Ultrasonic actuator
US7737604B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2009 |
| Grant date | Jun 15, 2010 |
| Priority date | — |
| Expiry date | May 20, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N2/028
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An ultrasonic actuator includes: an actuator body (5) including an actuator body (50); a control circuit (150) for setting a driving frequency; power supply sources (191, 192) for applying a driving voltage having the driving frequency to the actuator body; and a memory (170) for storing data related to a difference between antiresonance and resonance frequencies of the actuator body (50). The control circuit (150) determines, based on a reference frequency where a current value of a current fed to the piezoelectric element (50) is local minimum and the data stored in the memory (170), a lower limit of a control range of the driving frequency so that the lower limit is equal to or higher than a frequency where the current value of the current fed to the piezoelectric element (50) is local maximum and determines the driving frequency to be a frequency in the control range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.