Taiyo Yuden Co., Ltd.

Yutaka Doshida

Keiichi Hatano

Hiroshi Hamada

Takashi Tomita

Shigeo Ishii

Hiroyuki Shimizu

Sumiaki Kishimoto

Yoshiyuki Watanabe

Yukihiro Matsui

Shinichiro Ikemi

Takayuki Goto

Fumihisa Ito

Gouki Watanabe

Hiroshi Kishi

Tomohiro Harada

Katsuei Ishida

Taisei Irieda

Asa Yamamoto

Yasukazu Tokuhisa

Masafumi Tsukada

An electroacoustic transducer includes a piezoelectric speaker and a housing. The piezoelectric speaker has: a first vibration plate with a periphery; a piezoelectric element placed on at least one face of the first vibration plate; and multiple openings that are provided around the piezoelectric element and penetrate through the first vibration plate in its thickness direction that is a first axis direction. The housing has: a supporting part that directly or indirectly supports the periphery; and a sound introduction port that faces the piezoelectric speaker in the first axis direction. The sound introduction port is provided at a position where it does not overlap, in the first axis direction, a first opening having the largest open area among the multiple openings. The electroacoustic transducer can improve the acoustic characteristics of a piezoelectric speaker.

Electroacoustic transducer

A piezoelectric element which is a single-layer or laminated piezoelectric element has a first electrode, a second electrode, and a piezoelectric ceramic layer. The first electrode and second electrode contain silver by 50 percent by weight or more. The piezoelectric ceramic layer is placed between the first electrode and second electrode, and constituted by a polycrystalline substance of alkali niobate piezoelectric ceramic containing at least one alkali earth metal being calcium, strontium, or barium, and silver. According to this constitution, the electrical resistance and piezoelectric property can be improved, and consequently high reliability and good piezoelectric characteristics can be achieved.

Piezoelectric element and method of manufacturing the same

An electroacoustic transducer includes a dynamic speaker that generates a first acoustic sound, and a piezoelectric speaker that generates a second acoustic sound. The sum of the sound pressures of the first and second acoustic sounds in a crossover frequency range of the sound pressure of the first acoustic sound and the sound pressure of the second acoustic sound, is adjusted to be equal to or greater than 0.5 times the sound pressure of the first acoustic sound in the crossover frequency range so as to improve the acoustic properties in the crossover frequency range.

A piezoelectric ceramic speaker includes a piezoelectric element using a vibration sheet formed with piezoelectric ceramic having a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains, wherein the primary phase is constituted by ceramic grains expressed by a composition formula Pb {(ZrTi)&#xb7;(NiNb)&#xb7;(ZnNb)}O(where 0&#x3c;x&#x2264;0.85, 0&#x2264;y&#x3c;1, 0&#x3c;z&#x3c;1, x+y+z=1, and 0.45&#x2264;a&#x2264;0.60); and an enclosure which encloses the piezoelectric element.

Piezoelectric ceramic speaker using vibration sheet formed with piezoelectric ceramic

An electroacoustic transducer that can improve acoustic characteristics has a housing and a piezoelectric speaker. The piezoelectric speaker has a first vibration plate with a periphery part supported directly or indirectly on the housing, as well as a piezoelectric element placed at least on one side of the first vibration plate, and is constituted in such a way that its rigidity is asymmetric with respect to the center axis of the first vibration plate.

Electroacoustic transducer with dual vibration plate

In an embodiment, a piezoelectric speakerincludes a sheet memberand multiple piezoelectric vibration parts. The multiple piezoelectric vibration partseach have a vibration platesupported on the sheet memberin a vibratable manner, as well as a piezoelectric elementjoined to the vibration plate. In an embodiment, the piezoelectric speakerin combination with a dynamic speakerconstitutes an electroacoustic transducerL/R, and a pair of the electroacoustic transducersL,R constitute headphones. The piezoelectric speaker can improve sound pressures without lowering the resonance frequency.

Piezoelectric speaker and electroacoustic transducer

An electroacoustic transducer includes: a polygonal-shaped laminated piezoelectric element including alternately stacked piezoelectric layers and electrode layers, with the piezoelectric layers placed between at least one pair of electrode layers having different polarities; and a circular vibration plate on which the laminated piezoelectric element is placed. Of the piezoelectric layers sandwiched between the at least one pair of electrode layers, the total volume (V) of those effective layers that overlap the at least one pair of electrode layers as viewed from the stacking direction satisfies the condition below:0.2&#x3c0;&#x2264;2.0&#x3c0;wherein &#x3c0; represents the ratio of the circumference of a circle to its diameter, R represents the radius of the vibration plate, and ts represents the thickness of the vibration plate.

A piezoelectric speaker has a piezoelectric element and vibration plate. The piezoelectric element has a base body with a mounting surface, as well as first and second terminals that are formed on the mounting surface with a distance between them. The vibration plate has a conductive body joined to the piezoelectric element and having a principle surface facing the mounting surface, as well as a first hole with or without a bottom which is formed on the principle surface in a region facing the first terminal to form a space between the body and first terminal. The piezoelectric speaker is capable of preventing the external electrodes of the piezoelectric element from shorting to each other.

In an embodiment, an electroacoustic converter has an enclosure, piezoelectric sounding body, electromagnetic sounding body, passage, and wiring members. The piezoelectric sounding body includes a first vibration plate supported directly or indirectly on the enclosure, and a piezoelectric element placed at least on one side of the first vibration plate. The piezoelectric sounding body divides the interior of the enclosure into a first space and a second space. The electromagnetic sounding body has a second vibration plate and is placed in the first space. The passage is provided at the piezoelectric sounding body or around the piezoelectric sounding body, to connect the first space and second space. The wiring members are electrically connected to the piezoelectric element and led out toward the electromagnetic sounding body, from the piezoelectric element, through the first space or second space.

Electroacoustic converter

A piezoelectric ceramic has a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains present sporadically in the primary phase. The piezoelectric ceramic of high kr and high specific dielectric constant can be sintered at low temperature and exhibit minimal characteristics variations.

Piezoelectric ceramic, method of manufacturing same, and piezoelectric ceramic speaker using same

In an embodiment, an electroacoustic converter (earphone) has an enclosure, piezoelectric sounding body, electromagnetic sounding body, and passage. The piezoelectric sounding bodyincludes a vibration platehaving a periphery supported directly or indirectly on the enclosure, and a piezoelectric elementplaced at least on one side of the vibration plate. The piezoelectric sounding bodydivides the interior of the enclosureinto a first space Sand a second space S. The electromagnetic sounding bodyis placed in the first space S. A passageis provided in or around the piezoelectric sounding body, to connect the first space Sand second space S. The electroacoustic converter is capable of obtaining desired frequency characteristics easily.

Electroacoustic converter and electronic device

A piezoelectric device has a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains an alkali-containing niobate type perovskite composition which is represented by (LiNaK)(NbTa)O(wherein 0.04&#x2266;l&#x2266;0.1, 0&#x2266;m&#x2266;1, 0.95&#x2266;n&#x2266;1.05, 0&#x2266;o&#x2266;1) and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer. The piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition in terms of oxides relative to the perovskite composition.

Piezoelectric device with piezoelectric ceramic layer constituted by alkali-containing niobate type perovskite composition

In an embodiment, an electroacoustic converter (earphone) has an enclosure, piezoelectric sounding body, electromagnetic sounding body, and passage. The piezoelectric sounding bodyincludes a first vibration platehaving a periphery supported directly or indirectly on the enclosure, and a piezoelectric elementplaced at least on one side of the vibration plate. The piezoelectric sounding bodyhas a second vibration plate and divides the interior of the enclosureinto a first space Sand a second space S. The electromagnetic sounding bodyis placed in the first space S. The passageis provided in or around the piezoelectric sounding bodyto connect the first space Sand second space S. The electroacoustic converter is capable of obtaining desired frequency characteristics easily.

An electroacoustic transducer has a housing, piezoelectric speaker, dynamic speaker, and support member. The piezoelectric speaker includes a vibration plate having a first surface and a second surface on the opposite side of the first surface, as well as a piezoelectric element joined to at least one of the first surface and second surface, and divides the interior of the housing into a first space facing the first surface and a second space facing the second surface. The dynamic speaker is placed in the first space. The support member is constituted by a part of the housing or by a member different from the housing, has a supporting part facing the first surface or second surface, and supports the periphery of the first surface or second surface with the supporting part.

A dielectric porcelain composition with a sintering density of 93% or above, is expressed by the composition formula below: 100[1&#x2212;x(0.94BiNaTiO&#x2212;0.06BaTiO)&#x2212;xKNaNbO]+&#x3b1;CuO+&#x3b2;LiF (wherein x is between 0.14 and 0.28, and &#x3b1; and &#x3b2; meet either (I) &#x3b1; is between 0.4 and 1.5, and &#x3b2; is between 0 and 2.4, or (II) &#x3b1; is between 0 and 1.5, and &#x3b2; is between 0.2 and 2.4). The dielectric porcelain composition is Pb-free and can be sintered at low temperature, as well as a dielectric element having such composition.

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Takasaki, Japan

Yutaka Doshida