A control device of a piezoelectric drive device includes a drive pulse signal generation unit that generates a binary drive pulse signal, a drive signal generation unit that generates a drive signal which is applied to the piezoelectric element for drive from the drive pulse signal, a detection pulse signal generation unit that generates a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection, and a phase difference acquisition unit that acquires a phase difference between the drive pulse signal and the detection pulse signal, based on a rising edge and a falling edge of the drive pulse signal and a rising edge and a falling edge of the detection pulse signal.

A vibration driving device includes a vibration actuator including a vibrating body and a contact body, the vibrating body including an elastic body and an electromechanical energy conversion element, the contact body being in contact with the vibrating body and movable relatively to the vibrating body; and a control device including a signal generating circuit and a boosting circuit, the boosting circuit including an air-core transformer electrically connected to the signal generating circuit. The vibration actuator is configured to receive a signal output by the control device.

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 vibration wave motor comprises: an electromechanical conversion element; an elastic body which has a drive surface on which a vibration wave is generated due to vibration of the electromechanical conversion element; and a relative motion member which makes contact with the drive surface of the elastic body and is configured to rotationally drive by the vibration wave, the electromechanical conversion element having a density of from 4.2 to 6.0×10.sup.3 kg/m.sup.3, a plurality of grooves being provided on the drive surface side of the elastic body, and a value of T/(B+C) being within a range of from 1.3 to 2.8 when: depth of at least one groove of the plurality of grooves is defined as T; thickness from a base unit of the groove to a first surface is defined as B; and thickness of the electromechanical conversion element is defined as C.

A vibration actuator includes a vibrator including a shaft, an output transmission member penetrated by the shaft, and configured to rotate about the axis of the shall, and a fixed member configured not to move relative to the shaft and configured to move relative to the output transmission member. The fixed member includes a base portion and a projection portion protruding from the base portion to the output transmission member side, the vibration actuator includes a pressure reception member between the base portion and the output transmission member in an axial direction of the shaft, and wherein the projection portion and the output transmission member are in contact with each other in a direction orthogonal to the axial direction of the shaft, and the projection portion and the output transmission member are not in contact with each other in the axial direction of the shaft.

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 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 actuator that is capable of reducing differences in vibration phase and vibration amplitude without rising a voltage of a drive circuit when driving a contact member using a plurality of vibrators connected in series. A 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.

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

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.