A display apparatus according to an embodiment of the present disclosure includes: a display cell that displays an image and has a thin-plate shape; one or more vibration exciters that are disposed on rear-surface side of the display cell and cause the display cell to vibrate; and an opposing plate opposed to the display cell with an air gap in between. The display apparatus further includes a sound-spreading adjustment member that is disposed between the display cell and the two or more vibration exciters, and controls spreading of a sound generated by vibration caused by the two or more vibration exciters.

A piezoelectric actuator including an upper piezoelectric bimorph beam having a first upper piezoelectric layer, a second upper piezoelectric layer and at least three upper electrode layers extending between a first end and a second end of the upper piezoelectric bimorph beam; a lower piezoelectric bimorph beam having a first lower piezoelectric layer, a second lower piezoelectric layer and at least three lower electrode layers extending between a first end and a second end of the lower piezoelectric bimorph beam, and wherein the first end of the lower piezoelectric bimorph beam is coupled to the first end of the upper piezoelectric bimorph beam by a first joint, and the second end of the lower piezoelectric bimorph beam is coupled to second end of the upper piezoelectric bimorph beam; and a base member coupled to a center region of the lower piezoelectric bimorph beam.

The purpose of the present invention is to provide a glass sheet composite having satisfactory acoustic performance. The present invention relates to a glass sheet composite including a diaphragm that is vibrated by a vibrator, and a support member that is attached along an edge portion of the diaphragm to support the diaphragm, in which the diaphragm includes at least one glass sheet, and is supported on the support member through a fixing part that fixes the edge portion of the diaphragm to the support member, and a vibration-permitting part that permits vibration of the diaphragm.

The embodiments of the present disclosure may disclose a vibration sensor, including: an acoustic transducer and a vibration assembly connected with the acoustic transducer. The vibration assembly may be configured to transmit an external vibration signal to the acoustic transducer to generate an electric signal, the vibration assembly includes one or more groups of vibration diaphragms and mass blocks, and the mass blocks may be physically connected with the vibration diaphragms. The vibration assembly may be configured to make a sensitivity degree of the vibration sensor greater than a sensitivity degree of the acoustic transducer in one or more target frequency bands.

The embodiments of the present disclosure may disclose a vibration sensor, including: an acoustic transducer and a vibration assembly connected with the acoustic transducer. The vibration assembly may be configured to transmit an external vibration signal to the acoustic transducer to generate an electric signal, the vibration assembly includes one or more groups of vibration diaphragms and mass blocks, and the mass blocks may be physically connected with the vibration diaphragms. The vibration assembly may be configured to make a sensitivity degree of the vibration sensor greater than a sensitivity degree of the acoustic transducer in one or more target frequency bands.

A microelectromechanical systems (MEMS) die includes a first diaphragm and a second diaphragm, wherein the first diaphragm and the second diaphragm bound a sealed chamber. A stationary electrode is disposed within the sealed chamber between the first diaphragm and the second diaphragm. A tunnel passes through the first diaphragm and the second diaphragm without passing through the stationary electrode, wherein the tunnel is sealed off from the chamber. The MEMS die further includes a substrate having an opening formed therethrough, wherein the tunnel provides fluid communication from the opening, through the second diaphragm, and through the first diaphragm.

A piezoelectric microelectromechanical system microphone comprises a support substrate, a membrane including a piezoelectric material attached to the support substrate and configured to deform and generate an electrical potential responsive to impingement of sound waves on the membrane, and a compliant anchor including a trench defined in the support substrate about a portion of a perimeter of the membrane to increase sensitivity of the piezoelectric microelectromechanical system microphone.

A piezoelectric microelectromechanical system microphone comprises a support substrate, a membrane including a piezoelectric material attached to the support substrate and configured to deform and generate an electrical potential responsive to impingement of sound waves on the membrane, and a compliant anchor including a trench defined in the support substrate about a portion of a perimeter of the membrane to increase sensitivity of the piezoelectric microelectromechanical system microphone.

A method for determining the state of at least one sensor whose mechanical behaviour is nonlinear as a function of the amplitude of the pressure exerted against the sensor, the sensor and an electromechanical transducer being able to be coupled to a support, the method comprising the steps of: applying an electrical signal at a first amplitude to the terminals of the first electromechanical transducer, and determining a first set of values of a parameter characteristic of the electrical impedance of the first electromechanical transducer in response to the application of the electrical signal; applying the electrical signal at a second amplitude to the terminals of the first electromechanical transducer, and determining a second set of values of the parameter characteristic of the impedance; measuring a deviation between the first set of values and the second set of values; determining a state of the sensor as a function of the deviation between the first set of values and the second set of values.

A method for determining the state of at least one sensor whose mechanical behaviour is nonlinear as a function of the amplitude of the pressure exerted against the sensor, the sensor and an electromechanical transducer being able to be coupled to a support, the method comprising the steps of: applying an electrical signal at a first amplitude to the terminals of the first electromechanical transducer, and determining a first set of values of a parameter characteristic of the electrical impedance of the first electromechanical transducer in response to the application of the electrical signal; applying the electrical signal at a second amplitude to the terminals of the first electromechanical transducer, and determining a second set of values of the parameter characteristic of the impedance; measuring a deviation between the first set of values and the second set of values; determining a state of the sensor as a function of the deviation between the first set of values and the second set of values.