B is a side view showing a configuration of an actuator using the piezoelectric element of FIG. 43A.FIG. 44 is a plan view of an actuator comprising a hinge structure according to the invention.FIG. 45 is a plan view showing an actuator having no hinge structure according to the invention.FIG. 46A is a partial plan view showing an example configuration of the hinge structure of an actuator accordi