JP2018170592A - Voice coil and sound generating device including voice coil - Google Patents

Voice coil and sound generating device including voice coil Download PDF

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JP2018170592A
JP2018170592A JP2017065540A JP2017065540A JP2018170592A JP 2018170592 A JP2018170592 A JP 2018170592A JP 2017065540 A JP2017065540 A JP 2017065540A JP 2017065540 A JP2017065540 A JP 2017065540A JP 2018170592 A JP2018170592 A JP 2018170592A
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voice coil
wire
cnt
sound
carbon nanotube
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山下　智
Satoshi Yamashita
智 山下
英樹 會澤
Hideki Aizawa
英樹 會澤
大久保　典雄
Norio Okubo
典雄 大久保
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Furukawa Electric Co Ltd
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PROBLEM TO BE SOLVED: To provide a voice coil which can obtain sufficient acoustic pressure sensitivity while achieving further downsizing, has good manufacturability, and can realize a high permissible current.SOLUTION: A sound generating device 1 includes a housing body 10, a protective member 20 attached to the housing body, a driving unit 30, a terminal plate 40, and a cable 50 that electrically connects the terminal plate 40 and the outside. The driving unit 30 includes a voice coil 35 formed by winding an electric wire configured to allow a current corresponding to an electric signal of sound to flow therethrough and provided so as to be movable. A carbon nanotube wire constituting the voice coil 35 is formed by bundling a plurality of carbon nanotube aggregates having one or more layer structure.SELECTED DRAWING: Figure 1

Description

本発明は、ボイスコイル及び該ボイスコイルを備える音発生装置に関し、特にイヤホンやスピーカなどに内蔵されるボイスコイルに関する。   The present invention relates to a voice coil and a sound generator including the voice coil, and more particularly to a voice coil built in an earphone or a speaker.

従来、イヤホンやスピーカなどの音発生装置は、音の電気信号が流れるボイスコイルと、該ボイスコイルに直接的又は間接的に取り付けられた振動板とを備え、ボイスコイルに音の電気信号を流すことによって振動板を振動させ、この振動板の振動によってユーザが音を認識することが可能となっている。   2. Description of the Related Art Conventionally, a sound generator such as an earphone or a speaker includes a voice coil through which an electric signal of sound flows and a diaphragm attached directly or indirectly to the voice coil, and causes the electric signal of sound to flow through the voice coil. Thus, the diaphragm is vibrated, and the user can recognize the sound by the vibration of the diaphragm.

例えば、従来のボイスコイルを備える音発生装置として、筐体と、該筐体に取り付けられる振動部と磁気回路部とを有したスピーカユニットとを備えるイヤホンが開示されている。このイヤホンでは、上記振動部が、振動板と、ボイスコイルとを備え、該ボイスコイルが、長尺の平板状に形成されて、その長手方向が上記振動板の振動した際に生じる音の放射方向と略平行に配置されることで、スピーカユニットの小型化を図ることが可能とされている（特許文献１）。   For example, an earphone including a casing and a speaker unit having a vibration section and a magnetic circuit section attached to the casing is disclosed as a sound generation apparatus including a conventional voice coil. In this earphone, the vibration part includes a diaphragm and a voice coil, and the voice coil is formed in a long flat plate shape, and sound emission generated when the longitudinal direction of the diaphragm vibrates is generated. The speaker unit can be reduced in size by being arranged substantially parallel to the direction (Patent Document 1).

特開２００９−０４９７５７号公報JP 2009-049757 A

近年、イヤホン装着時の耳などへの負荷を減らし且つ十分な音量を得るために、従来よりも更に小型で且つ音圧感度の高いボイスコイルが求められている。音圧感度を上げるためには、ボイスコイルに十分な電流を流すことができ、且つボイスコイルを軽量にする必要がある。しかしながら、従来の銅線や銅クラッドアルミニウム線（ＣＣＡＷ：Copper-Clad Aluminum Wires）を用いたボイスコイルでは、銅線或いはＣＣＡＷの質量が大きいため、ボイスコイルを小型化するに伴って銅線或いはＣＣＡＷの質量に因る音圧感度の低下の影響が大きくなることから、十分な音圧感度が得られないという問題がある。   In recent years, in order to reduce the load on ears and the like when wearing earphones and to obtain a sufficient volume, a voice coil that is smaller and has higher sound pressure sensitivity than before has been demanded. In order to increase the sound pressure sensitivity, it is necessary to allow a sufficient current to flow through the voice coil and to reduce the weight of the voice coil. However, in the conventional voice coil using copper wire or copper-clad aluminum wires (CCAW), the copper wire or CCAW has a large mass, so as the voice coil is downsized, the copper wire or CCAW Since the influence of the decrease in the sound pressure sensitivity due to the mass of the sound increases, there is a problem that sufficient sound pressure sensitivity cannot be obtained.

また、従来のアルミニウム線を用いたボイスコイルの場合、アルミニウムは銅に比べて密度が３割程度であるため、質量の観点からは銅やＣＣＡＷに比べれば良好な音圧感度を得ることが可能であるものの、小型のボイスコイルに求められる外径０．０３ｍｍ以下の線材をアルミニウムで作製することは困難であり、製造性に劣る。更に、銅線、ＣＣＡＷあるいはアルミニウム線は、許容電流が小さいため、所定量以上の大電流を流すと断線が懸念されることから、これらの金属線で音圧感度の優れたボイスコイルを作製するには限界がある。   In the case of a voice coil using a conventional aluminum wire, since aluminum has a density of about 30% compared to copper, good sound pressure sensitivity can be obtained compared to copper or CCAW from the viewpoint of mass. However, it is difficult to produce a wire having an outer diameter of 0.03 mm or less, which is required for a small voice coil, with aluminum, which is inferior in manufacturability. Furthermore, since copper wire, CCAW or aluminum wire has a small allowable current, there is a concern about disconnection when a large current of a predetermined amount or more flows, so a voice coil with excellent sound pressure sensitivity is produced using these metal wires. Has its limits.

本発明の目的は、更なる小型化を実現しつつ十分な音圧感度を得ることができ、製造性が良好であり、加えて高許容電流を実現することができるボイスコイル及び該ボイスコイルを備える音発生装置を提供することにある。   An object of the present invention is to provide a voice coil capable of obtaining sufficient sound pressure sensitivity while realizing further downsizing, good manufacturability, and in addition, realizing a high allowable current, and the voice coil. The object is to provide a sound generating device.

すなわち、上記課題は以下の発明により達成される。
（１）音の電気信号に対応する電流を流すことが可能に構成された電線を巻回してなり、移動可能に設けられたボイスコイルであって、
前記電線は、１層以上の層構造を有する複数のカーボンナノチューブが束ねられてなるカーボンナノチューブ線材を有することを特徴とするボイスコイル。
（２）前記カーボンナノチューブ線材の平均外径が、１ｍｍ以下であることを特徴とする、上記（１）記載のボイスコイル。
（３）前記カーボンナノチューブ線材の平均外径が、０．０１ｍｍ以下であることを特徴とする、上記（２）記載のボイスコイル。
（４）前記カーボンナノチューブ線材を構成するカーボンナノチューブの個数に対する、２層構造又は３層構造を有するカーボンナノチューブの個数の和の比率が７５％以上であることを特徴とする、上記（１）〜（３）のいずれかに記載のボイスコイル。
（５）前記カーボンナノチューブ線材において、ラマン分光法におけるラマンスペクトルのＧバンドと結晶性に由来するＤバンドとの比であるＧ／Ｄ比が８０以上であることを特徴とする、上記（１）〜（４）のいずれかに記載のボイスコイル。
（６）前記電線が、前記カーボンナノチューブ線材の外周を被覆する絶縁被覆層を更に有することを特徴とする、上記（１）記載のボイスコイル。
（７）上記（１）〜（６）のいずれかに記載のボイスコイルを備える音発生装置。 That is, the said subject is achieved by the following invention.
(1) It is a voice coil that is movably provided by winding an electric wire configured to allow a current corresponding to an electrical signal of sound to flow.
The voice coil, wherein the electric wire has a carbon nanotube wire in which a plurality of carbon nanotubes having a layer structure of one or more layers are bundled.
(2) The voice coil according to (1) above, wherein an average outer diameter of the carbon nanotube wire is 1 mm or less.
(3) The voice coil according to (2) above, wherein the carbon nanotube wire has an average outer diameter of 0.01 mm or less.
(4) The ratio of the sum of the number of carbon nanotubes having a two-layer structure or a three-layer structure to the number of carbon nanotubes constituting the carbon nanotube wire is 75% or more. The voice coil according to any one of (3).
(5) In the carbon nanotube wire, the G / D ratio, which is the ratio of the G band of Raman spectrum in Raman spectroscopy to the D band derived from crystallinity, is 80 or more, (1) The voice coil according to any one of to (4).
(6) The voice coil according to (1), wherein the electric wire further includes an insulating coating layer that covers an outer periphery of the carbon nanotube wire.
(7) A sound generator including the voice coil according to any one of (1) to (6).

本発明によれば、更なる小型化を実現しつつ十分な音圧感度を得ることができ、製造性が良好であり、加えて高許容電流を実現することができる。   According to the present invention, sufficient sound pressure sensitivity can be obtained while further miniaturization is realized, manufacturability is good, and a high allowable current can be realized.

本発明の実施形態に係るボイスコイルを備える音発生装置の構成を概略的に示す分解斜視図である。It is a disassembled perspective view which shows schematically the structure of a sound generator provided with the voice coil which concerns on embodiment of this invention. （ａ）図１の音発生装置の駆動部の構造を示す断面図であり、（ｂ）はボイスコイルの構成を示す斜視図である。(A) It is sectional drawing which shows the structure of the drive part of the sound generator of FIG. 1, (b) is a perspective view which shows the structure of a voice coil. 図２（ｂ）の線Ｉ−Ｉに沿う断面を示す図である。It is a figure which shows the cross section along line II of FIG.2 (b). 本実施形態に係るボイスコイルを備える音発生装置の変形例を示す図である。It is a figure which shows the modification of a sound generator provided with the voice coil which concerns on this embodiment.

以下、本発明の実施形態を、図面を参照しながら詳細に説明する。
＜ボイスコイルの構成＞
図１は、本発明の実施形態に係るボイスコイルを備える音発生装置の構成を概略的に示す分解斜視図であり、図２（ａ）は、図１の音発生装置の駆動部の構造を示す断面図、図２（ｂ）はボイスコイルの構成を示す斜視図である。図１，２におけるボイスコイル及び音発生装置は、その一例を示すものであり、本発明に係るボイスコイル及び音発生装置の構成は、図１，２のものに限られないものとする。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Configuration of voice coil>
FIG. 1 is an exploded perspective view schematically showing a configuration of a sound generation device including a voice coil according to an embodiment of the present invention. FIG. 2A shows a structure of a drive unit of the sound generation device of FIG. FIG. 2B is a perspective view showing the configuration of the voice coil. The voice coil and the sound generator in FIGS. 1 and 2 show an example, and the configurations of the voice coil and the sound generator according to the present invention are not limited to those in FIGS.

図１に示すように、音発生装置１は、筐体本体１０と、筐体本体に取り付けられた保護部材２０と、駆動部３０と、端子板４０と、端子板４０と外部を電気的に接続するケーブル５０とを備える。この音発生装置１は、例えば耳栓型のイヤホンであり、ケーブル５０から供給される電気信号によって駆動部３０を振動させ、この振動によって音を発生させるダイナミック型の駆動方式を有している。本実施形態の音発生装置１は、耳栓型であるが、これに限らず、インナーイヤー型或いはオーバーヘッド型であってもよい。   As shown in FIG. 1, the sound generator 1 electrically connects a housing body 10, a protection member 20 attached to the housing body, a drive unit 30, a terminal plate 40, the terminal plate 40, and the outside. And a cable 50 to be connected. The sound generator 1 is, for example, an earplug type earphone, and has a dynamic drive system in which the drive unit 30 is vibrated by an electric signal supplied from a cable 50 and a sound is generated by the vibration. The sound generator 1 of the present embodiment is an earplug type, but is not limited to this, and may be an inner ear type or an overhead type.

駆動部３０は、筐体本体１０と保護部材２０との間に介装された略円形の枠体３１と、該枠体３１の中央部に取り付けられた円盤型のマグネット３２と、該マグネット３２の枠体３１とは反対側に固定された円盤型のプレート３３と、枠体３１の内部全体を覆って設けられた略円形の振動板３４と、音の電気信号に対応する電流を流すことが可能に構成された電線を巻回してなり、移動可能に設けられたボイスコイル３５とを有する。   The drive unit 30 includes a substantially circular frame 31 interposed between the housing body 10 and the protection member 20, a disk-shaped magnet 32 attached to the center of the frame 31, and the magnet 32. A disc-shaped plate 33 fixed to the opposite side of the frame 31, a substantially circular diaphragm 34 provided so as to cover the entire inside of the frame 31, and a current corresponding to an electrical signal of sound. It has a voice coil 35 that is formed by winding an electric wire that is configured to be movable and is movably provided.

枠体３１は、径方向中央部の凹部３１ａと、その外周に配置されたフランジ部３１ｂとを有しており、凹部３１ａにマグネット３２が収容されている。マグネット３２は、プレート３３と不図示のヨークが設けられた枠体３１との間に挟持されており、マグネット３２、プレート３３及び枠体３１が磁気回路を構成している。   The frame body 31 has a concave portion 31a in the central portion in the radial direction and a flange portion 31b disposed on the outer periphery thereof, and a magnet 32 is accommodated in the concave portion 31a. The magnet 32 is sandwiched between a plate 33 and a frame 31 provided with a yoke (not shown), and the magnet 32, the plate 33, and the frame 31 constitute a magnetic circuit.

振動板３４は、樹脂で一体成形されたダイヤフラムと呼ばれる部材であり、中央部３４ａと外周部３４ｂとで構成されている。中央部３４ａは、マグネット３２側とは反対側に膨らんだドーム形状を有している（図２（ａ））。外周部３４ｂの外縁は、枠体３１のフランジ部３１ｂに固定されている。振動板３４は、マグネット３２の軸方向（図中の矢印Ａ方向）に沿って移動可能に設けられている。   The diaphragm 34 is a member called a diaphragm integrally formed of resin, and includes a central portion 34a and an outer peripheral portion 34b. The central portion 34a has a dome shape that swells on the opposite side to the magnet 32 side (FIG. 2A). The outer edge of the outer peripheral portion 34 b is fixed to the flange portion 31 b of the frame body 31. The diaphragm 34 is provided so as to be movable along the axial direction of the magnet 32 (the direction of arrow A in the figure).

ボイスコイル３５は、振動板３４の保護部材２０とは反対側に取り付けられ、且つマグネット３２及びプレート３３の外周に亘って配置されている。このボイスコイル３５は、電線としてのカーボンナノチューブ線材１００（以下、ＣＮＴ線材という）が巻き回されることで形成された円環状部材であり（図２（ｂ））、ＣＮＴ線材１の端部１００ａ，１００ｂが端子板４０に接続されている。ボイスコイル３５は、その軸方向（矢印Ａ方向）一端部３５ａが振動板３４に固定されており、他端部３５ｂは固定されておらず、振動板３４と共にマグネット３２の軸方向（図中の矢印Ａ方向）に沿って移動可能に設けられている。   The voice coil 35 is attached to the opposite side of the diaphragm 34 from the protective member 20, and is disposed over the outer periphery of the magnet 32 and the plate 33. The voice coil 35 is an annular member formed by winding a carbon nanotube wire 100 (hereinafter referred to as a CNT wire) as an electric wire (FIG. 2B), and the end portion 100a of the CNT wire 1 is formed. , 100b are connected to the terminal board 40. The voice coil 35 has one end 35a in the axial direction (direction of arrow A) fixed to the diaphragm 34 and the other end 35b is not fixed, and the axial direction of the magnet 32 together with the diaphragm 34 (in the drawing). It is provided so as to be movable along the direction of arrow A).

本実施形態では、ＣＮＴ線材１がボイスコイル３５の電線を構成しているが、これに限らず、絶縁被覆が設けられたＣＮＴ線材１が電線を構成してもよい。すなわち、ボイスコイル３５の電線が、ＣＮＴ線材１と、該ＣＮＴ線材１の外周を被覆する１又は複数の絶縁被覆層とを有していてもよい。１又は複数の絶縁被覆層は、例えばエナメル或いは樹脂からなる。   In the present embodiment, the CNT wire 1 constitutes the electric wire of the voice coil 35, but is not limited thereto, and the CNT wire 1 provided with an insulating coating may constitute the electric wire. That is, the electric wire of the voice coil 35 may have the CNT wire 1 and one or a plurality of insulating coating layers covering the outer periphery of the CNT wire 1. The one or more insulating coating layers are made of, for example, enamel or resin.

＜ＣＮＴ線材、ＣＮＴ集合体及びＣＮＴの構成＞
ボイスコイル３５を構成するＣＮＴ線材１は、図３に示すように、１層以上の層構造を有する複数のカーボンナノチューブ１１１，１１１，・・・（以下、ＣＮＴという）で構成されるカーボンナノチューブ集合体１１０（以下、ＣＮＴ集合体という）の複数が束ねられてなる。ＣＮＴ線材１の平均外径は、好ましくは１ｍｍ以下、より好ましくは０．０３ｍｍ未満、更に好ましくは０．０１ｍｍ以下である。 <Configuration of CNT wire, CNT aggregate and CNT>
As shown in FIG. 3, the CNT wire 1 constituting the voice coil 35 is a set of carbon nanotubes composed of a plurality of carbon nanotubes 111, 111,... A plurality of bodies 110 (hereinafter referred to as CNT aggregates) are bundled. The average outer diameter of the CNT wire 1 is preferably 1 mm or less, more preferably less than 0.03 mm, and still more preferably 0.01 mm or less.

ＣＮＴ集合体１１０は、１層以上の層構造を有するＣＮＴの束であり、ＣＮＴ集合体１１０における複数のＣＮＴ１１１，１１１、・・・の軸方向がほぼ揃って配されている。ＣＮＴ集合体１１０の平均外径は、好ましくは２０ｎｍ〜８０ｎｍであり、ＣＮＴ１１１の最外層の平均幅寸法は、好ましくは１．０ｎｍ〜４．０ｎｍである。これら平均値は透過型電子顕微鏡画像に基づいて平均（Ｎ＝５０）をとって算出する。   The CNT aggregate 110 is a bundle of CNTs having a layer structure of one or more layers, and a plurality of CNTs 111, 111,... The average outer diameter of the CNT aggregate 110 is preferably 20 nm to 80 nm, and the average width dimension of the outermost layer of the CNT 111 is preferably 1.0 nm to 4.0 nm. These average values are calculated by taking the average (N = 50) based on the transmission electron microscope image.

ＣＮＴ集合体１１０を構成するＣＮＴ１１１は、単層構造又は複層構造を有する筒状体であり、それぞれＳＷＮＴ（single-walled nanotube）、ＭＷＮＴ（multi-walled nanotube）と呼ばれる。図３では便宜上、２層構造を有するＣＮＴのみを記載しているが、実際には、３層構造を有するＣＮＴが多数存在する。単層構造又は４層以上の層構造を有するＣＮＴはＣＮＴ集合体１１０に含まれてもよいが、２層又は３層構造を有するＣＮＴに比べて少量である。   The CNTs 111 constituting the CNT aggregate 110 are cylindrical bodies having a single-layer structure or a multi-layer structure, and are called SWNT (single-walled nanotube) and MWNT (multi-walled nanotube), respectively. In FIG. 3, only CNTs having a two-layer structure are shown for convenience, but there are actually many CNTs having a three-layer structure. CNTs having a single-layer structure or a layer structure of four or more layers may be included in the CNT aggregate 110, but the amount is smaller than that of a CNT having a two-layer or three-layer structure.

ＣＮＴ１１１は、六角形格子の網目構造を有する２つの筒状体１１１ａ，１１１ｂ（以下、単に「層」ともいう）が略同軸で配された３次元網目構造体となっており、ＤＷＮＴ（Double-walled nanotube）と呼ばれる。構成単位である六角形格子は、その頂点に炭素原子が配された六員環であり、他の六員環と隣接してこれらが連続的に結合している。   The CNT 111 is a three-dimensional network structure in which two cylindrical bodies 111a and 111b (hereinafter simply referred to as “layers”) having a hexagonal lattice network structure are arranged substantially coaxially. called walled nanotube). The hexagonal lattice, which is a structural unit, is a six-membered ring in which a carbon atom is arranged at the apex, and these are continuously bonded adjacent to another six-membered ring.

ＣＮＴ１１１の性質は、上記のような筒状体のカイラリティ（chirality）に依存する。カイラリティは、アームチェア型、ジグザグ型、及びそれ以外のカイラル型に大別され、アームチェア型は金属性、カイラル型は半導体性および半金属性、ジグザグ型は半導体性および半金属性の挙動を示す。よってＣＮＴの導電性はいずれのカイラリティを有するかによって大きく異なり、ＣＮＴ集合体の導電性を向上させるには、金属性の挙動を示すアームチェア型のＣＮＴの割合を増大させることが重要とされてきた。一方、半導体性を有するカイラル型のＣＮＴに電子供与性もしくは電子受容性を持つ物質（異種元素）をドープすることにより、金属的挙動を示すことが分かっている。また、一般的な金属では、異種元素をドープすることによって金属内部での伝導電子の散乱が起こって導電性が低下するが、これと同様に、金属性ＣＮＴに異種元素をドープした場合には、導電性の低下を引き起こす。   The properties of the CNT 111 depend on the chirality of the cylindrical body as described above. Chirality is roughly divided into armchair type, zigzag type, and other chiral types. Armchair type is metallic, chiral type is semiconducting and semimetallic, and zigzag type is semiconducting and semimetallic. Show. Therefore, the conductivity of CNTs varies greatly depending on which chirality is present, and in order to improve the conductivity of CNT aggregates, it has been important to increase the proportion of armchair CNTs that exhibit metallic behavior. It was. On the other hand, it has been found that doping a chiral CNT having semiconducting properties with a substance (heterogeneous element) having an electron donating property or an electron accepting property exhibits a metallic behavior. In addition, in general metals, doping of different elements causes scattering of conduction electrons inside the metal, resulting in a decrease in conductivity. Similarly, when metallic CNTs are doped with different elements. , Causing a decrease in conductivity.

このように、金属性ＣＮＴ及び半導体性ＣＮＴへのドーピング効果は、導電性の観点からはトレードオフの関係にあると言えることから、理論的には金属性ＣＮＴと半導体性ＣＮＴとを別個に作製し、半導体性ＣＮＴにのみドーピング処理を施した後、これらを組み合わせることが望ましい。しかし、現状の製法技術では金属性ＣＮＴと半導体性ＣＮＴとを選択的に作り分けることは困難であり、金属性ＣＮＴと半導体性ＣＮＴが混在した状態で作製される。このため、金属性ＣＮＴと半導体性ＣＮＴの混合物からなるＣＮＴ線材の導電性を向上させるには、異種元素・分子によるドーピング処理が効果的となるＣＮＴ構造を選択することが必要となる。   Thus, since the doping effect on metallic CNT and semiconducting CNT can be said to have a trade-off relationship from the viewpoint of conductivity, theoretically, metallic CNT and semiconducting CNT are produced separately. In addition, it is desirable to combine these after performing doping treatment only on the semiconducting CNTs. However, it is difficult to selectively produce metallic CNT and semiconducting CNT selectively with the current manufacturing technique, and the metallic CNT and semiconducting CNT are produced in a mixed state. Therefore, in order to improve the conductivity of a CNT wire made of a mixture of metallic CNTs and semiconducting CNTs, it is necessary to select a CNT structure in which doping treatment with different elements / molecules is effective.

ＣＮＴ線材１を構成する複数のＣＮＴ１１１，１１１，・・・の個数に対する、２層又は３層構造を有するＣＮＴの個数の和の比率は、７５％であるのが好ましい。２層又は３層構造のような層数が少ないＣＮＴは、それより層数の多いＣＮＴよりも比較的導電性が高い。また、ドーパントは、ＣＮＴの最内層の内部、もしくは複数のＣＮＴで形成されるＣＮＴ間の隙間に導入される。一般的なＣＮＴの層間距離はグラファイトの層間距離である０．３３５ｎｍと同等であり、多層ＣＮＴの場合その層間にドーパントが入り込むことはサイズ的に困難である。このことからドーピング効果はＣＮＴの内部および外部にドーパントが導入されることで発現するが、多層ＣＮＴの場合は最外層および最内層に接していない内部に位置するチューブのドープ効果が発現しにくくなる。以上のような理由により、複層構造のＣＮＴにそれぞれドーピング処理を施した際には、２層又は３層構造を有するＣＮＴでのドーピング効果が最も高い。また、ドーパントは、強い求電子性もしくは求核性を示す、反応性の高い試薬であることが多い。単層構造のＣＮＴは多層よりも剛性が弱く、耐薬品性に劣るためにドーピング処理を施すと、ＣＮＴ自体の構造が破壊されることがある。よって本発明ではＣＮＴ線材に含まれる２層又は３層構造を有するＣＮＴの個数に着目する。また、２層又は３層構造のＣＮＴの個数の和の比率が７５％未満であると、単層構造或いは４層以上の複層構造を有するＣＮＴの比率が高くなり、ＣＮＴ線材全体としてドーピング効果が小さくなり、低抵抗率が得られない。よって、２層又は３層構造のＣＮＴの個数の和の比率を上記範囲内の値とする。   The ratio of the sum of the number of CNTs having a two-layer or three-layer structure to the number of CNTs 111, 111,... Constituting the CNT wire 1 is preferably 75%. A CNT with a small number of layers, such as a two-layer or three-layer structure, is relatively more conductive than a CNT with a larger number of layers. In addition, the dopant is introduced into the innermost layer of the CNT or in a gap between the CNTs formed by a plurality of CNTs. In general, the interlayer distance of CNT is equivalent to 0.335 nm which is the interlayer distance of graphite, and in the case of multilayer CNT, it is difficult in terms of size to enter the dopant between the layers. From this, the doping effect is manifested by introducing dopants inside and outside the CNT, but in the case of multi-walled CNT, the doping effect of the tube located inside the outermost layer and the innermost layer that is not in contact with the innermost layer becomes difficult to manifest. . For the reasons described above, when doping treatment is performed on CNTs having a multi-layer structure, the doping effect is highest in CNTs having a two-layer or three-layer structure. In addition, the dopant is often a highly reactive reagent that exhibits strong electrophilicity or nucleophilicity. CNTs having a single-layer structure are less rigid than multilayers and are inferior in chemical resistance. Therefore, when a doping process is performed, the structure of the CNT itself may be destroyed. Therefore, the present invention focuses on the number of CNTs having a two-layer or three-layer structure included in the CNT wire. In addition, when the ratio of the sum of the number of CNTs having a two-layer or three-layer structure is less than 75%, the ratio of CNTs having a single-layer structure or a multi-layer structure of four or more layers is increased, and the CNT wire as a whole has a doping effect. Becomes small and low resistivity cannot be obtained. Therefore, the ratio of the sum of the number of CNTs having a two-layer or three-layer structure is set to a value within the above range.

また、ＣＮＴ線材１では、ラマンスペクトルのＧバンドと結晶性に由来するＤバンドとの比であるＧ／Ｄ比が８０以上であるのが好ましく、１５５以上であることが更に好ましい。Ｄバンドは、ラマンシフト１３５０ｃｍ−１付近に現れ、欠陥に由来するスペクトルのピークとも言える。よってこのＧバンドに対するＤバンドの比（Ｇ／Ｄ比）は、ＣＮＴ中の欠陥量の指標として用いられ、Ｇ／Ｄ比が大きい程、ＣＮＴ中の欠陥が少ないと判断される。上記Ｇ／Ｄ比が８０未満であると、結晶性が低く、良好な導電性を得難くなる。よってラマンスペクトルにおけるＧ／Ｄ比を上記範囲内の値とする。 In the CNT wire 1, the G / D ratio, which is the ratio of the G band of the Raman spectrum to the D band derived from crystallinity, is preferably 80 or more, and more preferably 155 or more. The D band appears in the vicinity of the Raman shift of 1350 cm −1 and can be said to be a spectrum peak derived from a defect. Therefore, the ratio of the D band to the G band (G / D ratio) is used as an index of the amount of defects in the CNT, and it is determined that the larger the G / D ratio, the fewer the defects in the CNT. When the G / D ratio is less than 80, the crystallinity is low and it is difficult to obtain good conductivity. Therefore, the G / D ratio in the Raman spectrum is set to a value within the above range.

ＣＮＴ線材１は、ＣＮＴの内側及びＣＮＴ−ＣＮＴ間の少なくとも一方にドーピングされた異種元素・分子を更に有していてもよい。ドーパントとしては、リチウム（Ｌｉ）、ナトリウム（Ｎａ）、カリウム（Ｋ）、ルビジウム（Ｒｂ）、セシウム（Ｃｓ）、ストロンチウム（Ｓｒ）、バリウム（Ｂａ）、フッ素（Ｆ）、塩素（Ｃｌ）、臭素（Ｂｒ）、ヨウ素（Ｉ）及び硝酸からなる群から選択された１又は複数の材料を選択することができる。ＣＮＴ線材１への異種元素・分子のドーピングにより、ＣＮＴ線材１の導電性を更に向上することができる。   The CNT wire 1 may further include a different element / molecule doped in at least one of the inside of the CNT and between the CNT-CNTs. As dopants, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), strontium (Sr), barium (Ba), fluorine (F), chlorine (Cl), bromine One or more materials selected from the group consisting of (Br), iodine (I), and nitric acid can be selected. By doping the CNT wire 1 with different elements / molecules, the conductivity of the CNT wire 1 can be further improved.

ここで、ボイスコイルの線材として、銅線或いはＣＣＡＷを選択した場合、上述のようにボイスコイルを小型化する程音圧感度を上げ難くなり、ボイスコイルの小型化と音圧感度（本実施形態では、音圧感度を「ｄＢ」と定義する）の向上はトレードオフの関係にあると言える。また、ボイスコイルの線材としてアルミニウム線を選択した場合、現状の技術では平均外径０．０３ｍｍ未満のアルミニウム線を作製することが困難であり、平均外径０．０３ｍｍ未満のアルミニウム線で構成されるボイスコイルを作製することができない。更に、銅線、ＣＣＡＷあるいはアルミニウム線は、許容電流（電流容量）が小さいため、所定量以上の大電流が流れるとジュール熱の発生により溶断する虞がある。   Here, when a copper wire or CCAW is selected as the voice coil wire, it becomes difficult to increase the sound pressure sensitivity as the voice coil is reduced in size as described above, and the voice coil is reduced in size and the sound pressure sensitivity (this embodiment). Then, it can be said that the improvement in the sound pressure sensitivity is defined as “dB” is in a trade-off relationship. In addition, when an aluminum wire is selected as the wire for the voice coil, it is difficult to produce an aluminum wire having an average outer diameter of less than 0.03 mm with the current technology, and the aluminum wire having an average outer diameter of less than 0.03 mm is used. Cannot produce a voice coil. Furthermore, since the allowable current (current capacity) of the copper wire, CCAW, or aluminum wire is small, there is a risk of melting due to the generation of Joule heat when a large current of a predetermined amount or more flows.

一方、本実施形態のボイスコイル３５はＣＮＴ線材１で構成されるので、ＣＮＴ線材１が銅線やＣＣＡＷと比較して質量（或いは密度）が格段に小さく、ボイスコイル３５の小型化しても音圧感度が低下せず、十分な音圧感度を維持することができ、更には音圧感度を向上することが可能となる。また、ボイスコイル３５の線材としてＣＮＴ線材を選択すれば、平均外径０．０３ｍｍ未満の線材を作製する際に、アルミニウム線と比較して良好な製造性を実現することが可能となる。また、ＣＮＴ線材１は、銅線、ＣＣＡＷ、アルミニウム線等の金属線と比較して許容電流が大きいため、ＣＮＴ線材１に大電流が流れたときでも、溶断の発生を抑制することが可能となる。   On the other hand, since the voice coil 35 of the present embodiment is composed of the CNT wire 1, the CNT wire 1 has a remarkably smaller mass (or density) than the copper wire or CCAW, and even if the voice coil 35 is reduced in size, sound can be heard. Pressure sensitivity does not decrease, sufficient sound pressure sensitivity can be maintained, and sound pressure sensitivity can be further improved. Also, if a CNT wire is selected as the wire for the voice coil 35, it is possible to achieve better manufacturability than an aluminum wire when producing a wire having an average outer diameter of less than 0.03 mm. Moreover, since the allowable current is large compared with metal wires, such as a copper wire, CCAW, and an aluminum wire, the CNT wire 1 can suppress the occurrence of fusing even when a large current flows through the CNT wire 1. Become.

＜ボイスコイルの製造方法＞
本実施形態のボイスコイルは、例えば以下の方法により製造される。
ＣＮＴは、浮遊触媒法（特許第5819888号）や、基板法（特許第5590603号）などの手法で作製することができる。ＣＮＴ線材は、乾式紡糸（特許第5819888号、特許第5990202号、特許第5350635号）や湿式紡糸（特許第5135620号、特許第5131571号、特許第5288359号）で作製することができる。ＣＮＴ線材は、複数本のＣＮＴ、ＣＮＴ集合体を撚らずに作製された単線であってもよいし、複数本のＣＮＴ、ＣＮＴ集合体を撚って作製された撚り線であってもよい。 <Voice coil manufacturing method>
The voice coil of this embodiment is manufactured by the following method, for example.
CNTs can be produced by a method such as a floating catalyst method (Patent No. 5819888) or a substrate method (Patent No. 5860603). The CNT wire can be produced by dry spinning (Patent No. 5819888, Patent No. 5990020, Patent No. 5350635) or wet spinning (Patent No. 5135620, Patent No. 5115771, Patent No. 5288359). The CNT wire may be a single wire produced without twisting a plurality of CNTs or CNT aggregates, or a stranded wire produced by twisting a plurality of CNTs or CNT aggregates. .

ＣＮＴ線材をボイスコイルに用いるためには絶縁被覆することが必要であるが、絶縁被覆の方法としては、銅線やアルミニウム線と同様に押出被覆やエナメルの焼付によって、ＣＮＴ線材の外周に絶縁被覆層を形成することができる。これにより、ＣＮＴ線材が絶縁被覆層で被覆されてなるＣＮＴ電線が作製される。   In order to use the CNT wire for the voice coil, it is necessary to perform insulation coating. However, as the method of insulation coating, the outer periphery of the CNT wire is insulated by extrusion coating or enamel baking like the copper wire or aluminum wire. A layer can be formed. Thereby, the CNT electric wire formed by coating the CNT wire with the insulating coating layer is produced.

続いて、マグネットのサイズに合わせた型に、絶縁被覆層で被覆されたＣＮＴ電線を１００回から１０００回程度巻き付けてコイルとする。これにより、ＣＮＴ電線が巻回されてなるボイスコイルが作製される。   Subsequently, a CNT electric wire covered with an insulating coating layer is wound about 100 to 1000 times around a mold according to the size of the magnet to form a coil. Thereby, the voice coil formed by winding the CNT electric wire is manufactured.

上述したように、本実施形態によれば、ボイスコイル３５が、音の電気信号に対応する電流を流すことが可能に構成された電線を巻回してなり且つ移動可能に設けられ、当該電線が、１層以上の層構造を有する複数のＣＮＴ１１１で構成されるＣＮＴ集合体１１０の複数が束ねられてなるＣＮＴ線材１を有するので、銅線やＣＣＡＷなどの金属線と比較して質量が格段に軽く、更なる小型化を実現しつつ十分な音圧感度を得ることができる。そして、このようなボイスコイル３５の更なる小型化により、イヤホン装着時における耳などへの負荷を低減して、長時間の装着時にも良好な装着感を得ることができ、また、十分な音圧感度の実現によって十分な音量を得ることができる。加えて、音圧感度の向上によってダイナミックレンジを広げることができ、ハイレゾリューション音源（音源データ）を表現力豊かな音で再生することが可能となる。   As described above, according to the present embodiment, the voice coil 35 is provided so as to be movably provided by winding an electric wire configured to flow an electric current corresponding to an electric signal of sound. Since it has the CNT wire 1 formed by bundling a plurality of CNT aggregates 110 composed of a plurality of CNTs 111 having a layer structure of one or more layers, the mass is markedly higher than that of a metal wire such as a copper wire or CCAW. It is light and sufficient sound pressure sensitivity can be obtained while realizing further downsizing. Further, by further downsizing the voice coil 35 as described above, it is possible to reduce the load on the ears when wearing the earphone, and to obtain a good wearing feeling even when wearing for a long time. A sufficient volume can be obtained by realizing the pressure sensitivity. In addition, the dynamic range can be expanded by improving the sound pressure sensitivity, and it becomes possible to reproduce high resolution sound sources (sound source data) with richly expressive sounds.

また、ボイスコイル３５の電線がＣＮＴ線材１００を有しており、ＣＮＴ線材１００の平均外径が１ｍｍ以下であるので、金属線と比較して音質感度を向上することができる。また、ＣＮＴ線材１００の平均外径を０．０１ｍｍ以下とすることで、ＣＣＡＷでは作製することが困難であった平均外径０．０１ｍｍ以下の電線にてボイスコイル３５を製造することができ、また、アルミニウム線では作製することが困難であった平均外径０．０３ｍｍ未満の電線にてボイスコイル３５を製造することができる。   Moreover, since the electric wire of the voice coil 35 has the CNT wire 100 and the average outer diameter of the CNT wire 100 is 1 mm or less, the sound quality sensitivity can be improved as compared with the metal wire. In addition, by setting the average outer diameter of the CNT wire 100 to 0.01 mm or less, the voice coil 35 can be manufactured with an electric wire having an average outer diameter of 0.01 mm or less, which was difficult to produce with CCAW. Moreover, the voice coil 35 can be manufactured with an electric wire having an average outer diameter of less than 0.03 mm, which is difficult to manufacture with an aluminum wire.

更に、ＣＮＴ線材１００は、銅線、ＣＣＡＷ、アルミニウム線等の金属線と比較して許容電流が格段に大きいため、ボイスコイル３５に大電流が流れた場合であってもＣＮＴ線材１００の断線を防止することができ、高許容電流を実現することができる。特に、平均外径０．０１ｍｍ以下のＣＮＴ線材１００を用いた場合、金属線と比較して断線を防止することができ、強度を向上することができる。   Furthermore, since the allowable current is much larger than that of a metal wire such as a copper wire, a CCAW, and an aluminum wire, the CNT wire material 100 is capable of breaking the CNT wire material 100 even when a large current flows through the voice coil 35. Can be prevented, and a high allowable current can be realized. In particular, when a CNT wire 100 having an average outer diameter of 0.01 mm or less is used, disconnection can be prevented and strength can be improved as compared with a metal wire.

また、ＣＮＴ線材１００を構成するＣＮＴ１１１の個数に対する、２層構造又は３層構造を有するＣＮＴの個数の和の比率が７５％以上であるので、２層又は３層構造のＣＮＴ比率が高いので導電性を向上することができる。   Further, since the ratio of the sum of the number of CNTs having a two-layer structure or a three-layer structure to the number of CNTs 111 constituting the CNT wire rod 100 is 75% or more, the CNT ratio of the two-layer structure or the three-layer structure is high. Can be improved.

更に、ラマン分光法におけるラマンスペクトルのＧバンドと結晶性に由来するＤバンドとの比であるＧ／Ｄ比が８０以上であるので、ＣＮＴ１１１中の欠陥が少なく、結晶性が高く、ＣＮＴ１１１単体の低抵抗率を実現することができ、ＣＮＴ線材１００の導電性を更に向上することができる。   Furthermore, since the G / D ratio, which is the ratio of the G band of the Raman spectrum in the Raman spectroscopy to the D band derived from crystallinity, is 80 or more, there are few defects in the CNT 111, high crystallinity, A low resistivity can be realized and the conductivity of the CNT wire 100 can be further improved.

以上、本発明の実施形態に係るＣＮＴ線材について述べたが、本発明は記述の実施形態に限定されるものではなく、本発明の技術思想に基づいて各種の変形および変更が可能である。   Although the CNT wire according to the embodiment of the present invention has been described above, the present invention is not limited to the described embodiment, and various modifications and changes can be made based on the technical idea of the present invention.

上記実施形態では、音発生装置１は、イヤホン等のウェアラブル型の音発生装置であるが、これに限らず、スピーカ等の設置型の音発生装置であってもよい。   In the above embodiment, the sound generation device 1 is a wearable sound generation device such as an earphone, but is not limited thereto, and may be an installation type sound generation device such as a speaker.

例えば、図４に示すように、音発生装置２は、径方向中央部に孔６１ａが設けられた円盤型のマグネット６１と、マグネット６１の径方向中央部に配置されたボイスコイル６２と、ボイスコイル６２に取り付けられたコーン型の振動板６３とを有する駆動部６０を備える。ボイスコイル６２は、音の電気信号に対応する電流を流すことが可能に構成された電線を巻回してなり、移動可能に設けられている。そして、ボイスコイル６２を構成する電線は、１層以上の層構造を有する複数のＣＮＴで構成されるＣＮＴ集合体の複数が束ねられてなるＣＮＴ線材１００を有している。
本変形例によっても、銅線やＣＣＡＷなどの金属線と比較して質量が格段に軽く、更なる小型化を実現しつつ十分な音圧感度を得ることができる。 For example, as shown in FIG. 4, the sound generator 2 includes a disk-shaped magnet 61 having a hole 61 a in the radial center portion, a voice coil 62 disposed in the radial center portion of the magnet 61, and a voice The drive part 60 which has the cone-shaped diaphragm 63 attached to the coil 62 is provided. The voice coil 62 is formed by winding an electric wire configured to allow a current corresponding to an electrical signal of sound to flow, and is movably provided. And the electric wire which comprises the voice coil 62 has the CNT wire rod 100 formed by bundling a plurality of CNT aggregates composed of a plurality of CNTs having a layer structure of one or more layers.
Also according to this modification, the mass is much lighter than that of a metal wire such as a copper wire or CCAW, and sufficient sound pressure sensitivity can be obtained while realizing further downsizing.

以下、本発明の実施例を説明する。
（実施例１）
先ず、浮遊触媒法で作製したＣＮＴを直接紡糸する方法（特許第5819888号）で平均直径０．００５ｍｍのＣＮＴを得た。このＣＮＴの本数を調節して適宜撚り合わせることで、平均外径０．０３ｍｍのＣＮＴ線材を得た。そして、得られたＣＮＴ線材をエナメル層で被覆してＣＮＴ電線とし、このＣＮＴ電線を用いてボイスコイルを作製した。ＣＮＴ電線は外径３０μｍ、長さ１ｍのものを用い、このＣＮＴ線材を所定回巻き回して外径１０ｍｍのボイスコイルを作製した。 Examples of the present invention will be described below.
Example 1
First, CNTs having an average diameter of 0.005 mm were obtained by a method of directly spinning CNTs produced by the floating catalyst method (Japanese Patent No. 5819888). By adjusting the number of CNTs and appropriately twisting them, a CNT wire having an average outer diameter of 0.03 mm was obtained. Then, the obtained CNT wire was covered with an enamel layer to form a CNT electric wire, and a voice coil was produced using this CNT electric wire. A CNT electric wire having an outer diameter of 30 μm and a length of 1 m was used, and this CNT wire was wound a predetermined number of times to produce a voice coil having an outer diameter of 10 mm.

（比較例１〜２）
銅線及びＣＣＡＷを用いたこと以外は、実施例１と同様にしてボイスコイルを作製した。 (Comparative Examples 1-2)
A voice coil was produced in the same manner as in Example 1 except that a copper wire and CCAW were used.

次に、実施例１及び比較例１〜２について、ボイスコイルの質量、音圧感度及び許容電流を測定、評価した。具体的には、実施例１、比較例１〜２で得られたボイスコイルの質量をそれぞれ測定し、また、実施例１、比較例１〜２で得られた各ボイスコイルに振動板と磁石を取り付けてスピーカを作製し、このボイスコイルに１ｍＷのシグナルを入力し、音圧感度を測定、評価した。更に、各ボイスコイルに流すことができる最大の電流量（許容電流）を測定、評価した。結果を表１に示す。   Next, with respect to Example 1 and Comparative Examples 1 and 2, the mass, sound pressure sensitivity, and allowable current of the voice coil were measured and evaluated. Specifically, the masses of the voice coils obtained in Example 1 and Comparative Examples 1 and 2 were respectively measured, and a diaphragm and a magnet were added to each voice coil obtained in Example 1 and Comparative Examples 1 and 2. A 1 mW signal was input to the voice coil, and the sound pressure sensitivity was measured and evaluated. Furthermore, the maximum amount of current (allowable current) that can be passed through each voice coil was measured and evaluated. The results are shown in Table 1.

Figure 2018170592
Figure 2018170592

表１から分かるように、ＣＮＴ線材で作製した実施例１のボイスコイルの質量は、銅線で作製した比較例１のボイスコイルの質量の４分の１以下、ＣＣＡＷで作製した比較例２のボイスコイルの質量の３分の１以下であり、ＣＮＴ線材で作製したボイスコイルは、銅或いはＣＣＡＷで作製したボイスコイルと比較して非常に軽量であることが分かった。   As can be seen from Table 1, the mass of the voice coil of Example 1 made of CNT wire is less than one-fourth of the mass of the voice coil of Comparative Example 1 made of copper wire, and that of Comparative Example 2 made of CCAW. It was found that the voice coil was less than one-third of the mass of the voice coil, and the voice coil made of CNT wire was very light compared to the voice coil made of copper or CCAW.

また、ＣＮＴ線材で作製した実施例１の音圧感度は、銅線で作製した比較例１のボイスコイルの音圧感度よりも１３ｄＢ、ＣＣＡＷで作製した比較例２のボイスコイルよりも１０ｄＢ高く、ＣＮＴ線材で作製したボイスコイルは、銅或いはＣＣＡＷで作製したボイスコイルと比較して高い音圧感度を得られることが分かった。   In addition, the sound pressure sensitivity of Example 1 made of CNT wire is 13 dB higher than the sound pressure sensitivity of the voice coil of Comparative Example 1 made of copper wire, and 10 dB higher than the voice coil of Comparative Example 2 made of CCAW, It was found that a voice coil produced with a CNT wire can obtain a higher sound pressure sensitivity than a voice coil produced with copper or CCAW.

更に、ＣＮＴ線材で作製した実施例１の許容電流は４．２Ａであり、銅線で作製した比較例１のボイスコイルの許容電流の９倍以上、ＣＣＡＷで作製した比較例２のボイスコイルの許容電流の１１倍以上であり、ＣＮＴ線材で作製したボイスコイルは、銅或いはＣＣＡＷで作製したボイスコイルと比較して高許容電流を実現できることが分かった。   Further, the allowable current of Example 1 made of the CNT wire is 4.2 A, which is 9 times or more of the allowable current of the voice coil of Comparative Example 1 made of copper wire, and that of the voice coil of Comparative Example 2 made of CCAW. It was found that the voice coil made of CNT wire is 11 times or more of the allowable current, and that a high allowable current can be realized as compared with a voice coil made of copper or CCAW.

（実施例２〜１０）
次に、上記と同様にＣＮＴの本数を調節して適宜撚り合わせることで平均外径の異なる複数のＣＮＴ線材を準備し、各ＣＮＴ線材をエナメル層で被覆し、所定回巻き回してボイスコイルを作製した。得られたボイスコイルに振動板と磁石を取り付けてスピーカを作製した。 (Examples 2 to 10)
Next, in the same manner as described above, a plurality of CNT wires having different average outer diameters are prepared by appropriately twisting and adjusting the number of CNTs. Produced. A speaker and a magnet were attached to the obtained voice coil.

（比較例３〜１１）
銅線を用いたこと以外は、実施例２〜１０と同様にしてスピーカを作製した。 (Comparative Examples 3 to 11)
A speaker was produced in the same manner as in Examples 2 to 10 except that a copper wire was used.

（比較例１２〜２０）
ＣＣＡＷを用いたこと以外は、実施例２〜１０と同様にしてスピーカを作製した。 (Comparative Examples 12 to 20)
A speaker was manufactured in the same manner as in Examples 2 to 10 except that CCAW was used.

次に、実施例２〜１０及び比較例３〜２０について、上記と同様の方法にて音圧感度を測定、評価した。結果を表２に示す。   Next, for Examples 2 to 10 and Comparative Examples 3 to 20, the sound pressure sensitivity was measured and evaluated by the same method as described above. The results are shown in Table 2.

Figure 2018170592
Figure 2018170592

表２から分かるように、実施例２〜３では、ＣＮＴ線材の平均外径はそれぞれ０．００８ｍｍ，０．０１ｍｍであり、音圧感度は１１１，１１０ｄＢであることから、十分な音圧感度を実現できることが分かった。   As can be seen from Table 2, in Examples 2 to 3, the average outer diameter of the CNT wire is 0.008 mm and 0.01 mm, respectively, and the sound pressure sensitivity is 111 and 110 dB. It turns out that it can be realized.

一方、比較例３〜４では、銅線の平均外径がそれぞれ０．００８ｍｍｍ，０．０１ｍｍであり、１ｍＷのシグナルを入力すると断線した。これは各銅線の許容電流を超えたためと推察される。したがって、線材の平均外径０．０１ｍｍ以下の範囲では、ＣＮＴ線材で作製したボイスコイルは、銅線で作製したボイスコイルと比較して高許容電流を実現できることが分かった。   On the other hand, in Comparative Examples 3 to 4, the average outer diameters of the copper wires were 0.008 mmmm and 0.01 mm, respectively, and disconnected when a 1 mW signal was input. This is presumed to be due to exceeding the allowable current of each copper wire. Therefore, it was found that in the range where the average outer diameter of the wire is 0.01 mm or less, the voice coil made of the CNT wire can realize a higher allowable current than the voice coil made of the copper wire.

また、比較例１２〜１３では、平均外径０．００８ｍｍｍ或いは０．０１ｍｍのＣＣＡＷを作製できなかった。よって、平均外径０．０１ｍｍ以下のＣＮＴ線材で作製したボイスコイルは、ＣＣＡＷで作製したボイスコイルと比較して良好な製造性を実現できることが分かった。   In Comparative Examples 12 to 13, CCAW having an average outer diameter of 0.008 mm or 0.01 mm could not be produced. Therefore, it was found that a voice coil produced with a CNT wire having an average outer diameter of 0.01 mm or less can achieve better productivity than a voice coil produced with CCAW.

また、実施例４〜１０では、ＣＮＴ線材の平均外径がそれぞれ０．０３ｍｍｍ，０．０５ｍｍ、０．０８ｍｍ，０．１ｍｍ，０．５ｍｍ，１ｍｍ，２ｍｍ、音圧感度がそれぞれ１１３，１１３，１１５，１１４，１０８，１０４，９７ｄＢであり、優れた音圧感度を実現できることが分かった。   In Examples 4 to 10, the average outer diameter of the CNT wire was 0.03 mm, 0.05 mm, 0.08 mm, 0.1 mm, 0.5 mm, 1 mm, 2 mm, and the sound pressure sensitivity was 113, 113, respectively. 115, 114, 108, 104, and 97 dB, and it was found that excellent sound pressure sensitivity can be realized.

一方、比較例５〜１０では、銅線の平均外径がそれぞれ実施例４〜１０と同じで、音圧感度はそれぞれ１０１，９９，１０２，１００，１０１，９８，９７ｄＢとなり、同外径のＣＮＴ線材と比較して音圧感度が劣った。比較例１１では、銅線の外径が実施例１１と同じで、音圧感度が９７ｄＢであり、同外径のＣＮＴ線材と比較して音圧感度に差は無かった。これは、線径が太くなることで、ボイスコイルの質量が重くなり、密度の違いによる音圧感度の差が出にくくなったためと推察される。   On the other hand, in Comparative Examples 5 to 10, the average outer diameter of the copper wire is the same as that of each of Examples 4 to 10, and the sound pressure sensitivity is 101, 99, 102, 100, 101, 98, and 97 dB, respectively. Sound pressure sensitivity was inferior compared to CNT wire. In Comparative Example 11, the outer diameter of the copper wire was the same as in Example 11, the sound pressure sensitivity was 97 dB, and there was no difference in sound pressure sensitivity compared to the CNT wire having the same outer diameter. This is presumably because the voice coil mass becomes heavier due to the thicker wire diameter, and the difference in sound pressure sensitivity due to the difference in density is less likely to occur.

比較例１４〜１９では、ＣＣＡＷの平均外径がそれぞれ実施例４〜１０と同じで、音圧感度はそれぞれ１０３，１０２，１０１，１０３，１０３，１０１ｄＢとなり、同平均外径のＣＮＴ線材と比較して音圧感度が劣った。比較例２０では、ＣＣＡＷの平均外径が実施例１１と同じで、音圧感度が９８ｄＢであり、同平均外径のＣＮＴ線材と比較して音圧感度に大きな差は無かった。   In Comparative Examples 14 to 19, the average outer diameter of CCAW is the same as that of Examples 4 to 10, respectively, and the sound pressure sensitivity is 103, 102, 101, 103, 103, and 101 dB, respectively, which is compared with the CNT wire having the same average outer diameter. The sound pressure sensitivity was inferior. In Comparative Example 20, the average outer diameter of CCAW was the same as in Example 11, the sound pressure sensitivity was 98 dB, and there was no significant difference in sound pressure sensitivity compared to the CNT wire having the same average outer diameter.

よって、線材の平均外径０．０１ｍｍ〜２ｍｍの範囲で、ＣＮＴ線材で作製したボイスコイルは、銅線或いはＣＣＡＷで作製したボイスコイルと比較して同等或いは優れた音圧感度が得られることが分かった。特に、線材の平均外径０．０１ｍｍ〜０．１ｍｍの範囲では、ＣＮＴ線材で作製したボイスコイルは、銅線或いはＣＣＡＷで作製したボイスコイルと比較して優れた音圧感度を実現できることが分かった。   Therefore, in the range of the average outer diameter of the wire from 0.01 mm to 2 mm, the voice coil made of the CNT wire can obtain the same or superior sound pressure sensitivity as compared with the voice coil made of copper wire or CCAW. I understood. In particular, in the range of the average outer diameter of the wire from 0.01 mm to 0.1 mm, it can be seen that a voice coil made of CNT wire can achieve superior sound pressure sensitivity compared to a voice coil made of copper wire or CCAW. It was.

１ 音発生装置
２ 音発生装置
１０ 筐体本体
２０ 保護部材
３０ 駆動部
３１ａ 凹部
３１ｂ フランジ部
３１ 枠体
３２ マグネット
３３ プレート
３４ 振動板
３４ａ 中央部
３４ｂ 外周部
３５ ボイスコイル
４０ 端子板
５０ ケーブル
６０ 駆動部
６１ マグネット
６２ ボイスコイル
６３ 振動板
１００ カーボンナノチューブ線材（ＣＮＴ線材）
１００ａ，１００ｂ ＣＮＴ線材の端部
１１０ カーボンナノチューブ集合体（ＣＮＴ集合体）
１１１ カーボンナノチューブ（ＣＮＴ）
１１１ａ，１１１ｂ 筒状体 DESCRIPTION OF SYMBOLS 1 Sound generator 2 Sound generator 10 Case main body 20 Protection member 30 Drive part 31a Concave part 31b Flange part 31 Frame 32 Magnet 33 Plate 34 Diaphragm 34a Center part 34b Outer part 35 Voice coil 40 Terminal board 50 Cable 60 Drive part 61 Magnet 62 Voice coil 63 Diaphragm 100 Carbon nanotube wire (CNT wire)
100a, 100b CNT wire end 110 Carbon nanotube aggregate (CNT aggregate)
111 Carbon nanotubes (CNT)
111a, 111b cylindrical body

Claims (7)

音の電気信号に対応する電流を流すことが可能に構成された電線を巻回してなり、移動可能に設けられたボイスコイルであって、
前記電線は、１層以上の層構造を有する複数のカーボンナノチューブが束ねられてなるカーボンナノチューブ線材を有することを特徴とするボイスコイル。 It is a voice coil that is movably provided by winding an electric wire configured to allow a current corresponding to an electrical signal of sound to flow,
The voice coil, wherein the electric wire has a carbon nanotube wire in which a plurality of carbon nanotubes having a layer structure of one or more layers are bundled. 前記カーボンナノチューブ線材の平均外径が、１ｍｍ以下であることを特徴とする、請求項１記載のボイスコイル。   The voice coil according to claim 1, wherein an average outer diameter of the carbon nanotube wire is 1 mm or less. 前記カーボンナノチューブ線材の平均外径が、０．０１ｍｍ以下であることを特徴とする、請求項２記載のボイスコイル。   The voice coil according to claim 2, wherein an average outer diameter of the carbon nanotube wire is 0.01 mm or less. 前記カーボンナノチューブ線材を構成するカーボンナノチューブの個数に対する、２層構造又は３層構造を有するカーボンナノチューブの個数の和の比率が７５％以上であることを特徴とする、請求項１〜３のいずれか１項に記載のボイスコイル。   The ratio of the sum of the number of carbon nanotubes having a two-layer structure or a three-layer structure to the number of carbon nanotubes constituting the carbon nanotube wire is 75% or more. The voice coil according to item 1. 前記カーボンナノチューブ線材において、ラマン分光法におけるラマンスペクトルのＧバンドと結晶性に由来するＤバンドとの比であるＧ／Ｄ比が８０以上であることを特徴とする、請求項１〜４のいずれか１項に記載のボイスコイル。   5. The carbon nanotube wire according to claim 1, wherein a G / D ratio, which is a ratio between a G band of a Raman spectrum in Raman spectroscopy and a D band derived from crystallinity, is 80 or more. The voice coil according to claim 1. 前記電線が、前記カーボンナノチューブ線材の外周を被覆する絶縁被覆層を更に有することを特徴とする、請求項１記載のボイスコイル。   The voice coil according to claim 1, wherein the electric wire further includes an insulating coating layer covering an outer periphery of the carbon nanotube wire. 請求項１〜６のいずれか１項に記載のボイスコイルを備える音発生装置。   A sound generator provided with the voice coil of any one of Claims 1-6.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112021002856T5 (en) 2020-05-20 2023-03-02 Rohm Co., Ltd. TRANSDUCER, METHOD OF CONTROL AND SYSTEM

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010135566A (en) * 2008-12-04 2010-06-17 Seiko Epson Corp Electromagnetic coil, electric machine device, and device using electric machine device
US20110033078A1 (en) * 2009-08-05 2011-02-10 Tsinghua University Voice coil lead wire and loudspeaker using the same
US20110064257A1 (en) * 2009-09-17 2011-03-17 Tsinghua University Voice coil and loudspeaker using the same
US20160057544A1 (en) * 2014-08-21 2016-02-25 Plugged Inc. Carbon Nanotube Copper Composite Wire for Acoustic Applications
JP2016048877A (en) * 2014-08-28 2016-04-07 パナソニックＩｐマネジメント株式会社 Conducting wire, coil using the same and loudspeaker using the coil
WO2017033482A1 (en) * 2015-08-24 2017-03-02 古河電気工業株式会社 Aggregate of carbon nanotubes, carbon nanotube composite material, and carbon nanotube wire

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010135566A (en) * 2008-12-04 2010-06-17 Seiko Epson Corp Electromagnetic coil, electric machine device, and device using electric machine device
US20110033078A1 (en) * 2009-08-05 2011-02-10 Tsinghua University Voice coil lead wire and loudspeaker using the same
US20110064257A1 (en) * 2009-09-17 2011-03-17 Tsinghua University Voice coil and loudspeaker using the same
US20160057544A1 (en) * 2014-08-21 2016-02-25 Plugged Inc. Carbon Nanotube Copper Composite Wire for Acoustic Applications
JP2016048877A (en) * 2014-08-28 2016-04-07 パナソニックＩｐマネジメント株式会社 Conducting wire, coil using the same and loudspeaker using the coil
WO2017033482A1 (en) * 2015-08-24 2017-03-02 古河電気工業株式会社 Aggregate of carbon nanotubes, carbon nanotube composite material, and carbon nanotube wire

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112021002856T5 (en) 2020-05-20 2023-03-02 Rohm Co., Ltd. TRANSDUCER, METHOD OF CONTROL AND SYSTEM

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