being mounted on the bottom of the wall of the casing;
- a magnetic head for recording and reproducing information on and from the magnetic disk;
- carriage means arranged in the casing, for supporting the magnetic head for movement in the radial direction of the magnetic disk;
- drive means arranged in the casing, for moving the carriage means, the drive means including upper and lower yokes and a magnet attached to one of the upper and lower yokes;
- and
- a cover magnetically coupled to the magnet through the upper yoke, for closing the open top of the casing and including a magnetically permeable section which faces the upper yoke and consists essentially of a material with a magnetic permeability higher than that of the casing, so that magnetic flux of the magnet bound for an opposite pole of the magnet flows in the magnetically permeable section;
- whereby leakage of magnetic flux through the cover is substantially prevented.
6 more elements
A magnetic disk apparatus comprising:
- a casing having a bottom wall, a plurality of sidewalls, and an open top;
- a magnetic disk arranged in the casing;
- means for rotating the magnetic disk, the rotating means being mounted on the bottom of the wall of the casing;
- a magnetic head for recording and reproducing information on and from the magnetic disk;
- carriage means arranged in the casing, for supporting the magnetic head for movement in the radial direction of the magnetic disk;
- drive means arranged in the casing, for moving the carriage means, the drive means including upper and lower yokes and a magnet attached to one of the upper and lower yokes;
- a cover magnetically coupled to the magnet through the upper yoke, for closing the open top of the casing;
- and
- means for preventing a magnetic flux from the magnet from leaking to the outside of the cover by causing the magnetic flux that is bound for an opposite pole of the magnet to flow in the cover, the preventing means including a magnetically permeable section of a permeability material with a magnetic permeability higher than that of the casing and constituting at least that portion of the cover which faces the upper yoke.
6 more elements
Dependencies are inferred from the claim text.