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:
Jun. 11, 1991
Filed:
Sep. 27, 1989
Applicant:
Inventors:
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 7708 ; 360 7702 ;
Abstract
A magnetic disk apparatus has a circuit for detecting the recorded position of servo information, used for aligning a magnetic head, on a target track of a magnetic disk. The circuit discriminates the track's data area and the servo information area by determining an amplitude difference between detection signals equal or close to a discrimination frequency and the harmonic component of the discrimination frequency. If the amplitude difference exceeds a predetermined value, a servo area is discriminated. If the value is lower than the threshold, a data area is discriminated.