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:
Dec. 07, 2010
Filed:
Jun. 15, 2009
Mineo Moribe, Kawasaki, JP;
Masakazu Taguchi, Kawasaki, JP;
Atsushi Tanaka, Kawasaki, JP;
Toshiba Storage Device Corporation, Tokyo, JP;
Abstract
A magnetic disk apparatus includes a magnetic disk, a magnetic head, a reverse-pulse detector, and a re-magnetizer. The magnetic disk includes a data recording area and a servo-pattern area. The magnetic regions of the servo-pattern area have been pre-magnetized in the same direction or pre-magnetizing direction. The magnetic head is arranged to reciprocate radially of the magnetic disk. The reverse-pulse detector is provided for reading the servo-pattern area with the magnetic head before data recording or reproducing with respect to the data recording area is performed. The reverse-pulse detector detects, from servo reproduction signal pulses, reverse pulses corresponding to the reversal of magnetization direction relative to the pre-magnetizing direction. The re-magnetizer causes the magnetic head to perform the re-magnetizing of the magnetic regions in the servo-pattern area when the count of reverse pulses is not smaller than a threshold number.