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:
Apr. 15, 2008
Filed:
Aug. 27, 2004
Masami Yamamoto, Chiba, JP;
Akihiro Ito, Chiba, JP;
Masato Tanaka, Chiba, JP;
Shinji Morinaga, Chiba, JP;
Tetsuya Iwamoto, Chiba, JP;
Masami Yamamoto, Chiba, JP;
Akihiro Ito, Chiba, JP;
Masato Tanaka, Chiba, JP;
Shinji Morinaga, Chiba, JP;
Tetsuya Iwamoto, Chiba, JP;
Seiko Precision Inc., Chiba, JP;
Abstract
The rotational torque of an electromagnetic actuator having a stator and rotor, such as a stepping motor, is increased. The electromagnetic actuator includes a rotor () having multiple magnetic poles (Nr, Nr, Nr, Nr, Nr, Sr, Sr, Sr, Sr, Sr) on a circumferential surface () and a plurality of stators () in an electromagnet form. The stator () has a pair of magnetic poles () facing the circumferential surface () of the rotor (), and an auxiliary yoke () made of a soft magnetic material member extending in a circumferential direction (A) over an angular range (γ) larger than a spread angle (α) of the magnetic poles (Nr, Sr) of the rotor () in the circumferential direction (A) is provided between the pair of magnetic poles ().