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. 26, 2006
Filed:
Feb. 13, 2003
Iwao Oshimi, Odawara, JP;
Kiyotada Itou, Odawara, JP;
Katsumoto Onoyama, Hiratsuka, JP;
Yosuke Hamada, Odawara, JP;
Iwao Oshimi, Odawara, JP;
Kiyotada Itou, Odawara, JP;
Katsumoto Onoyama, Hiratsuka, JP;
Yosuke Hamada, Odawara, JP;
Hitachi Global Storage Technologies Japan, Ltd., Odawara, JP;
Abstract
In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby. For this object, a SAM pattern in a servo information region is changed for each head and recorded. Then, the SAM pattern is read to determine which head makes access to a disk surface and the head is compared with a head to which a direction of making access is given thereby to make an error check. Moreover, by the use of a marker pattern of rotational synchronization compensating data added to the servo information, an error check of the head making access to the disc surface is conducted.