A method for sensing an abnormality of a piezoelectric drive device is a method for sensing a vibration abnormality of the piezoelectric drive device having a substrate and thin-film piezoelectric elements placed on the substrate and controlling amplitude of the piezoelectric elements using a drive control signal, and the method includes sensing the vibration abnormality by a drive voltage corresponding to the drive control signal.

A vibration-type drive apparatus provided to solve the task includes a control unit that outputs a command signal, a drive unit that outputs a drive signal in accordance with the command signal, a vibrator unit in which two or more vibrators that vibrate in accordance with the drive signal are connected, a drive signal analyzing unit that analyzes the drive signal and outputs an analysis result, and a determining unit that determines whether there is a break in wiring lines respectively coupled to the vibrators in accordance with the analysis result.

An actuator with a rectangular shape] is made of polarized electromechanical material having two large main surfaces and at least four side surfaces, two of which being longer than the other two side surfaces. At least one friction element is arranged on at least one of the shorter side surfaces. At least two active electrodes are arranged on one of the main surfaces, with one common electrode arranged on the other of the main surfaces The electromechanical material of the actuator is excitable to perform standing wave deformations due to an electric field generated therein for moving the friction element to drive an element. The actuator aspect ratio for its length to its thickness is between 3.9 and 4.1 and an aspect ratio for the length relative to width is between 2 and 5.

A control method for a piezoelectric drive device having a vibrating portion including a piezoelectric element and a transmitting portion, synthesizing longitudinal vibration and flexural vibration by energization to the piezoelectric element to vibrate the vibrating portion and make elliptic motion of the transmitting portion, and moving a driven member by the elliptic motion of the transmitting portion, includes controlling a movement amount of the driven member by changing amplitude of the longitudinal vibration with amplitude of the flexural vibration kept constant.

A control method for a piezoelectric drive device having a vibrating portion including a piezoelectric element and a transmitting portion, synthesizing longitudinal vibration and flexural vibration by energization to the piezoelectric element to vibrate the vibrating portion and make elliptic motion of the transmitting portion, and moving a driven member by the elliptic motion of the transmitting portion, includes controlling a movement amount of the driven member by changing amplitude of the longitudinal vibration with amplitude of the flexural vibration kept constant.

A piezoelectric actuator includes a vibration portion, a support portion that is integrally configured with the vibration portion and supports the vibration portion, and a piezoelectric element that is disposed on the vibration portion. The piezoelectric element includes a piezoelectric film including columnar crystal grains extending in a thickness direction. When a thickness of the piezoelectric film is referred to as T [μm] and an average diameter of the crystal grains in the width direction is referred to as D [μm], T/D is within a range of 10 to 100. The thickness T of the piezoelectric film is larger than or equal to 2 μm. A standard deviation of diameters of the crystal grains in the width direction is less than or equal to 1.8 μm.

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.

In a vibration unit, a piezoelectric element enters an internal space of a through hole; and thereby, a second case member can be arranged proximate to a first case member. Therefore, a thickness of the vibration unit can be reduced, namely, a height of the vibration unit can be reduced. As described above, since the thickness of the vibration unit is reduced, a size of the vibration unit can be reduced.

A vibration device that includes a flat plate that has a first main surface and a second main surface; a vibrator that is configured to vibrate along a first direction parallel to the first main surface; a connecting member that connects the vibrator to the first main surface of the flat plate; a support member having a cavity or a recess in a portion thereof facing the vibrator; and a cushioning material connecting the first main surface of the flat plate to the support member, the cushioning material being disposed so as to not overlap with the vibrator in a plan view of the vibration device. A combined length of the vibrator and the connecting member in a second direction perpendicular to the first main surface of the flat plate is larger than a length of the cushioning material in the second direction.

A piezoelectric motor comprises a frame having a first frame side and a second frame side; a first actuator assembly and a second actuator assembly. The first actuator assembly comprises a first piezoelectric actuator and two rollers, each of the rollers is pressed between the first piezoelectric actuator and the first frame side. The second actuator assembly comprises a second piezoelectric actuator and two rollers, each of the rollers is pressed between the second piezoelectric actuator and the second frame side. The motor further comprises at least one pre-loaded spring provided between the first actuator assembly and the second actuator assembly, pushing the first actuator assembly and the second actuator assembly against the first frame side and the second frame side, respectively.