JPS61123389A - Pamametric speaker - Google Patents

Pamametric speaker

Info

Publication number
JPS61123389A
JPS61123389A JP24513684A JP24513684A JPS61123389A JP S61123389 A JPS61123389 A JP S61123389A JP 24513684 A JP24513684 A JP 24513684A JP 24513684 A JP24513684 A JP 24513684A JP S61123389 A JPS61123389 A JP S61123389A
Authority
JP
Japan
Prior art keywords
ultrasonic transducer
transducer array
acoustic filter
waves
wave
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.)
Granted
Application number
JP24513684A
Other languages
Japanese (ja)
Other versions
JPH0576839B2 (en
Inventor
Mikiro Iwasa
幹郎 岩佐
Tsuneo Tanaka
恒雄 田中
Yoichi Kimura
陽一 木村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP24513684A priority Critical patent/JPS61123389A/en
Priority to DE19853590430 priority patent/DE3590430T1/en
Priority to PCT/JP1985/000469 priority patent/WO1986001670A1/en
Priority to US06/862,349 priority patent/US4823908A/en
Publication of JPS61123389A publication Critical patent/JPS61123389A/en
Publication of JPH0576839B2 publication Critical patent/JPH0576839B2/ja
Granted legal-status Critical Current

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
    • H04R27/00—Public address systems
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/28—Sound-focusing or directing, e.g. scanning using reflection, e.g. parabolic reflectors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H04R1/345—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2217/00—Details of magnetostrictive, piezoelectric, or electrostrictive transducers covered by H04R15/00 or H04R17/00 but not provided for in any of their subgroups
    • H04R2217/03—Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

PURPOSE:To make a speaker compact and to sharpen the directional character by integrating an ultrasonic transducer array with a reflection plate. CONSTITUTION:The ultrasonic transducer array 1 is maintained and disposed on the focus of the parabolic surface of the reflection plate 7 by a plastic arm 8, and sound filter 10 is connected with front of reflection 7. Thus, by integrating the array 1, a filter 10 and the reflection plate 7 the attenuation of the 2nd wave sound pressure level becomes 4dB, the attenuation of the 1st wave becomes 30dB. Therefore, the sharp directional character can be obtained.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は超音波に対する空気の非線形性を利用したパラ
メトリック効果を有するスピーカに関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker having a parametric effect that utilizes the nonlinearity of air with respect to ultrasonic waves.

従来の技術 従来から拡声装置において、音の指向特性をスポットラ
イトの様に鋭くして、周囲騒音の影響を受けずにある特
定の範囲の人々にだけ聞かせたいと言う要求は展示会な
どで個々の出品物ごとに別々の説明を行ないたい時や、
駅ホームでの案内放送などの用途で強いものがあった。Conventional Technology Traditionally, in public address systems, there has been a demand for making the directional characteristics of sound as sharp as a spotlight so that only a certain range of people can hear it without being affected by ambient noise. When you want to provide separate explanations for each item on display,
It was useful for applications such as announcements on station platforms.

この様な用途には従来ホー／スピーカが主として用いら
れて来たが、ホーンスピーカの指向特性はその長さと口
径に強く依存し、特に音声の様に低音域で鋭い指向特性
を得るには、長さ９口径共に極めて大きなものになると
いう欠点があった。Conventionally, horn/speakers have been mainly used for such applications, but the directional characteristics of a horn speaker strongly depend on its length and aperture, and in order to obtain sharp directional characteristics in the low frequency range, such as voice, it is necessary to It had the disadvantage of being extremely large in length and nine calibers.

一方近年超音波の非線形相互作用の一種であるパラメト
リック効果を用いたスピーカ（パラメトリックスピーカ
）が従来に比べてはるかに鋭い指向特性が得られること
から注目されている。まず従来のパラメトリックスピー
カについて説明する。On the other hand, in recent years, speakers that use a parametric effect, which is a type of nonlinear interaction of ultrasonic waves (parametric speakers), have been attracting attention because they can obtain much sharper directivity characteristics than conventional speakers. First, conventional parametric speakers will be explained.

第５図は従来のパラメトリックスピーカの構成？示すも
のである。第５図において１は圧電振動子を用いた超音
波トランスデユーサを蜂の巣状に並べてアレイ化した超
音波トランスデユーサアレイである。２は音声信号源で
あシ、この出力全変調器３に入力する。ここで音声信号
は、搬送波を４０Ｋ［ｌＺとして振幅変調されパワーア
ンプ５ｔ−経て超音波トランスデューサアレイ１に入力
される。Is Figure 5 the configuration of a conventional parametric speaker? It shows. In FIG. 5, reference numeral 1 denotes an ultrasonic transducer array in which ultrasonic transducers using piezoelectric vibrators are arranged in a honeycomb shape. 2 is an audio signal source, the output of which is input to all modulators 3; Here, the audio signal is amplitude-modulated using a carrier wave of 40K[lZ] and is input to the ultrasonic transducer array 1 via a power amplifier 5t.

６は超音波全吸収するための音響フィルタであり、超音
波トランスデユーサ１と受聴者９の間に設置されている
。Reference numeral 6 denotes an acoustic filter for completely absorbing ultrasonic waves, and is installed between the ultrasonic transducer 1 and the listener 9.

上述したパラメトリックスピーカにおいテ超音波トラン
スジー−サアレイ１から放射された振幅変調超音波の搬
送波と上下の側帯波とは空中で非線形相互作用を起こし
、鋭い指向特性を有する変調波が発生する。ここで超音
波トランスジ為−サアレイ１から出た振幅変調波のこと
を１次波、その１次波の非線形相互作用の結果として生
じたもとの変調波（音声信号）を２次波と称する。In the above-mentioned parametric speaker, the carrier wave of the amplitude modulated ultrasonic wave emitted from the ultrasonic transducer array 1 and the upper and lower sideband waves cause nonlinear interaction in the air, and a modulated wave having sharp directional characteristics is generated. Here, the amplitude modulated wave emitted from the ultrasonic transducer array 1 is referred to as a primary wave, and the original modulated wave (sound signal) generated as a result of nonlinear interaction of the primary wave is referred to as a secondary wave.

ところで、パラメトリックスピーカで実用レベルの可聴
音を発生させるには１４０ｄＢ或いはそれ以上の極めて
強い超音波を空中に放射しなければならず、この様な強
い超音波を直接人体に浴びせることは、なんらかの障害
が起きるかも知れなく危険である。その対策としては超
音波トランスデューサアレイ１と受聴者９との間に１次
波である超音波全吸収し、２次波だけは透過させる音響
フィルタを設置していた。By the way, in order to generate a practical level of audible sound with a parametric speaker, it is necessary to emit extremely strong ultrasonic waves of 140 dB or more into the air, and directly bombarding the human body with such strong ultrasonic waves may cause some kind of damage. This is dangerous as it may occur. As a countermeasure, an acoustic filter was installed between the ultrasonic transducer array 1 and the listener 9, which completely absorbed the first-order ultrasonic wave and transmitted only the second-order wave.

発明が解決しようとする問題点 しかしながらパラメトリック効果による２次波の音源を
形成するためには、上記従来の構成では少なくとも超音
波トランスデューサアレイ１と音響フィルタ６とｔ−１
ｍ程度以上離さなければならない。その上に音響フィル
タ６は形状保持の困難な柔軟な材料が適しており、又人
体に対する安全性全考慮すると、直径２ｍ程度が必要で
大きなものとなり超音波トランスジー−サアレイ１と一
体化することも困難であった。Problems to be Solved by the Invention However, in order to form a secondary wave sound source by a parametric effect, in the above conventional configuration, at least the ultrasonic transducer array 1, the acoustic filter 6, and the t-1
They must be separated by at least about m. In addition, the acoustic filter 6 is suitably made of a flexible material that is difficult to maintain its shape, and in consideration of safety to the human body, it needs to be large, with a diameter of about 2 m, and must be integrated with the ultrasonic transducer array 1. It was also difficult.

更にビデオテープレコーダの音声の様に映像と一体とな
った音の場合には、映像と音との方向が同一である方が
音像が自然となり望ましい。しかし従来のパラメトリッ
クスピーカを受聴する場合、スピーカ金受聴者の前に設
置すると、音響フィルタ６が映像の邪魔になったり、ま
た２次波が受聴者勺周囲の壁に反射して全く別の所で高
い音圧レベルの２次波が聞こえたシする。これらを防ぐ
ためには超音波トランスデユーサアレイ１並びに音響フ
ィルタｅ全受聴者の上方に設置する方が望ましい。そう
すると映像と音との方向を一致させることは困難であり
、映像が不自然になると言う欠点があった。Furthermore, in the case of sound that is integrated with the image, such as the sound of a video tape recorder, it is desirable that the direction of the image and the sound be the same because the sound image will be more natural. However, when listening to conventional parametric speakers, if the speaker is placed in front of the listener, the acoustic filter 6 may interfere with the image, or the secondary waves may be reflected off the walls surrounding the listener and sent to a completely different location. I heard a secondary wave with a high sound pressure level. In order to prevent these problems, it is preferable to install the ultrasonic transducer array 1 and the acoustic filter e above all listeners. In this case, it is difficult to match the directions of the video and the sound, resulting in a disadvantage that the video becomes unnatural.

本発明は上記問題点に鑑み、超音波トランスジ為−サア
レイ１と音響フィルタ６とを一体化し、２次波の指向特
性は従来通りに鋭く、かつ人体に有害であると思われる
１次波を有効に減衰させるパラメトリックスピーカを提
供するものである。In view of the above-mentioned problems, the present invention integrates the ultrasonic transducer array 1 and the acoustic filter 6, so that the directional characteristics of the secondary waves are as sharp as before, and the primary waves that are considered to be harmful to the human body are eliminated. This provides a parametric speaker that provides effective attenuation.

問題点を解決するための手段 上記問題点全解決するために本発明のパラメトリックス
ピーカは、超音波トランスデユーサアレイと、所定の間
隔をもち放物面もしくは回転楕円体面を有した反射板及
び音響フィルタとがらなり、それデれを一体化した構成
を備えたものである。Means for Solving the Problems In order to solve all the above problems, the parametric speaker of the present invention includes an ultrasonic transducer array, a reflector having a paraboloid or spheroidal surface with a predetermined interval, and an acoustic It has a structure that integrates the filter and the gap.

作用 本発明は上記した構成によって超音波トランスデューサ
アレイから放射された振幅変調波（１次波）及び１次波
の非線形相互作用の結果から生じる可聴周波（２次波）
を直接聞くのではなく、反肘板に当てることによってそ
れぞれの反射音を聞くことになる。Operation The present invention uses the above-described configuration to generate an amplitude modulated wave (primary wave) emitted from an ultrasonic transducer array and an audio frequency (secondary wave) generated as a result of the nonlinear interaction of the primary wave.
Instead of hearing the sound directly, you will hear the reflected sound of each by applying it to the anti-elbow board.

反射板に音響フィルタを設けた時は、１次波。When an acoustic filter is installed on the reflector, it is a primary wave.

２次波は共に反射板で反射するが、その時反射前と反射
後の２回音響フィルタを通過する時に２次波の音圧レベ
ル、指向特性は殆んど影響することなく１次波の音圧レ
ベルは大きく減衰する。Both secondary waves are reflected by the reflector, but at that time, when they pass through the acoustic filter twice, before and after reflection, the sound pressure level and directional characteristics of the secondary wave are hardly affected, and the sound of the primary wave is reflected. The pressure level is greatly attenuated.

又超音波トランスデューサアレイと音響フィルタと全反
射板で介することによって柔軟で形状保持が困難な音響
フィルタを反射板に取付けられ、超音波トラメスデュー
サアレイ、反射板及び音響フィルタを一体化できコンパ
クトな構成が可能となる。In addition, by interposing the ultrasonic transducer array, acoustic filter, and total reflection plate, the acoustic filter, which is flexible and difficult to maintain its shape, can be attached to the reflection plate, and the ultrasonic transducer array, reflection plate, and acoustic filter can be integrated into a compact design. configuration is possible.

実施例 以下本発明の実施例のパラメトリックスピーカについて
図面を参照しながら説明する。EXAMPLES Below, parametric speakers according to examples of the present invention will be described with reference to the drawings.

第１図は本発明の第１の実施例における構成を示す。第
１図において、７は放物面からなる反射板で、反射板γ
の長径は１．２ｍで強化プラスチック製であり、反射板
７の放物面の焦点には超音波トランスデユーサアレイ１
が設置されている。８は超音波トランスデユーサアレイ
を保持するためのプラスチック製のアーム、１０は厚さ
５０１ＬｉＬの発泡ウレタンからなる音響フィルタで、
反射板７の前面に接着されており、この音響フィルタ１
０により１次波は殆んど吸収し、かつ２次波は殆んどを
透過させる。その他の構成は第６図に示す従来例と同様
である。そこで超音波トランスデユーサアレイ１から放
射された１次波及び空中で発生した２次波を測定した。FIG. 1 shows the configuration of a first embodiment of the present invention. In Fig. 1, 7 is a reflector made of a paraboloid, and the reflector γ
It has a long diameter of 1.2 m and is made of reinforced plastic.
is installed. 8 is a plastic arm for holding the ultrasonic transducer array; 10 is an acoustic filter made of urethane foam with a thickness of 501 LiL;
This acoustic filter 1 is glued to the front surface of the reflector 7.
0, most of the primary waves are absorbed and most of the secondary waves are transmitted. The other configurations are the same as the conventional example shown in FIG. Therefore, the primary waves radiated from the ultrasonic transducer array 1 and the secondary waves generated in the air were measured.

まず音響フィルタ１ｏの有無による１次波の反射波の音
圧レベルを比較すると、音響フィルタ１０が無い時は約
１４０ｄＢ　であったものが、音響フィルタ１０を設置
すると約１１０ｄＢへと３０ｄＢ低下した。一方、２次
波については１Ｋ［Ｉｚの音圧レベルで比較すると音響
フィルタ１０が無い時は約７０　ｄＢ　、　　音響フィ
ルタ１ｏを有する時は約ｅ　ｓ　（ＩＢと４ｄＢ低下し
た。First, comparing the sound pressure level of the reflected primary wave with and without the acoustic filter 10, it was about 140 dB without the acoustic filter 10, but when the acoustic filter 10 was installed, it decreased by 30 dB to about 110 dB. On the other hand, regarding the secondary waves, when comparing the sound pressure level of 1K[Iz, it is about 70 dB without the acoustic filter 10, and about es (4 dB lower than IB) when the acoustic filter 1o is included.

次に反射面の中心から２ｍの距離における１ＫＩｚの指
向特性を第２図に示す。第２図において実線ａは本実施
例のパラメ）　ＩＪソックピーカの場合の指向特性、点
線すは焦点に従来の圧電型平板スピーカを置いた時の指
向特性である。Next, FIG. 2 shows the directivity characteristics of 1KIz at a distance of 2 m from the center of the reflecting surface. In FIG. 2, the solid line a represents the directional characteristics of the IJ sock speaker (parameters of this embodiment), and the dotted line represents the directional characteristics when a conventional piezoelectric flat speaker is placed at the focal point.

°以上の様に本実施例によれば、超音波トランスデュー
サアレイ１と音響フィルタ１ｏ及び反射板７を一体化し
た構成で、２次波の音圧レベルは４ｔｉＪ、か減衰せず
、１次波は３０　ｄＢ減少させ、かつ従来のスピーカと
比較してサイドローブが少なく鋭い指向特性が得られる
。°As described above, according to this embodiment, with the configuration in which the ultrasonic transducer array 1, the acoustic filter 1o, and the reflection plate 7 are integrated, the sound pressure level of the secondary wave is 4tiJ, and the primary wave is not attenuated. 30 dB, and sharp directivity characteristics with fewer side lobes than conventional speakers can be obtained.

次に本発明の第２の実施例について図面を参照しながら
説明する。第３図は本発明の第２の実施例の構成を示す
。第３図において、１１は放物面を有する反射板であり
、たて１．２　ｍ　＋横１用でアルミニウム製である。Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows the configuration of a second embodiment of the invention. In FIG. 3, reference numeral 11 is a reflecting plate having a parabolic surface, and is made of aluminum and has a length of 1.2 m and a width of 1.

また、反射板１１の焦点には超音波トランスデユーサア
レイ１が設置されている。以上は第１図の構成と同様な
ものである。Further, an ultrasonic transducer array 1 is installed at the focal point of the reflection plate 11. The above configuration is similar to the configuration shown in FIG.

第１図の構成と異なるのは、たて０．８ｍ、横１．２ｍ
、高さ１．２ｍの大きさの木製スピーカボックス１２の
中に超音波Ｉ・ランスデューサアレイ１と反射板１１を
固定した点であって、１だ、スピーカボックス１２の前
面にあたる部分は開口とし、その面に５０ｊＬｌｌ厚の
発泡ウレタンフオームを使用した音響フィルタ１３を取
付けたものである。スピーカボックス１２の内面は全体
にわたり吸音材１４を貼付けておく。The difference from the configuration in Figure 1 is that the height is 0.8m and the width is 1.2m.
, the ultrasonic transducer array 1 and the reflector 11 are fixed in a wooden speaker box 12 with a height of 1.2 m, and the front part of the speaker box 12 is an opening. , an acoustic filter 13 made of urethane foam with a thickness of 50 mm is attached to that surface. A sound absorbing material 14 is pasted over the entire inner surface of the speaker box 12.

以上の構成によれば、音響フィルタ１３は１次波を殆ん
ど吸収し、かつ２次波は殆んど透過させるものである。According to the above configuration, the acoustic filter 13 absorbs most of the primary waves and transmits most of the secondary waves.

スピーカボックス１２の中に設けた超音波トランスデュ
ーサアレイ１から放射された音（１次波及び２次波）は
反射板１１で反射し、スピーカボックス１２の開口部か
ら外部へと放射されるが、開口部に取付けられた音響フ
ィルタ１３によって１次波の音圧レベルは２５　ｄＢ　
低下し、２次波の１ＫＦＩｚにあける音圧レベルは約２
ｄＢ程度低下する。次に音響フィルタ１３から２ｍの距
離におけるＩＫＨｚの指向特性全第４図に示すが、第１
の実施例と変わらなく鋭い特性が得られる。The sound (primary waves and secondary waves) emitted from the ultrasonic transducer array 1 provided in the speaker box 12 is reflected by the reflection plate 11 and radiated to the outside from the opening of the speaker box 12. The sound pressure level of the primary wave is 25 dB due to the acoustic filter 13 attached to the opening.
The sound pressure level for 1KFIz of the secondary wave is approximately 2.
It decreases by about dB. Next, the IKHz directivity characteristics at a distance of 2 m from the acoustic filter 13 are shown in FIG.
The same sharp characteristics as in the embodiment are obtained.

以上のように超音波トランスデユーサアレイ１と反射板
１１及び音響フィルタ１３をスピーカボックス１２に組
み込むことによって完全に一体構造のパラメトリックス
ピーカになり、２次波の音圧レベル、指向特性には殆ん
ど影響することなく、高い音圧レベルの１次波を大きく
減衰する効果が得られる。又スピーカボックス１ｏに組
み込むことによって高い音圧レベルの１次波が乱反射し
て全く別の方向へ放射されるという様なことは完全に防
止できる。As described above, by incorporating the ultrasonic transducer array 1, the reflector 11, and the acoustic filter 13 into the speaker box 12, a parametric speaker with a completely integrated structure is obtained, and the sound pressure level and directional characteristics of the secondary waves are almost unchanged. It is possible to obtain the effect of greatly attenuating the primary wave of a high sound pressure level without any influence. Furthermore, by incorporating it into the speaker box 1o, it is possible to completely prevent primary waves with high sound pressure levels from being diffusely reflected and radiated in completely different directions.

なお、第１の実施例の構成で反射板金ビデオグロジェク
タ等のスクリーンの横に設置すれば、従来のパラメトリ
ックスピーカでは困難な映像と音の方向を一致させる事
が可能になる。If the configuration of the first embodiment is installed next to a screen such as a reflective sheet metal video projector, it becomes possible to match the directions of video and sound, which is difficult with conventional parametric speakers.

なお、第１．第２の実施例とも反射板を放物面としたが
、回転楕円体面でもよい。この場合超音波トランスデ息
−サアレイ１金回転楕円体面の第１の焦点に置けば、２
次波は上記回転楕円体面の第２の焦点に収束するので指
向性がより鋭くなる。In addition, 1. Although the reflecting plate in the second embodiment is a paraboloid, it may also be a spheroidal surface. In this case, if the ultrasonic transducer array is placed at the first focus of the gold spheroid surface, then 2
Since the next wave converges on the second focal point of the spheroidal surface, the directivity becomes sharper.

また反射板の材質においても強化プラスチック。The material of the reflector is also reinforced plastic.

アルミニウムの他、アクリル、塩化ビニールその他一般
のグラスチック、鉄板、ガラスもしくはそれらの複合材
料上使用してもよい。In addition to aluminum, it may be used on acrylic, vinyl chloride, general glass, iron plates, glass, or composite materials thereof.

発明の効果 以上のように本発明は超音波トランスデλ−サアレイと
放物面もしくは回転楕円体面からなる反射板及び音響フ
ィルタとからな９、以下に記すような効果を有する。Effects of the Invention As described above, the present invention comprises an ultrasonic transducer array, a reflection plate having a parabolic or spheroidal surface, and an acoustic filter9, and has the following effects.

（１）音源である超音波トランスデューサアレイと反射
板を介した音響フィルタが一体構造になり、コンパクト
なパラメトリックスピーカの実用化を可能ならしめる。(1) The ultrasonic transducer array that is the sound source and the acoustic filter via the reflector are integrated into an integrated structure, making it possible to put a compact parametric speaker into practical use.

（２）、超音波トランスデューサアレイと反射板をスピ
ーカボックスの中に組み込むことによって、１次波が乱
反射して全く別方向への放射防止が可能となり強力超音
波による人体への影響をなくせる。(2) By incorporating the ultrasonic transducer array and the reflector into the speaker box, it is possible to diffusely reflect the primary waves and prevent them from being radiated in completely different directions, thereby eliminating the effects of powerful ultrasonic waves on the human body.

（３）音響フィルタを設けた反射板を使用することで、
ビデオの様に映像と一体となった音の発生が可能となる
。(3) By using a reflector with an acoustic filter,
It is possible to generate sound that is integrated with the image, like in a video.

（４）回転楕円体面を有した反射板を用い第１の焦点か
ら音源を放射した場合、第２の焦点へ収束されることに
なり、従来のパラメトリックスピーカよりさらに鋭い指
向特性が実現可能となる。(4) If a reflector with a spheroidal surface is used to emit a sound source from the first focal point, it will be converged to the second focal point, making it possible to achieve even sharper directional characteristics than conventional parametric speakers. .

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の第１の実施例におけるパラメトリック
スピーカの構成図、第２図は第１の実施例における超音
波トランスデューサアレイと圧電型平板スピーカの指向
特性図、第３図は同第２の実施例におけるガラス）　Ｉ
Ｊフックピーカの構成図、第４図は第２の実施例におけ
るパラメトリックスピーカの指向特性図、第６図は従来
のパラメトリックスピーカの構成図である。 １・・・・・・超音波トランスジューサアレイ、２・・
・・・・音声信号源、３・・・・・・変調器、４・・・
・・・搬送波発振器、５°パ・・・パワーアンプ、７，
１１・旧・・反射板、８・・・・・・アーム、９・・・
・・・受聴者、１０．１３・・・・・・音響フィルタ、
１２°°°・・・スピーカボックス、１４・・・・・・
吸音材。 代理人の氏名　弁理士　中　尾　敏　男　はが１名第２
図FIG. 1 is a configuration diagram of a parametric speaker according to a first embodiment of the present invention, FIG. 2 is a directional characteristic diagram of an ultrasonic transducer array and a piezoelectric flat speaker according to the first embodiment, and FIG. glass in the examples) I
FIG. 4 is a configuration diagram of a J-hook speaker, FIG. 4 is a directional characteristic diagram of a parametric speaker in the second embodiment, and FIG. 6 is a configuration diagram of a conventional parametric speaker. 1... Ultrasonic transducer array, 2...
...Audio signal source, 3...Modulator, 4...
...Carrier wave oscillator, 5° power amplifier, 7,
11. Old... Reflector, 8... Arm, 9...
...listener, 10.13...acoustic filter,
12°°°...speaker box, 14...
Sound absorbing material. Name of agent: Patent attorney Toshio Nakao, 1st person, 2nd person
figure

Claims (4)

【特許請求の範囲】[Claims] （１）媒質の非線形パラメトリック効果によって有限振
幅音波から可聴周波を発生させるための超音波トランス
デューサアレイと、前記超音波トランスデューサアレイ
から放射された音を反射させるため所定の間隔をもち、
前記超音波トランスデューサアレイに設けられた反射板
と、前記反射板の前面又は前方に設けられた超音波を吸
収するための音響フィルタとからなり、前記超音波トラ
ンスデューサアレイと反射板が接続又は一体化構造にな
っていることを特徴とするパラメトリックスピーカ。(1) an ultrasonic transducer array for generating audio waves from finite amplitude sound waves by nonlinear parametric effects of a medium; and a predetermined interval for reflecting the sound emitted from the ultrasonic transducer array;
The ultrasonic transducer array comprises a reflecting plate provided on the ultrasonic transducer array, and an acoustic filter for absorbing ultrasonic waves provided on or in front of the reflecting plate, and the ultrasonic transducer array and the reflecting plate are connected or integrated. A parametric speaker characterized by its structure. （２）反射板の超音波トランスデューサアレイ側が凹状
の放物面もしくは回転楕円体面を有し、かつ前記反射板
に音響フィルタを設けたものからなることを特徴とする
特許請求の範囲第１項記載のパラメトリックスピーカ。(2) The ultrasonic transducer array side of the reflection plate has a concave paraboloid or spheroidal surface, and the reflection plate is provided with an acoustic filter. parametric speaker. （３）反射板が有する放物面及び回転楕円体面の焦点に
設けた前記超音波トランスデューサアレイと音響フィル
タとを筐体によって一体に組合わせた構造からなること
を特徴とする特許請求の範囲第１項又は第２項記載のパ
ラメトリックスピーカ。(3) The ultrasonic transducer array provided at the focal point of the parabolic and spheroidal surfaces of the reflecting plate and an acoustic filter are integrally combined by a housing. The parametric speaker according to item 1 or 2. （４）反射板の材質としてプラスチック、アルミニウム
、鉄、ガラスもしくはそれらの複合材料からなることを
特徴とする特許請求の範囲第１項、第２項または第３項
に記載のパラメトリックスピーカ。(4) The parametric speaker according to claim 1, 2, or 3, wherein the material of the reflecting plate is plastic, aluminum, iron, glass, or a composite material thereof.
JP24513684A 1984-08-28 1984-11-20 Pamametric speaker Granted JPS61123389A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP24513684A JPS61123389A (en) 1984-11-20 1984-11-20 Pamametric speaker
DE19853590430 DE3590430T1 (en) 1984-08-28 1985-08-26 Loudspeaker system with a pronounced directional effect
PCT/JP1985/000469 WO1986001670A1 (en) 1984-08-28 1985-08-26 Directional speaker system
US06/862,349 US4823908A (en) 1984-08-28 1985-08-26 Directional loudspeaker system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24513684A JPS61123389A (en) 1984-11-20 1984-11-20 Pamametric speaker

Publications (2)

Publication Number Publication Date
JPS61123389A true JPS61123389A (en) 1986-06-11
JPH0576839B2 JPH0576839B2 (en) 1993-10-25

Family

ID=17129164

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24513684A Granted JPS61123389A (en) 1984-08-28 1984-11-20 Pamametric speaker

Country Status (1)

Country Link
JP (1) JPS61123389A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5359857A (en) * 1992-05-08 1994-11-01 Nippon Sanso Corporation Installation for air liquefaction separation and process therefor
JP2005354473A (en) * 2004-06-11 2005-12-22 Seiko Epson Corp Ultrasonic transducer and ultrasonic speaker employing it
JP2007184900A (en) * 2005-12-07 2007-07-19 Seiko Epson Corp Drive control method of electrostatic-type ultrasonic transducer, electrostatic-type ultrasonic transducer, ultrasonic speaker using electrostatic-type ultrasonic transducer, audio signal reproducing method, superdirectional acoustic system, and display
US7564986B2 (en) 2004-06-21 2009-07-21 Seiko Epson Corporation Ultrasonic speaker and projector
ITTO20090501A1 (en) * 2009-07-01 2011-01-02 Dipartimento Di Biolog Animale Ed Ecologia Cent HIGHLY DIRECTIVITY DEVICE FOR SOUND REPRODUCTION
JP2012029110A (en) * 2010-07-23 2012-02-09 Nec Corp Oscillation device
JP2012029111A (en) * 2010-07-23 2012-02-09 Nec Corp Oscillation device
JP2012239026A (en) * 2011-05-11 2012-12-06 Denso Corp Parametric speaker

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5359857A (en) * 1992-05-08 1994-11-01 Nippon Sanso Corporation Installation for air liquefaction separation and process therefor
JP2005354473A (en) * 2004-06-11 2005-12-22 Seiko Epson Corp Ultrasonic transducer and ultrasonic speaker employing it
US7564986B2 (en) 2004-06-21 2009-07-21 Seiko Epson Corporation Ultrasonic speaker and projector
US8009846B2 (en) 2004-06-21 2011-08-30 Seiko Epson Corporation Ultrasonic speaker and projector
JP2007184900A (en) * 2005-12-07 2007-07-19 Seiko Epson Corp Drive control method of electrostatic-type ultrasonic transducer, electrostatic-type ultrasonic transducer, ultrasonic speaker using electrostatic-type ultrasonic transducer, audio signal reproducing method, superdirectional acoustic system, and display
ITTO20090501A1 (en) * 2009-07-01 2011-01-02 Dipartimento Di Biolog Animale Ed Ecologia Cent HIGHLY DIRECTIVITY DEVICE FOR SOUND REPRODUCTION
JP2012029110A (en) * 2010-07-23 2012-02-09 Nec Corp Oscillation device
JP2012029111A (en) * 2010-07-23 2012-02-09 Nec Corp Oscillation device
JP2012239026A (en) * 2011-05-11 2012-12-06 Denso Corp Parametric speaker

Also Published As

Publication number Publication date
JPH0576839B2 (en) 1993-10-25

Similar Documents

Publication Publication Date Title
US4823908A (en) Directional loudspeaker system
US20050207590A1 (en) Method of reproducing audio sound with ultrasonic loudspeakers
JP3267231B2 (en) Super directional speaker
US6606389B1 (en) Piezoelectric film sonic emitter
MXPA01001031A (en) Acoustic device using bending wave modes.
JPH11164384A (en) Super directional speaker and speaker drive method
JP2008244964A (en) Electrostatic type ultrasonic transducer, electrostatic type transducer, ultrasonic speaker, speaker arrangement, audio signal playback method using electrostatic type ultrasonic transducer, directional acoustic system, and display device
JPS585637B2 (en) headphone
JPS61123389A (en) Pamametric speaker
JPH0754995B2 (en) Parametric speaker
JP3356847B2 (en) Sound source configuration method
JPS60201799A (en) Electroacoustic transducer
JPH0728463B2 (en) Parametric speaker
JPH0550196B2 (en)
WO2021255510A1 (en) Flat panel loudspeaker
JPH04215399A (en) Super-directional speaker
US3365021A (en) Speaker enclosure
JP3230459B2 (en) Speaker
KR960012984B1 (en) High output speaker unit for thin type
JPS62200998A (en) Parametric speaker
JPH0728462B2 (en) Parametric speaker
JP3700841B2 (en) Sound field control device
JPH04351099A (en) Ultrasonic parametric loudspeaker
Kumar HEAVY HYPERSONIC DUAL ACOUSTIC SYSTEM
JPH0582799B2 (en)