A vibration type motor includes a vibrator, a friction member extending in a predetermined direction and including a first surface in pressed contact with the vibrator and a second surface positioned on a side opposed to the first surface and a holding member holding the friction member. The first surface forms with a surface adjacent thereto a first corner portion extending in a direction parallel with the predetermined direction, the second surface forms with a surface adjacent thereto a second corner portion, the first corner portion is different in radius of curvature from the second corner portion, either one of the first surface and the second surface is in contact with the holding member, either one of the first corner portion and the second corner portion has a radius of curvature smaller than the other.

A vibration actuator includes an elastic body on which at least one projection is formed and a vibrating body including an electromechanical conversion device, and drives a driven member that is in contact with a contact portion of the projection by causing an end portion of the projection to perform an ellipsoidal movement in response to a combination of two vibration modes generated in the vibrating body when an alternating driving voltage is applied. The elastic body is formed integrally with the projection and a bonding portion between the projection and the electromechanical conversion device. A space is provided between the contact portion and the electromechanical conversion device to which the projection is bonded. The spring portion is provided between the bonding portion and the contact portion and causes the projection to exhibit a spring characteristic when the contact portion is pressed by the driven member.

A small-sized vibration motor. The vibration motor includes a vibrator having a piezoelectric element, a contact member brought into friction contact with the vibrator, and a fixing member to which the contact member is fixed. The vibrator and the contact member are moved relative to each other in a driving direction by high-frequency vibration of the piezoelectric element. The contact member includes a sliding portion brought into friction contact with the vibrator when the vibrator and the contact member are moved relative to each other in the driving direction, and fixed portions via which the contact member is fixed to the fixing member. The fixed portions are formed at respective locations alongside the sliding portion in a second predetermined direction orthogonal to the first predetermined direction, and also inward of opposite ends of the contact member in the first predetermined direction.

A vibration wave motor, includes a vibrator including an electro-mechanical energy conversion element and an elastic body, and a contact body, wherein the elastic body includes a flat plate portion on which the electro-mechanical energy conversion element is fixed, and a protruding portion, wherein the protruding portion includes a contact portion, a side wall portion, and a coupling portion that is configured to couple the contact portion and the side wall portion, and wherein a predetermined inequality is satisfied, where a thickness of the side wall portion in a direction orthogonal to the pressure direction is t1, and a distance in the pressure direction from a second surface of the flat plate portion to the coupling portion is h1, the second surface of the flat plate portion facing a first surface of the flat plate portion on which the electro-mechanical energy conversion element is fixed.

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 type actuator is provided that includes a first member that has a vibrator; a second member that extends in a predetermined direction and has a friction sliding surface where the vibrator is press-contacted; a third member that rotatably holds the second member with respect to an axis parallel to the predetermined direction; and a pressing unit that generates a first force for rotating the second member with respect to the axis relative to the third member. The first member is sandwiched between the second member and the third member by the first force. The first member is driven in a driving direction parallel to the predetermined direction relative to the second member by the vibration of the vibrator.

A vibrator of a vibration-type driving device according to an aspect of the present invention includes a first vibrating member that includes first protrusions protruding in a first direction, a second vibrating member that includes second protrusions protruding in a direction that is opposite to the first direction, and an electric-mechanical energy conversion element that is fixed to the first vibrating member. The first protrusions and the second protrusions each have a hollow structure, and the first vibrating member and the second vibrating member are disposed in such a manner that a surface of the first vibrating member on which the first protrusions are not formed and a surface of the second vibrating member on which the second protrusions are not formed face each other.

A control apparatus for a vibration-type actuator which improves acceleration performance and deceleration performance in driving the vibration-type actuator. The vibration-type actuator moves a vibrating body and a driven body relatively to each other. A vibration state of the vibrating body is detected based on a vibrating voltage or driving current generated in response to vibrations of the vibrating body. A relative speed of the vibrating body and the driven body is detected, and based on the detected vibration state and the detected relative speed, the vibration state of the vibrating body is controlled.

A driving device includes a plurality of motive power generators that receive electric power supply and generate motive power, the plurality of motive power generators form a plurality of sets of motive power generators in which two or more of the motive power generators are electrically parallel-connected, and the plurality of sets of motive power generators are electrically series-connected. A driving device includes a plurality of vibrators that receive electric power supply and vibrate and provide drive power for driving a driven member to the driven member, the plurality of vibrators form a plurality of sets of vibrators in which two or more of the vibrators are electrically parallel-connected, and the plurality of sets of vibrators are electrically series-connected.

A piezoelectric actuator includes a vibrating plate having a piezoelectric material, and a contact part provided in an end portion of the vibrating plate in contact with a driven part, wherein the contact part has a first portion in contact with the driven part and a second portion provided between the first portion and the vibrating plate and having lower rigidity than the first portion. Further, a width of the second portion in a direction crossing an arrangement direction of the first portion and the second portion is smaller than a width of the first portion in the crossing direction.