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. 28, 2000
Filed:
Jan. 13, 1999
Masahito Kobayashi, Ushiku, JP;
Iwao Oshimi, Kanagawa-ken, JP;
Yoshio Soyama, Odawara, JP;
Akio Shioya, Shizuoka-ken, JP;
Yuji Hata, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A disk apparatus has a position signal detector for detecting the position of a head with a specified sampling period, a controller operating a manipulated variable to control positioning of the head using a microprocessor and a digital/analogue converter with which the manipulated variable is converted. At least one or more timing registers set the timing of the conversion carried out by the D/A converter and at least one or more manipulated variable registers set a manipulated variable that is converted into digital/analogue form at the set timing. In addition, the controller has advancing means to make a target position trajectory advance towards a specified time, a feedforward controller to receive the output of the advancing means and to calculate a feedforward control variable on the basis of a target trajectory, and a feedback controller to produce a feedback output variable on the basis of a target trajectory that is delayed relative to a target position trajectory by a specified time.