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.

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 driving apparatus of a vibration-type actuator includes a driving circuit configured to drive a vibration unit including a plurality of vibrators, a detection unit configured to detect a sum of power consumption consumed by the plurality of vibrators, and a driving frequency setting unit configured to set a driving frequency within a frequency range depending on the sum of power consumption detected by the detection unit.

A piezoelectric motor may include a stator, a rotor rotating about a rotational axis and at least one piezoelectric element driving the rotor and maintained by the stator. Mechanical reliability and performance levels of a piezoelectric motor may be increased in that the at least one piezoelectric element may be mounted in an oscillating housing that oscillates with respect to the stator about the pivot axis.

A piezoelectric drive device for vibrating a vibrating body to make a tip of a protruding part make a rotational motion of drawing an elliptic orbit to thereby drive a driven member, wherein the vibrating body includes a substrate, a driving piezoelectric element configured to vibrate the substrate, and a detecting piezoelectric element configured to detect a vibration of the substrate, the driving piezoelectric element includes a first driving piezoelectric element for making the vibrating body perform a stretching vibration in a first direction, and a second driving piezoelectric element for making the vibrating body perform a flexural vibration in a second direction perpendicular to the first direction, the detecting piezoelectric element is arranged with the first driving piezoelectric element in the first direction, and there is provided a voltage control section for controlling a magnitude of a voltage to be applied to the first driving piezoelectric element.

A vibration drive device that is capable of preventing the controllability from becoming unstable when the speed control is switched between frequency control and pulse width control. A controller controls driving of a vibration actuator by applying an alternating voltage to an electromechanical energy conversion element. A switching pulse is generated by switching a DC voltage. A maximum duty ratio of the switching pulse is determined based on a driving condition of the vibration actuator. The driving of the vibration actuator is controlled by switching between frequency control and pulse width control. A gain for frequency control and a gain for pulse width control are set according to the maximum duty ratio so as to prevent electric power or electric current from exceeding an electric power limit or an electric current limit, set in advance.

A piezoelectric motor includes: a stator having an elastic body, a piezoelectric element and a sliding member adhesively attached to the elastic body; a rotor having an annular member, which includes a disc spring portion and a basic body portion in contact with the sliding member, and a fixture portion to which the annular member is fixed; and a shaft that rotates with the rotor, wherein the disc spring portion of the annular member is fixed to the fixture portion which is fixed to the shaft.

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 piezoelectric driving device includes a first substrate having cleavability, and a piezoelectric element placed above the first substrate, wherein a cleavage direction of the first substrate and a direction in which a shear force is applied do not coincide in a plan view of the first substrate. Further, an angle formed by the cleavage direction of the first substrate and the direction in which the shear force is applied is equal to or larger than 20? in the plan view of the first substrate. Furthermore, the first substrate contains silicon single crystal.

An embodiment of a harvester apparatus comprising two or more charge pump stages may include at least a first charge pump stage to receive an alternating current source, and a second charge pump stage coupled to the first charge pump stage.