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 element includes: a substrate; a first electrode which is disposed on the substrate; a piezoelectric body layer which is disposed on the first electrode, which has a plurality of layers configured to contain a piezoelectric body material, and in which the total thickness of the plurality of layers is within a range of 1.6 m to 10 m; and an intermediate layer which is disposed on an interlayer of the piezoelectric body layer, and which is configured to contain titanium.

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.

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 control method of a piezoelectric driving device which includes a vibrator including a piezoelectric element and vibrating by application of a drive signal to the piezoelectric element, a driven unit moving by the vibration of the vibrator, a drive signal generation unit generating the drive signal based on a pulse signal, the control method including: stopping the application of the drive signal to the piezoelectric element at the time when a driving speed of the driven unit is a reference speed, in a case of stopping driving of the driven unit.

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 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.

A piezoelectric actuator includes a vibrating plate having a piezoelectric material, and a contact part provided in an end portion of the vibrating plate in contact with a driven part, wherein the contact part has a first portion in contact with the driven part and a second portion provided between the first portion and the vibrating plate and having lower rigidity than the first portion. Further, a width of the second portion in a direction crossing an arrangement direction of the first portion and the second portion is smaller than a width of the first portion in the crossing direction.

A piezoelectric drive apparatus for a motor, the apparatus including a substrate having a longitudinal direction and a widthwise direction perpendicular to the longitudinal direction, a piezoelectric element provided on the substrate and having a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode, and a contact section that is attached to a front end section of the substrate in the longitudinal direction thereof or in contact with the front end section of the substrate in the longitudinal direction thereof and comes into contact with a driven body, wherein the longitudinal direction of the substrate roughly coincides with a direction in which Young's modulus is minimized in a plane of the substrate.