Patent ID: 6863383

Claim:
A piezoelectric transducer, comprising: a plurality of piezoelectric ceramic layers; and a plurality of electrodes spaced in a direction along a plane of the piezoelectric ceramic layers as well as in a thickness direction of the piezoelectric ceramic layers, the plurality of electrodes including: a first set of electrodes spaced in the thickness direction of the piezoelectric ceramic layers and defining therebetween a first area that is polarized parallel to an opposing direction of electrodes of the first set and in the thickness direction of the piezoelectric ceramic layers, a second set of electrodes spaced in the direction along the plane and in the thickness direction of the piezoelectric ceramic layers, the second set of electrodes including electrodes substantially coplanar with the electrodes of the first set, and the second set of electrodes defining, between electrodes opposed in the direction along the plane of the piezoelectric ceramic layers, second areas that are polarized perpendicular to the opposing direction of the electrodes of the second set and in the thickness direction of the piezoelectric ceramic layers, the second areas being defined one on each side of the first area in the direction along the plane of the piezoelectric ceramic layer, and the second areas being substantially level with the first area, wherein upon application of a drive voltage to the first and second sets of electrodes, an electric field is generated in each of the second areas perpendicular to the polarization direction and each of the second areas is obliquely deformed by a piezoelectric shear effect to unidirectionally shift the first area, and an electric field is generated in the first area parallel to the polarization direction and the first area is deformed by a piezoelectric longitudinal effect to increase the thickness of the piezoelectric ceramic layers.