Patent ID: 9016834
Filing Date: 2015-04-28
Classification: B41J

Abstract:
1. A liquid ejection head, comprising: a flow channel unit having a plurality of pressure chambers arranged in a plane; and piezoelectric actuators which change volume of the plurality of pressure chambers so as to apply pressure to liquid inside the plurality of the pressure chambers respectively, wherein the piezoelectric actuators comprise: a diaphragm which constitutes one wall of the plurality of pressure chambers; a common electrode formed on a surface of the diaphragm; a piezoelectric layer formed on a surface of the common electrode; a plurality of ring-shaped individual electrodes formed on a surface of the piezoelectric layer and formed in regions which overlap respectively with marginal portions which are non-central portions of the plurality of pressure chambers, as viewed from a direction perpendicular to the plane; and central electrodes connected electrically to the common electrode, and formed so as not to make contact with the plurality of ring-shaped individual electrodes in inner regions of the plurality of ring-shaped individual electrodes, as viewed from the direction perpendicular to the plane, wherein: the piezoelectric layer has holes having a smaller planar dimension than the central electrodes and being formed in regions on the surface of the piezoelectric layer which overlap with central portions of the plurality of pressure chambers; and the central electrodes and the common electrode are connected electrically via a metal film formed inside the holes.