To provide a piezoelectric actuator wherein friction or rubbing is less likely to be produced.
The piezoelectric actuator includes a first piezoelectric element (23) that is provided between a base member (11) and a relative displacement member (12), and can be elongated and contracted in a first direction from the base member to the displacement member; a second piezoelectric element (24), that is provided between the base member and the relative displacement member and can be elongated and contracted in a second direction different from the first direction; a driving member (22) that is brought into contact with the displacement member by elongation and contraction of the first piezoelectric element and the second piezoelectric element and thereby relatively displaces the relative displacement member; and a control unit (30) that controls the first piezoelectric element and the second piezoelectric element so that the following is implemented when the driving member is brought into contact with the displacement member, by the elongation and contraction of the first piezoelectric element so that the travel speed of the driving member and the travel speed of the relative displacement member are equal to each other, in the direction of relative displacement of the relative displacement member.
Takayuki Suga
Naomasa Shiraishi