| Patent application number | Description | Published |
|---|
| 20080284284 | RESONANT ACTUATOR - A resonant actuator includes a driving unit having a displacement element that vibrates at a resonance frequency or in a frequency range in the vicinity of a resonance frequency and having a driven member that is driven by the displacement element, in which the displacement element has a piezoelectric ceramic body made of a bismuth layered compound. The displacement direction of the displacement element is preferably substantially the same as the direction of polarization of the piezoelectric ceramic body. The bismuth layered compound is preferably oriented such that the direction of the c crystallographic axis is substantially perpendicular to the direction of polarization of the piezoelectric ceramic body. More preferably, the degree of c-axis orientation is determined to be at least about 75% by the Lotgering method. Thereby, it is possible to provide a resonant actuator having a large saturated vibration velocity, minimizing reductions in the resonance frequency fr and the mechanical quality factor Qm without the destabilization of the vibration velocity even at a high vibration velocity, and having a large amount of displacement even at a high electric field. | 11-20-2008 |
| 20080284286 | PIEZOELECTRIC CERAMIC AND METHOD FOR MAKING THE SAME, AND PIEZOELECTRIC RESONATOR AND METHOD FOR MAKING THE SAME - A piezoelectric ceramic whose resonance frequency temperature characteristic can be easily adjusted is provided. It contains first and second parts ( | 11-20-2008 |
| 20090302961 | RESONANT ACTUATOR - A piezoelectric ceramic base member is formed of a bismuth layer compound to have a bar shape. Main electrodes and are provided on two end surfaces of the piezoelectric ceramic base member in an oscillation direction, and connection electrodes are formed at side-surface central portions of the piezoelectric ceramic base member and are electrically connected to the main electrodes through extraction conductors interposed therebetween, respectively. In addition, the oscillation and polarization directions are set in the same direction, and the piezoelectric ceramic base member is driven at a resonant frequency or at a frequency in the vicinity thereof. In the piezoelectric ceramic base member, the crystal c axis is preferably oriented in a direction orthogonal to the polarization direction. Accordingly, a resonant actuator can be realized which is able to obtain a high oscillation speed since having a large mechanical quality factor Qm, and the oscillation of which is not disturbed by mechanical factors. | 12-10-2009 |
