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 vibration wave motor includes an element configured to be displaced by application of voltage, and an annular elastic body having a bottom surface coming into contact with the element and a drive surface having a groove, configured to drive a moving element by a vibration wave produced on the drive surface by displacement of the element. The element has a density of 4.2 to 6.010.sup.3 kg/m.sup.3. 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 bottom surface, and W represents a radial width of the elastic body.

A method of manufacturing a vibration type actuator providing a satisfactory actuator performance even when an increase in speed is achieved and having a contact spring. The actuator includes an elastic member and a hollow protrusion having a side wall portion protruding with respect to a surface of the elastic member, a contact portion configured to come into contact with a body, and a first connection portion connecting the side wall portion and the contact portion, the method includes, forming the hollow protrusion including the side wall portion and a distal end portion by performing drawing on an elastic plate and forming the contact portion and the first connection portion by performing drawing or squeezing on the distal end portion, wherein the contact portion is surrounded by the first connection portion.

An ultrasonic electromechanical stator includes two vibration bodies, a link member connecting the two vibration bodies along a connection direction and a stator support. Each of the vibration bodies includes a respective electromechanical element and is configured to perform bending vibrations in a bending direction when an alternating voltage is applied to the electromechanical elements. The link member has a contact portion intended for contacting a surface of a body to be moved. The link member has a respective mechanical link connecting portion to the vibrating bodies. Each of the vibration bodies is mechanically attached to the stator support by at least two attachment tabs on at least one side, in a direction transverse to both the connection direction and the bending direction, of the respective vibration bodies. Also an ultrasonic electromechanical motor having such an ultrasonic electromechanical stator is disclosed.

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.

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.

A contact body that makes it possible to easily verify whether or not the resin has been properly impregnated in the pores. A metallic sintered body having a plurality of pores, as a main body, is in contact with a vibration element in a vibration actuator. The contact body includes a sliding portion that has a sliding surface in contact with the vibration element, and a non-sliding portion adjacent to the sliding portion and not in contact with the vibration element. The non-sliding portion is provided with a resin lump containing hard particles and resin, and the resin lump is formed to be lower in height in a vertical direction than the sliding surface. In the sliding portion, part of hard particles and resin is exposed on the sliding surface.

A vibration actuator capable of adjusting the position of a vibration element with respect to a contact body. The vibration actuator includes a vibration element unit and a contact body capable of relative movement to each other. The vibration element unit includes a first vibration element in contact with the contact body, an urging unit that brings the first vibration element and the contact body into contact with each other with predetermined pressure force, a first holding member that holds the first vibration element, a base, a first supporting member that slidably supports the first holding member in a direction in which the first vibration element is pressed against the contact body, and a first connection member that is rotatably connected to the first supporting member and rotatably connected to the base about an axis parallel to a direction of the relative movement.

A vibration actuator that is reduced in the change of posture of a vibration element with respect to a contact body. The vibration element unit and the contact body are movable relative to each other. The vibration element unit includes a vibration element in contact with the contact body, a first holding member that holds the vibration element, a base, a first supporting member that is fixed to the base, and movably supports the first holding member in a direction orthogonal to a friction sliding surface of the contact body in slide contact with the vibration element, while maintaining the vibration element in a predetermined posture with respect to the contact body, and an urging unit that is arranged on the base independently of the first supporting member and presses the vibration element in a direction orthogonal to the friction sliding surface of the contact body.

A piezoelectric driving device includes: a substrate including a fixed portion, and a vibrating body portion which is provided with a piezoelectric element and is supported by the fixed portion; and a contact portion which comes into contact with a driven body, and transmits movement of the vibrating body portion to the driven body, the contact portion is provided at an end portion in the longitudinal direction of the vibrating body portion, and a difference between a distance between the end portion when the contact portion is not pressed against the driven body and a tip end of the contact portion, and a distance between the end portion when the contact portion is pressed against the driven body and the tip end, is smaller than a total amplitude in the longitudinal direction in a case where the vibrating body portion is driven.