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. 19, 2000
Filed:
Feb. 04, 1998
Koichi Aikawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Disclosed is a method of demodulating a position signal in a magnetic disk device for reading servo burst signals, which have been recorded in a servo area of a magnetic disk, by a head, and outputting a position signal, which indicates a deviation from a reference position on a track, using the servo burst signals that have been read. The position signal demodulating method includes (1) recording first and second servo burst signals in the servo area alternately in the radial direction, (2) digitally sampling the first and second servo burst signals, which have been read by the head, at a frequency two or more times greater than a servo burst signal frequency, (3) calculating area information of each of first and second servo burst signal waveforms by summing absolute values of the digitally sampled values in regard to each of the first and second servo burst signals, and (4) outputting, as a position signal, the difference between the area information of the first servo burst signal waveform and the area information of the second servo burst signal waveform.