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 rotary-to-linear motion converter includes: a drive portion including a vibrating portion vibrating by a piezoelectric body and a convex portion coupled to the vibrating portion; a housing; a rotating member including a first screw portion and a driven surface that contacts the convex portion and that receives driving force of the drive portion, the rotating member pivoting around an axial center relative to the housing; a linearly moving member including a second screw portion threadably engaging with the first screw portion; and a restricting portion that is disposed at the housing and that restricts rotation of the linearly moving member.

A piezoelectric vibrator has a first frequency region where the phase difference between a pickup signal representing the vibration of the piezoelectric vibrator and a drive signal that drives the piezoelectric vibrator does not monotonously change in accordance with the frequency of the drive signal and a second frequency region where the phase difference monotonously changes in accordance with the frequency of the drive signal. A method for controlling a piezoelectric driving apparatus including the piezoelectric vibrator controls the frequency of the drive signal in such a way that pickup voltage representing the amplitude of the pickup signal is fixed in the first frequency region and controls the frequency of the drive signal in such a way the pickup voltage is fixed with the phase difference maintained smaller than or equal to a prespecified value in the second frequency region.

A piezoelectric motor includes a driven member rotating around a rotation axis, and a plurality of piezoelectric vibrators rotating the driven member by transmitting drive forces to the driven member. The plurality of piezoelectric vibrators includes a first piezoelectric vibrator and a second piezoelectric vibrator at a larger distance from the rotation axis than the first piezoelectric vibrator. The control method for the driven member includes, for acceleration of the driven member, rotating the driven member by the drive force of the second piezoelectric vibrator when a rotation velocity of the driven member is lower than a first velocity, and rotating the driven member by the drive force of the first piezoelectric vibrator when the rotation velocity of the driven member is equal to or higher than the first velocity.

A method for sensing an abnormality of a piezoelectric drive device is a method for sensing a vibration abnormality of the piezoelectric drive device having a substrate and thin-film piezoelectric elements placed on the substrate and controlling amplitude of the piezoelectric elements using a drive control signal, and the method includes sensing the vibration abnormality by a drive voltage corresponding to the drive control signal.

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 drive unit for driving a passive element relative to an active element includes a resonator and excitation device, at least a first arm including, at an outer end of the arm, a first contact element that is movable by way of oscillating movements of the first arm, thereby driving the passive element relative to the active element. The passive element includes a first contact area, arranged to be in contact with a first contact element of the first arm. A magnetic element is arranged to exert a magnetic force causing a relative force between the active element and passive element, whereby the first contact area is pressed against the first contact element with a pre-stress force.

Provided is a vibration wave motor, including: a vibrator including a piezoelectric element and a vibrating plate; a friction member, which includes a friction-contact surface to be brought into contact with the vibrator, and is configured to perform relative movement with respect to the vibrator by vibration generated by the vibrator; and a guide mechanism, which includes a first guide member, a second guide member, and a rolling member arranged between the first guide member and the second guide member, and is configured to guide the relative movement, wherein the first guide member includes a groove portion formed of a first surface and a second surface to be brought into contact with the rolling member, and wherein the first surface is longer than the second surface in a direction of the relative movement.

A control method for a piezoelectric drive device includes a piezoelectric vibrator having a vibrating portion and a distal end portion coupled to the vibrating portion, in which the distal end portion makes elliptic motion by a stretching vibration and a flexural vibration of the vibrating portion, a driven member driven by the elliptic motion of the distal end portion, and a drive signal generation circuit outputting a stretching vibration drive signal that generates the stretching vibration and a flexural vibration drive signal that generates the flexural vibration in the piezoelectric vibrator, and the method includes, when the driven member is stopped, superimposing and outputting a modulation signal for amplitude modification on the stretching vibration drive signal by the drive signal generation circuit.

A piezoelectric drive device includes a rotor having a driven part and rotating around a rotation axis, a vibrating unit having a piezoelectric element and applying a drive force for rotating the rotor to the driven part by displacement of the piezoelectric element, and a bearing supporting the rotor. The driven part has a first portion, a second portion, and a third portion sequentially connected, the first portion has a predetermined region along an axial direction of the rotation axis and coupled to an inner ring of the bearing within the predetermined region, the second portion overlaps with the bearing in a plan view from the axial direction, and the third portion has a contact surface in contact with the vibrating unit at an inner side of both ends of the predetermined region in a plan view from a direction perpendicular to the axial direction.