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. 24, 2007
Filed:
Jul. 01, 2005
Jun Matsuzaki, Shiojiri, JP;
Takashi Kawaguchi, Shiojiri, JP;
Reiko Nagahama, Shiojiri, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A frequency of a drive signal supplied to a piezoelectric element is swept within a specific range, a detection signal indicating the vibrating state of a vibrating member is detected, and the sweep speed of the drive signal frequency supplied to the piezoelectric element is controlled based on this detection signal. Thus, even if nonuniformities occur in the drive frequency of the piezoelectric element due to fluctuations in the surrounding temperature or the load, such nonuniformities can be overcome without any adjustments, and the piezoelectric element can be reliably driven. Also, since the sweep speed of the drive signal frequency is at a high speed when the vibrating member is in a non-drive state, needless drive signal output time during which the piezoelectric element cannot be driven can be reduced, needless power consumption can be curtailed, and nonuniformities in the drive speed of the driven object can also be reduced.