JPS60165200A - Piezoelectric speaker - Google Patents
Piezoelectric speakerInfo
- Publication number
- JPS60165200A JPS60165200A JP2023384A JP2023384A JPS60165200A JP S60165200 A JPS60165200 A JP S60165200A JP 2023384 A JP2023384 A JP 2023384A JP 2023384 A JP2023384 A JP 2023384A JP S60165200 A JPS60165200 A JP S60165200A
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- piezoelectric vibrator
- sound pressure
- reinforcing plate
- diaphragm
- 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
- 239000000919 ceramic Substances 0.000 claims abstract description 20
- 230000003014 reinforcing effect Effects 0.000 claims description 17
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 230000002787 reinforcement Effects 0.000 abstract description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052709 silver Inorganic materials 0.000 abstract description 3
- 239000004332 silver Substances 0.000 abstract description 3
- 229920000728 polyester Polymers 0.000 abstract description 2
- 229920001225 polyester resin Polymers 0.000 abstract description 2
- 239000004645 polyester resin Substances 0.000 abstract description 2
- 230000003247 decreasing effect Effects 0.000 abstract 3
- 230000005855 radiation Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 229910001369 Brass Inorganic materials 0.000 description 2
- 239000010951 brass Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 210000004709 eyebrow Anatomy 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、たとえば、ラジオ、ステレオ装置等に使用さ
れる圧電型スピーカに関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a piezoelectric speaker used, for example, in radios, stereo equipment, and the like.
従来例の構成とその問題点
近年、音響機器の軽量化、省電力化のため、圧電型スピ
ーカが研究開発され、ツイータ等の高音域再生用スピー
カ、受話器ユニット等として多く利用されるようになっ
てきた。Conventional configurations and their problems In recent years, piezoelectric speakers have been researched and developed in order to reduce the weight and power consumption of audio equipment, and have come to be widely used as speakers for high-frequency reproduction such as tweeters, receiver units, etc. It's here.
以下に従来の圧電型スピーカについて説明する。A conventional piezoelectric speaker will be explained below.
第１図は、圧電型スピーカの半断面図であり、１は円形
の圧電振動子、２は振動板、３はフレームである。第２
図（ａ−）は従来の圧電振動子１の上面図、第２図（ｂ
）は同正面図を示すもので、欽電極４が両面に形成され
た圧電セラミック板６，６で、黄銅やステンレス鋼で形
成される補強板７を挾み込み接着構成されている。この
ように構成された圧電振動子１のほぼ中心に、紙、樹脂
フィルム等で成形された振動板２の中心頂部が接合され
、さらに振動板２の周辺部がフレーム３の周辺部に接着
されていた。FIG. 1 is a half-sectional view of a piezoelectric speaker, in which 1 is a circular piezoelectric vibrator, 2 is a diaphragm, and 3 is a frame. Second
Figure (a-) is a top view of a conventional piezoelectric vibrator 1;
) shows a front view of the same, in which a reinforcing plate 7 made of brass or stainless steel is sandwiched between piezoelectric ceramic plates 6, 6 with electrodes 4 formed on both sides and bonded together. The center top of a diaphragm 2 made of paper, resin film, etc. is bonded to approximately the center of the piezoelectric vibrator 1 configured in this manner, and the peripheral portion of the diaphragm 2 is further bonded to the periphery of a frame 3. was.
以上のように構成された圧電型スピーカについて、以下
、その動作を説明する。The operation of the piezoelectric speaker configured as above will be described below.
圧電振動子１は、崖電セラミック板６が径方向に伸びの
応力を発生する時、圧電セラミック板６が綿みの応力を
発生するように電気的に配線されており、交流電気入ノ
、を加えると多重共振系としてたわみ振動を発生する。The piezoelectric vibrator 1 is electrically wired so that when the piezoelectric ceramic plate 6 generates an elongation stress in the radial direction, the piezoelectric ceramic plate 6 generates a stiff stress. When added, flexural vibration is generated as a multi-resonant system.
圧電型スピーカは第４図に示す等価回路で表わされ、入
力電圧Ｖに対したわみ振動による刀体数人を持って、Ｆ
＝ＡＶの駆動力が圧電振動子１から発生し、その駆動力
で圧電振動子の機械インピーダンスス４．振動板２の機
械インピーダンスＺ。、放射機械インピーダンス２．
を速度Ｖで動かして音響出力を得ている。A piezoelectric speaker is represented by the equivalent circuit shown in Fig. 4, and has several blades due to flexural vibration with respect to input voltage V.
= AV driving force is generated from the piezoelectric vibrator 1, and the mechanical impedance of the piezoelectric vibrator 4. Mechanical impedance Z of diaphragm 2. , radiation mechanical impedance 2.
is moved at a speed of V to obtain acoustic output.
なお、ｃｄは制動答量である。また、圧電振動子１の力
係数人１機械インピーダンスＺ、は次に示す（１）式、
（２）式で表わされる。Note that cd is the amount of braking response. In addition, the force coefficient of the piezoelectric vibrator 1 and the mechanical impedance Z are expressed by the following equation (1):
It is expressed by equation (2).
Ｚｌ−２π（ｔ１ρ１＋ｔ２ρ２ンｒｐ２− −−・
−（２）Ｆ（ｒａ）
ただし、
ｔ５．圧電セラミック板の厚さ
ρ、：圧奄セラミック板の密度
Ｅｌ、圧電セラミック板のヤング率
ｄ３１：圧電セラミック板の圧電定数
σ１ ：圧電セラミック板のポアソン比ｒｐ：圧電振動
子の半径
２ｔ２：補強板の厚さ
ρ２ ：補強板の密度
ｒｐ：圧電振動子の半径
Ｆ（ｒａ）、Ｇ（ｒａ） ：圧電振動子の振動モード関
数ｒａ、圧電振動子と振動板との結合半径である。Zl−2π(t1ρ1+t2ρ2nrp2− --・
-(2)F(ra) However, t5. Thickness ρ of the piezoelectric ceramic plate: Density El of the piezoelectric ceramic plate, Young's modulus of the piezoelectric ceramic plate d31: Piezoelectric constant σ1 of the piezoelectric ceramic plate: Poisson's ratio rp of the piezoelectric ceramic plate: Radius 2 of the piezoelectric vibrator t2: Reinforcement plate Thickness ρ2: Density rp of reinforcing plate: Radius of piezoelectric vibrator F(ra), G(ra): Vibration mode function ra of piezoelectric vibrator, coupling radius between piezoelectric vibrator and diaphragm.
圧電振動子１の中心付近では、圧電振動子１が多重共振
系で多くの共振を持つにもかかわらず、各共振間で反共
振の影響が少なく、この圧電型スピーカは比較的広帯域
にわたり再生音圧を得ることができる。Near the center of the piezoelectric vibrator 1, even though the piezoelectric vibrator 1 has many resonances in a multi-resonance system, there is little effect of anti-resonance between each resonance, and this piezoelectric speaker can reproduce sound over a relatively wide band. pressure can be obtained.
しかしながら、上記従来の構成では補強板７に黄銅やス
テンレス等の金属を用いているだめ、補強板７の密度Ｐ
２ が犬きく、（２）式で表わされる圧電振動子１の機
械インピーダンスＺ、が大きくなる。一方（り式で表わ
される刀体数人は補強板７の密度ρ２ には無関係で必
見第４図に示す等価回路図において振動板２の機械イン
ピーダンスＺ。However, in the conventional configuration described above, metal such as brass or stainless steel is used for the reinforcing plate 7, and the density of the reinforcing plate 7 is P.
2 increases, the mechanical impedance Z of the piezoelectric vibrator 1 expressed by equation (2) increases. On the other hand, the mechanical impedance Z of the diaphragm 2 in the equivalent circuit diagram shown in FIG.
及び放射機械インピーダンス２．の端子に加わる力Ｆ′
を低下させてしまっていた。又、圧電振動子１の機械イ
ンピーダンスＺ１ は第４図に表わされるような共振系
でリアクタンス成分か太きいだめ、振動板２、及び音響
放射系が持つ機械抵抗成分による共振の制動も困難とな
り、圧電型スピーカとしてその出力音圧周波数特性は、
第６図点線１２に示すように共振のピークの高い、そし
て各共振間の音圧レベルの低いという欠点を有していた
。and radiation mechanical impedance2. The force F′ applied to the terminal of
It was causing a decline in In addition, the mechanical impedance Z1 of the piezoelectric vibrator 1 is a reactance component in a resonant system as shown in FIG. As a piezoelectric speaker, its output sound pressure frequency characteristics are
As shown by the dotted line 12 in FIG. 6, this had the drawbacks of a high resonance peak and a low sound pressure level between each resonance.
発明の目的
本発明は上記従来の問題点を解消するもので、各共振の
ピークを低減し、かつ各共振間の周波数帯域で出力音圧
を向上することができる圧電型スピーカを提供すること
を目的とする。Purpose of the Invention The present invention solves the above-mentioned conventional problems, and aims to provide a piezoelectric speaker that can reduce the peak of each resonance and improve the output sound pressure in the frequency band between each resonance. purpose.
発明の構成
上記目的を達成するため本発明は、両面に導電性の電極
層を持つ２枚の圧電セラミック板と、前記２枚の圧電セ
ラミック板で挾持されかつ樹脂で形成された補強板とを
有し、前記２枚の圧電セラミック板と前記補強板とを駆
動源として構成した圧電振動子を備えており、圧電振動
子の力係数を変化させずに、圧電振動子の機械インピー
ダンス。Structure of the Invention In order to achieve the above object, the present invention comprises two piezoelectric ceramic plates having conductive electrode layers on both sides, and a reinforcing plate sandwiched between the two piezoelectric ceramic plates and made of resin. and a piezoelectric vibrator configured with the two piezoelectric ceramic plates and the reinforcing plate as a driving source, the mechanical impedance of the piezoelectric vibrator is maintained without changing the force coefficient of the piezoelectric vibrator.
機、械リアクタンス成分を低減し、各共振、のピーク音
圧を低減し、かつ、各共振間の周波数帯域で出力音圧を
向上しようとするものである。This aims to reduce the mechanical reactance component, reduce the peak sound pressure of each resonance, and improve the output sound pressure in the frequency band between each resonance.
実施例の説明
以下、本発明の一実施例を第１図、第３図〜第６図を用
いて説明する。第３図は本発明の一実施例における圧電
型スピーカの圧電振動子の構成を示すもので、第３図＋
ａ１は圧電振動子１の上面図、第３図（−ｂ）Ｈ回正面
図である。第３図（ａ）、（ｂ）において、９，１０は
銀電極８が両面に形成されている圧電セラミック板で、
ポリエステル樹脂で形成される補強板１１を挾み込み圧
電振動子１を構成しており、第１図に示す圧電型スピー
カの半断面図における圧電振動子１となる。この圧電振
動子１のほぼ中心に紙を成形した振動板２今結合し、さ
らに振動板２の周辺部をフレーム３の周辺部に接着し圧
電型スピーカが構成される。DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 3 to 6. Figure 3 shows the configuration of a piezoelectric vibrator of a piezoelectric speaker in an embodiment of the present invention.
a1 is a top view of the piezoelectric vibrator 1, and FIG. 3(-b) is an H-fold front view. In FIGS. 3(a) and 3(b), 9 and 10 are piezoelectric ceramic plates on which silver electrodes 8 are formed on both sides,
A reinforcing plate 11 made of polyester resin is inserted to form a piezoelectric vibrator 1, which is the piezoelectric vibrator 1 in a half-sectional view of a piezoelectric speaker shown in FIG. A diaphragm 2 made of paper is bonded to approximately the center of the piezoelectric vibrator 1, and the periphery of the diaphragm 2 is further bonded to the periphery of a frame 3 to construct a piezoelectric speaker.
以上のように構成された本実施例について以下その動作
を説明する。The operation of this embodiment configured as above will be described below.
まず、圧電振動子１は、圧電セラミック板９゜１０の伸
縮によりたわみ振動を発生し、多重共振の駆動源となる
。その時の等価回路は第４図に示すようになり、刀体数
人は（２）式に示すように圧電セラミック板９，１０の
厚さと補強板１１の厚さの関数となり従来の金属性の補
強板７と同し厚さであれば、圧電振動子１からの４駆動
力Ｆ＝ＡＶは従来と同等に得られる。一方圧電振動子１
の機械インピーダンスＺ１ は、（１）式で表わされる
ように圧電セラミック板９，１０のｊ皇さ、・補強板１
１の厚さに加え、各々の密度の関数とになっているため
、補強板１１をポリエステルにすることにより機械イン
ピーダンスＺ１ を低減でき１１機械リアクタンス成分
も低減される。これにより、圧電振動子１が共振する周
波数においては、圧電振動子１の機械リアクタンス成分
が小さくなるため、振動板２の機械抵抗成分及び放射抵
抗成分により、共振のピーク音圧が大巾に制動され、又
各々の共振間でも振動板２の機械インピーダンス２゜と
放射機械インピーダンスｚ４の端子間に加えられる力Ｆ
を大きくできるため、出力音圧が向上し第６図の実線１
３に示すような平坦な音圧周波数特性が得られる。First, the piezoelectric vibrator 1 generates flexural vibration due to the expansion and contraction of the piezoelectric ceramic plate 9° 10, and serves as a multi-resonant driving source. The equivalent circuit at that time is shown in Figure 4, and the number of blades is a function of the thickness of the piezoelectric ceramic plates 9 and 10 and the thickness of the reinforcing plate 11, as shown in equation (2), compared to the conventional metallic one. If the thickness is the same as that of the reinforcing plate 7, the driving force F=AV from the piezoelectric vibrator 1 can be obtained in the same manner as in the conventional case. On the other hand, piezoelectric vibrator 1
The mechanical impedance Z1 of the piezoelectric ceramic plates 9 and 10 is expressed by equation (1).
In addition to the thickness of 1, it is a function of each density, so by making the reinforcing plate 11 of polyester, the mechanical impedance Z1 can be reduced, and the mechanical reactance component of 11 can also be reduced. As a result, at the frequency at which the piezoelectric vibrator 1 resonates, the mechanical reactance component of the piezoelectric vibrator 1 becomes small, so the resonance peak sound pressure is greatly damped by the mechanical resistance component and the radiation resistance component of the diaphragm 2. Also, between each resonance, the force F applied between the terminals of the mechanical impedance 2° of the diaphragm 2 and the radiation mechanical impedance z4 is
can be increased, the output sound pressure is improved and the solid line 1 in Figure 6
A flat sound pressure frequency characteristic as shown in Fig. 3 can be obtained.
尚、補強板１１は導電性樹脂で形成してもよく、又、補
強板表面に金属イ２料を蒸着し導電性を持たせてもよい
。以上の構成では、機械インピーダンスを低下するとと
もに、電極端子を兼ねることができるという効果を有（
７そいる。Note that the reinforcing plate 11 may be formed of a conductive resin, or may be made conductive by vapor-depositing a metal oxide on the surface of the reinforcing plate. The above configuration has the effect of lowering mechanical impedance and also being able to function as an electrode terminal (
There are 7.
発明の効果
以上のように本発明は、圧電振動子の補強板を樹脂で形
成することにより各共振のピーク音圧を制動し、かつ各
々の共振間の周波数帯域で出力音圧を向上できる優れた
圧電型スピーカを実現できるものである。Effects of the Invention As described above, the present invention has the advantage of damping the peak sound pressure of each resonance and improving the output sound pressure in the frequency band between each resonance by forming the reinforcing plate of the piezoelectric vibrator with resin. This makes it possible to realize a piezoelectric speaker.
第６図は圧％型スピーカの出力音圧周波数特性図である
。FIG. 6 is an output sound pressure frequency characteristic diagram of a pressure % type speaker.
１・・・・圧電振動子、２・・・・・振動板、３・・・
・・・フレーム、８・・・・銀電極、９，１Ｑ・・・・
・・圧電セラミック板、１１・・・・・・補強板。1... Piezoelectric vibrator, 2... Vibration plate, 3...
...Frame, 8...Silver electrode, 9,1Q...
...Piezoelectric ceramic plate, 11...Reinforcement plate.
代理人の氏名 弁理士 中 尾 敏 男 ほか１名第１
図
第２図
第４図
第５図
眉仮数（Ｈｉｌ−Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 4 Figure 5 Eyebrow mantissa (Hil-
Claims (3)
ック板と、前記２枚の圧電セラミック板で挾持され゛か
つ樹脂で形成された補強板とを有し、前記２枚の圧電セ
ラミック板と前記補強板とを駆動源として構成した圧電
振動子を備えたことを特徴とする圧′電型スピーカ。(1) It has two piezoelectric ceramic plates having conductive electrode layers on both sides, and a reinforcing plate sandwiched between the two piezoelectric ceramic plates and made of resin, A piezoelectric speaker comprising a piezoelectric vibrator configured with a ceramic plate and the reinforcing plate as a driving source.
特許請求の範囲第１項記載の圧電型スピーカ。(2) The piezoelectric speaker according to claim 1, wherein the reinforcing plate is made of conductive resin.
たことを特徴とする特許請求の範囲第１項記載の圧電型
スピーカ。(3) A piezoelectric speaker according to claim 1, characterized in that a metal feed is deposited on the surface of the reinforcing plate to impart electrical conductivity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023384A JPS60165200A (en) | 1984-02-06 | 1984-02-06 | Piezoelectric speaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023384A JPS60165200A (en) | 1984-02-06 | 1984-02-06 | Piezoelectric speaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60165200A true JPS60165200A (en) | 1985-08-28 |
Family
ID=12021460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2023384A Pending JPS60165200A (en) | 1984-02-06 | 1984-02-06 | Piezoelectric speaker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60165200A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9302292B2 (en) | 2014-03-14 | 2016-04-05 | Industrial Technology Research Institute | Piezoelectric electroacoustic transducer |
| US9473856B2 (en) | 2014-04-18 | 2016-10-18 | Industrial Technology Research Intitute | Piezoelectric electroacoustic transducer |
-
1984
- 1984-02-06 JP JP2023384A patent/JPS60165200A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9302292B2 (en) | 2014-03-14 | 2016-04-05 | Industrial Technology Research Institute | Piezoelectric electroacoustic transducer |
| US9473856B2 (en) | 2014-04-18 | 2016-10-18 | Industrial Technology Research Intitute | Piezoelectric electroacoustic transducer |
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