A micromechanical sound transducer according to a first aspect includes a first bending transducer with a free end and a second bending transducer with a free end, the two bending transducers being arranged in a mutual plane, wherein the free end of the first bending transducer is separated from the free end of the second bending transducer via a slit. The second bending transducer is excited in-phase with the vertical vibration of the first bending transducer. A micromechanical sound transducer according to a second aspect includes a first bending transducer that is excited to vibrate vertically and a diaphragm element extending vertically to the first bending transducer, the diaphragm element being separated from a free end of the first bending transducer via a slit.

The invention relates to an electromagnetic actuator, which can be connected to a backside of a plate like structure and which comprises a voice coil, a magnet system and a spring arrangement connecting the voice coil and a movable part of the magnet system. The spring arrangement comprises at least two spiral springs each having at least three spring legs. The spring legs run in radial and tangential direction in a clockwise or counterclockwise winding direction and are rotational symmetric around the coil axis. The winding directions of the spiral springs are chosen in a way that rotations around the coil axis caused by a relative movement between the voice coil and the movable part of the magnet system in the excursion direction are oriented in opposite directions. The invention also relates to an output device with a plate like structure and an electromagnetic actuator connected thereto.

The present disclosure relates to a display apparatus, especially having a display panel generating sounds. A display apparatus according to the present disclosure includes: a display module; a back cover at a rear surface of the display module; a depression recessed into the back cover from a first surface of the back cover with a first width and a first depth; a penetration through from a second surface of the back cover to the depression with a second width smaller than the first width and a second depth corresponding to a difference between a thickness of the back cover and the first depth; and a first piezo vibration unit disposed at a stepped portion between the penetration and the depression.

The present disclosure relates to a flexible vibration film and a display apparatus having the same. A flexible vibration film includes: a vibration layer; a first electrode layer disposed on a bottom surface of the vibration layer; and a second electrode layer disposed on a top surface of the vibration layer, wherein the vibration layer includes: a first vibration unit having a first vibration characteristics; a second vibration unit having a second vibration characteristics; and a flexible insulating part disposed between the first vibration unit and the second vibration unit, and wherein the first electrode layer includes: a first part corresponding to the first vibration unit; and a second part corresponding to the second vibration unit.

A display device includes a display panel including a display layer including light-emitting elements disposed on a substrate, and a sensor electrode layer disposed on the display layer. The sensor electrode layer includes a first sound electrode and a second sound electrode; a vibration layer electrically contacting the first sound electrode and the second sound electrode and being deformed in response to a first sound driving voltage applied to the first sound electrode and a second sound driving voltage applied to the second sound electrode; and sensor electrodes disposed on the vibration layer. The sensor electrodes sense an input.

The invention relates to an electrodynamic transducer having a magnetic mass connected to a frame with first and second axially offset suspensions. The suspensions permit translational displacement of the magnetic mass with respect to the frame and have multiple springs. The direction of orientation of the springs of the first suspension is opposite that of the springs of the second suspension, such that each suspension blocks the axial rotation of the other suspension.

Disclosed is an electronic device, comprising a first exciter, a second exciter, and a first panel and a second panel that are provided oppositely. The first exciter is configured to control the first panel to vibrate, such that the first panel radiates a first sound wave. The second exciter is configured to control the second panel to vibrate, such that the second panel radiates a second sound wave. The electronic device of the present invention is provided with the two exciters to control each of the two panels to vibrate and radiate sound waves, such that both the first panel and the second panel can serve as a sound source. Controlling a vibration pattern of the second panel also enables control over a sound field of the first sound wave radiated by the first panel.

Embodiments of the present disclosure describe an MEMS sound transducer having an actuator and a structure surrounding the actuator, wherein the actuator is separated from the surrounding structure by one or several slits. Furthermore, the sound transducer includes at least one first diaphragm arranged on the actuator along at least one of the one or several slits; and at least one second diaphragm arranged on the surrounding structure along the slit of the one or several slits.

A refrigerator with a sound reproducing capability is provided. The refrigerator may include a cabinet forming an exterior of the refrigerator and having an upper surface portion, a lower surface portion, a side surface portion, and a rear surface portion, a door coupled to the cabinet, a vibration module attached to an inner surface of at least one among the door, the upper surface portion, the side surface portion, the rear surface portion, and the lower surface portion, and a controller configured to control vibration of the vibration module. The vibration strength of the vibration module and power supplied to the vibration module may be determined by a trained model trained through machine learning, an area of artificial intelligence (AI). In addition, the refrigerator may include a communicator, and may operate in conjunction with an external device via 5G communication.

A piezoelectric element comprising a compound represented by Formula 1, a piezoelectric device including the piezoelectric element, a vibration module including the piezoelectric device, and a display apparatus including the piezoelectric device are provided, where

(1−x)(Li.sub.zNa.sub.0.5-zK.sub.0.5)(Nb.sub.1-ySb.sub.y)O.sub.3.Math.xCaZrO.sub.3  [Formula 1]

where x, y, and z have a range of 0.001≤x≤0.2, a range of 0≤y≤0.5, and a range of 0≤z≤0.2, respectively.