A lens barrel includes: an electromechanical conversion element; an elastic body having a joining surface, a drive surface, and grooves; a motion member rotating by vibration wave of the drive surface; a rotating ring having a recess part and rotating by rotation of the motion member; a moving ring engaged to the recess part and moving to an optical axis direction by rotation of the rotating ring; and a lens held in the moving ring; wherein the element is made of a material having sodium potassium niobate, potassium niobate, sodium niobate or barium titanate, wherein a value of T/(B+C) is within a range of from 1.3 to 2.8 when: length from the drive surface to a base unit of the groove is defined as T; length from the base unit of the groove to the joining surface is defined as B; and thickness of the element is defined as C.

A zero-voltage zero-current soft switching type driving method for an ultrasonic motor is provided, relating to the technical field of driving of a two-phase actuator. The disclosure solves the problems of high loss, high heat amount and the like in a traditional ultrasonic motor driving circuit. The method provided realizes resonance between series inductors and buffer capacitors by means of an optimal design of the inductance of matching inductors, the capacitance of buffer capacitors, a dead time value and a delay time value, thereby causing a power tube to realize zero-voltage and zero-current switching. Two signal input ends of a two-phase pseudo full bridge inverter are connected to a power grid, and two signal output ends of the two-phase pseudo full bridge inverter are respectively connected to two signal input ends of a matching circuit; and the output ends of the matching circuit are respectively connected to a two-phase ultrasonic motor.

A piezoelectric resonator includes a vibrating part having a pair of principal surfaces in an obverse-reverse relationship, and a side surface configured to couple the pair of principal surfaces to each other, and a protruding part which is provided to the vibrating part, and is configured to transmit a drive force generated by a vibration of the vibrating part to a driven part, wherein the vibrating part has a pair of vibrating plates including a first vibrating plate and a second vibrating plate stacked on one another in afirst direction in which the pair of principal surfaces are arranged side by side, the first vibrating plate has a flexural vibrating piezoelectric element configured to flexurally vibrate the vibrating part in a third direction perpendicular to a second direction in which the driven part and the protruding part are arranged side by side in a plan view of the principal surfaces, either one or both of the first vibrating plate and the second vibrating plate have a stretching vibrating piezoelectric element configured to make the vibrating part perform a stretching vibration in the second direction, and the side surface is provided with a plurality of terminals electrically coupled to the flexural vibrating piezoelectric element and the stretching vibrating piezoelectric element.

A vibration actuator is capable of reducing differences in vibration phase and vibration amplitude without raising a voltage of a drive circuit when driving a contact member using a plurality of vibrators connected in series. The vibration actuator includes a vibrator device and a contact member that moves relative to the vibrator device. The vibrator device includes transformers of which primary coils are connected in series, and vibrators that are respectively connected in parallel to secondary coils of the transformers.

The driving apparatus comprises a vibrating body which includes an electro-mechanical energy conversion device, and drives a vibration-wave motor which moves the vibrating body and a driven body relatively to each other. The electro-mechanical energy conversion device has sensor electrodes that output detecting signals corresponding to vibrations of the vibrating body. Based on the detecting signals, the driving apparatus determines a direction in which the vibrating body and the driven body are to be moved relatively to each other.

A drive control device includes: a vibration wave drive device that includes an elastic body, a vibration body including an electro-mechanical energy conversion element, and a contact body in contact with the vibration body, and a control unit of the vibration wave drive device. The drive control device includes: a first detector configured to detect an electric current that is supplied to the vibration wave drive device or consumed electric power, and a second detector configured to detect relative positions or relative speed of the vibration body and the contact body. A control mode in which the vibration wave drive device is decelerated on a basis of a detection result obtained by the first and/or the second detector is included.

A vibration wave motor includes an annular oscillator, and an annular moving member provided so as to be in press contact with the oscillator. The oscillator includes an annular vibrating plate, and an annular piezoelectric element provided on a first surface of the vibrating plate. The vibrating plate is in contact with the moving member via a second surface of the vibrating plate, which is opposite the first surface. The piezoelectric element has a plurality of drive phase electrodes. When a driving region represents a region of the oscillator in which the drive phase electrodes are provided, and a non-driving region represents a remaining region of the oscillator, a contact area ratio S1 between the vibrating plate and the moving member in the non-driving region is less than a contact area ratio S2 between the vibrating plate and the moving member in the driving region.

A vibration actuator that is capable of reducing difference of vibration velocities when a contact member is driven using a plurality of vibrators includes a vibrator device and the contact member, which moves relative to the vibrator device. The vibrator device includes the plurality of vibrators, which are connected in series, and a plurality of inductors, which are connected in parallel to the respective vibrators.

A piezoelectric drive device has a first piezoelectric vibrator and a second piezoelectric vibrator each include a vibrating portion and a distal end portion in which the distal end portion make elliptic motion by stretching vibration and flexural vibration of the vibrating portion, a driven member driven by the elliptic motion of the distal end portion, a drive signal generation circuit that outputs stretching vibration drive signals to the first piezoelectric vibrator and the second piezoelectric vibrator, a first boosting circuit provided between the first piezoelectric vibrator and the drive signal generation circuit, a second boosting circuit provided between the second piezoelectric vibrator and the drive signal generation circuit, and a control circuit that controls boosting amounts of the stretching vibration drive signals.

A piezoelectric resonator includes a vibrating part having a pair of principal surfaces in an obverse-reverse relationship, and a side surface configured to couple the pair of principal surfaces to each other, and a protruding part which is provided to the vibrating part, and is configured to transmit a drive force generated by a vibration of the vibrating part to a driven part, wherein the vibrating part has a pair of vibrating plates including a first vibrating plate and a second vibrating plate stacked on one another in afirst direction in which the pair of principal surfaces are arranged side by side, the first vibrating plate has a flexural vibrating piezoelectric element configured to flexurally vibrate the vibrating part in a third direction perpendicular to a second direction in which the driven part and the protruding part are arranged side by side in a plan view of the principal surfaces, either one or both of the first vibrating plate and the second vibrating plate have a stretching vibrating piezoelectric element configured to make the vibrating part perform a stretching vibration in the second direction, and the side surface is provided with a plurality of terminals electrically coupled to the flexural vibrating piezoelectric element and the stretching vibrating piezoelectric element.