Patent ID: 7638932

Claim:
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 four divided electrodes respectively disposed on four areas defined by dividing the principal surface of the associated piezoelectric layer into two parts in the longitudinal and transverse directions, and a first connection electrode for providing connection between two of the four divided electrodes respectively disposed on two of the areas opposed along a first-diagonal-line direction of the principal surface of the associated piezoelectric layer, the second feed electrode layer has four divided electrodes respectively disposed on the four areas, and a second connection electrode for providing connection between two of the four divided electrodes respectively disposed on two of the areas opposed along a second-diagonal-line direction of the principal surface of the associated piezoelectric layer, the first and second connection electrodes are formed on parts of longitudinally middle parts of the associated piezoelectric layers except both transverse end parts of the associated piezoelectric layers, respectively, the common electrode is connected to an external electrode disposed on an outer surface of the piezoelectric element, the two divided electrodes of the first feed electrode layer respectively disposed on two of the areas opposed along the first-diagonal-line direction are connected through an external electrode disposed on the outer surface of the piezo electric element to the two divided electrodes of the second electrode layer respectively disposed on two of the areas opposed along the first-diagonal-line direction, and the two divided electrodes of the first feed electrode layer respectively disposed on two of the areas opposed along the second-diagonal-line direction are connected through an external electrode disposed on the outer surface of the piezoelectric element to the two divided electrodes of the second electrode layer respectively disposed on two of the areas opposed along the second-diagonal-line direction.