The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 2005
Filed:
Apr. 04, 2001
Hiroki Kitahori, Fujisawaa, JP;
Kenji Kuroki, Fujisawa, JP;
Hiroshi Matsuda, Zama, JP;
Satoshi Noguchi, Fujisawa, JP;
Mutsuro Ohta, Yokohama, JP;
Keishi Takahashi, Fujisawa, JP;
Hitoshi Tamura, Kanagawa-ken, JP;
Hiroki Kitahori, Fujisawaa, JP;
Kenji Kuroki, Fujisawa, JP;
Hiroshi Matsuda, Zama, JP;
Satoshi Noguchi, Fujisawa, JP;
Mutsuro Ohta, Yokohama, JP;
Keishi Takahashi, Fujisawa, JP;
Hitoshi Tamura, Kanagawa-ken, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A magnetic circuit is provided in an enclosure that can efficiently generate magnetic flux from the enclosure, configuring a magnetic disk, to a magnetic disk. Thus, by providing such a magnetic circuit, a magnetic field different from that in other enclosure parts, that is, a local magnetic field, is generated from the magnetic circuit in case the disk device is set in an external magnetic field. Hence, this local magnetic field can effectively erase data in the magnetic disk. In particular, since the local magnetic field is generated even if the external magnetic field is weak, it is possible to not only suppress the demagnetization of permanent magnets used in the spindle motor at minimum, but also effectively erase data in the magnetic disk.