A first main plate has a first principal surface and a second principal surface. A second main plate has a third principal surface, a fourth principal surface, and an aperture. A piezoelectric element is provided on the first main plate and vibrates the first main plate. A first frame is disposed outside an outer peripheral end of the first main plate. First connecting portions connect the first main plate and the first frame to each other. Apertures are formed between the first connecting portions and connect a space adjacent to the first principal surface and a space adjacent to the second principal surface to each other. The second frame is disposed outside an outer peripheral end of the first frame. A second connecting portion connects the first frame and the second frame to each other.

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 pump system contains a pair of pumps each of which contains a vibration actuator vibrated by electromagnetic drive and can discharge fluid due to drive of the vibration actuator. The pump system has a vibration suppression mode in which the pair of the pumps are driven so that vibration of the vibration actuators of the pair of pumps is cancelled each other and a vibration generation mode in which the pair of the pumps are driven so that the vibration of the vibration actuators of the pair of pumps is superimposed with each other.

A linear compressor employing a piezoelectric actuator operating in resonance at a frequency substantially below its natural resonant frequency, which is usually of the order of 10 kHz. Low frequency resonance operation of the actuator, of the order of 100 Hz., is achieved by incorporating the actuator and its housing with the moving compression piston, such that the moving mass is substantially increased, and by reduction of the effective piezoelectric stiffness using hydraulic amplification of the actuator displacement. Both these procedures result in a reduction of the actuator resonant frequency. The hydraulic amplification is achieved by using a hydraulic chamber with different sized pistons, linking the actuator motion with motion of the actuator housing, to which the compressor piston is attached. The high efficiency achieved and the lack of moving parts or the need for lubricating oil makes the compressor ideal for use in high reliability and high purity applications.

A first main plate has a first principal surface and a second principal surface. A second main plate has a third principal surface, a fourth principal surface, and an aperture. A piezoelectric element is provided on the first main plate and vibrates the first main plate. A first frame is disposed outside an outer peripheral end of the first main plate. First connecting portions connect the first main plate and the first frame to each other. Apertures are formed between the first connecting portions and connect a space adjacent to the first principal surface and a space adjacent to the second principal surface to each other. The second frame is disposed outside an outer peripheral end of the first frame. A second connecting portion connects the first frame and the second frame to each other.

A pump system contains a vibration actuator which can be electromagnetically driven by applying an alternating-current voltage E thereto, a sealed chamber connected to a suction port and a discharge port, and a movable wall for changing a volume of the sealed chamber. The movable wall is displaced due to drive of the vibration actuator to supply fluid in the sealed chamber into a target object. The pump system controls an effective value of the alternating-current voltage E so that an amplitude Y of the vibration actuator is constant.

A piezoelectric pump includes a leaf spring including a disc portion defining an actuator, an outer frame portion defining a housing, and an elastic support portion. The actuator flexurally vibrates from a center portion of a principal surface thereof to an outer periphery thereof. The elastic support portion includes a beam portion and connection portions and elastically supports the disc portion on the outer frame portion. The beam portion extends in a gap between the disc portion and the outer frame portion in a direction along an outer periphery of the disc portion. A first of the connection portions connects the beam portion to the disc portion. Second and third connection portions are offset from the first connection portion and connect the beam portion to the outer frame portion.

A first main plate has a first principal surface and a second principal surface. A second main plate has a third principal surface, a fourth principal surface, and an aperture. A piezoelectric element is provided on the first main plate and vibrates the first main plate. A first frame is disposed outside an outer peripheral end of the first main plate. First connecting portions connect the first main plate and the first frame to each other. Apertures are formed between the first connecting portions and connect a space adjacent to the first principal surface and a space adjacent to the second principal surface to each other. The second frame is disposed outside an outer peripheral end of the first frame. A second connecting portion connects the first frame and the second frame to each other.

A method for compensating a signal of a motor includes acquiring an original signal and nonlinear parameters of the motor; calculating a compensation signal for the original signal according to the acquired nonlinear parameters; and loading the calculated compensation signal into the motor to excite the motor to vibrate. An electronic apparatus and a storage medium are also provided. In this method, the original excitation signal is compensated for nonlinearity according to the nonlinear motor parameters, and is then used for exciting the motor. Therefore, the actual vibration effect can be closer to the expected effect as designed, which can bring more desirable tactility experience.

A fluid pump includes a pump body having upper and lower parts, each comprising a substantially cylindrical side wall closed at one end by a substantially circular end wall and partially closed at the opposite end by an actuator disposed in a plane substantially parallel to and between the end walls. A single cavity is thereby formed having upper and lower portions. The cavity encloses the actuator and is bounded by the end walls and side walls of the pump body and the surfaces of the actuator. A substantially open actuator support structure connects the actuator to the pump body and enables free flow of fluid between the upper and lower cavity portions. At least two apertures are provided through the pump body walls, at least one of which is a valved aperture. All of the apertures located substantially at the centres of the end walls are valved apertures. In use, the actuator oscillates in a direction substantially perpendicular to the plane of the end walls causing an acoustic wrapped standing wave to exist in the cavity and thereby causing fluid flow through said apertures.