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. 20, 1990
Filed:
Sep. 21, 1989
Applicant:
Inventors:
Takamasa Kitano, Tokyo, JP;
Terumitsu Okamoto, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318696 ; 318685 ; 318701 ; 318671 ; 360 7804 ; 360 7813 ;
Abstract
A circuit for controllably and finely driving a stepping motor, which moves a magnetic head over a magnetic disk, by using the combination of current values which are individually approximated to a sine wave and a cosine wave. The circuit allows a magnetic head to move at a high speed across the tracks of a magnetic disk toward a desired track, while after such a movement of the head lowering the remaining oscillation frequency of the stepping motor to allow servo to be applied immediately, thereby enhancing rapid operations of the apparatus.