Abstract: A piezoelectric type electric acoustic converter achieves large improvement in shatter resistance strength, increased operating efficiency and reduced size, and includes piezoelectric ceramic layers which are laminated to form a laminate. Main surface electrodes are disposed on the front and back main surfaces of the laminate, and an internal electrode is disposed between respective ceramic layers. A side electrode which connects the main surface electrodes, and a side electrode which is conducted to the internal electrode are formed on the side surface of the laminate. All the ceramic layers are polarized in the same direction, and by applying an alternating signal between the main surface electrodes and the internal electrode, bending vibration of the laminate occurs. The front and back surfaces of the laminate is almost entirely covered with resin-layers.

Abstract: A piezoelectric sounding body includes a metal plate, an insulating layer disposed on the top surface of the metal plate, and a piezoelectric body in which a plurality of piezoelectric ceramic layers are laminated with an internal electrode disposed therebetween and the piezoelectric ceramic layers are polarized in the thickness direction so as to be opposite to each other, the top and bottom surfaces of which external electrodes are provided, and on the bottom surface of which is bonded to the insulating layer.

Abstract: A piezoelectric type electric acoustic converter achieves large improvement in shatter resistance strength, increased operating efficiency and reduced size, and includes piezoelectric ceramic layers which are laminated to form a laminate. Main surface electrodes are disposed on the front and back main surfaces of the laminate, and an internal electrode is disposed between respective ceramic layers. A side electrode which connects the main surface electrodes, and a side electrode which is conducted to the internal electrode are formed on the side surface of the laminate. All the ceramic layers are polarized in the same direction, and by applying an alternating signal between the main surface electrodes and the internal electrode, bending vibration of the laminate occurs. The front and back surfaces of the laminate is almost entirely covered with resin-layers.

Abstract: A piezoelectric electro-acoustic transducer includes a piezoelectric vibration plate having a plurality of piezoelectric ceramic layers laminated to each other with an internal electrode being interposed between the ceramic layers, and main surface electrodes provided on the front and back surfaces thereof, whereby area bending vibration is produced by applying an AC signal between the main surface electrodes and the internal electrode, respectively, a resin film having a size that is greater than the piezoelectric vibration plate and having the piezoelectric vibration plate bonded substantially to the central portion of the surface thereof, and a casing which accommodates the piezoelectric vibration plate and the resin film. The piezoelectric vibration plate has an area of about 40% to about 70% of that of the resin film.

Abstract: A piezoelectric electroacoustic transducer includes two electrodes, a substantially square piezoelectric diaphragm producing a bending vibration in the thickness direction thereof in response to application of an alternating voltage between the two electrodes, a housing for housing the piezoelectric diaphragm, an elastic sealant for sealing the gap between the periphery of the diaphragm and the inner side surface of the housing, supports, disposed in the housing, for supporting at least two mutually opposing sides of the piezoelectric diaphragm or the four corners of the piezoelectric diaphragm, grooves which are disposed in the housing so as to face the periphery of the rear surface of the piezoelectric diaphragm and in which the elastic sealant is filled, and walls defining inner portions of the grooves, arranged such that the upper surfaces of the walls are located below those of the supports, for preventing the elastic sealant from flowing out to the bottom of the housing.

Abstract: A piezoelectric electroacoustic transducer includes a substantially square piezoelectric diaphragm flexually vibrating in a plate-thickness direction in response to application of an alternating signal between electrodes, a substantially rectangular insulating case having a supporting member disposed inside sidewalls of the case for supporting the diaphragm, terminals having internal connections exposed in a vicinity of the supporting member and external connections exposed outside the case and electrically connecting to the internal connections, a first adhesive applied to a shortest route located between the external periphery of the diaphragm and the internal connections and connecting the diaphragm to the internal connections so as to fix the diaphragm to the case, a conductive adhesive applied to electrodes of the diaphragm and the internal connections via the upper surface of the first adhesive by detouring from the shortest route to connect the diaphragm to the internal connections for electrically con

Abstract: A piezoelectric electroacoustic transducer includes a piezoelectric diaphragm having a substantially rectangular shape which vibrates in the thickness direction when an alternating current is applied between electrodes of the piezoelectric diaphragm, a housing which stores the piezoelectric diaphragm, and a pair of terminals formed in the housing by insert molding. One end of each terminal is inserted inside the housing and includes a body portion fixed to the housing and wing portions which extend from both sides of the body portion toward the corners of the housing. The wing portions are not fixed to the housing, and stress-relieving portions are disposed between the body portion and the wing portions so that the wing portions are able to move toward the inside of the housing. Each electrode of the piezoelectric diaphragm is connected to at least one of the wing portions of the terminals by a conductive adhesive.

Abstract: A piezoelectric electroacoustic transducer is miniaturized and has a reduced frequency, and even when a diaphragm has a warp or winding, the resonance frequency is be stabilized. The piezoelectric electroacoustic transducer includes a substantially rectangular piezoelectric diaphragm flexurally vibrating in a thickness direction in response to the application of an alternating signal between electrodes and a casing for accommodating the piezoelectric diaphragm, wherein the casing is provided with supporting members for supporting four corners of the piezoelectric diaphragm.

Abstract: A piezoelectric electroacoustic transducer includes a substantially square piezoelectric diaphragm flexually vibrating in a plate-thickness direction in response to application of an alternating signal between electrodes, a substantially rectangular insulating case having a supporting member disposed inside sidewalls of the case for supporting the diaphragm, terminals having internal connections exposed in a vicinity of the supporting member and external connections exposed outside the case and electrically connecting to the internal connections, a first adhesive applied to a shortest route located between the external periphery of the diaphragm and the internal connections and connecting the diaphragm to the internal connections so as to fix the diaphragm to the case, a conductive adhesive applied to electrodes of the diaphragm and the internal connections via the upper surface of the first adhesive by detouring from the shortest route to connect the diaphragm to the internal connections for electrically con

Abstract: A piezoelectric acoustic component includes a diaphragm having a substantially rectangular piezoelectric plate including front and back surfaces, an electrode disposed on the front surface, a substantially rectangular metal plate bonded to the back surface of the substantially rectangular piezoelectric plate directly or via an electrode disposed on the back surface of the substantially rectangular piezoelectric plate, an insulating cap having an upper wall, four side walls extending from the upper, a pair of support members arranged to support the diaphragm at the inside of the two of four sides walls opposed to each other, and a plate shaped substrate having a first electrode section and a second electrode section. The diaphragm is disposed the insulating cap. Two of four side edges of the diaphragm are opposed to each other and fixed to the pair of support members. A gap is formed between the other two of four side edges of the diaphragm and the cap and is sealed by elastic sealing material.

Abstract: An electroacoustic transducer includes a diaphragm including a substantially rectangular metal plate and a substantially rectangular piezoelectric plate having electrodes on an upper surface and a lower surface thereof, with one of the electrodes being connected to the metal plate. A support medium including retaining parts for retaining two shorter sides of the diaphragm is provided. The shorter sides of the diaphragm are fixed to the retaining parts by an adhesive having a Young's Modulus after curing that is between about 4.0×104 N/m2 and about 5.0×106 N/m2. Gaps between the two longer sides of the diaphragm and the support member are sealed by an elastic sealant. The diaphragm is arranged to undergo bending vibration in a longitudinal bending mode by applying a predetermined electrical signal between the metal plate and the opposing electrode provided on the piezoelectric plate.

Abstract: A piezoelectric type electric acoustic converter achieves large improvement in shatter resistance strength, increased operating efficiency and reduced size, and includes piezoelectric ceramic layers which are laminated to form a laminate. Main surface electrodes are disposed on the front and back main surfaces of the laminate, and an internal electrode is disposed between respective ceramic layers. A side electrode which connects the main surface electrodes, and a side electrode which is conducted to the internal electrode are formed on the side surface of the laminate. All the ceramic layers are polarized in the same direction, and by applying an alternating signal between the main surface electrodes and the internal electrode, bending vibration of the laminate occurs. The front and back surfaces of the laminate is almost entirely covered with resin-layers.

Abstract: A piezoelectric acoustic component includes a unimorph-type vibration body, a mounting substrate, and a cover. The vibration body includes a substantially rectangular piezoelectric plate and a substantially rectangular metallic plate bonded to the back side of the piezoelectric plate. Longitudinal opposite end portions of the vibration body are fixed onto the mounting substrate via respective support members. The metallic plate of the vibration body is fixedly connected to a first electrode located on the mounting substrate via one of the support members, whereas the electrode located on the front side of the piezoelectric plate is connected to a second electrode located on the mounting substrate via a conductive wire. A gap between the mounting substrate and each of lateral opposite end portions of the vibration body is charged with silicone rubber, thereby defining an acoustic space between the vibration body and the mounting substrate.

Abstract: A method of manufacturing a resonance element includes the steps of preparing a multilayered body having a plurality of piezoelectric layers and a plurality of inner electrodes laminated to each other, forming an insulating film on one surface of the multilayered body at exposed portions of the inner electrodes, the insulating film having a plurality of openings constituting substantially parallel rows which are substantially parallel to the laminating direction of the multilayered body, forming an outer electrode on substantially the entire surface on which the insulating film is formed, forming a plurality of grooves on the surface on which the outer electrode is formed and cutting the multilayered body substantially parallel to the grooves, wherein a first group of the openings in a first of the rows are disposed on every alternate exposed portion of the internal electrodes, and a second group of remaining openings in a second row adjacent to the first row are disposed on each of the remaining alternate ex

Abstract: A piezoelectric component includes a substrate on which a piezoelectric resonator is mounted with supporting members interposed therebetween. The substrate is covered by a cap which is arranged to cover the piezoelectric resonator. A rubber-like elastic material such as a silicone resin is injected through a hole of the cap to cover the periphery of the piezoelectric resonator. Preferably, the Young's modulus of the rubber-like elastic material is not larger than about 12 kgf/cm.sup.2.

Abstract: A piezoelectric resonator which vibrates in a longitudinal vibration mode includes first insulating films disposed on a side surface of a base member so as to cover at least part of exposed portions of a first group of the internal electrodes and second insulating films disposed on the side surface of the base member so as to cover at least part of the exposed portions of a second group of the internal electrodes. A first thin-film external electrode extends continuously in the longitudinal direction of the base member on the first insulating films and a second thin-film external electrode extends continuously in the longitudinal direction of the base member on the second insulating film. A first conductive resin film and a second conductive resin film are respectively provided on the first thin-film external electrode and the second thin-film external electrode such that even if the thin-film external electrodes are broken or damaged, the piezoelectric resonator still functions.

Abstract: A piezoelectric resonator includes a piezoelectric resonator element vibrating in a longitudinal vibration mode and having a mounting surface, wherein a resin material is provided on the mounting surface of the piezoelectric resonator element, and the resin material has a hardness of about 0 to about 50 in units defined in the JIS-A standards and/or an elastic modulus of about 0.1 to 10 MPa.

Abstract: A piezoelectric component achieves a desired Qm by using a presently available piezoelectric material. The piezoelectric component includes a supporting substrate on which pattern electrodes are provided. Electroconductive supporting members are disposed on the pattern electrodes, and a piezoelectric resonator is mounted on the supporting members. External electrodes of the piezoelectric resonator and the pattern electrodes are electrically connected to each other by the supporting members. Gaps between the piezoelectric resonator and the supporting substrate are filled with a first elastic material element. A second material element may be provided on the surface of the piezoelectric resonator disposed opposite to the surface of the resonator facing the supporting substrate. Only one of these elastic material elements or both these elastic material elements may be used.

Abstract: A piezoelectric resonator having a small spurious resonance, a large frequency difference .DELTA.F between the resonant frequency and the anti-resonant frequency, adjustable capacitance, and high design flexibility includes a base member formed by laminating, for example, a plurality of piezoelectric layers and internal electrodes. When the length, width, and thickness of the base member are indicated by L, W and T, respectively, the dimensions of the member are selected to satisfy the conditions of L.gtoreq.2W and L.gtoreq.2T. The base member is polarized at both ends of each internal electrode in opposite directions. A groove is preferably formed on one lateral surface of the base member, and at both sides of the groove, the internal electrodes are alternately covered with two insulating films. The two insulating films are respectively formed to cover the different internal electrodes. External electrodes are formed on both sides of the groove of the base member and are connected to the internal electrodes.

Abstract: A ladder filter has a piezoelectric resonator having reduced spurious vibrations and having a wider range of selection of the difference .DELTA.F between the resonant frequency and the antiresonant frequency, and has a substantially reduced size. The ladder filter includes an insulating substrate on which four pattern electrodes are provided. Four lands are respectively formed as portions of the four pattern electrodes. Another land is formed as a portion of the second pattern electrode. External electrodes of four piezoelectric resonators adapted to vibrate in a longitudinal vibration mode and capable of being mounted in a surface mount manner are connected to the land of the pattern electrodes by supporting members made of an electroconductive material. The four piezoelectric resonators are arranged in a row in the order of a first series resonator, a first parallel resonator, a second parallel resonator and a second series resonator.