JPH01135299A - Piezoelectric loudspeaker - Google Patents
Piezoelectric loudspeakerInfo
- Publication number
- JPH01135299A JPH01135299A JP29373787A JP29373787A JPH01135299A JP H01135299 A JPH01135299 A JP H01135299A JP 29373787 A JP29373787 A JP 29373787A JP 29373787 A JP29373787 A JP 29373787A JP H01135299 A JPH01135299 A JP H01135299A
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- diaphragm
- board
- plate
- metallic
- 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
- 238000013016 damping Methods 0.000 claims abstract description 21
- 239000000919 ceramic Substances 0.000 claims abstract description 14
- 229910052751 metal Inorganic materials 0.000 claims description 22
- 239000002184 metal Substances 0.000 claims description 22
- 230000002093 peripheral effect Effects 0.000 abstract description 8
- 239000000463 material Substances 0.000 abstract description 4
- 239000011347 resin Substances 0.000 abstract description 2
- 229920005989 resin Polymers 0.000 abstract description 2
- 238000002788 crimping Methods 0.000 abstract 2
- 238000005187 foaming Methods 0.000 abstract 1
- 239000000853 adhesive Substances 0.000 description 7
- 230000001070 adhesive effect Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000005236 sound signal Effects 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001084 poly(chloroprene) Polymers 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
Landscapes
- Piezo-Electric Transducers For Audible Bands (AREA)
Abstract
Description
【発明の詳細な説明】
一産業上の利用分野−
本発明は圧電セラミック板で駆動する圧電型発音器に関
し、特に、平坦な周波数特性を有し広帯域再生可能な圧
電型スピーカに関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a piezoelectric sound generator driven by a piezoelectric ceramic plate, and more particularly to a piezoelectric speaker that has flat frequency characteristics and is capable of reproducing a wide band.
一従来の技術−
小型電子機器における音声再生等の目的から、従来では
、第５図に示すような圧電型スピーカが提案されている
。即ち、この圧電型スピーカは、面積のある金属振動板
Ａの表面に圧電セラミック板Ｂを貼り合わせて構成した
圧電振動板を備えるものて、軟質保持部材Ｃを介して圧
電振動板の外周部を固定リングＤに支持しである。BACKGROUND ART Conventionally, a piezoelectric speaker as shown in FIG. 5 has been proposed for the purpose of audio reproduction in small electronic devices. That is, this piezoelectric speaker is equipped with a piezoelectric diaphragm constructed by bonding a piezoelectric ceramic plate B to the surface of a metal diaphragm A with a large area. It is supported by a fixed ring D.
したがって、このような構造の圧電型スピーカでは、外
部接続リートＥの間に音声信号を印加すると、圧電振動
板が振動して音圧振動が得られるが、圧電振動板には特
有の共振周波数があるので、圧電セラミック板Ｂに音声
信号を人力すると、共振周波数及びこの高次周波数近く
で圧電振動板が強く振動して平坦な周波数特性を得るこ
とができない。Therefore, in a piezoelectric speaker with such a structure, when an audio signal is applied between the external connection leads E, the piezoelectric diaphragm vibrates and sound pressure vibration is obtained, but the piezoelectric diaphragm has a unique resonance frequency. Therefore, when an audio signal is manually applied to the piezoelectric ceramic plate B, the piezoelectric diaphragm vibrates strongly near the resonance frequency and this higher-order frequency, making it impossible to obtain a flat frequency characteristic.
このため、従来では、前述した圧電振動板の共振運動を
抑制する軟質制動板Ｆを金属振動板Ａの表面に接着剤Ｇ
で接着する構造（第６図示）が提案されている。For this reason, in the past, a soft damping plate F for suppressing the resonance motion of the piezoelectric diaphragm was attached to the surface of the metal diaphragm A using an adhesive G.
A structure (shown in Figure 6) in which the adhesive is bonded with
一発明が解決しようとする問題点−
しかしながら、この構造によると、圧電振動板の共振運
動を減衰させる効果はあるが、制動板Ｆとして用いるゴ
ムやスポンジ等が接着剤Ｇに含まれる溶剤で解けて制動
板Ｆの物性が変化し、接着剤Ｇの塗布量及び経時的な硬
度変化により期待するような周波数特性を得ることがで
きなかった。また、この構造では、圧電振動板と制動板
Ｆとの間の接着工程及び強度の管理がむずかしく、しば
しば接着の具合により特性にバラツキを生じさせる原因
となったりあるいは、制動板Ｆが剥離して共振抑制効果
が損なわれてしまう場合があった。Problems to be Solved by the Invention - However, although this structure has the effect of damping the resonant motion of the piezoelectric diaphragm, the rubber, sponge, etc. used as the damping plate F cannot be dissolved by the solvent contained in the adhesive G. As a result, the physical properties of the brake plate F changed, and the expected frequency characteristics could not be obtained due to the amount of adhesive G applied and changes in hardness over time. In addition, with this structure, it is difficult to control the bonding process and strength between the piezoelectric diaphragm and the brake plate F, which often causes variations in characteristics depending on the condition of the bond, or the brake plate F may peel off. There were cases where the resonance suppression effect was lost.
本発明の目的は、以上に述べたような従来の圧電型スピ
ーカの製作上及び周波数特性上の問題に鑑み、容易に期
待するような広帯域及びより平坦な周波数特性が得られ
る構造を得るにある。SUMMARY OF THE INVENTION In view of the above-mentioned problems in manufacturing and frequency characteristics of conventional piezoelectric speakers, it is an object of the present invention to provide a structure that can provide a wide band and flatter frequency characteristics as easily expected. .
一問題点を解決するための手段−
この目的を達成するため、本発明は、貼り合わされた圧
電セラミック板及び金属振動板からなる圧電振動板を備
える圧電型スピーカにおいて、前記金属振動板と等しい
外形をもつ軟質制動板を、金属振動板の表面に重ね合わ
せ、同制動板の外周部を固定リングに固定または支持す
ることを提案するものである。Means for Solving a Problem - In order to achieve this object, the present invention provides a piezoelectric speaker including a piezoelectric diaphragm made of a piezoelectric ceramic plate and a metal diaphragm bonded together, which has an outer shape equal to that of the metal diaphragm. The present invention proposes that a soft damping plate having the following properties be superimposed on the surface of a metal diaphragm, and the outer peripheral portion of the damping plate may be fixed or supported by a fixing ring.
−実施例−
以下、第１図から第４図について本発明の実施例の詳細
を説明する。-Embodiments- Hereinafter, details of embodiments of the present invention will be explained with reference to FIGS. 1 to 4.
第１図は本発明の第１実施例による圧電型スピーカの断
面図であり、符号゛°１°゛は両面に導電層２ａ、２ｂ
を形成された圧電セラミック板を示している。この小型
の圧電セラミック板１の片面は、導電性のある面積板即
ち金属振動板３に一体的に貼り合わされて圧電振動板４
を構成する点では、従来と同様である。即ち、金属振動
板３とは反対側の圧電セラミック板１の表面及び金属振
動板３には、外部接続リード５Ａ、５Ｂがそれぞれ接続
され、これらの外部接続リード５Ａ。FIG. 1 is a cross-sectional view of a piezoelectric speaker according to a first embodiment of the present invention.
A piezoelectric ceramic plate is shown. One side of this small piezoelectric ceramic plate 1 is integrally bonded to a conductive area plate, that is, a metal diaphragm 3, and a piezoelectric diaphragm 4
The structure is the same as the conventional one. That is, external connection leads 5A and 5B are connected to the surface of the piezoelectric ceramic plate 1 on the opposite side of the metal diaphragm 3 and to the metal diaphragm 3, respectively.
５Ｂの間に電気的な音声信号を印加することにより圧電
振動板４が振動される。そして、第１実施例の場合、前
記圧電セラミック板１とは反対側の金属振動板３の表面
には、金属振動板３と等しい外径寸法に成形されたゴム
、発泡樹脂等の軟質制動板６が単に重ね合わされた状態
で接触され、これらの金属振動板３及び制動板６は固定
リング７の内部に位置された後、固定リング７により挟
持することにより外周部を全周に亘って固定関係に置か
れる。この工程では、挟持圧力を選択するだけで圧電振
動板４の周辺支持剛性を変化できるため、特定の金属振
動板３及び制動板６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型スピーカを得ることがで
きる。The piezoelectric diaphragm 4 is vibrated by applying an electrical audio signal between 5B and 5B. In the case of the first embodiment, on the surface of the metal diaphragm 3 opposite to the piezoelectric ceramic plate 1, a soft damping plate made of rubber, foamed resin, etc. molded to have the same outer diameter as the metal diaphragm 3 is provided. 6 are simply overlapped and contacted, and after these metal diaphragm 3 and brake plate 6 are positioned inside the fixing ring 7, the outer periphery is fixed over the entire circumference by being held by the fixing ring 7. placed in a relationship. In this process, the peripheral support rigidity of the piezoelectric diaphragm 4 can be changed simply by selecting the clamping pressure, so by managing the clamping pressure according to the material of the specific metal diaphragm 3 and damping plate 6, various frequency characteristics can be adjusted. A piezoelectric speaker can be obtained.
第１実施例による圧電型スピーカは、以上に述べたよう
に、等径の軟質制動板６を金属振動板３に単に重ね合わ
せて外周部を固定リング７に固定した構造であるから、
管理の困難な接着工程を省略できるばかりでなく、接着
剤の塗布量等のバラツキにより経時的に周波数特性が変
化するおそれのない、安定した品質の圧電型スピーカを
提供できる。また、第１実施例構造の試作例によれば、
圧電振動板４の見かけ上の共振周波数が低域側に移行し
かつ低音域での音圧が高くなり、比較的大ぎな音響出力
が得られたが、この現象は、制動板６の周辺部を介して
圧電振動板４の周辺部を固定リング７に固定したことに
より、見かけ上の共振周波数が低域側に移動したものと
思われる。さらに、第１実施例の構造について、固定リ
ング７への挟持圧力を変えて周波数特性を測定したとこ
ろ、挟持圧の選択により使用可能帯域及び種々の周波数
での振幅、つまり音質がかなり変化することがわかった
。As described above, the piezoelectric speaker according to the first embodiment has a structure in which the soft damping plate 6 of equal diameter is simply superimposed on the metal diaphragm 3 and the outer peripheral part is fixed to the fixing ring 7.
Not only can a bonding process that is difficult to manage be omitted, but also a piezoelectric speaker of stable quality can be provided without the risk of frequency characteristics changing over time due to variations in the amount of adhesive applied. Moreover, according to the prototype example of the structure of the first embodiment,
The apparent resonant frequency of the piezoelectric diaphragm 4 shifted to the lower frequency side and the sound pressure in the lower frequency range increased, resulting in a relatively large acoustic output. It is thought that by fixing the peripheral portion of the piezoelectric diaphragm 4 to the fixing ring 7 via the diaphragm 4, the apparent resonant frequency was shifted to the lower frequency side. Furthermore, when we measured the frequency characteristics of the structure of the first embodiment by changing the clamping pressure on the fixed ring 7, we found that the usable band and the amplitude at various frequencies, that is, the sound quality, changed considerably depending on the selection of clamping pressure. I understand.
第２図は、金属振動板３として直径
５５□、厚み０．１１ｎｎ＋のアルミ板を、制動板６と
して直径５５１１ＩＩ、厚み２１．ｌｌ、ｌのネオブレ
ン系発泡材を用い、直径２５−１厚さ０１−の圧電セラ
ミック板１で加振させた場合の周波数特性である。即ち
、曲線ａは制動板６を用いない場合の圧電型スピーカの
周波数特性であり、曲線すは第１実施例構造の周波数特
性である。両回線ａ、ｂの比較から理解されるように、
制動板６を用いない圧電型スピーカでは、５００ Ｈ２
付近の共振周波数及びその高次共振周波数で、際立った
鋭い共振現象が観察されるが、第１実施例の構造では、
これらの共振周波数での共振振幅が充分に抑制され、こ
の結果、比較的平坦な周波数特性が得られるのが解る。In FIG. 2, the metal diaphragm 3 is an aluminum plate with a diameter of 55□ and a thickness of 0.11 nn+, and the brake plate 6 is an aluminum plate with a diameter of 5511 II and a thickness of 21. This is the frequency characteristic when a piezoelectric ceramic plate 1 with a diameter of 25-1 and a thickness of 0-1 is vibrated using a neoprene foam material of 11 and 1. That is, curve a is the frequency characteristic of the piezoelectric speaker without using the brake plate 6, and curve 2 is the frequency characteristic of the structure of the first embodiment. As can be understood from the comparison of both lines a and b,
For a piezoelectric speaker that does not use the brake plate 6, 500 H2
A remarkable sharp resonance phenomenon is observed at the nearby resonance frequency and its higher-order resonance frequency, but in the structure of the first example,
It can be seen that the resonance amplitudes at these resonance frequencies are sufficiently suppressed, resulting in relatively flat frequency characteristics.
第３図は本発明の第２実施例による圧電型スピーカを示
し、第１実施例と同一構造部分については、同一符号を
付して示しである。FIG. 3 shows a piezoelectric speaker according to a second embodiment of the present invention, in which structural parts that are the same as those in the first embodiment are denoted by the same reference numerals.
即ち、第２実施例による圧電型スピーカは、金属振動板
３と同一外径の制動板６Ａを用いる点では前述した第１
実施例の場合と同一構造であるが、制動板６Ａの中心部
に圧電セラミック板１の外径の１７２程度のボア８を形
成した点に特徴がある。つまり、この第２実施例では、
圧電振動板４全体の制振効果上有効でない制動板６Ａの
中心部の材料を取除いて制動板６Ａの実質的な共振抑制
効果を増進させである。That is, the piezoelectric speaker according to the second embodiment is different from the first embodiment in that the damping plate 6A having the same outer diameter as the metal diaphragm 3 is used.
Although the structure is the same as that of the embodiment, the feature is that a bore 8 having an outer diameter of about 172 mm, which is the outer diameter of the piezoelectric ceramic plate 1, is formed in the center of the brake plate 6A. In other words, in this second embodiment,
By removing the material at the center of the damping plate 6A which is not effective in suppressing the vibration of the piezoelectric diaphragm 4 as a whole, the substantial resonance suppressing effect of the damping plate 6A is enhanced.
したがって、第２実施例による圧電型スピーカによると
、制動板６Ａによる共振抑制効果がより向上する。第２
図の曲線Ｃは、他の部分の寸法及び材料を第１実施例と
等しくしかつボア８の口径を２０゜とじた第２実施例構
造の周波数特性であるが、この曲線Ｃと他の曲線ａ、ｂ
との比較から理解されるように、第２実施例構造では、
共振振幅がより低減され、平坦な周波数特性が得られか
つこの平坦な周波数帯域は約５０〜１０Ｋｈの範囲であ
るので、通常の音声再生の周波数帯域を確保できる。Therefore, according to the piezoelectric speaker according to the second embodiment, the resonance suppression effect by the damping plate 6A is further improved. Second
Curve C in the figure is the frequency characteristic of the structure of the second embodiment, in which the dimensions and materials of other parts are the same as those of the first embodiment, and the diameter of the bore 8 is reduced by 20 degrees. a, b
As can be understood from the comparison with the structure of the second embodiment,
Since the resonance amplitude is further reduced and a flat frequency characteristic is obtained, and this flat frequency band is in the range of approximately 50 to 10 Kh, a frequency band for normal audio reproduction can be secured.
第４図は本発明の第３実施例による圧電型スピーカを示
し、この実施例は固定リング７Ａに対する圧電振動板４
の取付構造に特徴がある。つまり、外径を制動板６と同
一寸法とされた金属振動板３の周辺部が接着剤９を用い
て部分的に制動板６に固定され、同制動板６を接着剤１
０を用いて固定リング７Ａの内周フランジ７ａに固定し
である。したがって、この第３実施例構造では、制動板
６を介して圧電振動板４の周辺部が固定リング７Ａに支
持されることになるが、このような構造によっても、前
述した第１、第２実施例の場合と同様の作用効果を得る
ことができる。FIG. 4 shows a piezoelectric speaker according to a third embodiment of the present invention, in which a piezoelectric diaphragm 4 is attached to a fixing ring 7A.
The mounting structure is distinctive. That is, the peripheral part of the metal diaphragm 3 whose outer diameter is the same as that of the brake plate 6 is partially fixed to the brake plate 6 using the adhesive 9, and the brake plate 6 is fixed to the brake plate 6 using the adhesive 1.
0 to the inner peripheral flange 7a of the fixing ring 7A. Therefore, in the structure of this third embodiment, the peripheral part of the piezoelectric diaphragm 4 is supported by the fixing ring 7A via the brake plate 6. The same effects as in the example can be obtained.
一発明の効果−
以上の説明から明らかなように、本発明によれば、圧電
振動板を構成する金属振動板に対して、金属振動板と同
一外径に成形した軟質制動板を接触状態におき、圧電振
動板及び制動板を固定リングに固定または支持するたけ
で、周波数特性が平坦かつ広帯域の圧電型スピーカを得
ることができる。Effects of the Invention As is clear from the above description, according to the present invention, a soft damping plate formed to have the same outer diameter as the metal diaphragm is brought into contact with the metal diaphragm that constitutes the piezoelectric diaphragm. By simply fixing or supporting the piezoelectric diaphragm and damping plate on the fixing ring, a piezoelectric speaker with flat frequency characteristics and a wide band can be obtained.
第１図は本発明の第１実施例による圧電型スピーカの断
面図、第２図は同圧電型スピーカの周波数特性図、第３
図は本発明の第２実施例による圧電型スピーカの断面図
、第４図は本発明の第３実施例による圧電型スピーカの
断面図、第５図は従来の圧電型スピーカの断面図、第６
図は他の従来の圧電型スピーカの断面図である。
１・・・圧電セラミック板、
３・・・金属振動板、
４・・・圧電振動板、
６．６Ａ・・・制動板、
７．７Ａ・・・固定リング。
特許出願人 岩嶋通信機株式会社
第１図
第４図 ５Ａ ５８
第２図FIG. 1 is a sectional view of a piezoelectric speaker according to a first embodiment of the present invention, FIG. 2 is a frequency characteristic diagram of the same piezoelectric speaker, and FIG.
4 is a sectional view of a piezoelectric speaker according to a third embodiment of the present invention, FIG. 5 is a sectional view of a conventional piezoelectric speaker, and FIG. 6
The figure is a sectional view of another conventional piezoelectric speaker. DESCRIPTION OF SYMBOLS 1... Piezoelectric ceramic plate, 3... Metal diaphragm, 4... Piezoelectric diaphragm, 6.6A... Braking plate, 7.7A... Fixed ring. Patent applicant Iwashima Tsushinki Co., Ltd. Figure 1 Figure 4 5A 58 Figure 2
Claims (1)
らなる圧電振動板を備える圧電型スピーカにおいて、前
記金属振動板と等しい外形をもつ軟質制動板を、金属振
動板の表面に重ね合わせ、同制動板の外周部を固定リン
グに固定または支持したことを特徴とする圧電型スピー
カ。1) In a piezoelectric speaker equipped with a piezoelectric diaphragm made of a piezoelectric ceramic plate and a metal diaphragm bonded together, a soft damping plate having the same external shape as the metal diaphragm is superimposed on the surface of the metal diaphragm, and the damping plate A piezoelectric speaker characterized in that the outer periphery of the piezoelectric speaker is fixed or supported by a fixing ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29373787A JPH01135299A (en) | 1987-11-20 | 1987-11-20 | Piezoelectric loudspeaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29373787A JPH01135299A (en) | 1987-11-20 | 1987-11-20 | Piezoelectric loudspeaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01135299A true JPH01135299A (en) | 1989-05-26 |
Family
ID=17798587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29373787A Pending JPH01135299A (en) | 1987-11-20 | 1987-11-20 | Piezoelectric loudspeaker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01135299A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH039597U (en) * | 1989-06-10 | 1991-01-29 | ||
| EP0936842A1 (en) * | 1995-09-25 | 1999-08-18 | Noise Cancellation Technologies, Inc. | Piezo speaker for improved passenger cabin audio systems |
| EP1001653A2 (en) | 1998-11-02 | 2000-05-17 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric loudspeaker |
| US6751324B2 (en) | 2000-03-21 | 2004-06-15 | Pioneer Corporation | Speaker device |
| JP2014057251A (en) * | 2012-09-13 | 2014-03-27 | Kyocera Corp | Sound generator, sound generating device, and electronic apparatus |
| JP2014127748A (en) * | 2012-12-25 | 2014-07-07 | Kyocera Corp | Acoustic generator, acoustic generating device, and electronic apparatus |
| TWI505722B (en) * | 2012-08-30 | 2015-10-21 | Kyocera Corp | Sound generator, sound generating device and electronic machine |
-
1987
- 1987-11-20 JP JP29373787A patent/JPH01135299A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH039597U (en) * | 1989-06-10 | 1991-01-29 | ||
| EP0936842A1 (en) * | 1995-09-25 | 1999-08-18 | Noise Cancellation Technologies, Inc. | Piezo speaker for improved passenger cabin audio systems |
| EP1001653A2 (en) | 1998-11-02 | 2000-05-17 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric loudspeaker |
| US6747395B1 (en) | 1998-11-02 | 2004-06-08 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric loudspeaker |
| US6751324B2 (en) | 2000-03-21 | 2004-06-15 | Pioneer Corporation | Speaker device |
| TWI505722B (en) * | 2012-08-30 | 2015-10-21 | Kyocera Corp | Sound generator, sound generating device and electronic machine |
| JP2014057251A (en) * | 2012-09-13 | 2014-03-27 | Kyocera Corp | Sound generator, sound generating device, and electronic apparatus |
| JP2014127748A (en) * | 2012-12-25 | 2014-07-07 | Kyocera Corp | Acoustic generator, acoustic generating device, and electronic apparatus |
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