Murata Manufacturing Co., Ltd.

Masakazu Yamauchi

Tetsuo Takeshima

Manabu Sumita

Shigemasa Kusabiraki

Yuko Yokoi

Kazuchika Yamada

Junichi Murakami

Toshio Imanishi

Sahutboon Kittayawanich

Pongsakorn Surintum

Takaaki Kaji

A piezoelectric sound generation component is provided that includes a piezoelectric vibration plate, a case with a case body and a lid that accommodates the piezoelectric vibration plate in an inner space formed by the case body and the lid, and a pin terminal provided to the lid so that the pin terminal is abutted on the piezoelectric vibration plate. The case body has a first top wall and a first circumferential wall. The lid has a second top wall, a second circumferential wall, and a protruding portion that contacts the first circumferential wall of the case body. The protruding portion has a first surface that is abutted on a contact surface, facing the first top wall, of the first circumferential wall and a second surface that couples the first surface to the second circumferential wall and is separated from the first circumferential wall.

Piezoelectric sound generation component

A piezoelectric sounding component includes a diaphragm that includes a metal plate and a piezoelectric body formed on the metal plate. A casing includes a bottom wall and side walls defining an open sound chamber. The casing also includes a supporting portion on which the diaphragm is supported to cover the open end of the chamber. A terminal is formed on the casing and serves to apply voltage to the diaphragm. An elastic adhesive fixes the diaphragm to the supporting portion and a conductive adhesive is formed on the elastic adhesive and electrically connects the terminal and the diaphragm. An elastic sealing material forms a frame-like sealing portion that seals a gap between outer peripheral edges of the diaphragm and an inner surfaces of the casing. The elastic sealing material also used to cover at least part of an exposed surface of the piezoelectric body to form a protective portion that protects the surface of the piezoelectric body. The protective portion contacts the sealing portion.

Piezoelectric sounding component

A piezoelectric sounding component includes a diaphragm that includes a metal plate and a piezoelectric body formed on the metal plate. The diaphragm bends and vibrates according to application of voltage to the piezoelectric body. A casing that includes a bottom wall, side walls, and a supporting portion to support the diaphragm in inside edge portions of the side walls. The side walls extending from edges of the bottom wall in a thickness direction and includes a first wall, a second wall positioned to face the first wall, and a third wall positioned between the first wall. Two or more terminals that are formed on the first wall or the third wall serve to apply voltage to the diaphragm. Two or more elastic adhesives join the side walls and the diaphragm between the two or more terminals and the diaphragm. Two or more conductive adhesives are formed on the two or more elastic adhesives and join the two or more terminals and the diaphragm. The diaphragm is supported by the supporting portion and accommodated in the casing so that a gap formed between the first wall and the diaphragm is smaller than a gap formed between the second wall and the diaphragm.

A sound generating device includes a case and a diaphragm fixed to the inner surfaces of first to fourth side wall portions of the case via a support member. An air chamber surrounded by a top plate, the diaphragm, and portions of the first to fourth side wall portions is formed. A sound emitting chamber that extends between the air chamber and the atmosphere outside of the case terminates at a sound emitting hole which extends across a plurality of surfaces of the case

Sound generating device

A piezoelectric sounding component includes a diaphragm that includes a metal plate and a piezoelectric body formed on the metal plate. The diaphragm bends and vibrates according to application of voltage to the piezoelectric body. A casing includes a bottom wall, side walls which, in combination with the diaphragm define a sound chamber. The diaphragm is supported by a support portion formed in the casing such that outer peripheral edges of the diaphragm are spaced from inner surfaces of the casing. A terminal is located on the casing and is electrically connected to the diaphragm. At least two elastic adhesives join the diaphragm to the casing and respective conductive adhesives extend over its associated elastic adhesive from the diaphragm to a respective terminal. A frame-like sealing portion seals a gap between the outer peripheral edge of the diaphragm and the inner surfaces of the casing. A recessed portion is formed in a portion of the support portion facing the terminal such that the first elastic adhesive extends over the recessed portion.

A piezoelectric sound component that includes a resin sheet, a piezoelectric diaphragm, and a casing. The piezoelectric diaphragm vibrates by bending, and is attached to at least part of a central portion of the resin sheet excluding a peripheral portion of the resin sheet. The casing holds the peripheral portion of the resin sheet. The casing supports at least one corner portion of the piezoelectric diaphragm.

Piezoelectric sound component

A piezoelectric sounding body in which a stable high sound pressure can be obtained over a wide frequency band. The piezoelectric sounding body includes a resin film, a piezoelectric vibrating plate attached to the center of one surface of the resin film with a tackiness layer, and a case supporting the periphery of the resin film. The piezoelectric vibrating plate is formed in a rectangular shape. An adhesive is applied between the middle of each long side of the piezoelectric vibrating plate and the resin film, along each long side of the piezoelectric vibrating plate. The separation between the piezoelectric vibrating plate and the tackiness layer can be prevented during sounding, and a stable sound pressure can be obtained for a prolonged period.

Piezoelectric sounding body

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. The inner peripheral surface of the case is provided with a supporting portion having a frame shape that is larger than that of the piezoelectric vibration plate, and the outer peripheral portion of the resin film having no piezoelectric vibration plate bonded thereto is supported by the supporting portion of the case.

Piezoelectric electro-acoustic transducer

A piezoelectric electroacoustic transducer includes a substantially rectangular piezoelectric diaphragm having an internal electrode, a plurality of laminated piezoelectric ceramic layers having the internal electrode interposed between two of the piezoelectric ceramic layers, principal-surface electrodes disposed on top and bottom principal surfaces of the piezoelectric diaphragm, the piezoelectric diaphragm generating surface bending-vibrations in response to application of an alternating signal between the principal-surface electrodes and the internal electrode, a resin film that is larger than the piezoelectric diaphragm and having the piezoelectric diaphragm affixed onto substantially a central portion of a front surface thereof, and a housing having a support for supporting the outer periphery of the resin film. The resin film has heat resistance at least a reflow-soldering temperature and at least one undulated portion bending in the front and rear directions thereof and formed in the outer periphery thereof, and the perimeter of the resin film including the four corners thereof is fixed to the support of the housing by adhesion.

Piezoelectric electroacoustic transducer

A three-terminal filter using the area flexural vibration mode is smaller than filters using the area expansion vibration mode or the length vibration mode, and is easily adjusted to produce a desired frequency by changing the thickness and length of the three-terminal filter. The three-terminal filter includes three electrodes having a substantially square shape, and two piezoelectric layers having a substantially square shape, which are alternately laminated. The piezoelectric layers are polarized in the same thickness direction as the thickness direction, or in opposite thickness directions. The three-terminal filter further includes one surface electrode that functions as an input electrode, another surface electrode that functions as an output electrode, and an internal electrode that functions as a ground electrode.

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Nagaokakyo, Japan

Masakazu Yamauchi