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 control apparatus to control a vibration motor includes a control unit. The vibration motor includes a vibration body and a contact body contacting the vibration body. The control apparatus applies alternating voltages, generated based on pulse width and frequency of pulse signals, to an electro-mechanical energy conversion element of the vibration motor to cause relative movement between the vibration and contact bodies at a target velocity. The pulse width and the frequency are (i) set such that a first steady velocity exceeds the target velocity, before the relative movement starts, and (ii) changed such that a second steady velocity is less than the first steady velocity, after the relative movement starts, and before an actual velocity at a time of the relative movement exceeds the target velocity. The pulse width or the frequency is controlled such that the relative movement is performed at the target velocity.

A control apparatus to control a vibration motor includes a control unit. The vibration motor includes a vibration body and a contact body contacting the vibration body. The control apparatus applies alternating voltages, generated based on pulse width and frequency of pulse signals, to an electro-mechanical energy conversion element of the vibration motor to cause relative movement between the vibration and contact bodies at a target velocity. The pulse width and the frequency are (i) set such that a first steady velocity exceeds the target velocity, before the relative movement starts, and (ii) changed such that a second steady velocity is less than the first steady velocity, after the relative movement starts, and before an actual velocity at a time of the relative movement exceeds the target velocity. The pulse width or the frequency is controlled such that the relative movement is performed at the target velocity.

A reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.

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.

Disclosed herein is a microelectromechanical (MEMS) device, including a rotor and a first piezoelectric actuator mechanically coupled to the rotor. The first piezoelectric actuator is electrically coupled between a first signal node and a common voltage node. A second piezoelectric actuator is mechanically coupled to the rotor, and is electrically coupled between a second signal node and the common voltage node. Control circuitry includes a drive circuit configured to drive the first and second piezoelectric actuators, a sense circuit configured to process sense signals generated by the first and second pizeoelectric actuators, and a multiplexing circuit. The multiplexing circuit is configured to alternate between connecting the drive circuit to the first piezoelectric actuator while connecting the sense circuit to the second piezoelectric actuator, and connecting the drive circuit to the second piezoelectric actuator while connecting the sense circuit to the first piezoelectric actuator.

A drive control device is provided that drives an ultrasonic motor element including a piezoelectric element. The drive control device includes a voltage divider circuit unit resistor forming a voltage divider circuit unit together with an identification resistor that identifies the ultrasonic motor element; a control circuit unit connected to the voltage divider circuit unit and that sets a drive condition of the ultrasonic motor element according to a voltage of an identification signal for identifying the ultrasonic motor element; and a drive circuit unit that applies a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit.

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.

There is provided a control method for a piezoelectric driving device including a vibrating body including a piezoelectric element for driving and configured to vibrate when a driving signal is applied to the piezoelectric element for driving, a section to be driven that is driven by the vibration of the vibrating body, and a driving-signal generating section configured to generate the driving signal using a pulse signal generated based on a target pulse duty ratio. When the target pulse duty ratio is smaller than a predetermined value, the driving signal generated by the driving-signal generating section is an intermittently generated periodic signal.