JP2786531B2 - Super directional speaker - Google Patents
Super directional speakerInfo
- Publication number
- JP2786531B2 JP2786531B2 JP28176890A JP28176890A JP2786531B2 JP 2786531 B2 JP2786531 B2 JP 2786531B2 JP 28176890 A JP28176890 A JP 28176890A JP 28176890 A JP28176890 A JP 28176890A JP 2786531 B2 JP2786531 B2 JP 2786531B2
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- transducer array
- waves
- directional speaker
- ultrasonic transducer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000758 substrate Substances 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 239000011358 absorbing material Substances 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Classifications
-
- 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
- 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)
- Multimedia (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Circuit For Audible Band Transducer (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 極めて指向性の強い音帯域をつくる超音波パラメトリ
ックトランスデューサアレイに関する。Description: TECHNICAL FIELD The present invention relates to an ultrasonic parametric transducer array that creates a sound band with extremely high directivity.
［従来の技術］ 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出願は比較的多く見
られる。2. Description of the Related Art There are relatively many applications relating to a speaker having a parametric effect utilizing the nonlinearity of air with respect to ultrasonic waves.
この方式のスピーカは、電気的に大きなエネルギーを
必要とする割には、音としての出力は小さく一般のスピ
ーカ方式に比べると極めて効率が悪い欠点がある。ま
た、前記パラメトリック効果によって生じる二次波の可
聴音波の出力を高めるためには、一次波の超音波の出力
を高める必要があり、必然的に人体に有害な超音波が発
せられることになる。このため、超音波を吸収するフィ
ルター材と可聴音波を反射する反射板を組合せた出願が
見られる。The loudspeaker of this type has a drawback that the output as a sound is small and the efficiency is extremely low as compared with a general loudspeaker type, although large electric energy is required. Also, in order to increase the output of the secondary audible sound wave generated by the parametric effect, it is necessary to increase the output of the primary wave ultrasonic wave, which inevitably emits a harmful ultrasonic wave to the human body. For this reason, there have been applications in which a filter material that absorbs ultrasonic waves and a reflector that reflects audible sound waves are combined.
その中で、特願昭59−245136（発明の名称：パラメト
リックスピーカ，出願人：松下電器産業（株））を従来
例として説明すると、第４図に見られるように、内面に
吸音材014を設けたスピーカボックス012の一隅に設置さ
れた超音波トランスデューサアレイ01（駆動源・音源）
と放物面を有する反射板011との位置関係を考慮した配
設が必要である。Among them, Japanese Patent Application No. 59-245136 (Title of Invention: Parametric Speaker, Applicant: Matsushita Electric Industrial Co., Ltd.) is described as a conventional example. As shown in FIG. 4, a sound absorbing material 014 is provided on the inner surface. Ultrasonic transducer array 01 (drive source / sound source) installed in one corner of speaker box 012 provided
It is necessary to dispose it in consideration of the positional relationship between the reflector and the reflecting plate 011 having a paraboloid.
すなわち、反射面から反射し音響フィルタ013を経て
受聴者９に至る二次波（可聴音）の通過経路上から外れ
た位置に超音波トランスジューサアレイを設置する必要
があった。That is, it is necessary to install the ultrasonic transducer array at a position off the passage of the secondary wave (audible sound) that is reflected from the reflecting surface and passes through the acoustic filter 013 to the listener 9.
［発明が解決しようとする課題］ このため、一定の面積を有する反射板と超音波トラン
スジューサアレイをスピーカボックス012の中に組み込
む場合に、容積が大きいボックスが必要になり、用途面
で大きな制約となる。すなわち、この方式のスピーカの
最大の課題はコンパクト化にあった。[Problems to be Solved by the Invention] For this reason, when a reflector having a fixed area and an ultrasonic transducer array are incorporated in the speaker box 012, a box having a large volume is required, which imposes great restrictions on application. Become. In other words, the biggest problem with this type of speaker was downsizing.
さらに従来の構造では、反射面に対して超音波トラン
スデューサアレイの音波放出面が等間隔ではないため
（第４図中のl1,l2），反射音の音圧が不均一であっ
た。Further, in the conventional structure, the sound emitting surface of the ultrasonic transducer array is not equidistant from the reflecting surface (l 1 and l 2 in FIG. 4), so that the sound pressure of the reflected sound is not uniform.
［課題を解決するための手段］ 前記の従来法の欠点を解消して、広い用途に適合する
よう中心部に開孔を有するパラボラ状の基板の凹面に、
超音波トランスデューサアレイ（超音波を発する圧電振
動子を網目状に配列してアレイ化したもの）を構成し、
その基板の曲率半径の中心点附近に、超音波を吸収する
フィルターを有する可聴音波の反射板を配置し、さらに
前記基板の開孔部を可聴音波のみを透過するフィルター
で塞ぎ、その部分を構造の前面とし、前記反射板の背面
を構造の後面とするスピーカボックスを提供するもので
ある。[Means for Solving the Problems] In order to solve the above-mentioned drawbacks of the conventional method, a concave surface of a parabolic substrate having an opening in the center so as to be suitable for a wide range of applications,
An ultrasonic transducer array (an array of piezoelectric transducers that emit ultrasonic waves arranged in a mesh pattern) is configured,
Around the center of the radius of curvature of the substrate, an audible sound wave reflecting plate having a filter that absorbs ultrasonic waves is arranged, and the opening of the substrate is closed with a filter that transmits only audible sound waves, and the portion is structured. And a speaker box having a back surface of the reflector as a rear surface of the structure.
［作用］ 超音波（一次波）を放出する超音波トランスデューサ
アレイを、中心部を開孔したパラボラ状の基板の凹面に
配設し、この凹面に相対した位置、すなわち前記凹面の
曲率半径の原点にほぼ近い位置に、反射板を設けること
により、前記一次波と空気の非線形性により発生した指
向性の強い二次波（可聴音波）が前記反射板に反射し
て、前記パラボラ状基板の中心に開けられた孔を通って
放出する。[Action] An ultrasonic transducer array that emits ultrasonic waves (primary waves) is disposed on a concave surface of a parabolic substrate having a central portion opened, and a position corresponding to the concave surface, that is, the origin of the radius of curvature of the concave surface. A secondary wave (audible sound wave) having strong directivity generated by the non-linearity of the primary wave and air is reflected on the reflector by providing a reflector almost at a position near the center of the parabolic substrate. Discharge through holes drilled in.
［実施例］ 第１図は本発明による超音波パラメトリックトランス
デューサアレイ方式の超指向性スピーカの基本構成を示
すもので、図中の（１）は中心部に開孔を有するパラボ
ラ状基板、（２）は該パラボラ状基板の内面に配設され
た複数個の超音波トランスデューサアレイ，（３）は防
水を兼ねる超音波フィルター、（４）は可聴音波を反射
する反射板でその表面には超音波を吸収する超音波フィ
ルタ（５）を有している。また矢印（ａ）は超指向性可
聴音波の進行方向を示している。Embodiment FIG. 1 shows the basic configuration of a superdirective loudspeaker of the ultrasonic parametric transducer array type according to the present invention, in which (1) shows a parabolic substrate having an opening in the center, and (2) ) Is a plurality of ultrasonic transducer arrays disposed on the inner surface of the parabolic substrate, (3) is an ultrasonic filter which also serves as a waterproof, and (4) is a reflecting plate which reflects audible sound waves, and the surface has ultrasonic waves. An ultrasonic filter (5) that absorbs Arrow (a) indicates the traveling direction of the superdirective audible sound wave.
第２図は第１図に示した本発明による超指向性スピー
カの基本構成部分をスピーカボックスに収納し、実用性
を考慮した構成を示すもので、その断面図である。FIG. 2 is a sectional view showing a configuration in which the basic components of the super-directional speaker according to the present invention shown in FIG. 1 are housed in a speaker box and considering practicality.
図中の（10）はスピーカボックス，（11）はパラボラ
状基板を保持し、超音波トランスデューサアレイ（超音
波素子）を相互に撃ぐ配線を格納する背板である。なお
同図中の矢印（ｂ）は超音波トランスデューサアレイか
ら放出される一次波（超音波）の放出方向である。In the figure, (10) is a speaker box, and (11) is a back plate that holds a parabolic substrate and stores wirings that mutually strike an ultrasonic transducer array (ultrasonic element). Note that the arrow (b) in the figure is the emission direction of the primary wave (ultrasonic wave) emitted from the ultrasonic transducer array.
また、第３図は本発明による超指向性スピーカを駆動
させるための電気系統図である。図中（20）はパナーア
ンプで、テープレコーダなどの音響信号発生装置（30）
からの音響信号によって変調された超音波がトランスデ
ューサアレイに出力される。FIG. 3 is an electric system diagram for driving the super-directional speaker according to the present invention. In the figure, (20) is a panner amplifier, and an audio signal generator such as a tape recorder (30)
The ultrasonic wave modulated by the acoustic signal from is output to the transducer array.
［発明の効果］ 本発明の構造的な効果として （１）超音波トランスデューサアレイをパラボラ状基板
の凹面に構成したことにより、一次波（超音波）の集合
性が向上し、反射板で反射する二次波の可聴音波は狭い
範囲（ゾーン）に指向性を保ちながら、前記パラボラ状
基板中央部の開孔から外へ放出される。したがって、従
来平面的に超音波トランスデューサアレイを構成してい
た構造に比べ、稠密な音帯域をつくることができる。[Effects of the Invention] Structural effects of the present invention are as follows. (1) By forming the ultrasonic transducer array on the concave surface of the parabolic substrate, the collective property of the primary waves (ultrasonic waves) is improved, and the primary waves (ultrasonic waves) are reflected by the reflector. The secondary audible sound wave is emitted to the outside through an opening in the center of the parabolic substrate while maintaining directivity in a narrow range (zone). Therefore, a dense sound band can be created as compared with a structure in which an ultrasonic transducer array is conventionally formed in a plane.
（２）人体に有害とされている超音波は筐体（スピーカ
ボックス）内のフィルターは勿論、内壁にも吸収され
て、筐体に放出されることが少ない。(2) Ultrasonic waves deemed harmful to the human body are absorbed not only by the filter in the housing (speaker box) but also by the inner wall, and are hardly emitted to the housing.
（３）中心部の開孔から可聴音波を放出するパラボラ状
の音源構造にすることにより、スピーカのコンパクト化
が図れる。(3) The speaker can be made more compact by adopting a parabolic sound source structure that emits audible sound waves from the central opening.
第１図は、本発明の一実施例に係る超指向性スピーカの
基本構成斜視図、第２図は本発明によるスピーカボック
スの断面図、第３図は本発明によるスピーカシステムの
電気系統図、第４図は、従来の超音波パラメトリックス
ピーカを示す断面図。 第１図〜第３図の中で、１はパラボラ状基板、２は超音
波トランスデューサアレイ、３は超音波フィルター、４
は反射板、５は超音波フィルター、10はスピーカボック
ス、11は背板、20はパワーアンプ、30は音響信号発生装
置。FIG. 1 is a perspective view of a basic configuration of a super-directional speaker according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a speaker box according to the present invention, FIG. 3 is an electric system diagram of a speaker system according to the present invention, FIG. 4 is a sectional view showing a conventional ultrasonic parametric speaker. 1 to 3, 1 is a parabolic substrate, 2 is an ultrasonic transducer array, 3 is an ultrasonic filter,
Is a reflection plate, 5 is an ultrasonic filter, 10 is a speaker box, 11 is a back plate, 20 is a power amplifier, and 30 is an acoustic signal generator.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭60−106294（ＪＰ，Ａ) 特開 昭61−123389（ＪＰ，Ａ) 特開 平４−74097（ＪＰ，Ａ) 特開 平３−252299（ＪＰ，Ａ) 特開 昭61−146098（ＪＰ，Ａ) 特開 昭59−114994（ＪＰ，Ａ) 特公 平７−54995（ＪＰ，Ｂ２) 特公 昭55−47514（ＪＰ，Ｂ２) ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-106294 (JP, A) JP-A-61-123389 (JP, A) JP-A-4-74097 (JP, A) JP-A-3-106 252299 (JP, A) JP-A-61-146098 (JP, A) JP-A-59-114994 (JP, A) JP-B-7-54995 (JP, B2) JP-B-55-47514 (JP, B2)
Claims (2)
面に多数の超音波トランスデューサアレイを配置し、こ
の超音波トランスデューサアレイの曲率半径の中心点附
近に、表面に超音波を吸収するフィルターを有する可聴
音波の反射板を配設したことを特徴とする超指向性スピ
ーカ。An ultrasonic transducer array is disposed on a concave surface of a parabolic substrate having an opening in the center, and a filter for absorbing ultrasonic waves on the surface near a center point of a radius of curvature of the ultrasonic transducer array. A super-directional speaker comprising an audible sound wave reflecting plate having:
を透過するフィルター材を配設したことを特徴とする特
許請求の範囲第１項記載の超指向性スピーカ。2. The super-directional speaker according to claim 1, wherein a filter material that transmits only audible sound waves is provided in the opening of the parabolic substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28176890A JP2786531B2 (en) | 1990-10-22 | 1990-10-22 | Super directional speaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28176890A JP2786531B2 (en) | 1990-10-22 | 1990-10-22 | Super directional speaker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04215399A JPH04215399A (en) | 1992-08-06 |
| JP2786531B2 true JP2786531B2 (en) | 1998-08-13 |
Family
ID=17643705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28176890A Expired - Fee Related JP2786531B2 (en) | 1990-10-22 | 1990-10-22 | Super directional speaker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2786531B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7542579B2 (en) | 2004-09-16 | 2009-06-02 | Seiko Epson Corporation | Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer |
| US7564986B2 (en) | 2004-06-21 | 2009-07-21 | Seiko Epson Corporation | Ultrasonic speaker and projector |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3320849B2 (en) * | 1993-08-06 | 2002-09-03 | 株式会社東芝 | Ultrasound imaging device |
| JPH11164384A (en) * | 1997-11-25 | 1999-06-18 | Nec Corp | Super directional speaker and speaker drive method |
| JP5659598B2 (en) * | 2010-07-23 | 2015-01-28 | 日本電気株式会社 | Oscillator |
| JP5664450B2 (en) * | 2011-05-11 | 2015-02-04 | 株式会社デンソー | Parametric speaker |
| CN106076794B (en) * | 2016-08-24 | 2022-08-19 | 复旦大学 | Same-phase close-packed array type ultrasonic transmitting unit |
-
1990
- 1990-10-22 JP JP28176890A patent/JP2786531B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7564986B2 (en) | 2004-06-21 | 2009-07-21 | Seiko Epson Corporation | Ultrasonic speaker and projector |
| CN100544498C (en) * | 2004-06-21 | 2009-09-23 | 精工爱普生株式会社 | Ultrasonic speaker and projector |
| US7542579B2 (en) | 2004-09-16 | 2009-06-02 | Seiko Epson Corporation | Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer |
| US7949143B2 (en) * | 2004-09-16 | 2011-05-24 | Seiko Epson Corporation | Ultrasonic transducer, ultrasonic speaker, acoustic system, and control method of ultrasonic transducer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04215399A (en) | 1992-08-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |