Patent attributes
A method of driving a piezoelectric actuator which is constituted of a lower electrode film, a piezoelectric film and an upper electrode film that are layered successively onto a diaphragm, includes the step of: applying an electric field to the piezoelectric film in a direction opposite to the orientation direction of the piezoelectric film while continuously changing an intensity of the electric field from a first electric field intensity to a second electric field intensity, the first electric field intensity being smaller than a coercive electric field of the piezoelectric film, the second electric field intensity being larger than the coercive electric field of the piezoelectric film. The piezoelectric film is oriented in the orientation direction from the lower electrode film toward the upper electrode film.