A piezoelectric actuator comprises a substantially rectangular parallelepiped piezoelectric element. One outer surface of the piezoelectric element includes a first region, and a second region located such as to project from the first region and to overlap a region corresponding to an active portion in the one outer surface. The second region has a flat surface configured to come into contact with a body to be driven and to generate a frictional force therewith. The flat surface is shorter in a longitudinal direction of the piezoelectric element than in a lateral direction thereof. The flat surface is longer in the longitudinal direction of the piezoelectric element at a lateral center region thereof than at a lateral end region thereof.

A piezoelectric driving device includes a vibrating plate, a first electrode, a piezoelectric layer, a second electrode layer provided above the vibrating plate. An active section is formed in a portion where the first electrode layer, the piezoelectric layer, and the second electrode layer overlap one another. The active section has a longitudinal direction and a latitudinal direction in plan view. At both ends in the latitudinal direction, ends of the first electrode layer are disposed in the same positions as ends of the wiring layer or further on the outer side than the ends, ends of the second electrode layer are disposed in the same positions as the ends of the wiring layer or further on the inner side than the ends, and the ends of the first electrode layer are disposed further on the outer side than the ends of the second electrode layer.

A piezoelectric driving device includes: a piezoelectric vibrating body which includes a plurality of piezoelectric elements each formed of a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode, and is disposed at least one surface of the first surface and the second surface of the vibrating plate, wherein the plurality of piezoelectric elements are connected in series.

A piezoelectric drive device includes a vibrator having a vibrating portion including a piezoelectric element, and a convex portion placed in the vibrating portion, an urging member including a base, a holding portion holding the vibrator, and a spring portion coupled to the base at one end and coupled to the holding portion at another end and urging the convex portion toward a driven unit, wherein d1>d2 in a natural state in which the vibrator is not urged by the urging member, where a separation distance between the one end and the convex portion along directions of the longitudinal direction is d1 and a separation distance between the other end and the convex portion is d2, and |d1−d2| in an urging state in which the vibrator is urged toward the driven unit by the urging member is smaller than |d1−d2| in the natural state.

A piezoelectric driving device includes a piezoelectric vibrating body and a driving circuit. The piezoelectric vibrating body includes a contact which comes into contact with a driven member, and a piezoelectric element which generates vibration in accordance with a driving voltage. The driving circuit sets a driving frequency of the driving voltage to a first frequency and starts the driving at the time of initiation from a stopped state, and sets the driving frequency of the driving voltage to a second frequency lower than the first frequency in a driving state after the initiation.

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 method of controlling a piezoelectric motor as a piezoelectric drive device having a vibrator including piezoelectric elements, a rotor as a driven unit that moves at a target speed by vibration of the vibrator, and drive signal generation units that generate drive signals and output the drive signals to the piezoelectric elements, includes intermittently outputting the drive signals to the piezoelectric elements by the drive signal generation units, wherein a time when output of the drive signals is stopped is shorter than a time from when output of the drive signal is stopped to stoppage of the vibration.

There is provided a control method for a piezoelectric driving device including a vibrating body configured to vibrate when a driving signal including a periodic signal is applied to a 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. The driving-signal generating section detects voltage amplitude generated in the piezoelectric element for driving and generates the target pulse duty ratio based on the voltage amplitude. The driving signal includes an intermittent signal formed by an output period in which the periodic signal is output and a suspension period in which the output of the periodic signal is suspended. The driving-signal generating section detects the output-period voltage amplitude and does not detect the suspension-period voltage amplitude.

A piezo actuator comprises a piezo material having a first, top surface, a second, bottom surface, and a third, circumference surface. The piezo material has a polarity and the piezo material includes one or more mounting holes in the piezo material, the one or more mounting holes being positioned substantially central in at least the top surface or the bottom surface of the piezo material. The actuator also comprises at least one contact point for contacting a load to be actuated, the at least one contact point being positioned on the third, circumference, surface of the piezo material, and a set of electrodes being positioned on the top surface of the piezo material and at least one electrode being positioned at the bottom surface of the piezo material.

A piezoelectric drive device includes a vibrating part, and a control unit that controls vibration of the vibrating part, wherein the vibrating part includes a piezoelectric material having a first surface and a second surface in a front-back relation, a drive electrode having a first electrode arranged at the first surface and a second electrode arranged at the second surface, and vibrating the piezoelectric material when a drive signal from the control unit is input to the second electrode, and a detection electrode having a third electrode arranged at the first surface and a fourth electrode arranged at the second surface, and outputting a detection signal according to the vibration of the piezoelectric material to the control unit via the fourth electrode, and the first electrode and the third electrode are separated on the first surface, and the second electrode and the fourth electrode are separated on the second surface.