Murata Manufacturing Co., Ltd.

Yuko Yokoi

Tadashi Okuzawa

Masakazu Yamauchi

Kiyotaka Tajima

Kazuchika Yamada

Takashi Yamamoto

Tetsuo Takeshima

Manabu Sumita

Koji Yasojima

Junichi Murakami

Yoshitaka Nakamura

Takaaki Kaji

Ryuuji Morishita

Toshiyuki Sakai

A piezoelectric vibration plate includes a base that includes a central portion and a circumferential portion and has conductivity. A piezoelectric portion is provided on the central portion that performs bending vibration in a manner to reciprocate between both sides in a thickness direction of the base when a voltage is applied to the piezoelectric portion. The base includes at least one penetration portion positioned between the central portion and the circumferential portion, and at least one coupling portion that couples the central portion to the circumferential portion. The at least one coupling portion is arranged on a farthest position from a center, at which maximum displacement is generated in the bending vibration, of the central portion.

Piezoelectric vibration plate and piezoelectric sound generating component

A piezoelectric sound-generating component case that includes a case body for housing a vibrating plate and insert terminals that are provided in the case body for applying a voltage to the vibrating plate. The case body includes a bottom or base and a side wall that projects from the peripheral edge of the bottom. The case body is provided with an opening that opens on the leading end side, in the projection direction, of the side wall. The side wall has thick parts at least on the sides where the insert terminals are provided. In a plan view of the case body, the transverse direction width of the thick parts of the side wall is larger than the transverse direction width of the parts of the side wall that are adjacent to the thick parts.

Piezoelectric sound-generating component case and piezoelectric sound-generating 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 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 type electroacoustic transducer includes a piezoelectric vibrating plate including a plurality of piezoelectric ceramic layers laminated to each other with an internal electrode being interposed between the piezoelectric ceramic layers, and main surface electrodes disposed on the main surfaces on the front and back sides of the piezoelectric vibrating plate, whereby the piezoelectric vibrating plate is surface-flexural-vibrated in the thickness direction thereof with an AC signal applied between the main surface electrodes and the internal electrode, and a box having supporting portions on which the outer peripheral portions on the back side of the piezoelectric vibrating plate is supported, the piezoelectric vibrating plate having a protecting film substantially on the entire surface on the back-side only or on the front and back sides of the piezoelectric vibrating plate, and the protecting film being formed by applying a resin in a film-shape and hardening the resin, or by bonding an adhesive sheet and hardening the sheet, and the piezoelectric vibrating plate being warped on the front-side thereof by utilization of the hardening shrink stresses of the protecting films.

Piezoelectric acoustic transducer

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.

Piezoelectric electroacoustic transducer

A piezoelectric resonator includes an internal electrode sandwiched between two layers of ceramic piezoelectric substrates each having a substantially square shape. Surface electrodes are arranged on the front surface and the back surface of the piezoelectric substrate. Both of the piezoelectric substrates are polarization-treated in the substantially perpendicular direction relative to the main surfaces and in the opposite directions with respect to the sandwiched internal electrode. When a signal voltage is applied across the surface electrodes, the piezoelectric resonator is bending-deformed so as to become convex on one side of the main surfaces and become concave on the other side thereof.

Piezoelectric resonator

A piezoelectric element vibrating in a longitudinal vibration mode includes external electrodes which are provided on front and back major surfaces of a piezoelectric substrate. Conductive sections are fixed onto nodal portions of the piezoelectric element on one of the major surfaces of the piezoelectric substrate. The piezoelectric element is constructed such that a relationship T1/T is set at about 0.5 or less and a relationship L1/L is set at about 0.2 or less, where a thickness and a length of the piezoelectric element are T and L, respectively, and a thickness and a length of the support sections are T1 and L1, respectively.

Piezoelectric element and electronic component including same

A piezoelectric resonator includes a substantially rectangular shaped piezoelectric substrate having a pair of major surfaces and polarized in the thickness direction thereof and a pair of electrodes respectively disposed on the pair of major surfaces of the piezoelectric substrate. One of the electrodes is multiply divided along a dividing line which extends along the longitudinal direction of the piezoelectric substrate. The piezoelectric substrate is polarized such that two portions of the piezoelectric substrate sandwiching the dividing line are polarized in opposite directions.

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Toyama-ken, Japan

Yuko Yokoi