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:
Nov. 03, 1998
Filed:
Sep. 13, 1996
Susumu Yoshida, Kawasaki, JP;
Shuichi Hashimoto, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method of demodulating head position in a disk apparatus in which a head is moved toward a target cylinder using a position detection signal that has been recorded on a disk medium. This method includes the steps of: predicting, at a current sampling point, the position of the head at the next sampling point; moving the head by instructing a current for a motor based upon the predicted position; obtaining a position deviation which indicates deviation from the predicted position to the head position at the next sampling point by reading the position detection signal that has been recorded on the disk medium; demodulating the head position at the next sampling point using the position deviation signal and the predicted position; predicting position of the head at an immediately following sampling point using a value obtained by outputting the difference (traveling velocity) between predicted positions at neighboring sampling points via a first-order low-pass filter, the predicted position, a difference between the predicted position and the head position and the value of the current instructed for the motor, and instructing a current for the motor based upon the predicted position.