Patent ID: 7339310

Claim:
A laminated piezoelectric element comprising: a laminated piezoelectric element comprising piezoelectric layers composed of a ceramic capable of expanding and contracting upon application of a voltage, and internal electrode layers that supply voltage to the piezoelectric layers, the internal electrode layers and piezoelectric layers being alternately provided; a first external electrode layer provided on a side of the laminated piezoelectric element and electrically connected with the internal electrode layers; and, a second external electrode layer provided on a side of the laminated piezoelectric element and electrically connected with the internal electrode layers via the first external electrode layer; wherein, when the maximum width of the laminated piezoelectric element in the direction perpendicular to the direction of lamination is taken to be W 0 , the width of the first external electrode layer is taken to be W 1 , and the width of the second external electrode layer is taken to be W 2 , the relationship exists in which W 1 >W 2 and 2.5≦(W 2 /W 0 )×100≦60, and the laminated piezoelectric element has a piezoelectric active section that expands and contracts when a voltage is applied, and the second external electrode layer is provided continuously in the direction of lamination of the piezoelectric layers in the piezoelectric active section.