In a piezoelectric ejector assembly, a piezoelectric actuator is attached to an ejector mechanism, while a drive signal generator and a controller are coupled to the actuator. The drive signal generator is configured to generate a drive signal for driving the actuator to oscillate the ejector assembly. The controller is configured to control the drive signal generator to drive the actuator at a resonant frequency of the ejector assembly, and an auto-tuning circuit is provided to define the optimum drive signal frequency.

A piezoelectric adjustment apparatus has a piezo element whose movement is transmitted via a lever to a plunger. The plunger can be set against an abutment that is arranged at one side of the lever and a second abutment is provided at the other side of the lever.

An actuator device comprises an electroactive polymer actuator (116) and a control circuit for driving the electroactive polymer actuator. The control circuit comprises a voltage boosting circuit including at least a capacitor (114; C11, C12, C13). An electroactive polymer layer (110) forms the electroactive polymer actuator in an active region (112) as well as a dielectric layer of the capacitor in a passive region (111). This provides integration of components to enable cost reductions and miniaturization.

A method and apparatus for waking a battery pack from a dormant mode via shaking. The battery pack has a piezo electric device coupled to a semiconductor control circuit providing a power path between a positive terminal of a battery cell and a boot input of an ASIC charge/discharge controller powered by the battery cell. Shaking of the piezo electric device energizes the semiconductor control circuit, which engages the power path to power the initial booting of the ASIC charge/discharge controller.

The present disclosure provides a fingerprint recognition module, a driving method thereof, a manufacturing method thereof, and a display device. The fingerprint recognition module includes a receiving electrode layer, a piezoelectric material layer, and a driving electrode layer. The receiving electrode layer includes a plurality of receiving electrodes arranged in an array along a first direction and a second direction. The piezoelectric material layer is disposed on a side of the receiving electrode layer. The driving electrode layer is disposed on a side of the piezoelectric material layer remote from the receiving electrode layer and includes a plurality of driving electrodes arranged along the second direction. Each driving electrode is a strip electrode extending along the first direction, and overlaps with multiple receiving electrodes arranged along the first direction.

Methods and systems for applying charge to a piezoelectric element include and/or facilitate implementation of processes including cyclical multi-stage processes for: providing a piezoelectric element with an accumulated charge; providing one or more charge holding elements with a scavenged charge from the piezoelectric element; substantially removing or discharging a remaining charge from the piezoelectric element; and applying the scavenged charge to the piezoelectric element with an opposite polarity in relation to the polarity of the remaining charge.

There is provided a display panel including a piezoelectric device and a method for compensating properties of a piezoelectric device. According to the an exemplary embodiment of the present disclosure, the display panel includes: a panel; and a piezoelectric device coupled with the panel, wherein the piezoelectric device includes: a plurality of piezoelectric elements disposed at different positions of the panel and each configured to generate vibrations according to a driving signal; a driver configured to supply the driving signal to the plurality of piezoelectric elements; a plurality of acceleration sensors configured to detect acceleration information of vibrations in different regions of the panel; and a compensator configured to control the driving signal to compensate for property deviations of the plurality of piezoelectric elements, based on the acceleration information.

Provided is a method for controlling an ultrasonic motor to reduce noise sounding during low-speed rotation in a surveying instrument adopting the ultrasonic motor for a rotary shaft, and a surveying instrument for the same. In a method for controlling an ultrasonic motor according to an aspect of the present invention, in a low-speed rotation range of an ultrasonic motor, a ratio of an acceleration period as a time of application of the drive signal in a control cycle is controlled, and a time to start the acceleration period is randomly shifted for each control cycle. In a method for controlling an ultrasonic motor according to another aspect, a time to start the acceleration period is regularly shifted for each control cycle. In a method for controlling an ultrasonic motor according to still another aspect, second-half acceleration control and first-half acceleration control are alternately repeated.

An oscillator includes a second container as a container in which a vibrator is accommodated, a base substrate on which the second container is mounted, three or more protruding portions provided on the base substrate at positions overlapping the second container in a plan view, and a bonding member configured to bond the second container and at least one of the protruding portions.

A vibration wave motor includes a driven body, a vibrator including an annular vibration plate and an annular piezoelectric element, and a vibration damping member, which are arranged in sequence, wherein the vibration plate has, on a side facing the driven body, radially extending groove portions at X places, and, when center depths of the groove portions at X places are sequentially denoted by D1 to DX in a circumferential direction, D1 to DX vary along a curve obtained by superposing one or more sine waves, and wherein the vibration plate is locally supported by the vibration damping member in some or all antinode portions of a standing wave occurring when the vibration wave motor is driven.