A vibration device includes: a glass diaphragm; an exciter which is fixed to the glass diaphragm and vibrates the glass diaphragm; an enclosing member which defines an internal space by enclosing a portion, including a fixing position of the exciter, of the glass diaphragm, one end portion of the glass diaphragm being exposed to outside the internal space through an opening of the internal space; and a shielding member for acoustic shielding between the opening and the glass diaphragm, the shielding member dividing the glass diaphragm into an excitation region located inside the internal space and a vibration region located outside the internal space.

A speaker array includes a first speaker device having a first membrane and a first acoustic channel, the first membrane being configured to oscillate and generate a first ultrasonic acoustic signal configured to be transmitted at least partially in the first acoustic channel, the first acoustic channel including at least one dimension comparable to a dimension of a viscous boundary layer of air. A second speaker device includes a second membrane and a second acoustic channel, the second membrane being configured to oscillate and generate a second ultrasonic acoustic signal configured to be transmitted at least partially in the second acoustic channel, the second acoustic channel including at least one dimension comparable to the dimension of the viscous boundary layer of air. An audio output of the speaker array is the combined output of at least the first speaker device and the second speaker device.

A speaker array includes a first speaker device having a first membrane and a first acoustic channel, the first membrane being configured to oscillate and generate a first ultrasonic acoustic signal configured to be transmitted at least partially in the first acoustic channel, the first acoustic channel including at least one dimension comparable to a dimension of a viscous boundary layer of air. A second speaker device includes a second membrane and a second acoustic channel, the second membrane being configured to oscillate and generate a second ultrasonic acoustic signal configured to be transmitted at least partially in the second acoustic channel, the second acoustic channel including at least one dimension comparable to the dimension of the viscous boundary layer of air. An audio output of the speaker array is the combined output of at least the first speaker device and the second speaker device.

A sound generator includes a piezoelectric device, a first weight member disposed at a first portion of the piezoelectric device, a second weight member disposed at a second portion of the piezoelectric device, a first elastic member disposed at a third portion between the first portion and the second portion of the piezoelectric device, and a protection member configured to cover the piezoelectric device, the first weight member, the second weight member, and the first elastic member.

A piezoelectric microelectromechanical system microphone comprises a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric element, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and a dummy electrode electrically unconnected to the sensing electrode and disposed on a portion of the piezoelectric element that is free of the sensing electrode, the dummy electrode configured to reduce static deformation of the piezoelectric element caused by residual stresses in the piezoelectric element.

A piezoelectric microelectromechanical system microphone comprises a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric element, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and a dummy electrode electrically unconnected to the sensing electrode and disposed on a portion of the piezoelectric element that is free of the sensing electrode, the dummy electrode configured to reduce static deformation of the piezoelectric element caused by residual stresses in the piezoelectric element.

The glass sheet composite of the present invention includes at least two sheets, a liquid layer held between two adjacent sheets of the at least two sheets, and a seal material disposed between the two sheets so as to seal up the liquid layer, in which at least one of the two sheets is a glass sheet, the glass sheet composite including a light-shielding part disposed so as to overlay a boundary between the liquid layer and the seal material when the glass sheet composite is viewed in a plan view. Because of this, the boundary can be concealed, and this not only results in an improvement in designability and a wider choice of materials for the liquid layer and the seal material.

Provided are a loudspeaker and an audio video device. The loudspeaker includes a loudspeaker box and a drive unit. The loudspeaker box includes a middle frame, a first diaphragm and a second diaphragm. The first diaphragm and the second diaphragm are respectively disposed at the two ends of the middle frame, the first diaphragm, the second diaphragm and the middle frame are enclosed to form a sound cavity. The drive unit is disposed in the sound cavity. The drive unit comprises a U-iron, a magnet, a magnetic conductive plate and a voice coil. The magnet is disposed on the U-iron, the magnetic conductive plate is disposed on the magnet, and the voice coil is sleeved on the magnet and the magnetic conductive plate. The U-iron is disposed on the first diaphragm, and the voice coil is disposed on the second diaphragm.

Provided are a loudspeaker and an audio video device. The loudspeaker includes a loudspeaker box and a drive unit. The loudspeaker box includes a middle frame, a first diaphragm and a second diaphragm. The first diaphragm and the second diaphragm are respectively disposed at the two ends of the middle frame, the first diaphragm, the second diaphragm and the middle frame are enclosed to form a sound cavity. The drive unit is disposed in the sound cavity. The drive unit comprises a U-iron, a magnet, a magnetic conductive plate and a voice coil. The magnet is disposed on the U-iron, the magnetic conductive plate is disposed on the magnet, and the voice coil is sleeved on the magnet and the magnetic conductive plate. The U-iron is disposed on the first diaphragm, and the voice coil is disposed on the second diaphragm.

A MEMS microphone includes a substrate having an opening, a first diaphragm, a first backplate, a second diaphragm, and a backplate. The first diaphragm faces the opening in the substrate. The first backplate includes multiple accommodating-openings and it is spaced apart from the first diaphragm. The second diaphragm joints the first diaphragm together at multiple locations by pillars passing through the accommodating-openings in the first backplate. The first backplate is located between the first diaphragm and the second diaphragm. The second backplate includes at least one vent hole and it is spaced apart from the second diaphragm. The second diaphragm is located between the first backplate and the second backplate.