JPS5856563A - Transmission and reception unit for loudspeaker telephone set - Google Patents
Transmission and reception unit for loudspeaker telephone setInfo
- Publication number
- JPS5856563A JPS5856563A JP15502281A JP15502281A JPS5856563A JP S5856563 A JPS5856563 A JP S5856563A JP 15502281 A JP15502281 A JP 15502281A JP 15502281 A JP15502281 A JP 15502281A JP S5856563 A JPS5856563 A JP S5856563A
- Authority
- JP
- Japan
- Prior art keywords
- speaker
- microphones
- box
- directivity
- microphone
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/42—Systems providing special services or facilities to subscribers
- H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
- Circuit For Audible Band Transducer (AREA)
Abstract
Description
【発明の詳細な説明】
1%に双指向性又は無指向性とすると共に音響周波数特
性に優れ且つスピーカとマイクロホンとの音響結合を少
なくして小規模の画一通話ができる拡声ml話慣用送受
話ユニットに関する。[Detailed description of the invention] A loudspeaker ML communication system that is bidirectional or omnidirectional to 1%, has excellent acoustic frequency characteristics, and reduces acoustic coupling between the speaker and the microphone to enable small-scale uniform calls. Regarding the receiving unit.
従来のこの種の送受話ユニットは、例えば、同一のスピ
ーカボックスの上端にスピーカを、下端に1個の無指向
性のマイクロホンを、同一軸線上で互いに背を向は合っ
て設けたものがある。しかしこの場合は、上端に設けら
れたスピーカと下端に設けられたマイクロホンとの閣で
、送受話系の壇帳器の帰還パスとなっていわゆる音響結
合が生じ、ハウリング又はエフ−の現象を起すことがあ
る。これに対処してボイススイッチを設けて送受話状態
を切プ換えることがあるが、このようにすると状態切換
時に話尾、語頭が切断される現象を起すことがある.こ
のような音響結合による不具合を除去するためには、ス
ピーカとマイクロホンとの音響的な距離を大きくしなけ
ればならず、結局、送受話ユニット自体が大型化すると
いう欠点があった。Conventional transmitting/receiving units of this type include, for example, a speaker box provided with a speaker at the top end and one omnidirectional microphone at the bottom end facing away from each other on the same axis line. . However, in this case, so-called acoustic coupling occurs between the speaker installed at the top end and the microphone installed at the bottom end, which serves as a return path for the transmitter/receiver system, resulting in howling or f-phenomenon. Sometimes. To deal with this, a voice switch is sometimes installed to switch between transmitting and receiving, but this can sometimes result in the end or beginning of a sentence being cut off when the state is switched. In order to eliminate problems caused by such acoustic coupling, it is necessary to increase the acoustic distance between the speaker and the microphone, resulting in the disadvantage that the transmitter/receiver unit itself becomes larger.
また、上記従来例において、スピーカボックスの上端に
設けられたスピーカから受話者の耳に直接達する音波と
、一旦テーブル等の設i1iflで反射して達する音波
とはある特定の周波数において干渉して互いに打消し合
い、スピーカの音響周波数特性に深い谷ができることが
ある。In addition, in the above conventional example, the sound waves that directly reach the listener's ears from the speaker installed at the top of the speaker box and the sound waves that reach the listener's ears after being reflected from a table or other installation interfere with each other at a certain frequency. They may cancel each other out, creating deep valleys in the speaker's acoustic frequency response.
これをIK1図を参照して説明すると、スピーカ8から
受話者りの耳に直接達する直接波の経路をSLとしこの
経路長frlとする。一方、設置面T上の0潰で反射し
て受話者りの耳に達する反射波の経路をSOLとしこの
経路長trzとする。上記直接波と反射波とは同一の音
源8がら出たもので、これらのIk!Iw!差D1 r
21がその音波の波長λの7の奇数倍に相当する周波数
のときは、蚊両波は互いに干渉する。すなわち、=)λ
、・・・・・・のときに干渉現象が生じ、そのときの周
波数をf、音速faとするとt == Hの関係がある
から、
’l”−、(2==9− f
21rl−r21 21rl−r2+ ’ 2
1r1−r21 ”の周波数のときに、直接波と反射波
とは干渉して互いに打消し合い、スピーカSの音響周波
数特性上に周期的に深い谷ができる。そして、受話者■
」の高さh及び距離Xの値はほぼ一定であるから、主と
してスピーカSの高さZによって上記r1とr2の値が
定まハ経路差1rx r21の値が大きくなると、す
なわちスピーカSの高さZが大きくなると、第一の音響
周波数特性の谷である
fl−−一−1−一
21 rl r2 l
が、電話の音声帯域内(300Hz 〜34001(z
)に落ちてくることがある。このような場合は、スピ
ーカSからの受話′iiは非常に開きとシにくくなると
いう欠点があった。なお、sg1図において、受話者L
1r送話省の口[k1!侠え、スピーカSを送話用のマ
イクロホンに置き換えても可逆的に同様のことがいえ、
このような場合は、迷話音のマイクロホンへの久方の音
響周波数特性に深い谷ができることとなる。このような
音響周波数特性の乱れは、生として@接波と反射波との
干渉現象によるものであるから、マイクロホン又はスピ
ーカの位置を低くLycジ、或いは反射波の影響を除去
するようにすればよい。To explain this with reference to diagram IK1, the path of the direct wave from the speaker 8 directly reaching the listener's ear is defined as SL, and the path length is frl. On the other hand, let SOL be the path of the reflected wave that is reflected at the zero point on the installation surface T and reach the listener's ear, and the length of this path is trz. The above direct wave and reflected wave are emitted from the same sound source 8, and these Ik! Iw! Difference D1 r
When 21 is a frequency corresponding to an odd multiple of 7 of the wavelength λ of the sound wave, the two mosquito waves interfere with each other. That is, =)λ
An interference phenomenon occurs when . r21 21rl-r2+ ' 2
At a frequency of 1r1-r21'', the direct wave and the reflected wave interfere and cancel each other out, creating periodic deep valleys on the acoustic frequency characteristics of the speaker S.
Since the values of height h and distance As the height Z increases, the valley of the first acoustic frequency characteristic, fl--1-1-121 rl r2 l, falls within the voice band of the telephone (300Hz to 34001(z
) may fall. In such a case, there is a drawback that the reception 'ii from the speaker S becomes very difficult to receive. In addition, in the sg1 diagram, the receiver L
1r The mouth of the Ministry of Transmission [k1! The same thing can be said reversibly even if speaker S is replaced with a microphone for transmitting speech.
In such a case, a deep valley will be formed in the acoustic frequency characteristics of the stray speech to the microphone. Such disturbances in acoustic frequency characteristics are caused by the interference phenomenon between the exposed waves and reflected waves, so if the microphone or speaker is positioned low to eliminate the effects of Lyc waves or reflected waves. good.
本発明は上記事情に対処してなされたもので、スピーカ
の位置を低くすると共に一対又は複数対のマイクロホン
をスピーカボックスの上面に取り付けて反射波の影響を
除去し、音響周波数特性に優れ且つスピーカとマイクロ
ホンとの音響結合を少なくすると共に双指向性又は無指
向性として小規禎の会議通話ができる拡声電話機用送受
話ユニットを提供することを目的とする。The present invention was made in response to the above-mentioned circumstances, and it is possible to lower the position of the speaker and attach one or more pairs of microphones to the top surface of the speaker box to eliminate the influence of reflected waves, thereby achieving excellent acoustic frequency characteristics and a speaker box. An object of the present invention is to provide a transmitting/receiving unit for a loudspeaker telephone, which can reduce acoustic coupling between a microphone and a microphone, and can conduct conference calls in a bi-directional or non-directional manner.
以下、本発明の実施例を添付図面に基いて詳細に説明す
る。Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
第2図において、スピーカボックス1は、四角柱状、六
角柱状又は円筒状等の箱形の容器であって本発明による
送受話ユニットの筐体をなし、その底面2の隅部には脚
3.3、・・・・・・が取り付けられて、#底面2がテ
ーブル等の設置面4から浮いて保持されるようになって
いる。In FIG. 2, a speaker box 1 is a box-shaped container such as a rectangular prism, hexagonal prism, or cylinder, and serves as a housing for a transmitting/receiving unit according to the present invention, and has legs 3. 3, . . . are attached so that the bottom surface 2 is held floating above the installation surface 4 such as a table.
上記スピーカボックス1内には、その低面2をバッフル
面とし、スビーカコー/を下に向けて上記設置面4に対
向させ几スピーカ5が該底面2の中央部に設けられてい
る。このスピーカ5は、送信側からの受話音を拡声して
伝達するものである。上記スピーカ5から受話者に達す
る受話音は、該スピーカ5が設fIL面4に対向して低
い位置にあるので、第2図に矢印人で示すように、王と
して上記設fiirkJ4からの反射波である。この場
合、スピーカボックス1の底面2を@シ込んで受話者側
に来る圓折波もあるがこれは僅かであることと、上記ス
ピーカ5が低い位置に設けられていることから、前述の
干渉現象ははとんどなく、スピーカ5の受話音に音響周
波数特性上の乱れは少ない。Inside the speaker box 1, the lower surface 2 is used as a baffle surface, and a speaker 5 is provided at the center of the bottom surface 2, with the lower surface 2 facing downward and facing the installation surface 4. This speaker 5 amplifies and transmits the received sound from the transmitting side. Since the speaker 5 is located at a low position facing the installation plane 4, the received sound reaching the receiver from the speaker 5 is reflected from the installation FIIRKJ4 as a king, as shown by the arrow in FIG. It is. In this case, there is also a circular wave that penetrates the bottom surface 2 of the speaker box 1 and reaches the receiver side, but this is slight and because the speaker 5 is installed at a low position, the above-mentioned interference The phenomenon is rare, and there is little disturbance in the acoustic frequency characteristics of the received sound from the speaker 5.
上記スピーカボックス1の上面の鳩縁には、単一指向性
のマイクaホン5a、fibが2個一組で対になって設
けられている。このマイクロホン$a、5bは、上記ス
ピーカ5の中心軸7に対して、第2図では線対称の位置
に、第3図では点対称の位置に設けられ、且つ、第2図
に示すように、それぞれの指向性方向(矢印8a及び8
b)を互いに内側に向けて取り付けられている。上記マ
イクロホン6a、6bは、送話者からの音声を拾って拡
声電話装置に送る−のであるが、その単一指向性のため
その指向性方向の音声しか拾わない。例えば、第3図に
おいて、マイクロホン6aはその前方の送話者Pのみの
音声を拾い、後方の送話者?からの音声は拾わない。そ
れと同様にマイクロホン8bは?の音声は拾うが、Pか
らの音声は拾わない。このようにして、マイクロホン@
a、@bの一対としては双指向性を発揮することができ
る。また、上記のようにそれぞれのマイクロホン6轟、
6bは、その指向性方向を互いに内側に向けてスピーカ
ボックス1の上面の周縁Kfllけ九ので、!!2図に
示すように、送話者Pからの直接波PBは上記スピーカ
ボックス1の上方を経て何の障害もなく一方のマイクロ
ホン6aに至り、これに十分な感度で拾われる。このと
き、他方のマイクロホン6bに対しては、上記直接波P
Mは反指向性方向から至るため、皺マイクロホン6bに
はほとんど拾われない。一方、送話者Pからの音声のう
ち一旦設置面4上の膚0で反射し友後上紀一方のマイク
ロホン6aに向かう反射波は、スピーカボックス1の@
面上の点Cで再び反射されD方向に向かう几め、結局反
射波POCは上記マイクロホン6aKFi到達しない。On the dove edge of the upper surface of the speaker box 1, unidirectional microphones 5a and fib are provided in pairs. The microphones $a and 5b are provided at line-symmetrical positions in FIG. 2 and point-symmetrical positions in FIG. 3 with respect to the central axis 7 of the speaker 5, and as shown in FIG. , respective directivity directions (arrows 8a and 8
b) are attached with the two facing inward towards each other. The microphones 6a and 6b pick up the voice from the speaker and send it to the public address telephone system, but because of their unidirectionality, they only pick up the voice in that directional direction. For example, in FIG. 3, the microphone 6a picks up only the voice of the speaker P in front of it, and picks up the voice of only the speaker P behind it. It does not pick up audio from. Similarly, what about microphone 8b? The voice from P is picked up, but the voice from P is not picked up. In this way, the microphone @
As a pair of a and @b, bidirectionality can be exhibited. In addition, as mentioned above, each microphone 6 Todoroki,
6b are arranged at the periphery of the upper surface of the speaker box 1 with their directivity directed inwardly. ! As shown in FIG. 2, the direct wave PB from the speaker P passes above the speaker box 1 and reaches one of the microphones 6a without any obstruction, where it is picked up with sufficient sensitivity. At this time, the direct wave P is transmitted to the other microphone 6b.
Since M comes from the opposite direction, it is hardly picked up by the wrinkle microphone 6b. On the other hand, the reflected wave of the voice from the speaker P that is once reflected by the skin 0 on the installation surface 4 and goes towards the microphone 6a of the speaker box 1 is the @ of the speaker box 1.
The reflected wave POC is reflected again at the point C on the surface and moves in the direction D, and in the end the reflected wave POC does not reach the microphone 6aKFi.
なお、反射波の回折によりマイクロホン6aに至る波も
あるが、これは僅かで、はとんど無視することができる
。このような結果、送話者Pからの音声は、一方のマイ
クロホン6mに対してのみ直接波PBだけが至ることと
なる。このことから、上記マイクロホン6aに至る音波
において前述のような干渉現象はほとんど生ぜず、マイ
クロホン6aへの入力の音響周波数特性上の乱れを少な
くすることができる。他方のマイクロホン6bについて
も同様のことがいえる。Note that some waves reach the microphone 6a due to diffraction of the reflected waves, but this is very small and can be ignored. As a result, only the direct wave PB of the voice from the speaker P reaches one microphone 6m. For this reason, the aforementioned interference phenomenon hardly occurs in the sound waves reaching the microphone 6a, and disturbances in the acoustic frequency characteristics of the input to the microphone 6a can be reduced. The same can be said about the other microphone 6b.
上記一対のマイクロホ/@a、6bの出力備には、第4
図に示すように、その電気出力の差をとる差動アンプ9
が接続されている。この差動アンプ9は、スピーカ5の
受鈷音が設置[104で反射され7’C後にスピーカボ
ックス1の囲りを31IC込んでそれぞれスピーカ5か
ら等距離に設けられ九マイクロホン5a、fibにその
指向性方向から入力する音波toa、tabによるマイ
クロホン5m、5bの差動出力をとり、該両者の電気出
力を打消すことによシスビー力5とマイクロホン@a、
5bとの間の音響結合を減少させるものである。上記差
動アンプ9の出力eは、拡声電話装置に入力する。なお
、上記マイクロホン5a、ibはその指向性方向を互い
に内l1lIVc向けている九めに、第4図に示すよう
に、上記廻り込んで入力する音波10a、10bはそれ
ぞれマイクロホン6b、6aに対しては反指向性方向か
ら入力することと、マイクロホン@a、@btlc対し
て指向性方向から入力する音響的な距離が大きくなるこ
とから、これらのことによってもマイクロホンの指向性
方向を外側に向けた場合に比し、本発明においてはスピ
ーカ5とマイクロホン6暑、6bとの間の音響結合を減
少させることができる。The output equipment of the above pair of micro-holes/@a, 6b has a fourth
As shown in the figure, a differential amplifier 9 that takes the difference between the electrical outputs
is connected. This differential amplifier 9 is configured such that the sound from the speaker 5 is reflected by the installed [104], and after 7'C, the surroundings of the speaker box 1 are included in 31 ICs, and each of them is installed at the same distance from the speaker 5, and the nine microphones 5a and fib are connected to each other. By taking the differential output of the microphones 5m and 5b due to the sound waves toa and tab input from the directional direction and canceling the electrical output of both, the systembee force 5 and the microphone @a,
5b. The output e of the differential amplifier 9 is input to a loudspeaker telephone device. Additionally, the microphones 5a and ib have their directivity directed inwardly toward each other.As shown in FIG. input from the counter-directional direction, and the acoustic distance for input from the directional direction to microphones @a and @btlc is large. Compared to the case, according to the present invention, the acoustic coupling between the speaker 5 and the microphone 6b can be reduced.
なお、第3図からも明らかなように、一対のマイクロホ
ンfin、(ib及び差動アンプ9では双指向性となp
P P’方向に由交する方向の感度が鈍くなるので、
必要に応じて第5図に示すように、他の一対のマイクロ
ホン6C,6d及びその差動アンプを上記PP方向に直
交する方向に追加して設ければよい。このようにすると
四周に対してほとんど無指向性とすることができる。ま
た、第3図及び第5図においては、1イクロホンをスピ
ーカボックス1の各辺の中央部に設けたものとして示し
たが、本発明はこれに11Mうれす、スピーカボックス
1の対角線上に設けてもよい。なお、スピーカボックス
1#i、六角柱状又は円筒状等であってもよいことは前
述のとおりである。Note that, as is clear from FIG.
Since the sensitivity in directions intersecting the P P' direction becomes dull,
If necessary, as shown in FIG. 5, another pair of microphones 6C, 6d and their differential amplifiers may be additionally provided in a direction perpendicular to the PP direction. In this way, almost no directivity can be achieved around the four circumferences. In addition, in FIGS. 3 and 5, 1 microphone is shown as being installed in the center of each side of the speaker box 1, but the present invention has an 11M glass installed on the diagonal of the speaker box 1. It's okay. Note that, as described above, the speaker box 1#i may have a hexagonal columnar shape, a cylindrical shape, or the like.
本発明は以上欣明したように、スピーカ5をスピーカボ
ックス1の底面に設けてその位置を低くすると共に一対
又は複数対のマイクロホン6a、6b・・・・・・をス
ピーカボックス1の上面にその指向性方向を互いに内側
に向けて対称の位置に設けたので、直接波と設置面4か
らの反射波との干渉現!l!をほとんど無くシて、マイ
クロホy5a、fib・・・・・・の送話音及びスピー
カ5の受話音に音響周波数%柱上の乱hfはとんど無く
すことができる。また、指向性方向を互いに内1111
1K向けたマイクロホン5a、5b・・・・・・と差動
アンプ9との組合せにより、スピーカ5と上記マイクロ
ホンlia、5b・・・・・・との間の音響結合を減少
させることができる。さらに、単一指向性のマイクロホ
ン5a、fib・・・・・・をスピーカ5に対して対称
の位置に一対又は複数対設けることによって、双指向性
又は無指向性とすることができる。このような諸効果に
より、送話量中受話音が聞きとりにくいということもな
く、ま次、ハウリングやエコー、ブロッキングもなく、
さらに音声死角も生ぜずに数人のメンバーによる小規模
の会議通話を可能とすることができる。As described above, in the present invention, the speaker 5 is provided on the bottom surface of the speaker box 1 to lower its position, and one or more pairs of microphones 6a, 6b, . . . are provided on the top surface of the speaker box 1. Since the directivity directions are placed in symmetrical positions with each other facing inward, there is no interference between the direct waves and the reflected waves from the installation surface 4! l! It is possible to almost eliminate the disturbance hf on the acoustic frequency column in the transmitted sound of the micro-hoy 5a, fib, . . . and the received sound of the speaker 5. Also, the directivity directions are within 1111
By combining the microphones 5a, 5b, . . . for 1K and the differential amplifier 9, it is possible to reduce the acoustic coupling between the speaker 5 and the microphones lia, 5b, . Furthermore, by providing one or more pairs of unidirectional microphones 5a, fib, . Due to these effects, the receiving sound is not difficult to hear even during the transmission volume, and there is no feedback, echo, or blocking.
Furthermore, it is possible to make small-scale conference calls between several members without creating a voice blind spot.
第1図は音波の直接波と反射波との干渉現象を示す説明
図、第2図は本発明による拡声電話機用送受話ユニット
を示す正面図、第3図はその平面図、第4図は差動アン
プの接続を示す説明図、第5図は他の実施例を示す平面
図でおる。
1・・・・・・スピーカボックス
2・・・・・・底面
3・・・・・・脚
4・・・・・・設i面
5・・・・・・スピーカ
6 a、 6 b、 6 C,6d −・−−−−
マイクロホン
T・・・・・・中心軸
Ba、Bb・・・・・・指向性方向
9・・・・・・差動アンプ
出願人 冨士通株式会社
代理人 弁理士松祠宏四部、、′・。
E−1に
転15
第1図
第2図
第3図 第51
第4図FIG. 1 is an explanatory diagram showing the interference phenomenon between direct waves and reflected waves of sound waves, FIG. 2 is a front view showing a transmitting/receiving unit for a loudspeaker telephone according to the present invention, FIG. 3 is a plan view thereof, and FIG. FIG. 5 is an explanatory diagram showing the connection of the differential amplifier, and FIG. 5 is a plan view showing another embodiment. 1...Speaker box 2...Bottom surface 3...Legs 4...Installation side 5...Speaker 6 a, 6 b, 6 C, 6d ------
Microphone T...Central axis Ba, Bb...Directivity direction 9...Differential amplifier Applicant: Fujitsu Co., Ltd. Agent: Patent attorney Hiroshi Matsutoshi, 4th Department... . Transfer to E-115 Figure 1 Figure 2 Figure 3 Figure 51 Figure 4
Claims (1)
と、このスピーカボックスの底面をバッフル面とし上記
設置面に対向して諌底面の中央ISK設けられたスピー
カと1上記スピーカボツクスの上面において上記スピー
カの中心軸に対し対称の位置に設けられ且りその指向性
方向を互いに内@に向けた一対又は複数対の単一指向性
のマイクロホンと、上記各対のマイクロホンの電気出力
の差をとる差動アンプとからなることを特徴とする拡声
電話機用送受話ユニット。a speaker box that is held with its bottom surface floating above the installation surface; a speaker that uses the bottom surface of the speaker box as a baffle surface and is provided with a central ISK on the bottom surface facing the installation surface; and one speaker that is mounted on the top surface of the speaker box. a pair or multiple pairs of unidirectional microphones installed at symmetrical positions with respect to the central axis of A transmitting/receiving unit for a public address telephone, comprising a dynamic amplifier.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15502281A JPS5856563A (en) | 1981-09-30 | 1981-09-30 | Transmission and reception unit for loudspeaker telephone set |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15502281A JPS5856563A (en) | 1981-09-30 | 1981-09-30 | Transmission and reception unit for loudspeaker telephone set |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5856563A true JPS5856563A (en) | 1983-04-04 |
Family
ID=15596953
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15502281A Pending JPS5856563A (en) | 1981-09-30 | 1981-09-30 | Transmission and reception unit for loudspeaker telephone set |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5856563A (en) |
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WO2008001659A1 (en) * | 2006-06-29 | 2008-01-03 | Yamaha Corporation | Sound generating/collecting device |
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1981
- 1981-09-30 JP JP15502281A patent/JPS5856563A/en active Pending
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JP2007129487A (en) * | 2005-11-02 | 2007-05-24 | Yamaha Corp | Audio signal transmitting and receiving device |
US8243951B2 (en) | 2005-12-19 | 2012-08-14 | Yamaha Corporation | Sound emission and collection device |
WO2007072757A1 (en) * | 2005-12-19 | 2007-06-28 | Yamaha Corporation | Sound emission and collection device |
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JP2007174271A (en) * | 2005-12-22 | 2007-07-05 | Yamaha Corp | Sound emitting and collecting apparatus |
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