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:
Sep. 08, 1998
Filed:
Jan. 15, 1997
Tetsuyuki Hishikawa, Tokyo, JP;
NEC Corporation, , JP;
Abstract
In a magnetic disk apparatus adopting a data surface servo method, and an improved data surface servo method for the magnetic disk apparatus, a Gray code sector number is included in a Gray code region, and a servo zone counter is controlled to start its counting operation after the unquestionableness and the continuity of the Gray code sector number are confirmed. Therefore, it becomes possible to detect a rotational position of the disk in real time, and also possible to discriminate which of the fault of the servo zone counter and a misreading of the Gray code sector number is a trouble. Thus, reliability in detection of a rotational position of a magnetic disk is improved. By comparing the Gray code sector number with the servo zone number signal outputted from the servo zone counter, it is possible to detect the fault of the servo zone counter, and therefore, it is possible to prevent the writing operation based on an erroneous detection of the rotational position, thereby to avoid a data destroy.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile