A display apparatus according to an embodiment of the present disclosure includes: a thin plate-like display cell that displays an image; M exciters that are disposed on a back surface side of the display cell, and vibrate the display cell; and a driving section that drives the display cell and the M exciters.

A display apparatus according to an embodiment of the present disclosure includes: a thin plate-like display cell that displays an image; M exciters that are disposed on a back surface side of the display cell, and vibrate the display cell; and a driving section that drives the display cell and the M exciters.

An electronic device having a speaker includes: a housing having a front wall member; a cover member detachably attached to the front wall member; a fastening member arranged behind the cover member and fastened to the housing; and a first elastic member provided between the cover member and the fastening member. The cover member, the fastening member, and the first elastic member are arranged inside the housing. The speaker is arranged between the front wall member and the cover member. The front wall member and the cover member are formed so that a closed space is defined by a back surface of a vibration plate, the front wall member, and the cover member. The front wall member is provided with an opening communicating from outside of the housing to the front surface of the vibration plate. The first elastic member contacts the cover member and the fastening member.

A motor vehicle includes an acoustic device configured to generate and capture acoustic waves, the acoustic device includes a vehicle part having a vibration region, and an actuator arranged thereon and configured to for excitation and detection of vibrations of the vehicle part in the vibration region, wherein the region is modified compared to an adjacent region of the vehicle part and has greater sensitivity to excitations in the frequency range of the acoustic wave.

A system that includes a vehicle horn can reduce noise pollution caused by vehicles. The system can include a vehicle horn that has a signal-based mode and a sound-based mode. In the signal-based mode, the vehicle horn can output an electronic signal. In the sound-based mode, the vehicle horn can output an audible signal. The system can select one of the signal-based mode and the sound-based mode for the vehicle horn based on the driving environment data acquired by one or more sensors. Upon receiving a horn command, the system can cause the vehicle horn to output a signal based on the selected mode.

A display apparatus is disclosed, which includes a display panel including a first area and a second area, a first rear cover disposed below a rear surface of the display panel, a first sound generating module arranged in the first area to adjoining the display panel, and a second sound generating module arranged in the second area to be spaced apart from the display panel, wherein the first rear cover includes a first rear cover port hole formed to overlap the second sound generating module, the second sound generating module includes an enclosure disposed below a rear surface of the first rear cover and coupled with the first rear cover, and a second sound generating unit mounted in the enclosure, and the enclosure includes an enclosure port hole overlapped with the first rear cover port hole.

A display apparatus is disclosed, which includes a display panel including a first area and a second area, a first rear cover disposed below a rear surface of the display panel, a first sound generating module arranged in the first area to adjoining the display panel, and a second sound generating module arranged in the second area to be spaced apart from the display panel, wherein the first rear cover includes a first rear cover port hole formed to overlap the second sound generating module, the second sound generating module includes an enclosure disposed below a rear surface of the first rear cover and coupled with the first rear cover, and a second sound generating unit mounted in the enclosure, and the enclosure includes an enclosure port hole overlapped with the first rear cover port hole.

A concealed asset locator includes an enclosure with multiple external surfaces, wherein an external surface is configured as reflective surface, an electric notification device, a receiver relay positioned inside the enclosure and electrically coupled to the notification device, wherein the receiver relay is configured to activate the notification device in response to a received transmitter signal.

A concealed asset locator includes an enclosure with multiple external surfaces, wherein an external surface is configured as reflective surface, an electric notification device, a receiver relay positioned inside the enclosure and electrically coupled to the notification device, wherein the receiver relay is configured to activate the notification device in response to a received transmitter signal.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.