| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric actuator that keeps constant potentials of two types of common electrodes arranged on the same surface of a piezoelectric layer, respectively.SOLUTION: Common electrodes 44, 45 are arranged on an upper surface of a piezoelectric layer 42. The common electrode 44 includes: a plurality of opposition portions 44a opposite to substantially central portions of a plurality of individual electrodes 43 arrayed in two lines along a paper feed direction; two connection portions 44b connecting the opposition portions 44a together on the lines, respectively; and a coupling portion 44c connecting upper end portions of the two connection portions 44b together. The common electrode 45 is arranged so as to be surrounded by the two connection portions 44b and the coupling portion 44c on three sides. Wiring 47a-47e led out onto an upper surface of a diaphragm 41 is connected to the common electrodes 44, 45 and, specifically, on an upper surface of an insulating layer arranged on the upper surface of the piezoelectric layer 42 so as to cover the common electrodes 44, 45, the wiring 47e is connected to the common electrode 44 via a through hole 46a formed in the insulating layer and is extended across the coupling portion 44c. |
