VIBRATION TYPE ACTUATOR, OPTICAL INSTRUMENT, AND IMAGING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a vibration type actuator which can perform control of changing pressure force when relatively moving a friction member with vibration generated in a vibrator in a state where the vibrator is brought into pressure contact with the friction member by pressure means.SOLUTION: An ultrasonic motor 100 comprises a vibrator 104 to which a piezoelectric element 103 is fixed and a friction member 101 which has a frictional contact surface 101a with the vibrator 104. A pressure member 106 presses the vibrator 104 toward the friction member 101 with elastic force of a coil spring 107. A pressure force setting part 131 sets pressure force by transmitting the drive force of a pressure force setting motor 110 to a holding member 108 and changing the deflection amount of the coil spring 107 in accordance with the relative position of the holding member 108 with respect to the pressure member 106. The friction member 101 is relatively driven with respect to the vibrator 104 with the elliptic motion of the vibrator 104 in the state where a protrusion 102a of a diaphragm 102 is brought into pressure contact with a frictional contact surface 101a of the friction member 101 with the pressure force.SELECTED DRAWING: Figure 4