The present disclosure relates to driver circuitry for driving a piezoelectric transducer. The circuitry comprises: output stage circuitry configured to receive an input signal and to drive the piezoelectric transducer to produce the output signal; variable voltage power supply circuitry configured to output a supply voltage for the charge drive output stage circuitry, wherein the supply voltage output by the variable voltage power supply circuitry varies based on the input signal; a supply capacitor for receiving the supply voltage output by the variable voltage power supply circuitry; a reservoir capacitor; and circuitry for transferring charge between the reservoir capacitor and the supply capacitor.

A vibration driving device that improves controllability in low speed driving. The vibration driving device includes a vibration actuator that includes a vibrator that has an elastic member and an electro-mechanical energy conversion element, a contact member that contacts the vibrator, and a control device that controls drive of the vibration actuator. The control device includes a speed detection unit that detects speed information showing relative speed of the vibrator and the contact member, and an adjustment unit that decreases amplitude of vibration excited in the vibrator in a case where the speed detection unit detects that a state where the vibration actuator does not operate approximately and a state where the vibration actuator operates at a speed faster than a target driving speed occur alternately after starting to drive the vibration actuator.

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 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.

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.

Provided is a method of manufacturing an oscillator, including: arranging an electrode on a piezoelectric ceramics free from being subjected to polarization treatment, to thereby provide a piezoelectric element; bonding the piezoelectric element and a diaphragm to each other at a temperature T1; bonding the piezoelectric element and a power supply member to each other at a temperature T2; and subjecting the piezoelectric ceramics to polarization treatment at a temperature T3, in which the temperature T1, the temperature T2, and the temperature T3 satisfy a relationship T1>T3 and a relationship T2>T3.

A driving circuit for driving a piezoelectric load, can include: a rechargeable power supply; a power stage circuit coupled between the rechargeable power supply and the piezoelectric load; where during a first operation interval of an operation period, the rechargeable power supply charges the piezoelectric load through the power stage circuit, such that a power supply voltage signal provided to the piezoelectric load in the first operation interval corresponds to a reference voltage in a first interval; and where during a second operation interval of the operation period, the piezoelectric load charges the rechargeable power supply through the power stage circuit, such that the power supply voltage signal in the second operation interval corresponds to the reference voltage in a second interval.

A thin film actuator having transversely oriented structural stiffeners that serve to increase actuation stroke that results from longitudinal curvature. The thin film actuator may be deployed within electromechanical devices such that an actuatable deflection of a tip of the actuator plate produces the actuation stroke. The thin film actuator may include an actuator plate affixed to a substantially rigid frame structure. The actuator plate protrudes along a longitudinal axis away from the frame structure such that the actuator plate is cantilevered from the frame structure by some distance along this longitudinal axis. The thin film actuator includes a piezoelectric film on a surface of the actuator plate. Activation of the piezoelectric film generates tensile stress or compressive stress at the surface, thereby inducing a bending moment that causes the actuator plate to undergo longitudinal curvature and some lesser degree of transverse curvature.

The application describes systems for deriving haptic and audio drive signals from an input signal received via a single channel such as an audio channel.