Patent ID: 8179020

Claim:
A vibratory actuator comprising: an actuator body formed of or formed to include a piezoelectric element, and configured to perform a plurality of vibrations having different vibration directions; and a plurality of driver elements provided on a mounting surface which is one of side surfaces of the actuator body, and configured to perform an orbital motion in accordance with the vibrations of the actuator body to output a driving force in a predetermined driving direction, wherein the plurality of driver elements include a first driver element and a second driver element on the mounting surface at different positions in a direction along the driving direction, and the first driver element and the second driver element are located at different positions in a direction perpendicular to a plane in which the first and second driver elements perform the orbital motion, wherein the first driver element is included among n first driver elements in a first driver element group, and the second driver element is included among n second driver elements in a second driver element group located at a different position than the first driver element group along the driving direction (n: an integer of one or more), and a middle position t in the perpendicular direction between an N-th (N=1, 2, . . . , n) first driver element and an N-th second driver element which are numbered from one end in the perpendicular direction, to satisfy the following: t ={(2 N− 1)/(2 n )}× T (1) where t: a position in the perpendicular direction on the mounting surface with reference to the one end in the perpendicular direction n: the total number of the driver elements arranged in the perpendicular direction T: a thickness of the mounting surface in the perpendicular direction.