Ultrasonic motor, drive control system, optical apparatus, and vibrator
US10536097B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2016 |
| Grant date | Jan 14, 2020 |
| Priority date | — |
| Expiry date | Apr 26, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/8536
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An ultrasonic motor includes an annular vibrator and an annular moving member that is brought into pressure-contact with the vibrator. The vibrator includes an annular vibrating plate and an annular piezoelectric element. The piezoelectric element includes an annular lead-free piezoelectric ceramic piece, a common electrode arranged on one surface of the piezoelectric ceramic piece, and a plurality of electrodes arranged on the other surface of the piezoelectric ceramic piece. The plurality of electrodes include two drive phase electrodes, one or more non-drive phase electrodes, and one or more detection phase electrodes. A second surface of the vibrating plate includes a plurality of groove regions extending radially, and the depths of the groove regions change in a circumferential direction along a curve obtained by superimposing one or more sine waves on one another. The ultrasonic motor exhibits a sufficient drive speed while suppressing generation of an unnecessary vibration wave.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.