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:
Jul. 10, 2012
Filed:
Feb. 22, 2010
Toshihisa Komai, Hirosaki, JP;
Makoto Shiomi, Yokohama, JP;
Toshihisa Komai, Hirosaki, JP;
Makoto Shiomi, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Canon Precision Inc., Hirosaki-shi, JP;
Abstract
A method of driving a vibration wave motor enables proper frequency control of an AC voltage applied to the motor according to the rotational speed difference between the actual and target rotational speeds of the motor, even if frequency-rotational speed characteristics are not stored in advance. A target rotational speed of a moving member is set. A ratio of an amount of increase or decrease in a rotational speed of the moving member to an amount of update of a frequency of the AC voltage and a rotational speed difference between the target rotational speed and an actual rotational speed of the moving member are calculated. The amount of update of the frequency is calculated by dividing the calculated rotational speed difference by the calculated ratio. The frequency of the AC voltage is updated by using the calculated amount of update of the frequency.