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 control device for a vibration actuator includes a detection signal acquisition section adapted to obtain an alternating-current detection signal corresponding to a vibration of the resonator body from the resonator bodies, a phase difference detection section adapted to detect a phase difference between the drive signal and the detection signal with respect to the resonator bodies, a resonator body selection section adapted to select one from the resonator bodies, and a drive signal control section adapted to adjust a frequency of the drive signal so that the phase difference in the resonator body selected comes closer to a target value.

A support structure includes a fixed frame portion configured to provide a fixed connection point for the support structure. The support structure also includes a suspended frame portion configured to support the interactive device and configured to oscillate in a direction of motion relative to the fixed frame portion due to a force applied to at least one of the fixed frame portion or the suspended frame portion by an actuator configured to provide a haptic effect to the interactive device. Further, the support structure includes one or more support members coupled between the fixed frame portion and the suspended frame portion. The direction of motion is defined by the one or more support members. The one or more support members provide a restoring force that causes the suspended frame portion to undergo harmonic oscillation in the direction of motion in response to the force applied by the actuator.

A gripping device includes a rotating member having a pinion and rotating about a center axis of the pinion, a drive piezoelectric unit having a vibrating portion that vibrates with expansion and contraction of a piezoelectric material, and a convex portion provided in the vibrating portion, being in contact with the rotating member, and transmitting vibration of the vibrating portion to the rotating member, a rack meshing with the pinion and moving with rotation of the pinion, and a gripping part coupled to the rack, wherein a contact portion in which the convex portion and the rotating member are in contact is located outside of an outer circumference of the pinion in a plan view from a direction of a rotation axis of the rotating member.

A piezoelectric drive device includes a vibrating part which has a piezoelectric element, and drives a driven part using the piezoelectric element, and a first plate spring part configured to bias the vibrating part in a first direction from the vibrating part toward the driven part. The first plate spring part extends toward a second direction crossing the first direction, the first plate spring part is disposed so as to be opposed to the vibrating part in a third direction perpendicular to the first direction and the second direction, and when dividing the first plate spring part into a first portion and a second portion farther from the vibrating part than the first portion so that a length along the third direction is equally divided, a volume of the second portion is larger than a volume of the first portion.

A piezoelectric drive device includes a rotor which has an output section for outputting a rotational force and a transmission section disposed on an outer periphery of the output section, and rotates around a rotational axis, and a vibrating part which has a piezoelectric element, and rotates the rotor due to a deformation of the piezoelectric element. The transmission section has a first portion and a second portion different from each other in position in a radial direction from the output section toward the transmission section, the first portion is coupled to the output section, the second portion is higher in Young's modulus than the first portion, the second portion is higher in mass per unit volume than the first portion, and the vibrating part makes contact with the transmission section at a position overlapping the second portion in a plan view from an axial direction of the rotational axis.

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.

A piezoelectric actuator includes a vibrating section including a piezoelectric element, a distal end face, and a recess opened on the distal end face and a protrusion section including a base that overlaps the recess in plan view of the distal end face and is fixed to the distal end face and a projection that is provided in the base and projects in an opposite direction of the distal end face, the protrusion section transmitting a driving force of the vibrating section to a driven section. In plan view of the distal end face, the projection is disposed within a range of the recess.

A vibration type motor relatively moves in a first direction a vibrator whose vibration is excited by an electromechanical energy conversion element and a contact member configured to contact the vibrator and includes a vibrator holder configured to hold the vibrator, a holding mechanism configured to hold the vibrator holder so as to restrict a displacement of the vibrator holder in the first direction and to enable the vibrator holder to be displaced in a direction orthogonal to the first direction, a press mechanism configured to press the vibrator against the contact member in the second direction, and a damper configured to contact a plurality of components among the vibrator holder, components of the holding mechanism, and components of the press mechanism.

An acoustic device includes a piezoelectric element, an attachment member to which the piezoelectric element is attached, and a spacer. The piezoelectric element includes first and second principal surfaces opposing each other. The attachment opposes the first principal surface. The spacer is disposed between the piezoelectric element and the attachment member in such a manner as to form an acoustic space between the piezoelectric element and the attachment member. The spacer includes an adhesive layer including a principal surface in contact with the first principal surface and a principal surface in contact with the attachment member.