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. 19, 2016
Filed:
Jun. 04, 2012
Osamu Urano, Okaya, JP;
Osamu Urano, Okaya, JP;
Seiko Epson Corporation, , JP;
Abstract
A piezoelectric actuator includes a vibrating body including a piezoelectric device; a driving circuit that supplies a driving signal to the piezoelectric device; a phase difference detecting circuit that detects a phase difference between the driving signal and a detection signal detected based on vibration of the vibrating body; and a frequency controller that controls the frequency and power of the driving signal, wherein the frequency controller sets the power to an upper limit voltage value when the frequency is changed so that the phase difference falls within a predetermined range and sets the voltage to a lower limit voltage value smaller than the upper limit voltage value when the phase difference is outside the predetermined range.