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:
Oct. 21, 1997
Filed:
Dec. 20, 1994
Tatsuzo Ushiro, Kawaguchi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A motor includes a rotor magnet, driving coils and the detecting wire elements. The rotor magnet is mounted on a rotor yoke and has a plurality of magnetic pole pairs arranged at equal angular spacings, each having north and south poles. At least one pair of is unequally magnetized so that the north and south poles thereof are of unequal strength. The other magnetic pole pairs are equally magnetized so that the north and south poles thereof are of equal strength. The driving coils are provided on a stator yoke opposite from the rotor magnet. The detecting wire elements are provided on the stator yoke. The detecting wire elements are arranged at an angular spacing substantially equal to that of the magnetic pole pairs of the rotor magnet. The detecting wire elements generate output signals when the rotor yoke comprising the rotor magnet rotates to cause the unequally magnetized magnetic pole pair to move across from the detecting wire elements.