Drive device using electromechanical transducer and an apparatus employing the drive device
US5969464A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1997 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Apr 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N2/067
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive device which repeats charging and discharging at different velocities by applying drive pulses to a piezoelectric transducer, causes vibrations with different velocities in the piezoelectric transducer to cause contraction and expansion displacements in a driving member fixedly coupled with the piezoelectric transducer for moving a member frictionally coupled to the driving member. In order to provide stable driving force, stable driving velocity and precise movement, a piezoelectric transducer constituted by stacking a plurality of unit elements is divided into a plurality of blocks having different numbers of lamination layers for driving. A change in impedance by the division is compensated by a compensation circuit, or a plurality of driving circuits corresponding to the impedance are provided and a block and a driving circuit of the piezoelectric transducer are selected in accordance with the driving velocity and moving distance for driving.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.