JPH03270599A - Composite piezoelectric body - Google Patents
Composite piezoelectric bodyInfo
- Publication number
- JPH03270599A JPH03270599A JP7108490A JP7108490A JPH03270599A JP H03270599 A JPH03270599 A JP H03270599A JP 7108490 A JP7108490 A JP 7108490A JP 7108490 A JP7108490 A JP 7108490A JP H03270599 A JPH03270599 A JP H03270599A
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- ultrasonic probe
- piezoelectric element
- electromechanical coupling
- coupling coefficient
- 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
- 239000002131 composite material Substances 0.000 title claims description 30
- 230000008878 coupling Effects 0.000 claims abstract description 30
- 238000010168 coupling process Methods 0.000 claims abstract description 30
- 238000005859 coupling reaction Methods 0.000 claims abstract description 30
- 239000002861 polymer material Substances 0.000 claims abstract description 15
- 230000003247 decreasing effect Effects 0.000 claims abstract 4
- 239000000463 material Substances 0.000 claims description 28
- 239000000523 sample Substances 0.000 claims description 27
- 239000000919 ceramic Substances 0.000 claims description 15
- 229920000620 organic polymer Polymers 0.000 claims description 14
- 230000007423 decrease Effects 0.000 claims description 9
- 230000005855 radiation Effects 0.000 abstract description 4
- 238000002604 ultrasonography Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 239000003822 epoxy resin Substances 0.000 description 4
- 229920000647 polyepoxide Polymers 0.000 description 4
- 229920005749 polyurethane resin Polymers 0.000 description 4
- 229920002379 silicone rubber Polymers 0.000 description 4
- 239000004945 silicone rubber Substances 0.000 description 4
- 239000011358 absorbing material Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000007747 plating Methods 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 229910012463 LiTaO3 Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229910003781 PbTiO3 Inorganic materials 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、ソナーや超音波診断装置等のセンサーに用い
られる超音波探触子に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic probe used in sensors such as sonar and ultrasonic diagnostic equipment.
従来の技術
水や生体を対象としたソナーや超音波診断装置等の超音
波探触子に用いる圧電体の材料として、最近では圧電セ
ラミックスに不均一な厚さを持たせて広い周波数帯域を
得る構成の検討が行なわれている。一方、圧電体に設け
る電極の形状または吸音材によりサイドロープレベルを
低減して超音波ビームパターンを改良することにより、
高分解能の超音波画像を得ようとする方法の検討も行な
われている。Conventional technology Recently, piezoelectric ceramics have been made with non-uniform thickness to obtain a wide frequency band as piezoelectric materials used in ultrasonic probes such as sonar and ultrasonic diagnostic equipment for water and living bodies. The configuration is being considered. On the other hand, by reducing the side rope level and improving the ultrasonic beam pattern by using the shape of the electrodes provided on the piezoelectric body or the sound-absorbing material,
Studies are also being conducted on methods to obtain high-resolution ultrasound images.
このような超音波探触子の例として、特開昭６１−７８
９４９号公報に記載のものがある。これは、第７図（Ａ
）に示すように、複数の振動子１をアレイ状に配列して
超音波ビームを制御する超音波探触子であり、各振動子
１の電極２の面積を変化させたり、第７図（Ｂ）に示す
ように、振動子３の背面に設ける吸音材４の厚さを変え
て重みづけ（アポダイジング）を行なうことにより、不
要となるサイドロープレベルを低下するようにしたもの
である。As an example of such an ultrasonic probe, Japanese Patent Application Laid-open No. 61-78
There is one described in Japanese Patent No. 949. This is shown in Figure 7 (A
), this is an ultrasonic probe that controls an ultrasound beam by arranging a plurality of transducers 1 in an array. As shown in B), the unnecessary side rope level is reduced by changing the thickness of the sound absorbing material 4 provided on the back surface of the vibrator 3 and weighting it (apodizing).
発明が解決しようとする課題
しかしながら、このような従来の超音波探触子は、アレ
イ状に配列した各振動子に対し電極の形状を考慮して超
音波ビームパターンを構成することは、製造技術上にお
いて非常に困難であり、また吸音材の厚さを変えて振動
子に重みづけすることは、実際問題としては不可能であ
るという問題があった。Problems to be Solved by the Invention However, in such conventional ultrasonic probes, it is difficult to construct an ultrasonic beam pattern by considering the shape of the electrode for each transducer arranged in an array. However, it is extremely difficult to do so, and it is actually impossible to weight the vibrator by changing the thickness of the sound absorbing material.
本発明は、このような従来の問題を解決するものであり
、圧電体が広い周波数帯域特性を有し、圧電体に超音波
振幅分布を持たせて圧電体自身で重みづけを可能にさせ
ることにより、サイドロープレベルを低下させて超音波
画像を高分解能化できる優れた超音波探触子を提供する
ことを目的とする。The present invention solves these conventional problems by providing a piezoelectric material with wide frequency band characteristics, giving the piezoelectric material an ultrasonic amplitude distribution, and making it possible to weight the piezoelectric material itself. The present invention aims to provide an excellent ultrasonic probe that can lower the side rope level and improve the resolution of ultrasonic images.
課題を解決するための手段
本発明は、前記目的を達成するために、両端面に電極を
有し、中央部で電気機械結合係数が最も高く、周辺部に
行くにしたがって電気機械結合係数が徐々に小さくなる
ように複数の圧電体素子を配列して有機高分子材料によ
り結合した複合圧電体を備えたものである。両端面の電
極は、一方の端面に一方向に向いたあるいは同心円状の
アレイ電極を設け、他方の端面に共通電極を設けること
ができる。Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has electrodes on both end faces, and the electromechanical coupling coefficient is highest at the center and gradually decreases toward the periphery. It is equipped with a composite piezoelectric body in which a plurality of piezoelectric elements are arranged so as to be small in size and bonded together by an organic polymer material. Regarding the electrodes on both end faces, one end face may be provided with a unidirectional or concentric array electrode, and the other end face may be provided with a common electrode.
作用
本発明は、前記構成により、複合圧電体自身で超音波ビ
ームの振幅の強さを調整して重みづけをすることができ
るため、サイドロープレベルを低減した超音波ビームパ
ターンを形成して分解能の高い超音波画像を得ることが
できる。According to the present invention, with the above-mentioned configuration, the strength of the amplitude of the ultrasonic beam can be adjusted and weighted by the composite piezoelectric body itself, so that an ultrasonic beam pattern with a reduced side rope level can be formed and the resolution can be improved. It is possible to obtain high-quality ultrasound images.
実施例
以下、本発明の好ましい実施例について図面を参照して
説明する。EXAMPLES Hereinafter, preferred examples of the present invention will be described with reference to the drawings.
実施例１
第１図は本発明の各実施例に用いられる複合圧電体の基
本構造を示す概略斜視図、第２図は第１図に示した複合
圧電体の断面図である。第１図および第２図において、
１１は複合圧電体であり、１２は複数の圧電体素子であ
り、周波数定数の興なる同じ長さおよび大きさの四角柱
の圧電体素子１２ａおよび１２ｂを直交方向に互いに交
互に並べたものである。１３はこれら圧電体素子１２ａ
および１２ｂの間に充填されてこれらを互いに結合する
有機高分子材料であり、例えばシリコーンゴム、エポキ
シ樹脂、ポリウレタン樹脂等が使用される。１４．１５
は圧電体素子１２のそれぞれの端面に設けられた電極で
あり、めっき、蒸着、焼き付は等の方法により設けられ
る。各圧電体素子１２ａおよび１２ｂは、その両端面を
揃えられてその両端面に電極１４．１５が設けられるこ
とにより一次元の繋がりを有する。有機高分子材料１３
は、各圧電体素子１２同士の間隙に充填されることによ
り、三次元の繋がりを有する。そしてこれら電極１４．
１５に電圧を印加することにより、複合圧電体１１が機
械振動して、厚さｔに対応した周波数の超音波を発生さ
せる。Example 1 FIG. 1 is a schematic perspective view showing the basic structure of a composite piezoelectric material used in each example of the present invention, and FIG. 2 is a sectional view of the composite piezoelectric material shown in FIG. 1. In Figures 1 and 2,
11 is a composite piezoelectric material, and 12 is a plurality of piezoelectric elements, in which square prism piezoelectric elements 12a and 12b having the same length and size and having a frequency constant are arranged alternately in orthogonal directions. be. 13 are these piezoelectric elements 12a
and 12b to bond them together, such as silicone rubber, epoxy resin, polyurethane resin, etc. 14.15
are electrodes provided on each end face of the piezoelectric element 12, and are provided by plating, vapor deposition, baking, or other methods. Each piezoelectric element 12a and 12b has a one-dimensional connection by aligning both end surfaces and providing electrodes 14, 15 on both end surfaces. Organic polymer material 13
is filled in the gaps between the piezoelectric elements 12, thereby forming a three-dimensional connection. And these electrodes 14.
By applying a voltage to 15, the composite piezoelectric body 11 is mechanically vibrated to generate an ultrasonic wave having a frequency corresponding to the thickness t.
このような複数の圧電体素子を有機高分子材料で一体に
結合した複合圧・電体は、いわゆる１−３型と呼ばれ、
例えば文献（Ｐｒｏｃ、ＩＥＥＥ、１９８５ 、 Ｕｌ
ｔｏｒａｓｏｎｉｃｓ Ｓｙｍｐ、 ｐ６４３−ｐ６４
７ ）において公知であるが、従来のものは各圧電体素
子が同じ周波数定数を有するのに対し、本実施例におけ
る複合圧電体１１は、各圧電体素子１２が異なる周波数
定数を有しており、さらに周波数定数の異なる各圧電体
素子１２ａおよび１２ｂが二次元平面において互いに交
互に配列されているので、周波数帯域がより広くなり、
より短いパルスを得て、より高分解能の超音波画像を得
ることができる。なお、周波数定数は２種類以上異なっ
ていても良く、その配列も規則的でなくとも良い。A composite piezoelectric material in which multiple piezoelectric elements are combined together using an organic polymer material is called a 1-3 type.
For example, in the literature (Proc, IEEE, 1985, Ul
torasonics Symp, p643-p64
7), in contrast to the conventional piezoelectric element in which each piezoelectric element has the same frequency constant, in the composite piezoelectric element 11 of this embodiment, each piezoelectric element 12 has a different frequency constant. Furthermore, since the piezoelectric elements 12a and 12b having different frequency constants are arranged alternately on a two-dimensional plane, the frequency band becomes wider.
Shorter pulses can be obtained to obtain higher resolution ultrasound images. Note that two or more types of frequency constants may be different, and the arrangement thereof may not be regular.
第３図および第４図は、このような構造の複合圧電体を
用いた本発明による超音波探触子の第１の実施例を示し
ている。第３図および第４図において、２１は前記した
基本構造と同様な構成を有する複合圧電体、２２は一次
元の繋がりを有して直線状に配列された電気機械結合係
数の異なる四角柱の複数の圧電体素子、２３は各圧電体
素子２２の間隙に充填された三次元の繋がりを有するシ
リコーンゴム、エポキシ樹脂、ポリウレタン樹脂等の有
機高分子材料、２４は各圧電体素子２２の一方の端面に
めっき、蒸着、焼き付は等の方法により設けられた複数
列に配列されたアレイ電極、２５は、各圧電体素子２２
の他方の端面に設けられた共通電極である。２６は共通
電極２５側に設けられて超音波を効率良く伝搬させるた
めの音響整合層、２７は音響整合層２６側に設けられた
超音波ビームを集束するための音響レンズである。3 and 4 show a first embodiment of an ultrasonic probe according to the present invention using a composite piezoelectric material having such a structure. In FIGS. 3 and 4, 21 is a composite piezoelectric material having the same basic structure as described above, and 22 is a rectangular prism having a one-dimensional connection and arranged in a straight line with different electromechanical coupling coefficients. A plurality of piezoelectric elements; 23 is an organic polymer material such as silicone rubber, epoxy resin, or polyurethane resin that has a three-dimensional connection and is filled in the gap between each piezoelectric element 22; 24 is one of the piezoelectric elements 22; Array electrodes 25 arranged in multiple rows are provided on the end face by plating, vapor deposition, baking, etc., and each piezoelectric element 22
This is a common electrode provided on the other end surface of the . 26 is an acoustic matching layer provided on the common electrode 25 side to efficiently propagate ultrasonic waves, and 27 is an acoustic lens provided on the acoustic matching layer 26 side to focus the ultrasonic beam.
この音響レンズ２７は必要に応じて設けられる。This acoustic lens 27 is provided as necessary.
２８はアレイ電極２４側に設けられて超音波を吸収する
とともに複合圧電体２１を保持するための背面負荷材で
ある。Reference numeral 28 denotes a back loading material provided on the array electrode 24 side to absorb ultrasonic waves and to hold the composite piezoelectric body 21.
このような複合圧電体２１の構成は、いわゆるアレイ配
列型超音波探触子に用いられているものと同様であり、
その動作方法も同様である。すなわち、複合圧電体２１
に設けられた複数個のアレイ電極２４ａ、２４ｂ、２４
ｃ、＝２４ｎをある群だけ時間差を付けて電圧を印加し
、発生した超音波をある距離に収束させてこれを１チヤ
ンネルずつ走査させ、それぞれ生体内から反射してきた
超音波を受信し、これを画像処理してデイスプレィ上に
リアルタイムに表示して診断するものである。The configuration of such a composite piezoelectric body 21 is similar to that used in a so-called array type ultrasonic probe,
The method of operation is also similar. That is, the composite piezoelectric body 21
A plurality of array electrodes 24a, 24b, 24 provided in
c, = 24n, a voltage is applied to a certain group with a time difference, the generated ultrasonic waves are focused at a certain distance, and this is scanned one channel at a time, and each ultrasonic wave reflected from within the body is received. The image is processed and displayed on a display in real time for diagnosis.
この複合圧電体２１をアレイ電極２４の配列方向に対し
て直角をなす方向に切断したのが第４図に示す断面図で
あり、この方向に電気機械結合係数の異なる圧電体素子
２２を配列する。すなわち、中央部Ａに電気機械結合係
数の最も高い圧電体素子２２ａを配列し、周辺部ＢＳＣ
に行くにしたがって電気機械結合係数が徐々に小さくな
るように、それぞれ圧電体素子２２ｂ、２２ｃを配列す
る。The cross-sectional view shown in FIG. 4 is a cross-sectional view of this composite piezoelectric material 21 cut in a direction perpendicular to the direction in which the array electrodes 24 are arranged, and piezoelectric elements 22 having different electromechanical coupling coefficients are arranged in this direction. . That is, the piezoelectric elements 22a with the highest electromechanical coupling coefficient are arranged in the center part A, and the peripheral part BSC
The piezoelectric elements 22b and 22c are arranged so that the electromechanical coupling coefficient gradually decreases as the distance increases.
これら電気機械結合係数の異なる３種類の圧電体素子２
２ａ、２２ｂ、２２ｃは、例えば中央部Ａの圧電体素子
２２ａとしては東北金属社のＰＺＴ系の圧電セラミック
スＮ−２１（電気機械結合係数に３３＝０．７３）、そ
の外側部分Ｂの圧電体素子２２ｂとしては、同じく東北
金属社のＰＺＴ系の圧電セラミックスＮ−８（電気機械
結合係数に３３＝０．６７）、最外側部Ｃの圧電体素子
２２ｃとしては、東芝セラミックス社のＰｂＴｉＱｍ系
の圧電セラミックスＣ−２４（電気機械結合係数に３３
＝０．５４）を用い、各圧電体素子２２ａ、２２ｂ、２
２ｃの間隙にシリコーンゴム、エポキシ樹脂、ポリウレ
タン樹脂等の有機高分子材料２３を充填して複合圧電体
２１を構成する。Three types of piezoelectric elements 2 with different electromechanical coupling coefficients
2a, 22b, and 22c, for example, the piezoelectric element 22a in the center part A is PZT-based piezoelectric ceramic N-21 (electromechanical coupling coefficient: 33=0.73) manufactured by Tohoku Kinzoku Co., Ltd., and the piezoelectric element 22a in the outer part B is used as the piezoelectric element 22a. The element 22b is made of PZT-based piezoelectric ceramic N-8 (electromechanical coupling coefficient: 33=0.67), also made by Tohoku Kinzoku Co., Ltd., and the piezoelectric element 22c in the outermost part C is made of PbTiQm-based piezoelectric ceramic made by Toshiba Ceramics Co., Ltd. Piezoelectric ceramics C-24 (electromechanical coupling coefficient of 33
=0.54), each piezoelectric element 22a, 22b, 2
The composite piezoelectric body 21 is constructed by filling the gap 2c with an organic polymer material 23 such as silicone rubber, epoxy resin, or polyurethane resin.
このように構成することにより、中央部Ａの圧電体素子
２２ａから発生する超音波の放射振幅は、電気機械結合
係数が高い分だけ高くなり、周辺部Ｂ、Ｃに行くにつれ
て超音波の放射振幅が電気機械結合係数に対応して小さ
くなる。このため、アレイ電極２４の配列方向に対して
直角な方向に振幅の重みづけ（アポダイジング）を行な
うことができ、サイドロープレベルを小さくして分解能
の高い超音波画像を得ることができる。With this configuration, the radiation amplitude of the ultrasonic wave generated from the piezoelectric element 22a in the central portion A increases as the electromechanical coupling coefficient increases, and the radiation amplitude of the ultrasonic wave increases as it goes to the peripheral portions B and C. becomes smaller corresponding to the electromechanical coupling coefficient. Therefore, amplitude weighting (apodizing) can be performed in a direction perpendicular to the arrangement direction of the array electrodes 24, and a high-resolution ultrasonic image can be obtained by reducing the side rope level.
なお、本実施例１においては、電気機械結合係数の具な
る３種類の圧電体素子２２ａ、２２ｂ。In the first embodiment, there are three types of piezoelectric elements 22a and 22b having different electromechanical coupling coefficients.
２２ｃとして圧電セラミックスを用いた場合について説
明したが、その他に圧電セラミックスとＬＩＮｂＯａ、
ＬｉＴａＯ３等の単結晶またはポーラスな圧電セラミッ
クス等を組み合わせた圧電体材料を用いても同様な効果
が得られる。また、電気機械結合係数は、３種類でなく
、２種類または４種類以上であっても良い。Although the case where piezoelectric ceramics are used as 22c has been explained, piezoelectric ceramics and LINbOa,
A similar effect can be obtained by using a piezoelectric material that is a combination of single crystals such as LiTaO3 or porous piezoelectric ceramics. Furthermore, the number of electromechanical coupling coefficients may be two or four or more instead of three.
また本実施例１においては、電極がアレイ電極２４によ
り複数個に配列されたアレイ型超音波探触子の例として
説明したが、アレイ電極２４だけでなく複合圧電体２１
もアレイ電極２４ａ、２４ｂ、２４ｃ、・・・２４ｎと
同じ間隔に切断分割してアレイ状に配列させても同様な
効果が得られる。Furthermore, in the first embodiment, the explanation was given as an example of an array type ultrasonic probe in which the electrodes are arranged in a plurality of array electrodes 24, but in addition to the array electrodes 24, the composite piezoelectric
The same effect can be obtained even if the electrodes are cut and divided at the same intervals as the array electrodes 24a, 24b, 24c, . . . 24n and arranged in an array.
実施例２
次に、本発明の第２の実施例について第５図および第６
図を参照して説明する。第５図および第６図において、
３１は前記した基本構造と同様な構成を有する複合圧電
体であり、３２は一次元の繋がりを有して電気機械結合
係数の異なるごとにグループ分けされて同心円状に配列
された四角柱の複数の圧電体素子であり、３３は各圧電
体素子３２の間隙に充填された三次元の繋がりを有する
シリコーンゴム、エポキシ樹脂、ポリウレタン樹脂等の
有機高分子材料であり、３４はグループ分けされた各圧
電体素子３２ごとに一方の端面に同心円状にめっき、蒸
着、焼き付は等の方法により設けられたアレイ電極であ
り、３５は各圧電体素子３２の他方の端面に設けられた
共通電極である。３６は共通電極３５側に設けられて超
音波を効率良く伝搬させるための音響整合層、３７はア
レイ電極３４側に設けられて超音波を吸収するとともに
複合電体３１を保持するための背面負荷材である。各圧
電体素子３２としては、ＰＺＴ系、ＰｂＴｉＯ３系等の
圧電セラミックスが用いられている。Example 2 Next, regarding the second example of the present invention, FIGS.
This will be explained with reference to the figures. In Figures 5 and 6,
31 is a composite piezoelectric material having the same basic structure as described above, and 32 is a plurality of rectangular prisms which have one-dimensional connections and are grouped according to different electromechanical coupling coefficients and arranged concentrically. 33 is an organic polymer material such as silicone rubber, epoxy resin, polyurethane resin, etc. that has a three-dimensional connection filled in the gap between each piezoelectric element 32, and 34 is an organic polymer material filled in the gap between each piezoelectric element 32, An array electrode is provided concentrically on one end surface of each piezoelectric element 32 by plating, vapor deposition, baking, etc., and 35 is a common electrode provided on the other end surface of each piezoelectric element 32. be. 36 is an acoustic matching layer provided on the common electrode 35 side to efficiently propagate ultrasonic waves, and 37 is a back load provided on the array electrode 34 side to absorb ultrasonic waves and hold the composite electric body 31. It is a material. As each piezoelectric element 32, piezoelectric ceramics such as PZT type and PbTiO3 type are used.
アレイ電極３４は、同心円状に複数個配列された電極３
４ａ、３４ｂ、３４ｃ、 ・−３４ｎからなり、これら
各電極３４にほぼ対応して、電気機械結合係数の興なる
圧電体素子３２ａ、３２ｂ、３２ｃ、・・・３２ｎがグ
ループ分けして配列されている。すなわち、電極３４ａ
に対応する中央部Ａに電気機械結合係数の値が最も高い
圧電体素子３２ａが配置され、周辺部に行くにしたがっ
て電気機械結合係数の値が徐々に小さくなるように、そ
れぞれ圧電体素子３２ｂ、３２ｃ、・・・３２ｎが配列
されている。The array electrode 34 includes a plurality of electrodes 3 arranged concentrically.
4a, 34b, 34c, . . . -34n, and piezoelectric elements 32a, 32b, 32c, . There is. That is, the electrode 34a
The piezoelectric element 32a having the highest value of electromechanical coupling coefficient is arranged in the central part A corresponding to , and the piezoelectric element 32b, the value of the electromechanical coupling coefficient gradually decreases toward the periphery. 32c, . . . 32n are arranged.
このように構成された超音波探触子は、いわゆるアニユ
ラ−アレイ型超音波探触子であり、複合圧電体３１の各
アレイ電極３４に同じ電圧を印加すると、中央部Ａから
は超音波の放射振幅が最も大きく、周辺部に行くにした
がって超音波の放射振幅が徐々に小さくなった超音波振
幅分布を持たせることができる。したがって、半径方向
のどの方向においても振幅に重みっけをすることができ
、サイドローブレベルを小さくして高分解能の超音波画
像を得ることができる。The ultrasonic probe configured in this way is a so-called annular array type ultrasonic probe, and when the same voltage is applied to each array electrode 34 of the composite piezoelectric material 31, ultrasonic waves are emitted from the central portion A. It is possible to have an ultrasonic amplitude distribution in which the emission amplitude is the largest and the ultrasonic emission amplitude gradually decreases toward the periphery. Therefore, the amplitude can be weighted in any direction in the radial direction, and a high-resolution ultrasound image can be obtained by reducing the sidelobe level.
なお、本実施例２においては、電気機械結合係数の異な
る圧電体素子として圧電セラミックスを用いた場合につ
いて説明したが、その他に圧電セラミックスとＬｉＮｂ
Ｏ３、ＬｉＴａＯ３等の単結晶またはポーラスな圧電セ
ラミックス等を組み合わせた圧電体材料を用いても同様
な効果が得られる。In Example 2, a case was explained in which piezoelectric ceramics were used as piezoelectric elements with different electromechanical coupling coefficients, but piezoelectric ceramics and LiNb
A similar effect can be obtained by using a piezoelectric material that is a combination of single crystals such as O3, LiTaO3, or porous piezoelectric ceramics.
また、本実施例２においては、複合圧電体３１に設けた
アレイ電極３４に対応して電気機械結合係数の興なる圧
電体素子３２を配列した構成を示したが、各圧電体素子
３２の電気機械結合係数は各アレイ電極３４に対応しな
くても良く、要は中央部から周辺部にかけて電気機械結
合係数が徐々に小さくなるように、各圧電体素子を配列
すれば良い。Further, in the second embodiment, a configuration is shown in which the piezoelectric elements 32 having a high electromechanical coupling coefficient are arranged corresponding to the array electrode 34 provided on the composite piezoelectric body 31. The mechanical coupling coefficient does not have to correspond to each array electrode 34; the piezoelectric elements may be arranged so that the electromechanical coupling coefficient gradually decreases from the center to the periphery.
発明の効果
以上の説明から明らかなように、本発明は、両端面に電
極を有し、中央部で電気機械結合係数が最も高く、周辺
部に行くにしたがって電気機械結合係数が徐々に小さく
なるように複数の圧電体素子を配列して有機高分子材料
により結合した複合圧電体を備えているので、超音波の
放射振幅が中央部で高く、周辺部に行くにしたがって徐
々に小さくなった振幅分布を持たせることができ、サイ
ドローブレベルを低減した超音波ビームにより高分解能
の超音波画像を得ることができる。Effects of the Invention As is clear from the above explanation, the present invention has electrodes on both end faces, and the electromechanical coupling coefficient is highest at the center, and gradually decreases toward the periphery. Since it is equipped with a composite piezoelectric material in which multiple piezoelectric elements are arranged and bonded by an organic polymer material, the emission amplitude of ultrasonic waves is high in the center and gradually decreases as it goes to the periphery. A high-resolution ultrasound image can be obtained using an ultrasound beam with a reduced sidelobe level.
第１図は本発明の各実施例における複合圧電体の基本構
造を示す概略斜視図、第２図は同複合圧電体の断面図、
第３図は本発明の第１の実施例を示す超音波探触子の概
略斜視図、第４図は第３図に示す超音波探触子の断面図
、第５図は本発明の第２の実施例を示す超音波探触子の
概略平面図、第６図は第５図に示す超音波探触子の断面
図、第７図は従来の超音波探触子の一例を振幅分布とと
もに示す概略斜視図（Ａ）と概略断面図（Ｂ）である。
１１．２１．３１・・・複合圧電体、１２．２２゜３２
・・・圧電体素子、１３．２３．３３・・・有機高分子
材料、１４．１５・・・電極、２４．３４・・・アレイ
電極、２５．３５・・・共通電極、２６．３６・・・音
響整合層、２７・・・音響レンズ、２８．３７・・・背
面負荷材。FIG. 1 is a schematic perspective view showing the basic structure of a composite piezoelectric material in each embodiment of the present invention, FIG. 2 is a sectional view of the composite piezoelectric material,
3 is a schematic perspective view of an ultrasonic probe showing the first embodiment of the present invention, FIG. 4 is a sectional view of the ultrasonic probe shown in FIG. 3, and FIG. FIG. 6 is a cross-sectional view of the ultrasonic probe shown in FIG. 5, and FIG. 7 shows an example of a conventional ultrasonic probe with amplitude distribution. FIG. 2 is a schematic perspective view (A) and a schematic cross-sectional view (B) shown together with FIG. 11.21.31...Composite piezoelectric material, 12.22°32
...Piezoelectric element, 13.23.33...Organic polymer material, 14.15...Electrode, 24.34...Array electrode, 25.35...Common electrode, 26.36... ...Acoustic matching layer, 27...Acoustic lens, 28.37...Back load material.
Claims (12)
が最も高く、周辺部に行くにしたがって電気機械結合係
数が徐々に小さくなるように複数の圧電体素子を配列し
て有機高分子材料により結合した複合圧電体を備えたこ
とを特徴とする超音波探触子。(1) Electromechanical coupling coefficient is highest in the center and gradually decreases toward the periphery. An ultrasonic probe characterized by comprising a composite piezoelectric material bonded by a molecular material.
子材料が三次元の繋がりを有することを特徴とする請求
項（１）記載の超音波探触子。(2) The ultrasonic probe according to claim 1, wherein each piezoelectric element has a one-dimensional connection, and the organic polymer material has a three-dimensional connection.
徴とする請求項（２）記載の超音波探触子。(3) The ultrasonic probe according to claim (2), wherein each piezoelectric element is made of piezoelectric ceramics.
いることを特徴とする請求項（１）から（３）のいずれ
かに記載の超音波探触子。(4) The ultrasonic probe according to any one of claims (1) to (3), wherein each piezoelectric element has two or more different frequency constants.
行くにしたがって電気機械結合係数が徐々に小さくなる
ように複数の圧電体素子を直線状に配列して有機高分子
材料により結合した複合圧電体を備え、前記複合圧電体
をその圧電体素子の配列方向に直角な方向に並べてその
一方の端面に複数のアレイ電極をその並べた方向に設け
、他方の端面に共通電極を設けたことを特徴とする超音
波探触子。(5) A plurality of piezoelectric elements were arranged in a straight line and bonded by an organic polymer material so that the electromechanical coupling coefficient was highest in the center and gradually decreased toward the periphery. A composite piezoelectric material is provided, the composite piezoelectric material is arranged in a direction perpendicular to the arrangement direction of the piezoelectric elements, a plurality of array electrodes are provided on one end surface thereof in the arrangement direction, and a common electrode is provided on the other end surface. An ultrasonic probe characterized by:
子材料が三次元の繋がりを有することを特徴とする請求
項（５）記載の超音波探触子。(6) The ultrasonic probe according to claim (5), wherein each piezoelectric element has a one-dimensional connection, and the organic polymer material has a three-dimensional connection.
徴とする請求項（６）記載の超音波探触子。(7) The ultrasonic probe according to claim (6), wherein each piezoelectric element is made of piezoelectric ceramics.
いることを特徴とする請求項（５）から（７）のいずれ
かに記載の超音波探触子。(8) The ultrasonic probe according to any one of claims (5) to (7), wherein each piezoelectric element has two or more different frequency constants.
行くにしたがって電気機械結合係数が徐々に小さくなる
ようにグループ分けした複数の圧電体素子を同心円状に
配列して有機高分子材料により結合した複合圧電体を備
え、前記複合圧電体の一方の端面に前記グループ分けし
た圧電体素子に対応して複数のアレイ電極を同心円状に
設け、他方の端面に共通電極を設けたことを特徴とする
超音波探触子。(9) Organic polymer material is made by arranging multiple piezoelectric elements concentrically, which are grouped so that the electromechanical coupling coefficient is highest in the center and gradually decreases toward the periphery. A plurality of array electrodes are provided concentrically on one end surface of the composite piezoelectric material corresponding to the grouped piezoelectric elements, and a common electrode is provided on the other end surface of the composite piezoelectric material. Features of ultrasonic probe.
分子材料が三次元の繋がりを有することを特徴とする請
求項（９）記載の超音波探触子。(10) The ultrasonic probe according to claim 9, wherein each piezoelectric element has a one-dimensional connection, and the organic polymer material has a three-dimensional connection.
特徴とする請求項（１０）記載の超音波探触子。(11) The ultrasonic probe according to claim (10), wherein each piezoelectric element is made of piezoelectric ceramics.
ていることを特徴とする請求項（９）から（１１）のい
ずれかに記載の超音波探触子。(12) The ultrasonic probe according to any one of claims (9) to (11), wherein each piezoelectric element has two or more different frequency constants.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7108490A JPH03270599A (en) | 1990-03-20 | 1990-03-20 | Composite piezoelectric body |
| CA 2054698 CA2054698A1 (en) | 1990-03-20 | 1991-03-19 | Ultrasonic probe |
| EP19910906265 EP0480045A4 (en) | 1990-03-20 | 1991-03-19 | Ultrasonic probe |
| PCT/JP1991/000367 WO1991015090A1 (en) | 1990-03-20 | 1991-03-19 | Ultrasonic probe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7108490A JPH03270599A (en) | 1990-03-20 | 1990-03-20 | Composite piezoelectric body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03270599A true JPH03270599A (en) | 1991-12-02 |
Family
ID=13450309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7108490A Pending JPH03270599A (en) | 1990-03-20 | 1990-03-20 | Composite piezoelectric body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03270599A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002027594A (en) * | 2000-07-11 | 2002-01-25 | Hitachi Ltd | Ultrasonic probe and method for manufacturing the same |
| US7276838B2 (en) | 2003-07-08 | 2007-10-02 | Kabushiki Kaisha Toshiba | Piezoelectric transducer including a plurality of piezoelectric members |
| JP2009082385A (en) * | 2007-09-28 | 2009-04-23 | Fujifilm Corp | Ultrasonic probe |
| JP2012503370A (en) * | 2008-09-18 | 2012-02-02 | ビジュアルソニックス インコーポレイテッド | Ultrasonic transducer and other component manufacturing method |
| US9173047B2 (en) | 2008-09-18 | 2015-10-27 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US9184369B2 (en) | 2008-09-18 | 2015-11-10 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
-
1990
- 1990-03-20 JP JP7108490A patent/JPH03270599A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002027594A (en) * | 2000-07-11 | 2002-01-25 | Hitachi Ltd | Ultrasonic probe and method for manufacturing the same |
| US7276838B2 (en) | 2003-07-08 | 2007-10-02 | Kabushiki Kaisha Toshiba | Piezoelectric transducer including a plurality of piezoelectric members |
| US7309947B2 (en) | 2003-07-08 | 2007-12-18 | Kabushiki Kaisha Toshiba | Piezoelectric transducer including a plurality of piezoelectric members |
| CN100418481C (en) * | 2003-07-08 | 2008-09-17 | 株式会社东芝 | Piezoelectric transducer including a plurality of piezoelectric members |
| JP2009082385A (en) * | 2007-09-28 | 2009-04-23 | Fujifilm Corp | Ultrasonic probe |
| JP2012503370A (en) * | 2008-09-18 | 2012-02-02 | ビジュアルソニックス インコーポレイテッド | Ultrasonic transducer and other component manufacturing method |
| US9173047B2 (en) | 2008-09-18 | 2015-10-27 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US9184369B2 (en) | 2008-09-18 | 2015-11-10 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US9555443B2 (en) | 2008-09-18 | 2017-01-31 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US9935254B2 (en) | 2008-09-18 | 2018-04-03 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US10596597B2 (en) | 2008-09-18 | 2020-03-24 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US11094875B2 (en) | 2008-09-18 | 2021-08-17 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
| US11845108B2 (en) | 2008-09-18 | 2023-12-19 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
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