Abstract: A vibration device includes a bimorph type piezoelectric element having a first main surface and a second main surface facing each other and a vibration member bonded to the second main surface of the piezoelectric element. The piezoelectric element has a first active region disposed closer to the first main surface between the first and second main surfaces and a second active region disposed closer to the second main surface than the first active region between the first and second main surfaces. When a force generated in the first active region is F1, a force generated in the second active region is F2, and a force by which the vibration member restrains the second active region is Fr, F2?F1?Fr is satisfied.

Abstract: A piezoelectric element includes a piezoelectric body, an electrode layer, and a reinforcing layer. The piezoelectric body has a first main surface, a second main surface, and a side surface. The first main surface and the second main surface oppose each other. The side surface extends in an opposing direction in which the first main surface and the second main surface oppose each other in such a way as to connect the first main surface and the second main surface. The electrode layer is provided in the piezoelectric body. The reinforcing layer is provided on the first main surface. The electrode layer is provided opposing the first main surface and apart from the side surface. When viewed from the opposing direction, the electrode layer has a corner. When viewed from the opposing direction, the reinforcing layer overlaps the corner.

Abstract: A piezoelectric element includes a piezoelectric body, an external electrode, and an internal electrode. The internal electrode includes first and second internal conductors opposing each other. The first internal conductor includes first and second conductor portions continuous with each other. The second internal conductor includes a third conductor portion opposing the first conductor portion in a direction where the first and second internal conductors oppose each other, and a fourth conductor portion including a first region connected to the second conductor portion, and a second region continuous with the first region and continuous with the third conductor portion. The piezoelectric body includes a body portion located between the first and the second internal conductors, and formed with a through hole penetrating the body portion in the direction. The fourth conductor portion is located in the through hole and has a thickness increasing toward a center line of the through hole.

Abstract: A vibration device includes a piezoelectric vibrator having a piezoelectric element and a diaphragm having a pair of main surfaces facing each other, the piezoelectric element being bonded to the main surface, a vibration member where the piezoelectric vibrator is disposed, and an adhesive member disposed between the diaphragm and the vibration member and bonding the diaphragm and the vibration member. Each of the pair of main surfaces of the diaphragm has a rectangular shape when viewed from a facing direction of the pair of main surfaces, and the adhesive member is disposed in a facing manner on at least a pair of sides of the main surfaces.

Abstract: In a piezoelectric element, shift of a resonance point to a low-pitched sound side is achieved. A resonance point of a piezoelectric element moves to a low-pitched sound side when an active region is configured to be surrounded by an inactive region as in the configuration of the piezoelectric element. According to the piezoelectric element whose resonance point is moved to a low-pitched sound side, the piezoelectric element can realize a sound pressure that is sufficiently high for practical use when it is applied to an acoustic device.

Abstract: A piezoelectric element includes a piezoelectric element body including a first principal surface and a second principal surface opposing each other, and a plurality of external electrodes disposed on the first principal surface. A vibration member includes a third principal surface opposing the second principal surface. The piezoelectric element is joined to the third principal surface. A wiring member is electrically connected to the piezoelectric element. The wiring member includes a region located on the plurality of external electrodes and joined to the plurality of external electrodes. The region of the wiring member monolithically covers the plurality of external electrodes when viewed from a direction orthogonal to the first principal surface.

Abstract: A piezoelectric element includes a piezoelectric body layer, a first electrode, a second electrode, a third electrode, and a conductor. The piezoelectric body layer has rectangular first and second principal surfaces opposing each other, and includes a piezoelectric material. The first electrode is provided on the first principal surface. The second electrode is provided on the first principal surface in such a way that the second electrode is separated from the first electrode. The third electrode is provided on the second principal surface in such a way that the third electrode opposes the first electrode. The conductor is connected to the second electrode and the third electrode. The first electrode has a round corner being rounder than a corner part of the piezoelectric body layer when seen in an opposing direction of the first and second principal surfaces.

Abstract: A piezoelectric element includes a piezoelectric body including a piezoelectric material, and a first electrode and a second electrode provided on the piezoelectric body. The piezoelectric body includes a base and a plurality of drivers. The base includes a first main surface and a second main surface opposing each other. The plurality of drivers is arranged on the first main surface in such a way as to be separate from each other. Each of the plurality of drivers includes a third main surface contacting the first main surface and a fourth main surface opposing the third main surface. The base includes a plurality of first regions in which the plurality of drivers is provided and a second region provided between the first regions adjacent to each other. The base is curved.

Abstract: An ultrasonic transducer includes a case, a piezoelectric element, a wiring member, a foaming member, and a vibration damping material. The case includes a bottom wall. The piezoelectric element is disposed on the bottom wall inside the case. The wiring member is electrically connected to the piezoelectric element. The foaming member is disposed on the piezoelectric element. The vibration damping material is disposed between the piezoelectric element and the foaming member. The foaming member has a bottom surface opposing the piezoelectric element in a thickness direction of the piezoelectric element. A plurality of depressions is formed on the bottom surface. The vibration damping material bonds the piezoelectric element and the bottom surface.

Abstract: An audio device includes a vibration member, and a first piezoelectric vibrator and a second piezoelectric vibrator that are provided on the vibration member. A natural frequency of the first piezoelectric vibrator is larger than a natural frequency of the second piezoelectric vibrator.

Abstract: A vibration device includes a piezoelectric vibrator having a piezoelectric element and a diaphragm having a pair of main surfaces facing each other, the piezoelectric element being bonded to the main surface, a vibration member where the piezoelectric vibrator is disposed, and an adhesive member disposed between the diaphragm and the vibration member and bonding the diaphragm and the vibration member. Each of the pair of main surfaces of the diaphragm has a rectangular shape when viewed from a facing direction of the pair of main surfaces, and the adhesive member is disposed in a facing manner on at least a pair of sides of the main surfaces.

Abstract: A multilayer piezoelectric element includes a piezoelectric element body, a first internal electrode and a second internal electrode, a plurality of first connecting conductors, a plurality of second connecting conductors, and an external member. The piezoelectric element body is formed by laminating a plurality of piezoelectric element body layer. The piezoelectric element body includes a first main surface and a second main surface, and a side surface. The plurality of first connecting conductors are connected to the first internal electrode. The plurality of second connecting conductors are connected to the second internal electrode. The external member is conductive and is bonded to the first main surface in such a way as to cover the first end portions of the plurality of first connecting conductors. The external member is electrically connected to the plurality of first connecting conductors.

Abstract: A vibration device includes a bimorph type piezoelectric element having a first main surface and a second main surface facing each other and a vibration member bonded to the second main surface of the piezoelectric element. The piezoelectric element has a first active region disposed closer to the first main surface between the first and second main surfaces and a second active region disposed closer to the second main surface than the first active region between the first and second main surfaces. When a force generated in the first active region is F1, a force generated in the second active region is F2, and a force by which the vibration member restrains the second active region is Fr, F2?F1?Fr is satisfied.

Abstract: In a piezoelectric element, shift of a resonance point to a low-pitched sound side is achieved. A resonance point of a piezoelectric element moves to a low-pitched sound side when an active region is configured to be surrounded by an inactive region as in the configuration of the piezoelectric element. According to the piezoelectric element whose resonance point is moved to a low-pitched sound side, the piezoelectric element can realize a sound pressure that is sufficiently high for practical use when it is applied to an acoustic device.

Abstract: A piezoelectric element includes a piezoelectric element body including a first principal surface and a second principal surface opposing each other, and a plurality of external electrodes disposed on the first principal surface. A vibration member includes a third principal surface opposing the second principal surface. The piezoelectric element is joined to the third principal surface. A wiring member is electrically connected to the piezoelectric element. The wiring member includes a region located on the plurality of external electrodes and joined to the plurality of external electrodes. The region of the wiring member monolithically covers the plurality of external electrodes when viewed from a direction orthogonal to the first principal surface.

Abstract: A piezoelectric element includes first and second electrodes, a first piezoelectric body layer, and a plurality of first through-hole conductors. The first and second electrodes oppose each other. The first piezoelectric body layer is disposed between the first electrode and the second electrode. The plurality of first through-hole conductors penetrates the first piezoelectric body layer and is connected to the first electrode and the second electrode. When seen in an opposing direction of the first and second electrodes, the plurality of first through-hole conductors is arrayed in a matrix.

Abstract: In a piezoelectric element, internal stress generated in an inactive portion at the time of sintering when a piezoelectric element is fabricated or stress applied from the outside to the inactive portion is absorbed by a recess of a lower surface of a first through hole conductor and a recess of an upper surface of a second through hole conductor. Accordingly, for example, deformation, rupture, or the like of the through hole conductor is prevented, and conduction failure or disconnection of an electrode layer or a through hole conductor is prevented. Further, in the inactive portion, since a protrusion of the piezoelectric layer enters the recess of the through hole conductor, a holding force of the piezoelectric layer with respect to the through hole conductor increases, and deformation of the through hole conductor is prevented or obstructed.

Abstract: A piezoelectric element includes a piezoelectric body layer, a first electrode, a second electrode, a third electrode, and a conductor. The piezoelectric body layer has rectangular first and second principal surfaces opposing each other, and includes a piezoelectric material. The first electrode is provided on the first principal surface. The second electrode is provided on the first principal surface in such a way that the second electrode is separated from the first electrode. The third electrode is provided on the second principal surface in such a way that the third electrode opposes the first electrode. The conductor is connected to the second electrode and the third electrode. The first electrode has a round corner being rounder than a corner part of the piezoelectric body layer when seen in an opposing direction of the first and second principal surfaces.

Abstract: A piezoelectric device includes a body provided with a first region and a second region lined along a first direction. The first region deformably extends/contracts along the first direction. The second region deformably curves in such a manner that one or the other side in a second direction intersecting the first direction curves outward.