JPH05184172A - Ultrasonic oscillator - Google Patents

Abstract

PURPOSE:To construct such an actuator as is driven at low voltage and is actuated in two dimensions without using the resonance of an oscillator. CONSTITUTION:Between an elastic body 7 which has a projection 6 and is formed of stainless steel or other material and a lower stand 8, four laminated piezoelectric elements 9a-9d such as PZT's are secured by bonding or other methods. A controlling device divides an output of an oscillator into four wave forms of different phase by means of a variable phase shifter. Then, four outputs of different amplitude and different phase are obtained through an amplifier of variable gain. The four outputs are applied to the four laminated piezoelectric elements 9a-9d respectively.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、超音波振動を利用した
２次元動作のアクチュエータである超音波振動子に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibrator which is a two-dimensional actuator utilizing ultrasonic vibration.

【０００２】[0002]

【従来の技術】圧電素子に交流電圧を印加して得られる
超音波振動で弾性体に楕円運動を励起し、この弾性体に
接する物体との間に相対移動力を発生させることを応用
した超音波振動子は数多く提案されている。2. Description of the Related Art Ultrasonic vibration obtained by applying an alternating voltage to a piezoelectric element excites an elliptical motion in an elastic body to generate a relative moving force between the elastic body and an object in contact with the elastic body. Many acoustic wave oscillators have been proposed.

【０００３】例えば、図１１に示すのは、特開平２−７
８７５号公報に開示された超音波振動子で、１１Ａは斜
視図を、１１Ｂは平面図を示す。この振動子は、積層圧
電素子１でＺ方向の振動を励起し、側壁に対向して設け
た圧電素子２ａ，２ｂでＸ方向に振動子全体を屈曲運動
させ、このふたつを合成してＸ方向に楕円運動させてい
る。この様子を図１２に示す。同様に、側壁に対向して
設けた圧電素子３ａ，３ｂでＹ方向に屈曲させて、Ｙ方
向に楕円運動をさせている。さらに、このＸ，Ｙ，Ｚ方
向の振動を適当に合成することにより任意の方向に楕円
運動を励起することができる。図１２において、１２Ａ
はＺ方向、１２ＢはＸ，Ｙ方向の振動を示す。For example, FIG. 11 shows Japanese Patent Laid-Open No. 2-7.
In the ultrasonic transducer disclosed in Japanese Patent No. 875, 11A is a perspective view and 11B is a plan view. In this vibrator, the laminated piezoelectric element 1 excites vibrations in the Z direction, and the piezoelectric elements 2a and 2b provided facing the side walls cause the entire vibrator to bend in the X direction. It has an elliptic motion. This state is shown in FIG. Similarly, the piezoelectric elements 3a and 3b provided facing the side wall are bent in the Y direction to make an elliptic motion in the Y direction. Further, by appropriately synthesizing the vibrations in the X, Y, and Z directions, the elliptic motion can be excited in any direction. In FIG. 12, 12A
Indicates vibration in the Z direction, and 12B indicates vibrations in the X and Y directions.

【０００４】この振動子に図１３（１３Ａは斜視図、１
３Ｂは正面図）に示すように、板状のテーブル４を接触
させることにより、振動子とテーブル４とを相対移動さ
せ、１個の振動子で２次元動作可能なアクチュエータを
構成している。５で示すのは、積層圧電素子１上に設け
た突起部である。This vibrator is shown in FIG. 13 (13A is a perspective view, 1
3B, as shown in the front view), the plate-shaped table 4 is brought into contact with the vibrator, so that the vibrator and the table 4 are moved relatively to each other, thereby forming an actuator capable of two-dimensional operation with one vibrator. Reference numeral 5 denotes a protrusion provided on the laminated piezoelectric element 1.

【０００５】[0005]

【発明が解決しようとする課題】しかしながら、上記の
従来例では、振動子の屈曲をさせている圧電素子２ａ，
２ｂ，３ａ，３ｂに一層の圧電素子を使用しているた
め、屈曲の振幅を大きくするのには高電圧（数１００
Ｖ）を必要とし、駆動回路を高圧増幅器にするか、また
はトランス等の昇圧手段を必要とした。また、屈曲の振
動効率を高めるために、駆動周波数を振動子の共振周波
数と一致させているが、アクチュエータを構成する際の
振動子と板状のテーブル４との間の押圧力により共振周
波数が変わってしまうという欠点があった。However, in the above-mentioned conventional example, the piezoelectric element 2a in which the vibrator is bent,
Since a single-layer piezoelectric element is used for 2b, 3a, and 3b, a high voltage (several hundreds
V) was required, and the drive circuit was a high-voltage amplifier or a booster such as a transformer was required. Further, in order to increase the vibration efficiency of bending, the drive frequency is made to match the resonance frequency of the vibrator, but the resonance frequency is changed by the pressing force between the vibrator and the plate-shaped table 4 when forming the actuator. It had the drawback of changing.

【０００６】本発明は、かかる従来の欠点に鑑みてなさ
れたもので、低電圧駆動可能で、かつ振動子の共振を使
用しない２次元動作可能なアクチュエータを構成可能な
超音波振動子を提供することを目的とする。The present invention has been made in view of the above-mentioned conventional drawbacks, and provides an ultrasonic transducer which can be driven at a low voltage and which can constitute an actuator capable of two-dimensional operation without using resonance of the transducer. The purpose is to

【０００７】[0007]

【課題を解決するための手段】上記目的を達成するため
に、本発明は、突起部をもつ弾性体と、この弾性体に一
端を接合した３個以上の積層圧電素子と、この積層圧電
素子の他端に接合した下台とを具備して超音波振動子を
構成した。In order to achieve the above object, the present invention provides an elastic body having a projection, three or more laminated piezoelectric elements having one end joined to the elastic body, and the laminated piezoelectric element. An ultrasonic transducer was configured by including a lower table joined to the other end of the ultrasonic transducer.

【０００８】ここで、積層圧電素子の振動子の振幅およ
び位相は、各々独立に制御するとよい。Here, the amplitude and phase of the vibrator of the laminated piezoelectric element may be controlled independently.

【０００９】[0009]

【作用】上記構成の超音波振動子においては、３個以上
の積層圧電素子を直線以外に配置し、変位を制御すれ
ば、積層圧電素子の伸縮方向に垂直な平面を任意の方向
に傾けられる。この平面に垂直に設けられた突起部の先
端は、平面の傾きに応じた、積層圧電素子の伸縮方向に
垂直方向の成分の変位が得られる。この変位と、積層圧
電素子の伸縮による変位とを合成することにより、任意
の方向の楕円運動が得られる。In the ultrasonic vibrator of the above construction, if three or more laminated piezoelectric elements are arranged in a line other than a straight line and the displacement is controlled, the plane perpendicular to the expansion / contraction direction of the laminated piezoelectric element can be tilted in any direction. .. The tip of the protrusion provided perpendicularly to the plane can obtain the displacement of the component in the direction perpendicular to the expansion / contraction direction of the laminated piezoelectric element according to the inclination of the plane. By combining this displacement and the displacement due to expansion and contraction of the laminated piezoelectric element, an elliptical motion in an arbitrary direction can be obtained.

【００１０】[0010]

【実施例１】図１に実施例１の振動子の構成を、図２に
その制御装置を示す。振動子は、突起部６をもつステン
レス鋼等の弾性体７と下台８との間にＰＺＴ等の４本の
積層圧電素子９ａ〜９ｄを接着等の方法で固定してあ
る。一方、制御装置は、図２に示すように、発振器１０
の出力を、可変位相の移相器１１ｂ〜１１ｄで位相の異
なる４波形に分け、さらに可変ゲインの増幅器１２ａ〜
１２ｄを経て、振幅・位相の異なる４出力Ａ〜Ｄを得
る。なお、位相およびゲインは、制御機構１３により制
御される。[Embodiment 1] FIG. 1 shows the configuration of a vibrator of Embodiment 1, and FIG. 2 shows its control device. In the vibrator, four laminated piezoelectric elements 9a to 9d such as PZT are fixed between an elastic body 7 made of stainless steel or the like having a protrusion 6 and a lower base 8 by a method such as adhesion. On the other hand, the control device, as shown in FIG.
Is divided into four waveforms having different phases by the variable phase shifters 11b to 11d, and the variable gain amplifiers 12a to 12a to
After 12d, four outputs A to D having different amplitudes and phases are obtained. The phase and gain are controlled by the control mechanism 13.

【００１１】この４出力Ａ〜Ｄは４つの積層圧電素子９
ａ〜９ｄにそれぞれ印加する。この振動子の動作を図３
〜図７を用いて説明する。積層圧電素子９ａ，９ｂに変
位１４が得られるように、また、積層圧電素子９ｃ，９
ｄに変位１５が得られるように電圧を印加する。圧電素
子１６に積層圧電素子９ａと９ｂが、圧電素子１７に積
層圧電素子９ｃと９ｄがそれぞれ相当するものとする
と、図３の時間（１）〜（６）のそれぞれの場合の振動
子の状態は、図４の（１）〜（６）になる。この時、突
起部６の先端部分の動作に着目すると、図５の（１）〜
（６）に示すように、楕円軌跡を描く。ここで、圧電素
子１６に積層圧電素子９ｂと９ｃを、圧電素子１７に積
層圧電素子９ｄと９ａを対応させると、楕円軌跡が９０
度異なる方向に得られる。同様に、互いに９０度異なる
方向に計４種類の楕円軌跡が得られる。These four outputs A to D are four laminated piezoelectric elements 9
a to 9d, respectively. Figure 3 shows the operation of this oscillator.
~ It demonstrates using FIG. In order to obtain the displacement 14 in the laminated piezoelectric elements 9a and 9b, the laminated piezoelectric elements 9c and 9b
A voltage is applied so that the displacement 15 is obtained in d. Assuming that the piezoelectric elements 16 correspond to the laminated piezoelectric elements 9a and 9b and the piezoelectric element 17 corresponds to the laminated piezoelectric elements 9c and 9d, respectively, the state of the vibrator in each of the times (1) to (6) in FIG. Becomes (1) to (6) in FIG. At this time, focusing on the operation of the tip portion of the protrusion 6, (1) to FIG.
As shown in (6), an elliptical locus is drawn. Here, when the piezoelectric elements 16 correspond to the laminated piezoelectric elements 9b and 9c and the piezoelectric elements 17 correspond to the laminated piezoelectric elements 9d and 9a, the elliptical locus is 90.
Obtained in different directions. Similarly, a total of four types of elliptical loci can be obtained in directions different from each other by 90 degrees.

【００１２】また、積層圧電素子９ａに変位１８、積層
圧電素子９ｃに変位１９、積層圧電素子９ｂと９ｄに変
位２０が得られるように電圧を印加すれば、図７と図８
に示すように、振動子の四角形の対角方向に楕円軌跡が
得られる。積層圧電素子９ａ〜９ｄと変位１８〜２０の
対応を変えれば、振動子の四角形の対角方向に計４種類
の楕円軌跡が得られる。Further, if a voltage is applied so that displacement 18 is applied to the laminated piezoelectric element 9a, displacement 19 is applied to the laminated piezoelectric element 9c, and displacement 20 is applied to the laminated piezoelectric elements 9b and 9d, FIGS.
As shown in, an elliptical locus is obtained in the diagonal direction of the quadrangle of the vibrator. By changing the correspondence between the laminated piezoelectric elements 9a to 9d and the displacements 18 to 20, a total of four types of elliptical loci can be obtained in the diagonal direction of the quadrangle of the vibrator.

【００１３】以上を拡張して積層圧電素子９ａ〜９ｄを
変位の振幅と、位相を独立に制御するように電力を印加
すれば、２次元の任意の方向に楕円軌跡が得られること
がわかる。By expanding the above and applying electric power to the laminated piezoelectric elements 9a to 9d so as to independently control the amplitude and phase of displacement, it is understood that an elliptical locus can be obtained in any two-dimensional direction.

【００１４】なお、図１３に示すように、振動子と、
Ｘ，Ｙの２次元方向に相対的に可動となるようにテーブ
ル４を保持し、本実施例の突起部６とテーブル４を当接
させ、上記方法により、振動子の突起部６を楕円運動さ
せれば、振動子とテーブル４が２次元（平面）の相対運
動をするアクチュエータを構成できる。As shown in FIG. 13, a vibrator,
The table 4 is held so as to be relatively movable in the two-dimensional directions of X and Y, the projection 6 of this embodiment is brought into contact with the table 4, and the projection 6 of the vibrator is caused to move in an elliptical motion by the above method. By doing so, it is possible to configure an actuator in which the vibrator and the table 4 make a two-dimensional (plane) relative motion.

【００１５】[0015]

【実施例２】実施例２として、積層圧電素子３個を使っ
た例の振動子を図９に、この制御装置を図１０に示す。
実施例１と比較して特徴的なことは、積層圧電素子移相
器および振幅器が、各々１つずつ少ないため、安価に構
成できる点である。Second Embodiment As a second embodiment, a vibrator of an example using three laminated piezoelectric elements is shown in FIG. 9, and this controller is shown in FIG.
What is characteristic in comparison with the first embodiment is that the number of the laminated piezoelectric element phase shifters and the number of the amplitude shifters are reduced by one, respectively, so that it can be constructed at low cost.

【００１６】本実施例における作用・効果は、前記実施
例１と同様なので、詳細な説明は省略するが、積層圧電
素子９ａ〜９ｃの変位の振幅と位相を適当に制御するよ
うに、制御装置で、３種類の出力Ａ〜Ｃを得て圧電素子
９ａ〜９ｄに印加すれば、２次元の任意の方向に楕円軌
跡が得られる。実施例１で示したものと同様に、この楕
円運動を使ってアクチュエータを構成できる。Since the operation and effect of this embodiment are the same as those of the first embodiment, a detailed description thereof will be omitted, but a control device for appropriately controlling the displacement amplitude and phase of the laminated piezoelectric elements 9a to 9c. Then, if three types of outputs A to C are obtained and applied to the piezoelectric elements 9a to 9d, an elliptical locus can be obtained in a two-dimensional arbitrary direction. Similar to the one shown in the first embodiment, the actuator can be constructed by using this elliptic motion.

【００１７】[0017]

【発明の効果】以上のように、本発明の超音波振動子に
よれば、低電圧で駆動可能であり、また振動子の共振周
波数以外で駆動可能で、トンネル走査顕微鏡や原子間子
顕微鏡の探針のスキャナーを構成できる。As described above, according to the ultrasonic vibrator of the present invention, it can be driven at a low voltage and can be driven at a frequency other than the resonance frequency of the vibrator. A probe scanner can be configured.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例１の超音波振動子を示す斜視図
である。FIG. 1 is a perspective view showing an ultrasonic transducer according to a first embodiment of the present invention.

【図２】同振動子の制御装置を示す回路図である。FIG. 2 is a circuit diagram showing a control device for the vibrator.

【図３】同振動子を制御する波形図である。FIG. 3 is a waveform diagram for controlling the oscillator.

【図４】同振動子の振動変化状態を示す正面図である。FIG. 4 is a front view showing a vibration change state of the vibrator.

【図５】同振動子の楕円軌跡を示すグラフである。FIG. 5 is a graph showing an elliptic locus of the same oscillator.

【図６】同振動子を制御する波形図である。FIG. 6 is a waveform diagram for controlling the oscillator.

【図７】同振動子の振動変化状態を示す正面図である。FIG. 7 is a front view showing a vibration change state of the vibrator.

【図８】同振動子の楕円軌跡を示すグラフである。FIG. 8 is a graph showing an elliptic locus of the same oscillator.

【図９】本発明の実施例２の超音波振動子を示す斜視図
である。FIG. 9 is a perspective view showing an ultrasonic transducer according to a second embodiment of the present invention.

【図１０】同振動子の制御装置を示す回路図である。FIG. 10 is a circuit diagram showing a control device for the vibrator.

【図１１】従来の超音波振動子を示す斜視図および平面
図である。FIG. 11 is a perspective view and a plan view showing a conventional ultrasonic transducer.

【図１２】同振動子の振動状態を示す正面図である。FIG. 12 is a front view showing a vibrating state of the vibrator.

【図１３】同振動子を用いたアクチュエータの斜視図お
よび正面図である。13A and 13B are a perspective view and a front view of an actuator using the vibrator.

【符号の説明】[Explanation of symbols]

１，９ａ，９ｂ，９ｃ，９ｄ 積層圧電素子 ２ａ，２ｂ，３ａ，３ｂ 圧電素子 ５，６ 突起部 ７ 弾性体 ８ 下台 １０ 発振器 １１ｂ，１１ｃ，１１ｄ 移相器 １２ａ，１２ｂ，１２ｃ，１２ｄ 増幅器 １３ 制御機構 １６，１７ 圧電素子 1, 9a, 9b, 9c, 9d Multilayer piezoelectric element 2a, 2b, 3a, 3b Piezoelectric element 5,6 Projection part 7 Elastic body 8 Lower stand 10 Oscillator 11b, 11c, 11d Phase shifter 12a, 12b, 12c, 12d Amplifier 13 Control mechanism 16,17 Piezoelectric element

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 突起部をもつ弾性体と、この弾性体に一
端を接合した３個以上の積層圧電素子と、この積層圧電
素子の他端に接合した下台とを具備したことを特徴とす
る超音波振動子。1. An elastic body having a protrusion, three or more laminated piezoelectric elements having one end joined to the elastic body, and a lower base joined to the other end of the laminated piezoelectric element. Ultrasonic transducer. 【請求項２】 上記積層圧電素子の振動の振幅および位
相を各々独立に制御することを特徴とする請求項１記載
の超音波振動子。2. The ultrasonic vibrator according to claim 1, wherein the vibration amplitude and phase of the laminated piezoelectric element are independently controlled.