The invention pertains to a device for at least one low-frequency electric tank circuit, in which at least one electric conductor is an influencing component of the tank circuit due to its properties.

A display apparatus includes: a display panel configured to display an image, a vibration plate on a first surface of the display panel, a first structure on a second surface of the vibration plate, the first structure being configured to support the display panel, a first vibration-generating device configured to vibrate the vibration plate, and a separation part connected to the vibration plate and configured to separate a first space, facing a first surface opposite to the second surface of the vibration plate, from a second space facing the second surface of the vibration plate.

A semi-resonant actuator assembly includes a resonating body comprising a piezoelectric plate having a first length, a first width, and a first thickness, and an inactive plate having a second length substantially equal the first length, a second width substantially equal to the first width, and second thickness. A thickness of the resonating body is provided by a sum of the first thickness of the active piezoelectric plate and the second thickness of the inactive plate.

At least one of a first beam portion and second beam portions is provided with an out-of-plane vibration suppressing structure configured to suppress vibration of a movable portion in an out-of-plane direction vertical to an in-plane direction. Thus, unintentional occurrence of unintentional movement in the out-of-plane direction vertical to the in-plane direction can be suppressed. Furthermore, in this case, a size reduction of a device can be achieved in comparison with a case where a device includes a motor disposed for rotation driving, for example.

A piezoelectric vibrator has a first frequency region where the phase difference between a pickup signal representing the vibration of the piezoelectric vibrator and a drive signal that drives the piezoelectric vibrator does not monotonously change in accordance with the frequency of the drive signal and a second frequency region where the phase difference monotonously changes in accordance with the frequency of the drive signal. A method for controlling a piezoelectric driving apparatus including the piezoelectric vibrator controls the frequency of the drive signal in such a way that pickup voltage representing the amplitude of the pickup signal is fixed in the first frequency region and controls the frequency of the drive signal in such a way the pickup voltage is fixed with the phase difference maintained smaller than or equal to a prespecified value in the second frequency region.

A control device for a vibration actuator includes a detection signal acquisition section adapted to obtain an alternating-current detection signal corresponding to a vibration of the resonator body from the resonator bodies, a phase difference detection section adapted to detect a phase difference between the drive signal and the detection signal with respect to the resonator bodies, a resonator body selection section adapted to select one from the resonator bodies, and a drive signal control section adapted to adjust a frequency of the drive signal so that the phase difference in the resonator body selected comes closer to a target value.

A control apparatus to control a vibration motor includes a control unit. The vibration motor includes a vibration body and a contact body contacting the vibration body. The control apparatus applies alternating voltages, generated based on pulse width and frequency of pulse signals, to an electro-mechanical energy conversion element of the vibration motor to cause relative movement between the vibration and contact bodies at a target velocity. The pulse width and the frequency are (i) set such that a first steady velocity exceeds the target velocity, before the relative movement starts, and (ii) changed such that a second steady velocity is less than the first steady velocity, after the relative movement starts, and before an actual velocity at a time of the relative movement exceeds the target velocity. The pulse width or the frequency is controlled such that the relative movement is performed at the target velocity.

A self-oscillating piezoelectric actuator drive circuit includes a integrating circuit; an inverter (INV1), inverters (INV2 and INV3) inverting an output signal of the inverter (INV1), sense resistors (Rs1 and Rs2) connected to output sides of the inverters (INV2 and INV3), a positive feedback resistor (Rfb2) feeding back an output signal of the inverters (INV2 and INV3) to the integrating circuit; and a negative feedback resistor (Rfb1) feeding back a voltage generated from the sense resistors (Rs1 and Rs2, Rs1<Rs2 in terms of a resistance value) to the integrating circuit. In a startup state, the sense resistor (Rs2) and the inverter (INV3) are selected, and in an operating state after the startup state, the sense resistor (Rs1) and the inverter (INV2) are selected.

A display device includes a display panel, a main vibrator disposed on the display panel configured to generate a main vibration wave, and a plurality of sub-vibrators disposed on the display panel and spaced apart from the main vibrator and configured to the plurality of sub-vibrators configured to generate sub-vibration waves, respectively, wherein the plurality of sub-vibrators includes a first sub-vibrator disposed at a first distance from the main vibrator in a plan view, the first sub-vibrator being configured to generate a first sub-vibration wave; and a second sub-vibrator disposed at a second distance from the main vibrator in the plan view, the second sub-vibrator being configured to generate a second sub-vibration wave having a phase different from the first sub-vibration wave, and, wherein the second distance is different from the first distance.

A microelectromechanical system includes a piezoelectric drive and a control unit coupled to the piezoelectric drive and designed to control the piezoelectric drive based on a change of the admittance and/or the impedance of the piezoelectric drive.