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:
Feb. 01, 2005
Filed:
Mar. 14, 2003
Applicants:
Yasuhiko Yoshihisa, Nagano, JP;
Koichiro Yokoyama, Nagano, JP;
Tsunenobu Endo, Nagano, JP;
Inventors:
Assignee:
Seiko Epson Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 800 ;
U.S. Cl.
CPC ...
Abstract
A first current supplier supplies a first current to a first phase coil of a motor. A second current supplier supplies a second current to a second phase coil of the motor. A current selector selects a value of the first current and a value of the second current, so as to make constant at least one of a magnitude of a synthetic vector obtained by the selected value of the first current and the selected value of the second current at every microstep driving step of the motor, and an angular interval between synthetic vectors corresponding to adjacent microstep driving steps of the motor.