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.

A vibration actuator is capable of reducing differences in vibration phase and vibration amplitude without raising a voltage of a drive circuit when driving a contact member using a plurality of vibrators connected in series. The vibration actuator includes a vibrator device and a contact member that moves relative to the vibrator device. The vibrator device includes transformers of which primary coils are connected in series, and vibrators that are respectively connected in parallel to secondary coils of the transformers.

A variable voltage generator circuit is described for generating, from a substantially constant supply voltage V.sub.S, a variable high-voltage control voltage V.sub.C for a variable power capacitor (1) having a variable-permittivity dielectric. The control voltage generator circuit comprises a top-up circuit (10) for maintaining the voltage V.sub.Cin on an input capacitor (12) at least at supply voltage V.sub.S, and a bidirectional DC-DC converter circuit (20) having a variable voltage conversion factor G controlled by control input signal (27). The bidirectional DC-DC converter (20) is arranged to convert voltage, at the voltage conversion factor G, between the input capacitor voltage V.sub.Cin and the output voltage V.sub.C. When V.sub.C<G×V.sub.Cin, the DC-DC converter circuit (20) uses charge stored in the input capacitor (12) to charge the capacitive load (1). When V.sub.C>G×V.sub.Cin, the DC-DC converter circuit (20) uses charge stored in the load capacitance (1) to charge the input capacitor (12).

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.

A piezoelectric driving device includes: a driving portion to be brought into frictional contact with an object to be driven, which is moved with respect to a fixed body; and at least two piezoelectric portions, which are formed integrally with the driving portion, are arranged on a predetermined plane with the driving portion being sandwiched between the at least two piezoelectric portions, and are configured to be bent with respect to the predetermined plane when voltages are applied to the at least two piezoelectric portions, wherein outer edges of entirety of the at least two piezoelectric portions are fixed to the fixed body.

An actuator including a beam configured to support an object to be driven, and a drive source to which a drive signal is input, wherein the drive signal includes a drive waveform in a shape of sawtooth waveform, a rising of the drive waveform in the shape of sawtooth waveform includes a first staircase waveform and a second staircase waveform continuing from the first staircase waveform, the first staircase waveform generates oscillation of a ringing suppressing waveform for suppressing a ringing waveform to be generated in the second staircase waveform, and the object to be driven is driven to swing in a direction of rotating around the predetermined axis by driving the drive source.

An optical device includes a first reflector; a second reflector; an elastic support unit supporting the second reflector; a piezoelectric element on the elastic support unit; a light emitter configured to emit light having an oscillation wavelength; and circuitry configured to output a signal to apply drive voltage to the piezoelectric element to elastically deform the elastic support unit. The deformation of the elastic support unit changes a distance between the first reflector and the second reflector to change the oscillation wavelength of the light emitted from the light emitter.

A piezoelectric motorization system has a mechanically flexible body that has one or more surfaces for placing piezoelectric actuators. The system has groups of piezoelectric actuators each positioned on one of the surfaces of the mechanically flexible body that is connected to the electronic circuitry. The electronic circuitry controls the driving of the mechanical loads by the mechanically flexible body by injecting sets of control signals into different groups of actuators positioned on the mechanically flexible body. Each control signal operates groups of driving frequencies with an adjustable amplitude ratio and an adjustable phase difference among driving frequencies. And, under a set of boundary conditions exhibited by a set of structural dimensions of the mechanically flexible body, each control signal induces multi-mode resonance of the mechanically flexible body for driving the mechanical loads multi-dimensionally.

An electrical connection structure for connecting a piezoelectric element and an electrical circuit to each other with a conductive adhesive is described. The electrical connection structure includes an epoxy, a conductive component surrounded by the epoxy, and a trace feature implemented on top of the electrical connection structure.

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.