To make an inkjet printer head compact by adequately maintaining a distance between adjacent electrodes in a piezoelectric actuator 12.
A discrete electrode and a common electrode are formed so that they nip a piezoelectric sheet in a laminating direction and the piezoelectric sheet between both of the electrodes opposing in the laminating direction is formed to be an activating section corresponding to each pressurizing chamber. A pattern of the common electrode 37 is longitudinally formed on one plane face of the piezoelectric sheet 34 along a direction of an axis X. Dummy discrete electrodes 38 which are electrically connected to the respective discrete electrodes in the adjacent sheets in the laminating direction via an inner conductive electrode 42 penetrating the piezoelectric sheets in the thickness direction are formed to be away from an edge 37d1 extending along the direction of the axis X in the common electrode pattern by a predetermined distance e2. The extending direction of each of the dummy discrete electrodes 38 is inclined by an angle α with respect to a line perpendicular to the edge extending in the first direction.
Tadashi Higashino
Hiroyuki Nishi
Katsunori Muto