A vibration wave motor including: a vibrator; a friction member; and a pressurizing member configured to press the vibrator and the friction member into contact with each other. The vibrator and the friction member are relatively moved in a direction orthogonal to the pressurizing direction of the pressurizing member by vibrations generated on the vibrator, the vibrator and the friction member are configured so as to move in parallel with the pressurizing direction with respect to a fixed member, and the vibration wave motor further includes at least one first restricting portion that restricts a movable amount of the friction member in the pressurizing direction and at least one second restricting portion that restricts a movable amount of the vibrator in the pressurizing direction, such that the movable amount of the friction member is smaller than the movable amount of the vibrator in the pressurizing direction.

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 vibration actuator includes a vibrating body and a contact body having an annular shape. The vibrating body vibrates and includes an annular elastic body and an electro-mechanical energy conversion element. The contact body is in contact with the vibrating body and moves relative to the vibrating body. The contact body includes a base portion, a supporting portion annularly extending from the base portion in a radial direction of the annular shape of contact body, and a friction member that is on the supporting portion, is different in member from the supporting portion, and is in contact with the vibrating body. A first gap is between one end of the friction member and the supporting portion, and a second gap is between the one end of the friction member and the vibrating body.

An inertia drive motor is disclosed which includes an element to be driven, and a stator, the stator having: an elastic frame, at least one friction element arranged on the elastic frame and configured to be brought into frictional contact with the element to be driven, and a first electromechanical actuator and a second electromechanical actuator, which are configured to cause, by interaction, a deformation of the elastic frame, upon excitation with different excitation voltages having a sawtooth signal, so as to displace the at least one friction element for driving the element to be driven by stick-slip contact with the friction element.

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 piezoelectric drive device includes a piezoelectric element, a vibrating plate with a concave portion provided in a side surface, and a projecting portion provided between two side surfaces of the concave portion and having a spherical shape, an elliptical shape, or an egg shape, wherein a plurality of the piezoelectric elements and a plurality of the vibrating plates are stacked, and the concave portion includes a bottom surface.

A vibration wave motor includes a vibrator including an electrical-mechanical energy conversion element and an elastic member, a contact member in contact with the elastic member, and a supporting member that supports the vibrator, wherein the supporting member supports an outer periphery portion of the vibrator so as to be movable along a direction in which the vibrator is pressed toward the contact member, and selectively supports a node of a vibration of the vibrator.

Provided is a vibration wave motor including: a vibrator; a friction member configured to be brought into frictional contact with the vibrator; a first holding member holding the vibrator; a second holding member holding the first holding member; and a third holding member holding the second holding member, wherein the vibrator and the friction member move relative to each other, and wherein one side of the second holding member is configured to connect to the first holding member or the third holding member at a position where the second holding member overlaps the rectangular shape portion in a direction of the relative movement, and another side of the second holding member is configured to connect to the first holding member or the third holding member at a position where the second holding member overlaps the rectangular shape portion in a direction perpendicular to the direction of the relative movement.

An inertia drive motor is disclosed which includes an element to be driven, and a stator, the stator having: an elastic frame, at least one friction element arranged on the elastic frame and configured to be brought into frictional contact with the element to be driven, and a first electromechanical actuator and a second electromechanical actuator, which are configured to cause, by interaction, a deformation of the elastic frame, upon excitation with different excitation voltages having a sawtooth signal, so as to displace the at least one friction element for driving the element to be driven by stick-slip contact with the friction element.

A vibration actuator suppressed in generating abnormal noise while realizing size reduction. The vibration actuator includes a vibration element having a piezoelectric element and an elastic member, and a contact body in contact with the vibration element. The contact body has a direction in which the vibration element and the contact body move relative to each other as a longitudinal direction and a square bar shape substantially uniform in width and thickness in the longitudinal direction, and includes a first section and a second section which are formed with respective R surfaces different in curvature radius on an edge extending in the longitudinal direction, in an area where the contact body performs frictional sliding on the vibration element.