JPS5911240B2 - Electret capacitor type electroacoustic transducer - Google Patents
Electret capacitor type electroacoustic transducerInfo
- Publication number
- JPS5911240B2 JPS5911240B2 JP13236080A JP13236080A JPS5911240B2 JP S5911240 B2 JPS5911240 B2 JP S5911240B2 JP 13236080 A JP13236080 A JP 13236080A JP 13236080 A JP13236080 A JP 13236080A JP S5911240 B2 JPS5911240 B2 JP S5911240B2
- Authority
- JP
- Japan
- Prior art keywords
- electret
- electroacoustic transducer
- capacitor type
- type electroacoustic
- electrode
- 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.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/01—Electrostatic transducers characterised by the use of electrets
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
Description
【発明の詳細な説明】
本発明はエレクトレソト・コンデンサ型電気音響変換器
に係り、特に高調波歪を低減させたエレクトレット・コ
ンデンサ型電気音響変換器に関係する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electret capacitor type electroacoustic transducer, and more particularly to an electret capacitor type electroacoustic transducer with reduced harmonic distortion.
従来よりエレクトレット・コンデンサ型電気音響変換器
として例えば第１図に示す如きプッシュプル式エレクト
レット・コンテツサ型電気音響変換器が知られている。2. Description of the Related Art As an electret capacitor type electroacoustic transducer, for example, a push-pull type electret condenser type electroacoustic transducer as shown in FIG. 1 has been known.
つまり、少なくと゛も片面に導電層を有する振動電極２
が絶縁スペーサ３を介して、その両側にエレクトレット
と一体化された固定電極１，１′が対向する様に構成さ
れている。In other words, the vibrating electrode 2 has a conductive layer on at least one side.
are configured such that fixed electrodes 1 and 1' integrated with electrets face each other on both sides with an insulating spacer 3 interposed therebetween.
この様な電気音響変換器の高調波歪は振動電極面内の機
械的特性の不均一性、固定電極（エレクトレット）面内
の表面電位の不均一性及び振動電極と固定電極とのエア
ーギャップの部分的な不均一性によって生じるものと考
えられている。The harmonic distortion of such an electroacoustic transducer is caused by non-uniformity of mechanical properties within the plane of the vibrating electrode, non-uniformity of the surface potential within the plane of the fixed electrode (electret), and the air gap between the vibrating electrode and the fixed electrode. It is thought that this is caused by local non-uniformity.
この内振動電極面内の機械的特性はプラスチック薄膜の
製造技術の進歩と利用技術の進歩によりある程度均一な
機械特性を有する振動電極が得られているがエレクトレ
ソトを用いた固定電極面内の表面電位分布は必ずしも均
一なものが得られなかった。With regard to the mechanical properties within the plane of the vibrating electrode, advances in the manufacturing technology of plastic thin films and advancements in application technology have made it possible to obtain vibrating electrodes with somewhat uniform mechanical properties. A uniform potential distribution was not always obtained.
本発明は上記の点に鑑み特に高調波歪を低減させる事の
できるエレクトレソト・コンデンサ型電気音響変換器を
提供する事を目的とする。In view of the above points, it is an object of the present invention to provide an electroacoustic transducer of the electreso-condenser type that can particularly reduce harmonic distortion.
本発明は可動電極と、前記振動電極と対向する如く設け
られ両主面にそれぞれ金属層を有するエレクトレソトか
らなる固定電極とを具備したエレクトンソト・コンデン
サ型電気音響変換器であり、さらに固定電極の金属層の
内、振動電極と対面する側の金属層に電圧印加用の端子
を設ける事により製造が容易で、かつエレクトレソトの
表面電位が劣化等により低下した時に容易に回復する事
ができるというものである。The present invention is an electroacoustic transducer of an electron sotho capacitor type, which includes a movable electrode and a fixed electrode made of electrosotho, which is provided so as to face the vibrating electrode and has metal layers on both main surfaces. Providing voltage application terminals on the side of the metal layer that faces the vibrating electrode makes it easy to manufacture, and it can be easily recovered when the surface potential of the electresoret decreases due to deterioration, etc. It is something.
つまり本発明は例えば第２図にその構成断面図を示す如
く振動電極２と対向する如く設けられ、両主面にそれぞ
れ金属層１１，１１’，１３，１３’を有するエレクト
レット１ ２ ， １ ２’からなる固定電極１，１′
が配設されている。In other words, the present invention provides electrets 1 2 , 1 2 which are provided to face the vibrating electrode 2 and have metal layers 11 , 11 ′, 13 , 13 ′ on both principal surfaces, respectively, as shown in a cross-sectional view of the configuration in FIG. 2, for example. Fixed electrodes 1, 1' consisting of
is installed.
なお本発明の固定電極においてエレクトレット１２，１
２’は高い絶縁抵抗を持つ誘電体、例えば４弗化エチレ
ン、６弗化プロピレン共重合体、ポリエチレン、ポリプ
ロピレン等により構成する事ができ、また容易に分極さ
れるポリ弗化ビニリデン、ポリメチルメタアクリレート
などによっても構成できる。Note that in the fixed electrode of the present invention, the electret 12,1
2' can be made of a dielectric material with high insulation resistance, such as tetrafluoroethylene, hexafluoropropylene copolymer, polyethylene, polypropylene, etc., and can also be made of easily polarized polyvinylidene fluoride, polymethylmethacrylate, etc. It can also be composed of acrylate or the like.
また上記エレクトレッド１ ２ ， １ ２’の両主面
に設ける金属層１１，１１’，１３，１３’としては、
アルミニューム、銅、真ちゅうステンレス等を用いる事
ができ実用上０，１朋からｌ ｍｍ厚とする事が好まし
い。Further, the metal layers 11, 11', 13, 13' provided on both main surfaces of the electred 12, 12' are as follows:
Aluminum, copper, brass stainless steel, etc. can be used, and it is practically preferable to have a thickness of 0.1 mm to 1 mm.
この金属層１１，１１’，１３，１３’は予じめ従来の
熱エレクトレット化方法、エレクトロ・エレクトレット
化方法等によりエレクトレット１２，１２’を得た後接
着剤等を用い、その両主面に一体化した場合にも本願目
的は達成されるが、実用上はエレクトレソト化前の誘電
体層表面に金属層を一体化せしめ、しかる後金属層１１
および１３（又は１トおよび１３′）に直流電圧を印加
し、電圧印加状態から開回路状態とし、電圧印加を中止
する事によりエレクトレット化する事が好ましい。The metal layers 11, 11', 13, 13' are formed by forming the electrets 12, 12' in advance by a conventional thermal electret method, electro-electret method, etc., and then using an adhesive or the like on both main surfaces. Although the object of the present application can be achieved even if the metal layer is integrated, in practice, the metal layer is integrated with the surface of the dielectric layer before electroisolation, and then the metal layer 11 is integrated.
It is preferable to apply a DC voltage to and 13 (or 1 and 13'), change the voltage application state to an open circuit state, and then turn the circuit into an electret by discontinuing the voltage application.
つまり金属層を一体的に設けた後にエレクトレット化し
本発明に係る固定電極を得る場合には、均一な表面電位
を有すると共に、表面電位の制御が容易となり、その上
極性を自由に選定する事ができる等の利点を有する事が
できる。In other words, when a fixed electrode according to the present invention is obtained by integrally providing a metal layer and then converting it into an electret, it has a uniform surface potential, the surface potential can be easily controlled, and the polarity can be freely selected. It can have advantages such as:
また従来の如くエレクトレソト化時に、二次転移温度域
あるいは結晶分散が起る温度域への加熱処理を施す必要
もなく室温でのエレクトレット化が可能となり製造も容
易となる。In addition, there is no need to perform heat treatment to a secondary transition temperature range or a temperature range where crystal dispersion occurs during electretization as in the past, and electretization can be performed at room temperature, making production easier.
さらに第２図に示す如く、振動電極２と対面する金属層
１ ３ ， １ ３’に電圧印加用端子４，４′を設け
た場合には、第２図の如くエレクトレソト・コンデンサ
型電気音響変換器を組立後電圧印加用の端子１３，１３
’および信号入出力用の端子１１，１１′を用い直流電
圧を印加する事により、表面電位が均一でかつ所定の表
面電位に制御された固定電極を容易かつ確実に得る事が
できる。Furthermore, as shown in FIG. 2, when voltage application terminals 4, 4' are provided on the metal layers 13, 13' facing the vibrating electrode 2, an electreso-condenser type electroacoustic After assembling the converter, connect terminals 13, 13 for voltage application.
By applying a DC voltage using the signal input/output terminals 11 and 11', a fixed electrode having a uniform surface potential and controlled to a predetermined surface potential can be easily and reliably obtained.
さらに長期間の使用により、エレクトレソトが劣化して
表面電位が低下した場合には、上記端子１３，１３’お
よび１１，１１’を用い直流電圧を印加する事により容
易にエレクトレットｌ２，１２’（固定電極〕を所定の
表面電位に再生する事ができる。Furthermore, if the electret l2, 12' ( fixed electrode] can be regenerated to a predetermined surface potential.
以下本発明を具体例により詳細に説明する。The present invention will be explained in detail below using specific examples.
まず、エレクトレソト用の素体１２，１２’として厚さ
７５μｍのＦＥＰテフロン（４弗化エチレン・６弗化プ
ロピレン共重合体、デュポン社商品名）の両面に金属層
１ １ ， １ １’，１３ ， １３’として厚さ０
． ５ ｍｒｎのＡｌ板を接着一体化して径７０朋の円
板状に切抜き、中心部から同心円状に直径２ｍｍの空気
孔を１４０ケ設けた。First, metal layers 11, 11', Thickness 0 as 13, 13'
．． A 5 mrn Al plate was glued together and cut out into a disc shape with a diameter of 70 mm, and 140 air holes with a diameter of 2 mm were provided concentrically from the center.
次に振動電極２としてＡ１蒸着を施した厚さ４μのポリ
エステルフイルムの両側に絶縁スペーサ３を介して２枚
の上記円板状固定電極１，１′が対向する様に配設し、
さらに直流電圧印加用の端子４，４′と交流信号入出力
用の端子５，５′を設けた。Next, the two disk-shaped fixed electrodes 1 and 1' were arranged so as to face each other on both sides of a 4μ thick polyester film subjected to A1 vapor deposition as the vibrating electrode 2, with an insulating spacer 3 in between.
Furthermore, terminals 4 and 4' for applying DC voltage and terminals 5 and 5' for inputting and outputting AC signals are provided.
次に、固定電極１，１′の各々の交流信号入出力用の端
子５，５′を接地した。Next, the AC signal input/output terminals 5, 5' of the fixed electrodes 1, 1' were grounded.
そして直流高電圧電源より固定電極１，１′の各々の直
流電圧印加端子４，４′に−１ ０ ０ ０Ｖの直流電
圧を印加してエレクトレット化し、本発明に係るエレク
トレット・コンデンサ型電気音響変換器を得た。Then, a DC voltage of -1000 V is applied to each DC voltage application terminal 4, 4' of the fixed electrodes 1, 1' from a DC high voltage power supply to convert it into an electret, and the electret-capacitor electroacoustic conversion according to the present invention I got the equipment.
尚、比較のために従来例として誘電体の片面に金属板を
設けてコロナ放電により−９６０Ｖのエレクトレソトを
得、第１図に示す如くこのエレクトレットを固定電極と
する以外は前記実施例と同一のエレクトレット・コンデ
ンサ型電気音響変換器を得た。For comparison, as a conventional example, a metal plate was provided on one side of the dielectric to obtain an electret of -960V by corona discharge, and the same as the previous example except that this electret was used as a fixed electrode as shown in Fig. 1. An electret capacitor type electroacoustic transducer was obtained.
そこで上記実施例（曲線Ａ）及び比較例（曲線Ｂ）につ
いて固定電極の表面電位の分布を調べたところ第３図の
如き結果が得られた。Therefore, when the distribution of the surface potential of the fixed electrode was investigated for the above-mentioned example (curve A) and comparative example (curve B), the results shown in FIG. 3 were obtained.
上記の如ぐして得た本発明のエレクトレソト・コンデン
サ型電気音響変換器と同様のものを１０個、従来の第１
図の如きエレクトレット・コンデンサ型電気音響変換器
と同様のものを１０個製造し、それぞれについてＩＷ相
当の電気信号を入力して電気音響変換器として動作させ
、高調波ひずみ周波数特性と出力音圧周波数特性を測定
した。Ten pieces similar to the electresothocapacitor type electroacoustic transducer of the present invention obtained as described above,
We manufactured 10 pieces similar to the electret capacitor type electroacoustic transducer shown in the figure, and operated them as electroacoustic transducers by inputting an electric signal equivalent to IW to each of them, and measured the harmonic distortion frequency characteristics and output sound pressure frequency. Characteristics were measured.
その結果、本発明のエレクトレット・コンデンサ型電気
音響変換器の歪率は１０個全て０．３％以下であり、又
固定電極の表面電位の均一なものが得られた。As a result, the distortion factors of all 10 electret capacitor type electroacoustic transducers of the present invention were 0.3% or less, and the surface potential of the fixed electrodes was uniform.
これに対して、従来のエレクトレソト・コンデンサ型電
気音響変換器の歪率は１％から５％と大きく、しかもバ
ラツキも大きかった。On the other hand, the distortion factor of conventional electreso-condenser electroacoustic transducers is large, ranging from 1% to 5%, and also has large variations.
また出力音圧レベルは本発明のエレクトレット・コンデ
ンサ型電気音響変換器では１０個全て８ ９ ｄＢから
９ ０ ｄＢであった。In addition, the output sound pressure level was 89 dB to 90 dB for all ten electret capacitor type electroacoustic transducers of the present invention.
これに対して、従来のエレクトレット・コンデンサ型電
気音響変換器では８６ｄＢから９ １ ｄＢとバラツキ
が大きかった。On the other hand, the conventional electret capacitor type electroacoustic transducer had a large variation of 86 dB to 9 1 dB.
以上述べた本発明の実施例から明らかな如く、両主面に
金属層を設けたエレクトレソトを固定電極として用いる
ことにより、表面電位の均一なエレクトレソトが得られ
、かつ固定電極も平滑化することができるので固定電極
全面にわたって等しいエアーギャップが得られ、エレク
トレット・コンデンサ型電気音響変換器の高調波歪の発
生を一層防止できる。As is clear from the embodiments of the present invention described above, by using an electret electrode with metal layers on both main surfaces as a fixed electrode, an electret electrode with a uniform surface potential can be obtained, and the fixed electrode can also be smoothed. Therefore, an equal air gap can be obtained over the entire surface of the fixed electrode, and the occurrence of harmonic distortion in the electret capacitor type electroacoustic transducer can be further prevented.
すなわち、本発明を実施することにより極めて低歪のハ
イファイ化を図ったエレクトレソト・コンデンサ型電気
音響変換器を提供できる。In other words, by carrying out the present invention, it is possible to provide an electroacoustic transducer of extremely low distortion and high fidelity.
また本発明を実施することにより、出力電圧のバラツキ
カ少ないエレクトレット・コンデンサ型電気音響変換器
が得られる。Further, by implementing the present invention, an electret capacitor type electroacoustic transducer with less variation in output voltage can be obtained.
さらに振動極に対応する側の金属層に電圧印加用の端子
を設ける事によりエレクトレソト・コンデンサ型電気音
響変換器を組立ててからエレクトレット化する事も可能
な構造となり、又、エレクトレソトの表面電位が何らか
の原因で低下してもエレクトレット・コンデンサ型電気
音響変換器を解体せずに再びエレクトレソト化できると
いう利点がある。Furthermore, by providing a terminal for voltage application on the metal layer on the side corresponding to the vibrating pole, it becomes possible to assemble an electret capacitor type electroacoustic transducer and then convert it into an electret. Even if the electret capacitor type electroacoustic transducer decreases for some reason, it has the advantage that it can be converted to electret again without disassembling the electret capacitor type electroacoustic transducer.
また、本発明のエレクトレット・コンデンサ型電気音響
変換器において固定電極のエレクトレソトを互いに異符
号にエレクトレソト化することにより変換能率を６ｄＢ
上昇させることができ、より実用的なエレクトレソト・
コンデンサ型電気音響変換器を提供できる。Furthermore, in the electret capacitor type electroacoustic transducer of the present invention, the conversion efficiency can be increased by 6 dB by changing the electrets of the fixed electrodes to have opposite signs.
Can be raised and more practical electret
A capacitor-type electroacoustic transducer can be provided.
さらに本発明のエレクトレソト・コンデンサ型電気音響
変換器に用いるエレクトレット材料として実施例ではＦ
ＥＰテフロンを使用したが、従来のエレクトレットに適
する材料、例えばポリ弗化ビニリテツ、ポリメチル・メ
タアクリルレート、ポリエチレン、ポリプロピレンのい
ずれか一種もし《はこれらのブレンド物質または積層物
を使用しても本発明の目的を達成することができる。Further, as an electret material used in the electret capacitor type electroacoustic transducer of the present invention, F
Although EP Teflon was used, materials suitable for conventional electrets, such as polyvinylidene fluoride, polymethyl methacrylate, polyethylene, polypropylene, or blends or laminates thereof may also be used in the present invention. can achieve the objectives of
尚、本発明のエレクトレソト・コンデンサ型電気音響変
換器は前記した実施例のプッシュプル形のみならずシン
グル形にも同様の効果が得られることは言うまでもない
。It goes without saying that the electreso-capacitor type electroacoustic transducer of the present invention can provide similar effects not only to the push-pull type of the above-mentioned embodiments but also to the single type.
第１図は従来のエレクトレソト・コンデンサ型電気音響
変換器の構造例を示す断面図、第２図は本発明に係るエ
レクト・コンデンサ型電気音響変換器の構造例を示す断
面図、第３図は本発明に係るエレクトレット・コンデン
サ型電気音響変換器の特性を示す曲線図。
１，１′・・・・・・固定電極、１１，１１’，１３，
１３’・・・・・・金属層、１ ２ ， １ ２’・−
・・・エレクトレソト、２・・・・・・振動電極、３・
・・・・・絶縁スペーサ、４ ， ４’−・・・直流電
圧印加用の端子、５，５’・・・・・交流信号入出力用
の端子、６・・・・・・固定枠。FIG. 1 is a cross-sectional view showing an example of the structure of a conventional electro-condenser electroacoustic transducer, FIG. 2 is a cross-sectional view showing an example of the structure of an electro-acoustic transducer according to the present invention, and FIG. FIG. 2 is a curve diagram showing the characteristics of the electret capacitor type electroacoustic transducer according to the present invention. 1, 1'... Fixed electrode, 11, 11', 13,
13'...Metal layer, 1 2 , 1 2'・-
...electresotho, 2...vibration electrode, 3.
...Insulating spacer, 4, 4'--Terminal for DC voltage application, 5, 5'...Terminal for AC signal input/output, 6...Fixed frame.
Claims (1)
両主面にそれぞれ金属層を有するエレクトレソトからな
る固定電極とを具備した事を特徴とするエレクトレット
・コンデンサ型電気音響変換器。 ２ 特許請求の範囲第１項において、固定電極の金属層
の内、振動電極と対面する側の金属層に電圧印加用の端
子を設けた事を特徴とするエレクトレット・コンデンサ
型電気音響変換器。[Scope of Claims] 1. An electret capacitor type electroacoustic device comprising a vibrating electrode and a fixed electrode made of electret, which is provided to face the vibrating electrode and has metal layers on both principal surfaces. converter. 2. The electret capacitor type electroacoustic transducer according to claim 1, characterized in that among the metal layers of the fixed electrode, a terminal for voltage application is provided on the metal layer on the side facing the vibrating electrode.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13236080A JPS5911240B2 (en) | 1980-09-25 | 1980-09-25 | Electret capacitor type electroacoustic transducer |
| EP81107385A EP0048902A3 (en) | 1980-09-25 | 1981-09-18 | Method for manufacturing electret device and condenser type electro-acoustic transducer having electrets |
| CA000386656A CA1197605A (en) | 1980-09-25 | 1981-09-25 | Method for manufacturing electret device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13236080A JPS5911240B2 (en) | 1980-09-25 | 1980-09-25 | Electret capacitor type electroacoustic transducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5758499A JPS5758499A (en) | 1982-04-08 |
| JPS5911240B2 true JPS5911240B2 (en) | 1984-03-14 |
Family
ID=15079537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13236080A Expired JPS5911240B2 (en) | 1980-09-25 | 1980-09-25 | Electret capacitor type electroacoustic transducer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5911240B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWM395976U (en) * | 2010-06-30 | 2011-01-01 | Tsung-Hung Wu | Electret electroacoustic transducer |
-
1980
- 1980-09-25 JP JP13236080A patent/JPS5911240B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5758499A (en) | 1982-04-08 |
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