A displacement magnifying device includes a diaphragm structure including a substrate and a diaphragm provided separately from the substrate, actuators provided side by side with the diaphragm structure, and a first member including displacing sections coupled to both ends of the actuators and displaced according to displacement of the actuators. The displacing sections are coupled to the diaphragm of the diaphragm structure.

A piezoelectric motor includes a piezoelectric actuator, a holding member that holds the piezoelectric actuator, a housing in which the piezoelectric actuator and the holding member are placed, a first positioning pin that positions the holding member and the housing, and a first fixing part that fixes the first positioning pin. In the piezoelectric motor, the first positioning pin is fixed to one of the holding member and the housing, and a first hole portion in which the first positioning pin is placed is provided in the other of the holding member and the housing. The first fixing part fixes relative positions of the first hole portion and the first positioning pin.

A piezoelectric motor includes a piezoelectric actuator, a holding member that holds the piezoelectric actuator, a housing in which the piezoelectric actuator and the holding member are placed, a first positioning pin that positions the holding member and the housing, and a first fixing part that fixes the first positioning pin. In the piezoelectric motor, the first positioning pin is fixed to one of the holding member and the housing, and a first hole portion in which the first positioning pin is placed is provided in the other of the holding member and the housing. The first fixing part fixes relative positions of the first hole portion and the first positioning pin.

A piezoelectric drive device includes a vibrator having a vibrating portion including a piezoelectric element, and a convex portion placed in the vibrating portion, an urging member including a base, a holding portion holding the vibrator, and a spring portion coupled to the base at one end and coupled to the holding portion at another end and urging the convex portion toward a driven unit, wherein d1>d2 in a natural state in which the vibrator is not urged by the urging member, where a separation distance between the one end and the convex portion along directions of the longitudinal direction is d1 and a separation distance between the other end and the convex portion is d2, and |d1−d2| in an urging state in which the vibrator is urged toward the driven unit by the urging member is smaller than |d1−d2| in the natural state.

A piezoelectric drive device includes a vibrator having a vibrating portion including a piezoelectric element, and a convex portion placed in the vibrating portion, an urging member including a base, a holding portion holding the vibrator, and a spring portion coupled to the base at one end and coupled to the holding portion at another end and urging the convex portion toward a driven unit, wherein d1>d2 in a natural state in which the vibrator is not urged by the urging member, where a separation distance between the one end and the convex portion along directions of the longitudinal direction is d1 and a separation distance between the other end and the convex portion is d2, and |d1−d2| in an urging state in which the vibrator is urged toward the driven unit by the urging member is smaller than |d1−d2| in the natural state.

A vibrating actuator includes a contact body and a vibrating body that vibrates, has an energy conversion element, and has an elastic body in contact with the contact body to move relative to each other from the vibration. The contact body has a base part, a thin plate part, a support part, and a friction member. The thin plate part extends from the base part toward an annular center axis of the base part and the support part is disposed at an end of the thin plate part. The friction member is disposed to the support part as a member separate from the support part and in contact with the elastic body. Density of the friction member is higher than density of the thin plate part. A weight ratio of the thin plate part to a total weight of the friction member and the support part is 0.5 to 1.5.

A vibrating actuator includes a contact body and a vibrating body that vibrates, has an energy conversion element, and has an elastic body in contact with the contact body to move relative to each other from the vibration. The contact body has a base part, a thin plate part, a support part, and a friction member. The thin plate part extends from the base part toward an annular center axis of the base part and the support part is disposed at an end of the thin plate part. The friction member is disposed to the support part as a member separate from the support part and in contact with the elastic body. Density of the friction member is higher than density of the thin plate part. A weight ratio of the thin plate part to a total weight of the friction member and the support part is 0.5 to 1.5.

A lens barrel includes an element displaced by application of voltage; an elastic body having a contact surface coming into contact with the element, a drive surface to produce a vibration wave by displacement of the element, and a plurality of grooves; a moving element come into contact with the drive surface and rotated by the vibration wave; an annular ring rotated by rotating of the moving element; and a lens moved in an optical axis direction by rotating of the annular ring; wherein the element mainly contains a material having potassium sodium niobate, potassium niobate, sodium niobate, or barium titanate, wherein a value of [(T/B)÷W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the contact surface, and W represents a radial width of the elastic body.

A lens barrel includes an element displaced by application of voltage; an elastic body having a contact surface coming into contact with the element, a drive surface to produce a vibration wave by displacement of the element, and a plurality of grooves; a moving element come into contact with the drive surface and rotated by the vibration wave; an annular ring rotated by rotating of the moving element; and a lens moved in an optical axis direction by rotating of the annular ring; wherein the element mainly contains a material having potassium sodium niobate, potassium niobate, sodium niobate, or barium titanate, wherein a value of [(T/B)÷W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the contact surface, and W represents a radial width of the elastic body.

The invention relates to an annular or hollow cylindrical ultrasonic actuator, on the end faces of which are arranged n≥2 friction elements, and on the outer peripheral surface of which are arranged 2n excitation electrodes, spaced apart from one another in each case by a separating gap, each of the friction elements being arranged in the region of a separating gap, wherein, between friction elements that are adjacent with respect to the periphery of the ultrasonic actuator and are located on different end faces, two excitation electrodes are arranged such that, when the ultrasonic actuator is electrically excited, the friction elements of both end faces simultaneously perform a movement which is suitable for driving an element to be driven to rotate in the same direction. The invention further relates to an ultrasonic motor having an ultrasonic actuator of this kind and having a holding device in which the ultrasonic actuator is inserted.