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:
Aug. 30, 1994
Filed:
Jan. 17, 1992
Seiko Epson Corporation, Tokyo, JP;
Abstract
An ultrasonic step motor includes a stator and a rotor. A vibrator is mounted on the stator and a driving mechanism excites the vibrator causing the stator to induce a vibrating mode on the rotor. The rotor has a vibration mode in a selected direction and the stator exhibits a plurality of vibrating states which are changed in a time sequential manner. The vibrating states of the stator include a composite vibration of a travelling wave formed from two standing wave vibrations and a standing wave vibration. The rotor is formed of a non-uniform rigidity and mass distribution and the stator is formed with relief portions formed therein corresponding to loops of a standing wave vibration and projections corresponding to the nodes of the standing wave vibration.