A method for operating a drive unit having an active element with a resonator and an excitation structure for exciting oscillations in the resonator and thereby driving a passive element. The method includes driving the excitation structure with a driving signal, the driving signal being a periodic signal having driving pulses repeated with an excitation frequency. Depending on a control signal, modifying the driving signal, if the control signal is within a first range, by modifying the excitation frequency or modifying the shape of the driving pulses and, if the control signal is within a second range, repeatedly omitting driving pulses.

According to an example aspect of the present invention, there is provided a Microelectromechanical System, MEMS, mirror apparatus, comprising a MEMS mirror and at least two piezo actuators, wherein the at least two piezo actuators are connected to each other and configured to control, or controlling, movement of the MEMS mirror and a single supply drive signal connected to each of the at least two piezo actuators.

A virtual resistive load feedback circuit for driving a piezoelectric actuator is provided that accounts for a hysteresis error and drift within the movement of the actuator. The circuit may include a voltage divider and charge divider. A voltage monitor signal corresponding to a voltage of a driver signal and a current monitor signal corresponding to a current provided to the amplifier are combined by an operational amplifier and include electrical characteristics of the actuator such that the circuit approximates a virtual load across the actuator. A feedback portion of the operational amplifier may include a resistor and capacitor connected in parallel to provide the voltage and charge divide functions. The use of the virtual resistive circuit allows for the piezoelectric actuator to be ground referenced, with no external components connected directly to the actuator while gaining the feedback effect to counter the hysteresis and drifts errors of the actuator.

An ultrasonic device includes: a substrate provided with a first opening and a second opening; a support film that is provided on the substrate and blocks the first opening and the second opening; a transmitting piezoelectric film that is provided on the support film at a position which overlaps the first opening when viewed in a thickness direction of the substrate and is interposed between a pair of electrodes in the thickness direction of the substrate; and a receiving piezoelectric film that is provided on the support film at a position which overlaps the second opening when viewed in the thickness direction of the substrate and is interposed between a pair of electrodes in the thickness direction of the substrate. In the thickness direction of the substrate, a thickness dimension of the transmitting piezoelectric film is smaller than a thickness dimension of the receiving piezoelectric film.

A piezoelectric film includes a substrate having flexibility, and at least two piezoelectric elements provided to the substrate so as to be arranged at intervals of a first dimension along a first direction, the piezoelectric elements are each configured by stacking a first electrode film, a piezoelectric film made of an inorganic material, and a second electrode film along a thickness direction of the substrate, and an area between the piezoelectric elements adjacent to each other along the first direction forms a vibrational region which can be displaced in the thickness direction.

In an angular velocity sensor, a pair of support parts are separated from each other in an x-axis direction in an orthogonal coordinate system xyz. A main part extends along the x-axis. A pair of extension parts connect two ends of the main part and inner sides of the support parts. The driving arms extend from the main part alongside each other in a y-axis direction separated from each other in the x-axis direction. The detecting arm extends from the main part in the y-axis direction at a position which is between the pair of driving arms. The driving circuit supplies voltages so that the pair of driving arms vibrate so as to bend to inverse sides from each other in the x-axis direction. The detecting circuit detects the signal generated due to bending deformation of the detecting arm in the z-axis direction.

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.

A piezoelectric element includes: a first electrode and a second electrode; and a piezoelectric layer provided between the first electrode and the second electrode and having a perovskite structure, in which 0<P1/P2≤0.5 and 0<P1 where, when a positive predetermined voltage is applied to the piezoelectric layer, then a voltage applied to the piezoelectric layer is set to 0 V for 0.1 seconds, and then a triangular wave voltage waveform having a maximum voltage of the predetermined voltage is applied to the piezoelectric layer to obtain a hysteresis curve drawn counterclockwise, P1 is a residual polarization amount at a start point of the hysteresis curve and P2 is a residual polarization amount at an end point of the hysteresis curve.

The present invention is a piezoelectric actuator drive method, a piezoelectric actuator drive circuit, and a piezoelectric actuator drive system capable of causing a piezoelectric element to vibrate in a maximum amplitude state. The piezoelectric actuator drive circuit includes: an obtainment unit that obtains operation information pertaining to operation of the piezoelectric element in a period that is a part of one cycle of a drive cycle in which the piezoelectric element is driven; and a control unit that performs feedback control of a drive parameter for driving the piezoelectric element based on the operation information.

A backing member includes: a resin body including a lower surface and an upper surface opposite to each other; a plurality of leads each of which extends in a first direction from the lower surface toward the upper surface, and that are embedded at pitches in the resin body; and a plurality of insulating spacers each of which is provided between adjacent ones of the leads and extends in a second direction intersecting with the first direction, and that contact the leads.