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:
Mar. 13, 2001
Filed:
Sep. 17, 1998
Mitsunobu Watanabe, Kamakura, JP;
Tsuneo Hirose, Odawara, JP;
Atsushi Takayasu, Odawara, JP;
Yuji Yamane, Hiratsuka, JP;
Yusuke Mizuno, Hiratsuka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic disk drive has magnetic disks having tracks and a number of sectors forming each track. The tracks have an ID few track format and the drive is divided into a plurality of notches. The drive also includes a memory and a defect sector list, sector replacement list, defect track list and replacement track list, each of which is stored in the memory. Defective sectors and tracks in each notch are slipped during formatting, and further defective sectors and tracks detected subsequent to the formatting are skipped. Spare sectors in the notch are provided in a spare region to accommodate the slipped and skipped sectors and tracks, respectively. The defective sector list is supervised as a two stage table to reduce the required memory size for maintaining the list and to decrease the time required for searching the list.