JP2000201399A - Piezoelectric speaker - Google Patents
Piezoelectric speakerInfo
- Publication number
- JP2000201399A JP2000201399A JP25441699A JP25441699A JP2000201399A JP 2000201399 A JP2000201399 A JP 2000201399A JP 25441699 A JP25441699 A JP 25441699A JP 25441699 A JP25441699 A JP 25441699A JP 2000201399 A JP2000201399 A JP 2000201399A
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- piezoelectric vibrator
- metal
- viscoelastic body
- bonded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Diaphragms For Electromechanical Transducers (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は広帯域で平坦な再生
音圧特性を有する圧電スピーカに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric speaker having a wide band and flat reproduction sound pressure characteristic.
【０００２】[0002]
【従来の技術】従来、圧電スピーカは実開昭６３−８１
５９５号や特開平１−１３５２９９号に記載されたもの
が知られている。2. Description of the Related Art Conventionally, piezoelectric speakers have been disclosed in Japanese Utility Model Application Laid-Open No. 63-81.
No. 595 and JP-A-1-135299 are known.
【０００３】図１７は実開昭６３−８１５９５号に開示
されている、従来の圧電スピーカの構造を示しており、
2枚の薄い圧電材１１ａ，１１ｂが貼り合わされた圧電
振動板とその圧電振動板の中央部に接着された金属粉と
接着剤の混練物１３とから構成されるもので、混練物１
３で圧電スピーカの共振点での共振先鋭度Ｑが抑制さ
れ、振動モードが改善されるというものである。しか
し、このような圧電スピーカは、振動板中央部に接着さ
れた口径の小さな混練物の粘弾性体で共振ピークは少し
低減されるかもしれないが、十分な共振抑制効果は得ら
れず平坦な再生音圧周波数特性を得る事はできなかっ
た。FIG. 17 shows the structure of a conventional piezoelectric speaker disclosed in Japanese Utility Model Laid-Open No. 63-81595.
It is composed of a piezoelectric vibrating plate having two thin piezoelectric members 11a and 11b bonded together, and a kneaded material 13 of a metal powder and an adhesive bonded to the center of the piezoelectric vibrating plate.
In No. 3, the resonance sharpness Q at the resonance point of the piezoelectric speaker is suppressed, and the vibration mode is improved. However, such a piezoelectric speaker may have a small resonance peak due to a small-diameter kneaded viscoelastic material adhered to the center of the diaphragm, but cannot obtain a sufficient resonance suppression effect and cannot provide a flat resonance. The reproduction sound pressure frequency characteristics could not be obtained.
【０００４】また、図１８は特開平１−１３５２９９号
に開示されている従来の圧電スピーカ構造を示してお
り、金属振動板１５とその振動板１５の片面に貼り合わ
された薄い圧電材１６からなる圧電振動子と、金属振動
板の他方の面に重ねた状態で接触させられ金属振動板と
同じ外径寸法のゴム、発泡樹脂等の軟質制動板１９と、
金属振動板と制動板の外周を挟持し、外周部全部を固定
できるフレーム１７とで構成され、金属振動板１５と制
動板１９の材質に応じた挟持圧力の管理により種々の周
波数特性の圧電スピーカを得られるというものである。
しかし、このような圧電スピーカは金属振動板とそれと
同じ外径寸法を有するゴム、発泡樹脂等の軟質制動板と
金属振動板の外周部をフレームに挟持するように構成さ
れているが、軟質制動板がフレームまで伸びているた
め、振動子に誘起される振動力がフレームに伝達され、
大きな振動振幅が得られにくくなり、高い音圧再生が困
難であった。FIG. 18 shows a conventional piezoelectric speaker structure disclosed in Japanese Patent Application Laid-Open No. 1-135299, which comprises a metal vibration plate 15 and a thin piezoelectric material 16 bonded to one surface of the vibration plate 15. A piezoelectric vibrator, a soft braking plate 19 made of rubber, foamed resin, or the like having the same outer diameter as the metal vibrating plate, being brought into contact with the other surface of the metal vibrating plate in a state of being superimposed;
A piezoelectric speaker comprising a metal diaphragm and a frame 17 which clamps the outer periphery of the braking plate and can fix the entire outer periphery. The piezoelectric speaker has various frequency characteristics by controlling the clamping pressure according to the material of the metal diaphragm 15 and the braking plate 19. You can get.
However, such a piezoelectric speaker is configured such that a metal diaphragm, a soft braking plate having the same outer diameter as that of rubber or foam resin, and an outer peripheral portion of the metal diaphragm are sandwiched by a frame. Because the plate extends to the frame, the vibration force induced by the vibrator is transmitted to the frame,
It was difficult to obtain a large vibration amplitude, and it was difficult to reproduce a high sound pressure.
【０００５】[0005]
【発明が解決しようとする課題】この圧電スピーカにお
いては、構造が簡単で、再生周波数帯域幅が広く、再生
音圧周波数特性の平坦性が要求されている。This piezoelectric speaker is required to have a simple structure, a wide reproduction frequency bandwidth, and flatness of reproduction sound pressure frequency characteristics.
【０００６】本発明は、このような圧電スピーカにおい
て、構造が簡単で、再生音圧レベルが高く、再生周波数
帯域幅が広く、再生音圧周波数特性の平坦性を高める事
を目的とする。An object of the present invention is to provide a piezoelectric speaker having a simple structure, a high reproduction sound pressure level, a wide reproduction frequency bandwidth, and high flatness of reproduction sound pressure frequency characteristics.
【０００７】[0007]
【課題を解決するための手段】この課題を解決するため
に本発明の圧電スピーカは、金属振動板とその金属振動
板の片面、または両面に接着された圧電材とからなる圧
電振動子と、その圧電振動子の外周部を固定または支持
するフレームと、その圧電振動子の片面、または両面
に、圧電振動子のほぼ中央部に固着された内部損失の高
い粘弾性体とを備えたものである。In order to solve this problem, a piezoelectric speaker according to the present invention comprises: a piezoelectric vibrator comprising a metal diaphragm and a piezoelectric material adhered to one or both sides of the metal diaphragm; A frame comprising a frame for fixing or supporting the outer peripheral portion of the piezoelectric vibrator, and a viscoelastic body having a high internal loss fixed to a substantially central portion of the piezoelectric vibrator on one or both sides of the piezoelectric vibrator. is there.
【０００８】[0008]
【発明の実施の形態】以下、本発明の実施の形態につい
て、図1から図１５を用いて説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.
【０００９】（実施の形態１）図１は本発明の一実施の
形態における圧電スピーカを示し、図1において１は金
属振動板、２は薄い圧電材、３は金属振動板の外周を固
定または支持するフレーム、４ａは内部損失の大きい粘
弾性体（例えば、ブチルゴム、ネオプレーンゴム、シリ
コンゴム、発泡ウレタン、他）、５ａ，５ｂは電気入力
線である。(Embodiment 1) FIG. 1 shows a piezoelectric speaker according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a metal diaphragm, 2 denotes a thin piezoelectric material, and 3 denotes a fixed or fixed outer periphery of the metal diaphragm. The supporting frame, 4a is a viscoelastic body having a large internal loss (for example, butyl rubber, neoprene rubber, silicon rubber, urethane foam, etc.), and 5a, 5b are electric input lines.
【００１０】以上のように構成された圧電スピーカにつ
いて、その動作を述べる。金属振動板に薄い圧電材が貼
り合わされた圧電振動子に音声信号が加えられると、圧
電振動子は曲げモードで振動し、それによって周りの空
気が振動させられ音波が発生する。しかし、圧電振動子
自体には内部損失がほとんど無く、特定の周波数で共振
が発生する。図２に金属振動板の片面に薄い圧電材が貼
り合わされたモノモルフタイプの周辺固定の円形圧電振
動子の第１次〜第６次の共振モードを示し、円形振動板
の中心から外周までの変位特性を示している。このよう
な共振点近傍では、その振動振幅は非常に増大し、ま
た、共振点と共振点の間の特定の周波数では反共振が発
生し、その振動振幅は非常に小さくなり、その結果、再
生音圧周波数特性は山谷の大きな特性となる。このよう
な圧電振動子の再生音圧周波数特性の一例を図３（ａ）
に示す。このような圧電振動子の共振・反共振による音
圧特性の山谷を少なくするために、圧電振動子の中央部
に内部損失の高い粘弾性体を貼り合せることを行うが、
粘弾性体の大きさによって、共振を抑制する度合いが異
なってくる。The operation of the piezoelectric speaker configured as described above will be described. When an audio signal is applied to a piezoelectric vibrator in which a thin piezoelectric material is adhered to a metal vibrating plate, the piezoelectric vibrator vibrates in a bending mode, thereby vibrating the surrounding air and generating a sound wave. However, the piezoelectric vibrator itself has almost no internal loss, and resonance occurs at a specific frequency. FIG. 2 shows the first to sixth resonance modes of a peripherally fixed circular piezoelectric vibrator of a monomorph type in which a thin piezoelectric material is bonded to one surface of a metal diaphragm, from the center to the outer periphery of the circular diaphragm. 9 shows displacement characteristics. In the vicinity of such a resonance point, the vibration amplitude greatly increases, and at a specific frequency between the resonance points, anti-resonance occurs, and the vibration amplitude becomes very small. The sound pressure frequency characteristic has a large peak-valley characteristic. FIG. 3A shows an example of the reproduction sound pressure frequency characteristic of such a piezoelectric vibrator.
Shown in In order to reduce the peaks and valleys of the sound pressure characteristics due to the resonance and anti-resonance of the piezoelectric vibrator, a viscoelastic body having a high internal loss is attached to the center of the piezoelectric vibrator.
The degree to which resonance is suppressed varies depending on the size of the viscoelastic body.
【００１１】共振の抑制の度合いを示す一例として、厚
さ５ｍｍの粘弾性体について、図３（ｂ）に金属振動板
と粘弾性体の底の面積比が３％、図３（ｃ）に金属振動
板と粘弾性体の底の面積比が６％、図４（ａ）に金属振
動板と粘弾性体の底の面積比が１１％、図４（ｂ）に金
属振動板と粘弾性体の底の面積比が１７％、図５（ａ）
に金属振動板と粘弾性体の底の面積比が２５％、図５
（ｂ）に金属振動板と粘弾性体の底の面積比が５０％、
図５（ｃ）に金属振動板と粘弾性体の底の面積比が７０
％、図６（ａ）に金属振動板と粘弾性体の底の面積比が
８０％、図６（ｂ）に金属振動板と粘弾性体の底の面積
比が８５％、図６（ｃ）に金属振動板と粘弾性体の底の
面積比が１００％、のときの再生音圧特性の例を示す。As an example showing the degree of suppression of resonance, for a viscoelastic body having a thickness of 5 mm, the area ratio between the metal diaphragm and the bottom of the viscoelastic body is 3%, and FIG. The area ratio between the metal diaphragm and the bottom of the viscoelastic body is 6%, FIG. 4A shows the area ratio between the metal diaphragm and the bottom of the viscoelastic body is 11%, and FIG. The area ratio of the bottom of the body is 17%, FIG. 5 (a)
FIG. 5 shows that the area ratio between the metal diaphragm and the bottom of the viscoelastic body is 25%.
(B) The area ratio between the metal diaphragm and the bottom of the viscoelastic body is 50%,
FIG. 5C shows that the area ratio between the metal diaphragm and the bottom of the viscoelastic body is 70.
FIG. 6A shows an area ratio between the metal diaphragm and the viscoelastic body of 80%, and FIG. 6B shows an area ratio between the metal diaphragm and the viscoelastic body of 85%. 4) shows an example of the reproduced sound pressure characteristic when the area ratio between the metal diaphragm and the bottom of the viscoelastic body is 100%.
【００１２】従来の技術の図１７に示したように、振動
板の中央部に小さな口径の粘弾性体を貼り合せた場合
は、図２に示したように振動板中央部の振動変位の大き
な部分にのみ貼り合せただけになり、内部損失の高い粘
弾性体を用いても圧電振動子に対して質量としてのみ働
くだけで、振動を抑制するようには働きにくい。したが
って共振・反共振による音圧特性のピーク・ディップは
少しだけ軽減されるかも知れないが、スピーカの性能と
して必要な、平坦な音圧周波数特性を得る事はできな
い。このような場合の特性例を図３（ｂ）、（ｃ）に示
す。As shown in FIG. 17 of the prior art, when a small-diameter viscoelastic body is bonded to the center of a diaphragm, the vibration displacement at the center of the diaphragm is large as shown in FIG. Only the portions are bonded together, and even if a viscoelastic body having a high internal loss is used, it only works as a mass with respect to the piezoelectric vibrator and does not easily work to suppress vibration. Therefore, the peak dip of the sound pressure characteristic due to resonance / anti-resonance may be slightly reduced, but a flat sound pressure frequency characteristic required for speaker performance cannot be obtained. FIGS. 3B and 3C show characteristic examples in such a case.
【００１３】また、粘弾性体を振動板全面に貼り合せた
場合、すなわち粘弾性体の底面積を金属振動板の面積の
１００％としたとき、粘弾性体は外周部の固定部で振動
エネルギーがフレームに漏洩し、音圧レベルが低下する
という問題点がある。この状態の特性例を図６（ｃ）に
示す。When the viscoelastic body is attached to the entire surface of the diaphragm, that is, when the bottom area of the viscoelastic body is set to 100% of the area of the metal diaphragm, the viscoelastic body has vibration energy at a fixed portion on the outer peripheral portion. Is leaked to the frame, and the sound pressure level is reduced. FIG. 6C shows a characteristic example in this state.
【００１４】また、粘弾性体を振動板全面に貼り合わせ
るまでに至らなくとも、粘弾性体の底面積が金属振動板
の面積の８５％の場合でも、音圧特性に寄与する圧電振
動子の粘弾性体が貼り合わされていない部分の面積が小
さいために、音圧レベルは低下する。この状態の特性例
を図６（ｂ）に示す。Further, even if the viscoelastic body is not bonded to the entire surface of the diaphragm, even if the bottom area of the viscoelastic body is 85% of the area of the metal diaphragm, the piezoelectric vibrator which contributes to the sound pressure characteristic can be obtained. Since the area of the portion where the viscoelastic body is not bonded is small, the sound pressure level decreases. FIG. 6B shows a characteristic example in this state.
【００１５】さらに、粘弾性体の底面積が金属振動版の
面積の８０％の場合の特性は図６（ａ）のようになり、
面積比が８５％の場合と比較すると、音圧レベルが約１
０ｄＢも上昇し、スピーカとして十分な音圧レベルが得
られる。Further, the characteristics when the bottom area of the viscoelastic body is 80% of the area of the metal vibrating plate are as shown in FIG.
Compared to the case where the area ratio is 85%, the sound pressure level is about 1
The level increases by 0 dB, and a sound pressure level sufficient for a speaker can be obtained.
【００１６】図３（ａ）〜図６（ｃ）によると、スピー
カとして使用したい周波数帯域での特性のピーク・ディ
ップの差が２０ｄＢ以内であるものを平坦な再生特性と
みなせば、金属振動板と粘弾性体の底の面積比が１１％
以上８０％以下のときに平坦な特性が実現可能となる。According to FIGS. 3 (a) to 6 (c), if a difference in peak dip of a characteristic in a frequency band to be used as a speaker is within 20 dB is regarded as a flat reproduction characteristic, a metal diaphragm is used. And the area ratio of the bottom of the viscoelastic body is 11%
When it is at least 80%, flat characteristics can be realized.
【００１７】例えば、図４（ａ）の面積比１１％のとき
は４ｋＨｚ以上の帯域では音圧レベル偏差が１５ｄＢ程
度となり、スピーカとして良好な特性が得られる。For example, when the area ratio is 11% in FIG. 4A, the sound pressure level deviation is about 15 dB in a band of 4 kHz or more, and good characteristics as a speaker can be obtained.
【００１８】また、図５（ｂ）の面積比５０％のときは
２０ｋＨｚ以上の帯域で音圧レベル偏差が１８ｄＢ程度
となり、スピーカとして使用可能である。Further, when the area ratio is 50% in FIG. 5B, the sound pressure level deviation is about 18 dB in a band of 20 kHz or more, and the device can be used as a speaker.
【００１９】また、図６（ａ）の面積比８０％のときも
２０ｋＨｚ以上の帯域で、良好な周波数特性が得られて
いる。Also, when the area ratio is 80% in FIG. 6A, good frequency characteristics are obtained in a band of 20 kHz or more.
【００２０】したがって、本発明は圧電振動子に、金属
振動板の面積の１１％以上８０％以下の底面積を有する
粘弾性体を貼り合わせ、外周のフレームには圧電振動子
の金属振動板のみを接合させる構成としている。圧電振
動子の曲げ振動により、圧電振動子に貼り合わされた粘
弾性体は伸縮運動を強いられ、内部損失の高い粘弾性体
の伸縮運動により複数の共振モードを抑圧することがで
きる。また、粘弾性体がフレーム接触していないため、
粘弾性体を介してフレームに振動エネルギーが漏洩した
り、粘弾性体の底面積が大きすぎて、音圧再生に寄与す
る面積が低下することによる再生音圧レベルの低下も起
こらない。その結果、共振・反共振により発生する音圧
周波数特性の山谷が無くなり、平坦な再生特性を実現で
きるという効果がある。Therefore, according to the present invention, a viscoelastic body having a bottom area of 11% to 80% of the area of the metal vibrating plate is bonded to the piezoelectric vibrator, and only the metal vibrating plate of the piezoelectric vibrating plate is mounted on the outer peripheral frame. Are joined. The viscoelastic body bonded to the piezoelectric vibrator is forced to expand and contract by the bending vibration of the piezoelectric vibrator, and a plurality of resonance modes can be suppressed by the expansion and contraction movement of the viscoelastic body having a high internal loss. Also, since the viscoelastic body is not in frame contact,
Vibration energy does not leak to the frame via the viscoelastic body, and the bottom surface area of the viscoelastic body is too large, so that the area that contributes to sound pressure reproduction is reduced, so that the reproduction sound pressure level does not decrease. As a result, peaks and valleys in the sound pressure frequency characteristics generated by resonance and antiresonance are eliminated, and there is an effect that flat reproduction characteristics can be realized.
【００２１】なお、図７（ａ）〜（ｃ）は面積比７０％
のときに、粘弾性体の厚さを５ｍｍ、３ｍｍ、１ｍｍと
変更した場合の特性例である。このように、所望の特性
を得るために、粘弾性体の面積だけでなく、高さ、もし
くは形状を変化させることも可能である。FIGS. 7A to 7C show an area ratio of 70%.
This is a characteristic example in the case where the thickness of the viscoelastic body was changed to 5 mm, 3 mm, and 1 mm at the time. Thus, in order to obtain desired characteristics, it is possible to change not only the area of the viscoelastic body but also the height or the shape.
【００２２】（実施の形態２）図８は第1の発明の他の
実施の形態を示し、図８において、１は金属振動板、2
ａ、２ｂは薄い圧電材、３はフレーム、４ａは粘弾性体
である。金属振動板１の両面に薄い圧電材２a、２ｂを
貼り合せたバイモルフ型圧電振動子の少なくとも一方の
面に、圧電振動子の面積の１１〜８０％の底面積を有す
る粘弾性体が貼り合わされている。動作は実施の形態１
に述べたように、複数の振動モードを抑圧し、平坦な音
圧周波数特性が実現できる効果が得られる。(Embodiment 2) FIG. 8 shows another embodiment of the first invention. In FIG. 8, reference numeral 1 denotes a metal diaphragm,
a, 2b are thin piezoelectric materials, 3 is a frame, and 4a is a viscoelastic body. A viscoelastic body having a bottom area of 11 to 80% of the area of the piezoelectric vibrator is bonded to at least one surface of a bimorph type piezoelectric vibrator in which thin piezoelectric materials 2a and 2b are bonded to both surfaces of the metal vibration plate 1. ing. Operation is in the first embodiment
As described above, the effect of suppressing a plurality of vibration modes and realizing a flat sound pressure frequency characteristic can be obtained.
【００２３】（実施の形態３）図９は第１の発明の他の
実施の形態を示し、図９において、１は金属振動板、２
ａは薄い圧電材、３はフレーム、４ｂは粘弾性体であ
る。粘弾性体４bは中央に開口部のある粘弾性体であ
り、金属振動板１と薄い圧電材２ａの大きさ、密度、ヤ
ング率等の関係で振動モードが変化するため、開口部６
のある粘弾性体４ｂを貼り合せた時の方が音圧レベルを
下げずに平坦な音圧周波数特性を得る事ができる場合が
ある。粘弾性体４ｂは中央に開口部６を有しているが、
開口まで至らず中央部が薄くなったものでも同様な効果
が得られる。(Embodiment 3) FIG. 9 shows another embodiment of the first invention. In FIG. 9, reference numeral 1 denotes a metal diaphragm,
a is a thin piezoelectric material, 3 is a frame, and 4b is a viscoelastic body. The viscoelastic body 4b is a viscoelastic body having an opening in the center, and the vibration mode changes depending on the size, density, Young's modulus and the like of the metal vibration plate 1 and the thin piezoelectric material 2a.
When the viscoelastic body 4b having the elasticity is bonded, a flat sound pressure frequency characteristic can be obtained without lowering the sound pressure level in some cases. The viscoelastic body 4b has an opening 6 in the center,
A similar effect can be obtained even if the central part is thinned without reaching the opening.
【００２４】（実施の形態４）図１０は第２の発明の実
施の形態を示し、図１０において、１は金属振動板、２
ａは薄い圧電材、３はフレーム、４ａ、４ｃは粘弾性体
である。金属振動板１と薄い圧電材２ａが貼り合わされ
た圧電振動子の片面に、大きさ、または材質の異なる少
なくとも２種の異なる粘弾性体を多層に貼り合せた構造
を有するもので、2つの粘弾性体４ａ、４ｃ、および圧
電振動子は大きさ、密度、ヤング率、損失係数等が異な
るため、複雑な共振系が構成されるので、圧電振動子の
共振モードをより抑制するように作用し、より平坦な音
圧周波数特性を得ることができる。ここでは粘弾性体に
２層のものを示したが、３層以上に構成しても同様な効
果が得られる。(Embodiment 4) FIG. 10 shows an embodiment of the second invention. In FIG.
a is a thin piezoelectric material, 3 is a frame, 4a and 4c are viscoelastic bodies. It has a structure in which at least two different viscoelastic materials having different sizes or materials are laminated in one layer on one surface of a piezoelectric vibrator in which a metal vibration plate 1 and a thin piezoelectric material 2a are laminated. Since the elastic members 4a and 4c and the piezoelectric vibrator are different in size, density, Young's modulus, loss coefficient, and the like, a complicated resonance system is formed. Thus, a flatter sound pressure frequency characteristic can be obtained. Here, the viscoelastic body has two layers, but a similar effect can be obtained even if three or more layers are used.
【００２５】なお、図１、図８〜図１０は粘弾性体が圧
電振動子の片側にしか貼り付けられていないが、両側に
貼り付けてもよく、更に大きな抑制の効果が期待でき
る。Although FIGS. 1 and 8 to 10 show that the viscoelastic body is attached only to one side of the piezoelectric vibrator, it may be attached to both sides, so that a greater suppression effect can be expected.
【００２６】（実施の形態５）図１１は第３の発明の実
施の形態を示し、図１１において、１は金属振動板、2ａ
は薄い圧電材、３はフレーム、４ａ、４ｃは粘弾性体で
ある。金属振動板１と薄い圧電材２ａが貼り合わされた
圧電振動子の両面に互いに材料や寸法の異なる粘弾性体
４ａ、４ｃをそれぞれ貼り合せた構成をしている。圧電
振動子は共振点で大きな振動振幅で振動するが、両面に
互いに異なる粘弾性体を貼り合せられるため共振モード
が分散され、圧電振動子の共振を抑制する効果はさらに
大きくなり、比較的小さなまたは薄い粘弾性体を貼り合
せただけで音圧周波数特性が平坦になる効果が得られ
る。(Embodiment 5) FIG. 11 shows an embodiment of the third invention, in which 1 is a metal diaphragm, 2a
Is a thin piezoelectric material, 3 is a frame, 4a and 4c are viscoelastic bodies. Viscoelastic bodies 4a and 4c having different materials and dimensions are bonded to both sides of a piezoelectric vibrator in which a metal vibration plate 1 and a thin piezoelectric material 2a are bonded. Although the piezoelectric vibrator vibrates with a large vibration amplitude at the resonance point, different viscoelastic bodies are stuck on both surfaces, so that the resonance modes are dispersed, and the effect of suppressing the resonance of the piezoelectric vibrator is further increased, and is relatively small. Alternatively, the effect of flattening the sound pressure frequency characteristic can be obtained only by attaching a thin viscoelastic body.
【００２７】（実施の形態６）図１２は第４の発明の実
施の形態を示し、図１２において、１は金属振動板、２
ａは薄い圧電材、３はフレーム、４ｂ、４ｄは粘弾性体
である。金属振動板１と薄い圧電材２ａが貼り合わされ
た圧電振動子の一方の面に粘弾性体４ａ、４ｄをそれぞ
れ貼り合せた構成をしている。粘弾性体４ｂ，４ｄは同
心円形状に構成されたもので、粘弾性体の中央部４ｄと
周辺部４ｂで、比重、ヤング率、内部損失の異なる粘弾
性体から構成したものである。振動変位の大きい中央部
と比較的変位が小さい周辺部に貼り合せる材料を変化さ
せることで、最適な設計を可能にするものである。ここ
では、粘弾性体を同心円状に２つの部分に分けた構成で
説明しているが、３個以上の部分に分けた構成でも同様
な効果が得られる。(Embodiment 6) FIG. 12 shows a fourth embodiment of the present invention. In FIG.
a is a thin piezoelectric material, 3 is a frame, 4b and 4d are viscoelastic materials. Viscoelastic bodies 4a and 4d are bonded to one surface of a piezoelectric vibrator in which a metal vibration plate 1 and a thin piezoelectric material 2a are bonded. The viscoelastic bodies 4b and 4d are formed in concentric circles, and are made of viscoelastic bodies having different specific gravities, Young's moduli, and internal losses at a central portion 4d and a peripheral portion 4b. By changing the material to be bonded to the central portion where the vibration displacement is large and the peripheral portion where the displacement is relatively small, an optimal design can be realized. Here, the configuration in which the viscoelastic body is divided into two parts concentrically is described, but a similar effect can be obtained with a configuration in which three or more parts are divided.
【００２８】（実施の形態７）図１３は第５の発明の実
施の形態を示し、図１３において、１は金属振動板、２
ａは薄い圧電材、３はフレーム、４ａは粘弾性体、５は
粘弾性体より重く剛性のある物体（例えば金属、合金な
ど）である。金属振動板１と薄い圧電材２ａが貼り合わ
された圧電振動子の片面に粘弾性体４ａが貼り合せら
れ、その粘弾性体の他方の面に金属などの剛性のある物
体５が貼り合わされた構造を有するものである。粘弾性
体の他方の面に剛性のある物体５が貼り合わされた粘弾
性体は、より低い周波数で共振を発生し粘弾性体４ａを
より大きく振動させようとするため粘弾性体を小さくし
ても粘弾性の効果が大きくなり、圧電振動子のより低次
の共振モードから抑制するように作用し、より低い周波
数帯域から平坦な音圧周波数特性を達成する効果が得ら
れる。図１２、図１３では記していないが、他方の面に
剛性のある物体５が貼り合わされた粘弾性体を、圧電振
動子の両面に貼り合せれば更に大きな効果が期待でき、
更に、多層構造にした場合も同様な効果が得られる。(Embodiment 7) FIG. 13 shows an embodiment of the fifth invention. In FIG.
a is a thin piezoelectric material, 3 is a frame, 4a is a viscoelastic body, and 5 is an object (for example, metal, alloy or the like) which is heavier and more rigid than the viscoelastic body. A structure in which a viscoelastic body 4a is bonded to one surface of a piezoelectric vibrator in which a metal vibration plate 1 and a thin piezoelectric material 2a are bonded, and a rigid object 5 such as metal is bonded to the other surface of the viscoelastic body. It has. The viscoelastic body in which the rigid object 5 is bonded to the other surface of the viscoelastic body generates resonance at a lower frequency and makes the viscoelastic body 4a vibrate more greatly, so that the viscoelastic body is made smaller. Also, the effect of the viscoelasticity is increased, and the piezoelectric vibrator operates to suppress the lower order resonance mode of the piezoelectric vibrator, thereby obtaining an effect of achieving a flat sound pressure frequency characteristic from a lower frequency band. Although not shown in FIGS. 12 and 13, a greater effect can be expected if a viscoelastic body having a rigid object 5 bonded to the other surface is bonded to both surfaces of the piezoelectric vibrator.
Further, a similar effect can be obtained when a multilayer structure is used.
【００２９】（実施の形態８）図１４は第６の発明の実
施の形態を示し、図１４において、１ｂは開口部７を有
する金属振動板、２ａは薄い圧電材、４ｅは粘弾性体で
ある。図には記していないが、図１に示したと同様に金
属振動板１ｂの外周部はフレームに接合され、スピーカ
が構成される。金属振動板１ｂの開口部に粘弾性体４ｅ
が潜り込む構造を有するものであり、この構造により金
属振動板の制振性が一段と向上し、その結果圧電振動子
の共振による再生音圧周波数特性の平坦化が図られるも
のである。(Embodiment 8) FIG. 14 shows an embodiment of the sixth invention. In FIG. 14, 1b is a metal diaphragm having an opening 7, 2a is a thin piezoelectric material, and 4e is a viscoelastic material. is there. Although not shown in the drawing, the outer peripheral portion of the metal diaphragm 1b is joined to a frame as shown in FIG. 1 to form a speaker. A viscoelastic body 4e is provided in the opening of the metal diaphragm 1b.
In this structure, the vibration damping performance of the metal diaphragm is further improved, and as a result, the reproduced sound pressure frequency characteristics are flattened due to the resonance of the piezoelectric vibrator.
【００３０】（実施の形態９）図１５は第７の発明の実
施の形態を示し、図１５において、１は金属振動板、２
ａは薄い圧電材、３ｂは圧電振動子を固定または支持
し、開口部に向かうにしたがい徐々に開口部の断面積が
大きくなるホーン形状を有するフレーム、４ｄは圧電振
動子側では断面積が大きく、圧電振動子から離れるにし
たがいその断面積は小さくなる形状の粘弾性体である。
粘弾性体４ｄは圧電振動子の共振モードを抑制するよう
に作用し、更に、粘弾性体４ｄとフレーム３ｂの開口部
で構成される音道はホーン形状を構成するため、ホーン
効果により再生音圧レベルを高めることができ、また、
ホーンの形状を変えることにより、音圧再生の指向特性
も制御できると言う効果を有する。粘弾性体４ｄはホー
ン内部にあり、位相等価器の役割を持ち、高い周波数ま
で効率の高いスピーカが実現できる効果を有する。(Embodiment 9) FIG. 15 shows an embodiment of the seventh invention. In FIG.
a is a thin piezoelectric material, 3b is a frame having a horn shape that fixes or supports the piezoelectric vibrator and the cross-sectional area of the opening gradually increases toward the opening, and 4d has a large cross-sectional area on the piezoelectric vibrator side. The viscoelastic body is shaped such that its cross-sectional area decreases as the distance from the piezoelectric vibrator increases.
The viscoelastic body 4d acts to suppress the resonance mode of the piezoelectric vibrator, and the sound path formed by the viscoelastic body 4d and the opening of the frame 3b has a horn shape. Pressure level can be increased,
By changing the shape of the horn, it is possible to control the directivity of sound pressure reproduction. The viscoelastic body 4d is inside the horn, has a role of a phase equalizer, and has an effect that a highly efficient speaker can be realized up to a high frequency.
【００３１】（実施の形態１０）図１６は第７の発明の
もう一つの実施の形態を示し、図１６において、１は金
属振動板、2ａは薄い圧電材、３ｂは圧電振動子を固定
または支持し、開口部に向かうにしたがい徐々に開口部
の断面積が大きくなるホーン形状を有するフレーム、４
eは中央部に開口部を有し圧電振動子側はその断面積が
大きく、圧電振動子から離れるにしたがい断面積は小さ
くなる形状の粘弾性体である。実施の形態９に示したも
のと同様な効果が期待できる。(Embodiment 10) FIG. 16 shows another embodiment of the seventh invention. In FIG. 16, reference numeral 1 denotes a metal vibrating plate, 2a denotes a thin piezoelectric material, and 3b denotes a fixed piezoelectric vibrator. A frame having a horn shape that supports and gradually increases the cross-sectional area of the opening toward the opening;
“e” is a viscoelastic body having an opening at the center and having a larger cross-sectional area on the piezoelectric vibrator side and a smaller cross-sectional area as the distance from the piezoelectric vibrator increases. An effect similar to that shown in the ninth embodiment can be expected.
【００３２】なお、図１４、図１５では粘弾性体は圧電
振動子の片側にしか貼り付けていないが、両側に貼り付
けてもよく、更に大きな抑制効果が期待できる。In FIGS. 14 and 15, the viscoelastic body is adhered to only one side of the piezoelectric vibrator, but may be adhered to both sides, so that a greater suppression effect can be expected.
【００３３】また、金属振動板、圧電材、フレーム、粘
弾性体の底の形状は一般的には円形が考えられるが、多
角形で成形してもよく、それぞれが異なる形状で組み合
わされてもよい。所望の特性を得ることができ、スペー
スファクターがよく、かつ、外観のよい形状を任意に設
計可能である。The shape of the bottom of the metal diaphragm, the piezoelectric material, the frame, and the viscoelastic body may be generally circular, but may be formed in a polygonal shape, or may be combined in different shapes. Good. Desired characteristics can be obtained, a space factor is good, and a shape with good appearance can be arbitrarily designed.
【００３４】[0034]
【発明の効果】以上のように本発明によれば、金属振動
板の片面または両面に圧電材が貼り合わされた圧電振動
子の中央部にその圧電振動子の面積の１１以上８０％以
下の底面積を有する粘弾性体を貼り合せる事により、振
動エネルギーを外部に漏洩させずに圧電振動子の共振モ
ードを抑圧でき、音圧レベルが高く、また平坦な音圧周
波数特性を実現できるという顕著な効果が得られる。As described above, according to the present invention, the center of a piezoelectric vibrator in which a piezoelectric material is bonded to one or both surfaces of a metal vibrating plate has a bottom of 11 to 80% of the area of the piezoelectric vibrator. By attaching a viscoelastic body having an area, the resonance mode of the piezoelectric vibrator can be suppressed without leaking the vibration energy to the outside, and the sound pressure level is high, and a flat sound pressure frequency characteristic can be realized. The effect is obtained.
【図１】本発明の一実施の形態による圧電スピーカを示
す断面図FIG. 1 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図２】圧電振動子の振動モード図FIG. 2 is a vibration mode diagram of a piezoelectric vibrator.
【図３】圧電スピーカの再生音圧周波数特性図FIG. 3 is a reproduction sound pressure frequency characteristic diagram of a piezoelectric speaker.
【図４】圧電スピーカの再生音圧周波数特性図FIG. 4 is a reproduction sound pressure frequency characteristic diagram of a piezoelectric speaker.
【図５】圧電スピーカの再生音圧周波数特性図FIG. 5 is a reproduction sound pressure frequency characteristic diagram of a piezoelectric speaker.
【図６】圧電スピーカの再生音圧周波数特性図FIG. 6 is a reproduction sound pressure frequency characteristic diagram of a piezoelectric speaker.
【図７】粘弾性体の厚さを変更したときの圧電スピーカ
の再生音圧周波数特性図FIG. 7 is a reproduction sound pressure frequency characteristic diagram of the piezoelectric speaker when the thickness of the viscoelastic body is changed.
【図８】本発明の一実施の形態による圧電スピーカを示
す断面図FIG. 8 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図９】本発明の一実施の形態による圧電スピーカを示
す断面図FIG. 9 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図１０】本発明の一実施の形態による圧電スピーカを
示す断面図FIG. 10 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図１１】本発明の一実施の形態による圧電スピーカを
示す断面図FIG. 11 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図１２】本発明の一実施の形態による圧電スピーカを
示す断面図FIG. 12 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図１３】本発明の一実施の形態による圧電スピーカを
示す断面図FIG. 13 is a sectional view showing a piezoelectric speaker according to an embodiment of the present invention.
【図１４】本発明の一実施の形態による圧電スピーカの
金属振動板と粘弾性体接合部材とを示す断面図FIG. 14 is a sectional view showing a metal diaphragm and a viscoelastic body joining member of a piezoelectric speaker according to an embodiment of the present invention.
【図１５】本発明の一実施の形態によるホーン付き圧電
スピーカを示す断面図FIG. 15 is a sectional view showing a piezoelectric speaker with a horn according to an embodiment of the present invention.
【図１６】本発明の一実施の形態によるホーン付き圧電
スピーカを示す断面図FIG. 16 is a sectional view showing a piezoelectric speaker with a horn according to an embodiment of the present invention.
【図１７】従来の圧電スピーカを示す断面図FIG. 17 is a sectional view showing a conventional piezoelectric speaker.
【図１８】もう一つの従来の圧電スピーカを示す断面図FIG. 18 is a cross-sectional view showing another conventional piezoelectric speaker.
１ 金属振動板 ２ 薄い圧電材 ３ フレーム ４ａ，４ｂ，４ｃ，４ｄ，４ｅ，４ｆ 粘弾性体 ５ 剛体 ６ 粘弾性体に設けた開口部 ７ 金属振動板に設けた開口部 １１ａ，１１ｂ 薄い圧電材 １２ａ，１２ｂ，１２ｃ 電極部 １３ 金属紛と接着剤による混練物 １４ 電気入力線 １５ 金属振動板 １６ 薄い圧電材 １７ フレーム １８ａ，１８ｂ 電気入力線 １９ 制動板 DESCRIPTION OF SYMBOLS 1 Metal diaphragm 2 Thin piezoelectric material 3 Frame 4a, 4b, 4c, 4d, 4e, 4f Viscoelastic body 5 Rigid body 6 Opening provided in viscoelastic body 7 Opening provided in metal vibrating plate 11a, 11b Thin piezoelectric material 12a, 12b, 12c Electrode part 13 Kneaded material with metal powder and adhesive 14 Electric input line 15 Metal diaphragm 16 Thin piezoelectric material 17 Frame 18a, 18b Electric input line 19 Braking plate
───────────────────────────────────────────────────── フロントページの続き (72)発明者 武輪 弘行 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 岩佐 幹郎 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroyuki Takewa 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.
Claims (7)
薄板（以下に金属振動板と呼ぶ）に、その片面または両
面に圧電材が貼り合わされた圧電振動子と、前記圧電振
動子の概ね外周部を支持または固定するフレームと、前
記圧電振動子の片面または両面の概ね中央部に貼り合わ
され前記金属振動板の面積の１１％以上８０以下の底面
積を有する粘弾性体とを備えたことを特徴とする圧電ス
ピーカ。1. A piezoelectric vibrator comprising a rigid thin plate made of metal or polymer resin (hereinafter referred to as a metal vibrating plate) and a piezoelectric material bonded to one or both surfaces thereof, and a substantially outer periphery of the piezoelectric vibrator. And a viscoelastic body bonded to one or both sides of the piezoelectric vibrator at a substantially central portion thereof and having a bottom area of 11% to 80% of the area of the metal diaphragm. Characteristic piezoelectric speaker.
薄板（以下に金属振動板と呼ぶ）に、その片面または両
面に圧電材が貼り合わされた圧電振動子と、前記圧電振
動子の概ね外周部を支持または固定するフレームと、前
記金属振動板の面積の１１％以上８０％以下の底面積を
有し前記圧電振動子の片面または両面の概ね中央部に多
層状に貼り合わされた材料または形状の異なる２種以上
の粘弾性体とを備えたことを特徴とする圧電スピーカ。2. A piezoelectric vibrator comprising a rigid thin plate made of a metal or a polymer resin (hereinafter referred to as a metal vibrating plate) and a piezoelectric material bonded to one or both sides thereof, and a substantially outer periphery of the piezoelectric vibrator. A frame for supporting or fixing a portion, and a material or shape having a bottom area of 11% or more and 80% or less of the area of the metal vibrating plate and being laminated in a multilayer shape to a substantially central portion of one or both surfaces of the piezoelectric vibrator A piezoelectric speaker comprising two or more kinds of viscoelastic bodies different from each other.
薄板（以下に金属振動板と呼ぶ）に、その片面または両
面に圧電材が貼り合わされた圧電振動子と、前記圧電振
動子の概ね外周部を支持または固定するフレームと、前
記金属振動板の面積の１１％以上８０％以下の底面積を
有し前記圧電振動子の両面の概ね中央部に貼り合わされ
た、互いに材料または形状の異なる２種の粘弾性体とを
備えたことを特徴とする圧電スピーカ。3. A piezoelectric vibrator comprising a rigid thin plate made of a metal or a polymer resin (hereinafter referred to as a metal vibrating plate) and a piezoelectric material bonded to one or both surfaces thereof, and a substantially outer periphery of the piezoelectric vibrator. A frame for supporting or fixing the piezoelectric vibrator, and a frame having a bottom area of 11% or more and 80% or less of the area of the metal vibration plate, which is bonded to substantially the center of both surfaces of the piezoelectric vibrator and has different materials or shapes from each other. A piezoelectric speaker comprising a kind of viscoelastic body.
薄板（以下に金属振動板と呼ぶ）に、その片面または両
面に圧電材が貼り合わされた圧電振動子と、前記圧電振
動子の概ね外周部を支持または固定するフレームと、前
記金属振動板の面積の１１％以上８０％以下の底面積を
有し、比重、ヤング率、内部損失の異なる２種以上の材
料を同心円状に配置した粘弾性体とを備えたことを特徴
とする圧電スピーカ。4. A piezoelectric vibrator comprising a rigid thin plate made of a metal or a polymer resin (hereinafter referred to as a metal vibrating plate) and a piezoelectric material bonded to one or both surfaces thereof; And a frame for supporting or fixing a portion, and a concentrically arranged viscous material having a bottom area of 11% to 80% of the area of the metal diaphragm and different in specific gravity, Young's modulus and internal loss. A piezoelectric speaker comprising an elastic body.
薄板（以下に金属振動板と呼ぶ）に、片面または両面に
圧電材が貼り合わされた圧電振動子と、前記圧電振動子
の概ね外周部を支持または固定するフレームと、前記圧
電振動子の片面または両面の概ね中央部に貼り合わされ
た粘弾性体と、前記粘弾性体の他方の面に貼り合わされ
た、粘弾性体の比重より大きく剛性のある物体とを備え
たことを特徴とする圧電スピーカ。5. A piezoelectric vibrator in which a piezoelectric material is bonded to one or both sides of a rigid thin plate made of metal or polymer resin (hereinafter referred to as a metal vibrating plate), and a substantially outer peripheral portion of the piezoelectric vibrator. A frame for supporting or fixing the piezo-electric vibrator, a viscoelastic body bonded to a substantially central portion of one or both surfaces of the piezoelectric vibrator, and a rigidity larger than the specific gravity of the viscoelastic body bonded to the other surface of the viscoelastic body. A piezoelectric speaker, comprising:
薄板（以下に金属振動板と呼ぶ）に、片面または両面に
圧電材が貼り合わされた圧電振動子と、前記圧電振動子
の概ね外周部を支持または固定するフレームと、前記圧
電振動子に複数個の開口部を有し、この開口部に潜り込
み一体化した粘弾性体とを備えたことを特徴とする圧電
スピーカ。6. A piezoelectric vibrator in which a piezoelectric material is bonded to one or both sides of a rigid thin plate made of a metal or a polymer resin (hereinafter referred to as a metal vibrating plate), and a substantially outer peripheral portion of the piezoelectric vibrator. A piezoelectric vibrator comprising: a frame for supporting or fixing the piezoelectric vibrator; and a viscoelastic body having a plurality of openings in the piezoelectric vibrator and being integrated into the openings.
薄板（以下に金属振動板と呼ぶ）に、片面または両面に
圧電材が貼り合わされた圧電振動子と、前記圧電振動子
の概ね外周部を支持または固定するフレームと、前記フ
レームは開口部の断面積が音波の放射口に進むにつれ徐
々に大きくなるように音響ホーン形状を構成し、前記圧
電振動子の片面または両面の概ね中央部に貼り合わさ
れ、前記圧電振動子から音波の放射口に進むにつれ、そ
の断面積が小さくなる円錐形状の粘弾性体と備えた事を
特徴とする圧電スピーカ。7. A piezoelectric vibrator in which a piezoelectric material is bonded to one or both sides of a rigid thin plate made of metal or polymer resin (hereinafter referred to as a metal vibrating plate), and a substantially outer peripheral portion of the piezoelectric vibrator. A frame for supporting or fixing the same, the frame has an acoustic horn shape so that the cross-sectional area of the opening gradually increases as it goes to the sound wave emission port, and is substantially at the center of one or both sides of the piezoelectric vibrator. A piezoelectric speaker, comprising: a conical viscoelastic body that is attached and has a cross-sectional area that decreases as the acoustic wave goes from the piezoelectric vibrator to a sound wave emission port.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25441699A JP2000201399A (en) | 1998-11-02 | 1999-09-08 | Piezoelectric speaker |
| DE69939096T DE69939096D1 (en) | 1998-11-02 | 1999-10-28 | Piezoelectric speaker |
| EP99120895A EP1001653B1 (en) | 1998-11-02 | 1999-10-28 | Piezoelectric loudspeaker |
| US09/431,201 US6747395B1 (en) | 1998-11-02 | 1999-11-01 | Piezoelectric loudspeaker |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10-311770 | 1998-11-02 | ||
| JP31177098 | 1998-11-02 | ||
| JP25441699A JP2000201399A (en) | 1998-11-02 | 1999-09-08 | Piezoelectric speaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000201399A true JP2000201399A (en) | 2000-07-18 |
Family
ID=26541674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25441699A Pending JP2000201399A (en) | 1998-11-02 | 1999-09-08 | Piezoelectric speaker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000201399A (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100516544B1 (en) * | 2001-11-29 | 2005-09-22 | 마쯔시다덴기산교 가부시키가이샤 | Piezoelectric speaker |
| JP2007275819A (en) * | 2006-04-10 | 2007-10-25 | Nec Tokin Corp | Piezoelectric vibration unit and piezoelectric loudspeaker |
| JP2007281669A (en) * | 2006-04-04 | 2007-10-25 | Nec Corp | Speaker |
| JP2007531357A (en) * | 2004-02-27 | 2007-11-01 | ジョージア テック リサーチ コーポレイション | Harmonic CMUT element and manufacturing method |
| JP2010503466A (en) * | 2006-09-18 | 2010-02-04 | ライポソニックス， インコーポレイテッド | Transducer with shielding |
| DE202011002840U1 (en) | 2011-02-17 | 2011-06-30 | Ho Hsin Progressive Technology Co., Ltd | Piezoelectric area loudspeaker |
| JP2012015761A (en) * | 2010-06-30 | 2012-01-19 | Nec Corp | Oscillator |
| US8372011B2 (en) | 2004-02-27 | 2013-02-12 | Georgia Tech Research Corporation | Asymmetric membrane cMUT devices and fabrication methods |
| JPWO2011074579A1 (en) * | 2009-12-15 | 2013-04-25 | 日本電気株式会社 | Actuator, piezoelectric actuator, electronic device, vibration damping and vibration direction changing method |
| US8611945B2 (en) | 2011-03-24 | 2013-12-17 | Kyocera Corporation | Electronic device |
| JP2014039093A (en) * | 2012-08-10 | 2014-02-27 | Kyocera Corp | Acoustic generator, acoustic generating device, and electric device |
| KR101480938B1 (en) * | 2014-12-04 | 2015-01-14 | 범진시엔엘 주식회사 | Piezoelectric Speaker |
| WO2016182035A1 (en) * | 2015-05-13 | 2016-11-17 | オーツェイド株式会社 | Speaker unit |
-
1999
- 1999-09-08 JP JP25441699A patent/JP2000201399A/en active Pending
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100516544B1 (en) * | 2001-11-29 | 2005-09-22 | 마쯔시다덴기산교 가부시키가이샤 | Piezoelectric speaker |
| US8398554B2 (en) | 2004-02-27 | 2013-03-19 | Georgia Tech Research Corporation | Harmonic cMUT devices and fabrication methods |
| US8372011B2 (en) | 2004-02-27 | 2013-02-12 | Georgia Tech Research Corporation | Asymmetric membrane cMUT devices and fabrication methods |
| JP2007531357A (en) * | 2004-02-27 | 2007-11-01 | ジョージア テック リサーチ コーポレイション | Harmonic CMUT element and manufacturing method |
| JP4605395B2 (en) * | 2006-04-04 | 2011-01-05 | 日本電気株式会社 | Speaker |
| JP2007281669A (en) * | 2006-04-04 | 2007-10-25 | Nec Corp | Speaker |
| JP2007275819A (en) * | 2006-04-10 | 2007-10-25 | Nec Tokin Corp | Piezoelectric vibration unit and piezoelectric loudspeaker |
| JP2010503466A (en) * | 2006-09-18 | 2010-02-04 | ライポソニックス， インコーポレイテッド | Transducer with shielding |
| JPWO2011074579A1 (en) * | 2009-12-15 | 2013-04-25 | 日本電気株式会社 | Actuator, piezoelectric actuator, electronic device, vibration damping and vibration direction changing method |
| JP2012015761A (en) * | 2010-06-30 | 2012-01-19 | Nec Corp | Oscillator |
| DE202011002840U1 (en) | 2011-02-17 | 2011-06-30 | Ho Hsin Progressive Technology Co., Ltd | Piezoelectric area loudspeaker |
| US8611945B2 (en) | 2011-03-24 | 2013-12-17 | Kyocera Corporation | Electronic device |
| JP2014039093A (en) * | 2012-08-10 | 2014-02-27 | Kyocera Corp | Acoustic generator, acoustic generating device, and electric device |
| KR101480938B1 (en) * | 2014-12-04 | 2015-01-14 | 범진시엔엘 주식회사 | Piezoelectric Speaker |
| WO2016182035A1 (en) * | 2015-05-13 | 2016-11-17 | オーツェイド株式会社 | Speaker unit |
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