Abstract text

A piezoelectric actuator includes: a vibrator that includes a piezoelectric element, a first drive electrode and a second drive electrode, the piezoelectric element vibrated by a combination of at least two vibration modes including a first vibration mode and a second vibration mode, the first drive electrode applying a first drive signal that excites a vibration of the first vibration mode, the second drive electrode applying a second drive signal that excites a vibration of the second vibration mode; and a phase adjuster that adjusts a phase of at least one of the first and second drive signals.