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. 23, 1999
Filed:
Jul. 27, 1998
Applicant:
Inventors:
Naotoshi Iwazawa, Tokyo, JP;
Shigeru Shimonou, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318685 ; 318696 ; 318560 ;
Abstract
A stepping motor has Hall elements which detect the position of the rotor and which output detection signals that have the same period as the excitation period, and which leads the position of the rotor by 90 degrees. The stepping motor is driven by the output of a drive current that is obtained by multiplying the detection signals output from the Hall elements with a torque command signal that controls the output torque of the stepping motor.