A display apparatus includes a display panel configured to display an image, and a vibration device on a rear surface of the display panel to vibrate the display panel to generate a sound, the vibration device including a vibration array including a plurality of vibration modules.

Embodiments include a primary short circuit (PSC) coupled to a primary side of a transformer and a dampening element, coupled to a transducer coupled to a secondary side of the transformer, configured to dampen a received signal during a portion of a reverberation period. The PSC and the dampening element may be activated substantially simultaneously. Activation of the PSC circuit mitigates a parallel resonance otherwise arising, in part, in the transducer, but, increases the received signal by a DC shift voltage. The dampening element dampens the DC shift voltage. The received signal may be dampened prior to amplification of the received signal by an amplifier. The dampening facilitates earlier and more precise measurement, during the reverberation period, of at least one operating characteristic for the PAS sensor. Another embodiment prevents the DC shift voltage by selectively activating the PSC within a determined time of a zero-crossing of a given signal.

A display apparatus includes a display panel configured to display an image, a vibration generating device at a rear surface of the display panel to vibrate the display panel, and a supporting member at the rear surface of the display panel and including a first hole. The first hole may be disposed at a whole region or periphery of the vibration generating device.

A display apparatus includes a display panel configured to display an image, a vibration generating device at a rear surface of the display panel to vibrate the display panel, and a supporting member at the rear surface of the display panel and including a first hole. The first hole may be disposed at a whole region or periphery of the vibration generating device.

A display apparatus comprises a display device including a display panel and a back cover on a rear surface of the display panel, and a curvature variation device at the back cover to vary a curvature of the display device, the curvature variation device may include an arc member at a rear region of the display device parallel to a first direction, a supporting plate at the rear region of the display device, a rotation driver on the supporting plate, a rectilinear driver on the supporting plate to perform a rectilinear motion, a rotation link part coupled to a center portion of the arc member on the supporting plate to rotate the center portion of the arc member based on a rectilinear motion of the rectilinear driver, and a holder part rotatably supporting the center portion of the arc member on the supporting plate.

A display apparatus comprises a display device including a display panel and a back cover on a rear surface of the display panel, and a curvature variation device at the back cover to vary a curvature of the display device, the curvature variation device may include an arc member at a rear region of the display device parallel to a first direction, a supporting plate at the rear region of the display device, a rotation driver on the supporting plate, a rectilinear driver on the supporting plate to perform a rectilinear motion, a rotation link part coupled to a center portion of the arc member on the supporting plate to rotate the center portion of the arc member based on a rectilinear motion of the rectilinear driver, and a holder part rotatably supporting the center portion of the arc member on the supporting plate.

An ultrasonic atomization piece and manufacturing process thereof relate to the technical field of ultrasonic atomization. The piece comprises a piezoelectric ceramic sheet and at least one composite plate. The composite plate is fixed on one side of the piezoelectric ceramic sheet and includes a substrate and a conductive layer, the conductive layer is in contact with the piezoelectric ceramic sheet, the substrate is provided with atomizing apertures, and the substrate is a polymer film. Compared with the traditional stainless steel thin sheet, the polymer film is used as the substrate material; the force for the piezoelectric ceramic sheet to generate deformation requires being lower, so the piezoelectric ceramic sheet can pull the polymer film to generate deformation with less energy. The difficulty of drilling apertures is reduced, and metal residues splashing will not occur, thereby eliminating the adverse effect of metal residues on the passage efficiency of liquid.

An apparatus includes a test circuit to receive signals from a piezoelectric horn and a control circuit to determine whether to operate the apparatus in a silent test mode or a normal mode. The apparatus includes a control circuit to, based on a determination to operate in the normal mode, enable a driver circuit to drive the piezoelectric horn so as to output sound when activated by the driver circuit. The test circuit is to, based on a determination to operate in the silent test mode, cause the piezoelectric horn to generate a piezoelectric response, wherein the piezoelectric horn is silent while generating the piezoelectric response during the silent test mode, and cause evaluation of whether or not the piezoelectric horn is working correctly based upon the received signals from the piezoelectric horn.

An apparatus includes a test circuit to receive signals from a piezoelectric horn and a control circuit to determine whether to operate the apparatus in a silent test mode or a normal mode. The apparatus includes a control circuit to, based on a determination to operate in the normal mode, enable a driver circuit to drive the piezoelectric horn so as to output sound when activated by the driver circuit. The test circuit is to, based on a determination to operate in the silent test mode, cause the piezoelectric horn to generate a piezoelectric response, wherein the piezoelectric horn is silent while generating the piezoelectric response during the silent test mode, and cause evaluation of whether or not the piezoelectric horn is working correctly based upon the received signals from the piezoelectric horn.

The invention relates to a device for transmitting mechanical vibrations to flowable media. The device is characterized in that the normal amplitudes of the effective surface points of a resonator are substantially uniform during a resonant vibration, and an amplitude vector in the effective surface points of more than 50 percent of an effective surface is not substantially parallel to the normal vector of these effective surface points.