US 7,545,085 B2
Piezoelectric element and ultrasonic actuator
Yusuke Adachi, Osaka (Japan)
Assigned to Panasonic Corporation, Osaka (Japan)
Appl. No. 11/886,097
PCT Filed Jan. 19, 2007, PCT No. PCT/JP2007/050812
§ 371(c)(1), (2), (4) Date Sep. 11, 2007,
PCT Pub. No. WO2007/083752, PCT Pub. Date Jul. 26, 2007.
Claims priority of application No. 2006-013391 (JP), filed on Jan. 23, 2006.
Prior Publication US 2008/0179996 A1, Jul. 31, 2008
Int. Cl. H01L 41/047 (2006.01)
U.S. Cl. 310—365  [310/366] 11 Claims
OG exemplary drawing
 
1. A piezoelectric element obtained by alternately stacking generally rectangular piezoelectric layers and internal electrode layers, wherein
the internal electrode layers include a common electrode layer and feed electrode layers alternately placed in a stacking direction with the piezoelectric layers interposed between the common electrode layer and the feed electrode layers,
the common electrode layer has a common electrode,
the feed electrode layers include a first feed electrode layer disposed on a principal surface of one of the piezoelectric layers and a second feed electrode layer disposed on a principal surface of one of the piezoelectric layers different from the piezoelectric layer on the principal surface of which the first feed electrode layer is disposed,
the first feed electrode layer has a pair of electrically continuous first electrodes disposed on two areas opposed along a first-diagonal-line direction of the principal surface of the associated piezoelectric layer among four areas defined by dividing the principal surface of the associated piezoelectric layer into two parts in the longitudinal and transverse directions,
the second feed electrode layer has a pair of electrically continuous second electrodes disposed on two areas opposed along a second-diagonal-line direction of the principal surface of the associated piezoelectric layer among the four areas, and
the common electrode, the first electrodes, and the second electrodes are connected to associated external electrodes disposed on outer surfaces of the piezoelectric element.