JP2006174680A

JP2006174680A - Oscillator

Info

Publication number: JP2006174680A
Application number: JP2004373370A
Authority: JP
Inventors: Koji Ichikawa; 厚司市川; Takeshi Inaba; 剛稲葉
Original assignee: Pentax Corp
Current assignee: Pentax Corp
Priority date: 2004-09-30
Filing date: 2004-12-24
Publication date: 2006-06-29

Abstract

<P>PROBLEM TO BE SOLVED: To make the facing opposite ends of a piezoelectric oscillator drive, which moves in a lower-order mode of vibration, in an elliptical motion in the directions opposite to each other by a large driving force. <P>SOLUTION: The piezoelectric oscillator 10 has a plate-like piezoelectric elements 20, 20 and a shim. The piezoelectric elements 20, 20 are polarized in the thickness direction and have a first and second projection parts 21a, 21b which extend from center to both sides along a first direction D1. The tip ends of the first and second projection parts 21a, 21b have side parts 22 parallel to a second direction D2. A third and fourth projection parts 21c, 21d are formed on the piezoelectric elements 20, 20, so that each projection part reduces its width, as they extend from the center along the second direction D2. An electrode is provided on the surfaces of the piezoelectric elements 20, 20 and is divided into two or more along the second direction, to form the first and second electrodes 23a, 23b. The first and second electrodes 23a, 23b are applied with an AC voltage that has different phase and makes the side parts 22 move in an ellipse. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、超音波モータ等を駆動する振動子に関する。 The present invention relates to a vibrator for driving an ultrasonic motor or the like.

従来、板状の振動子を振動（以下、断らない限り振動は板状振動子の面内振動を指す）させることによって駆動する超音波モータが知られている。このような超音波モータを適用した鏡筒駆動装置が開示されている（特許文献１）。この鏡筒駆動装置においては、孔開き円板振動子の膨張収縮する対称振動（Ｒ、１）モードと非対称振動（１、１）モードとを用いて円板の外周上の１点を楕円運動させ、レンズの光軸と同軸に回転する回転体に対して孔開き円板振動子の楕円運動する点を光軸と平行な方向から加圧して回転体を回転させ、この回転を螺子機構により光軸方向の直進運動に変換して、レンズを光軸方向に移動させることが可能である。 2. Description of the Related Art Conventionally, there is known an ultrasonic motor that is driven by vibrating a plate-like vibrator (hereinafter, unless otherwise noted, vibration refers to in-plane vibration of the plate-like vibrator). A lens barrel drive device to which such an ultrasonic motor is applied is disclosed (Patent Document 1). In this lens barrel driving device, an elliptical motion is performed on one point on the outer periphery of the disk by using a symmetrical vibration (R, 1) mode and an asymmetric vibration (1, 1) mode in which the perforated disk vibrator expands and contracts. The point of elliptical movement of the perforated disk vibrator is pressed from the direction parallel to the optical axis against the rotating body that rotates coaxially with the optical axis of the lens, and the rotating body is rotated. It is possible to move the lens in the optical axis direction by converting it into a linear motion in the optical axis direction.

また、上述の孔開き円板振動子の対称振動（Ｒ、１）モードと非対称振動（１、１）モードとを用いてリニアモータを駆動することが開示されている（非特許文献１）。このリニアモータにおいては、孔開き円板振動子の１直径上の外周に設けた２点の接触部を半径方向の放射状伸縮と同じ方向の接線変位とを重ねて回転方向が互いに反対の楕円運動を行わせ、移動体に設けられたガイドを２点の接触部に向けて加圧して、移動体に接線方向の駆動力を与えることにより、移動体を直線駆動するものである。 Further, it is disclosed that the linear motor is driven using the symmetric vibration (R, 1) mode and the asymmetric vibration (1, 1) mode of the above-described perforated disk vibrator (Non-patent Document 1). In this linear motor, elliptical motions whose rotational directions are opposite to each other by overlapping two contact portions provided on the outer circumference on one diameter of the perforated disk vibrator with tangential displacement in the same direction as radial expansion and contraction in the radial direction. In this way, the guide provided on the moving body is pressurized toward the two contact portions, and a driving force in the tangential direction is applied to the moving body to linearly drive the moving body.

一般に超音波モータにおいては、振動子を共振状態にして駆動することにより出力を大きくしており、楕円運動させる場合は略直交する２つの振動の共振周波数を一致させることが実用上必要である。孔開き円板振動子では対称振動（Ｒ、１）モードと非対称振動（１、１）モードの共振周波数を一致させるために、所定の直径の孔が円板の中央に設けられる。 In general, in an ultrasonic motor, the output is increased by driving the vibrator in a resonance state, and it is practically necessary to match the resonance frequencies of two vibrations that are substantially orthogonal to each other when elliptically moving. In the perforated disk vibrator, a hole having a predetermined diameter is provided in the center of the disk in order to match the resonance frequencies of the symmetric vibration (R, 1) mode and the asymmetric vibration (1, 1) mode.

このような孔開き円板振動子は低い次数の面内振動モードを用いているため電極の位置誤差に影響されにくく、安定した振動を得ることが出来、上述のように直径上の外周２点で相手部材を同方向に駆動できるため、（非特許文献１）に開示されたリニアモータ等に適用するのに好適な振動子である。 Since such a perforated disk vibrator uses a low-order in-plane vibration mode, it is less affected by the position error of the electrode and can obtain a stable vibration. Therefore, since the counterpart member can be driven in the same direction, the vibrator is suitable for application to the linear motor disclosed in (Non-Patent Document 1).

しかし、回転体や移動体を加圧する際に、孔の内側に比較的大きな円周方向引張り応力が作用する。従って、例えばＰＺＴ等の圧電セラミックを振動発生部材に用いる場合に、圧電セラミックの引張り強度が弱いため、振動子から回転体等に対して強い押圧力を加えることが出来なかった。押圧力が弱いと振動子と回転体等との摩擦力も小さくなり、駆動力を大きくすることが出来なかった。
特開平１１−２７５８７８号公報タカヒロ・マスダ（Takahiro Masuda）、他２名、「ピエゾエレクトリック・リニア・モータ・ユージング（Ｒ，１）−（（１，１））モード・ディスク・イクイップト・ウィズ・ティータイプ・サポート・ジグス・フォー・リアライジング・イッツ・ファイン・パフォーマンス（Piezoelectric Linear Motor Using（Ｒ，１）−（（１，１））Mode Disk Equipped with T-Type Support Jigs for Realizing its Fine Performance）」、ジャパニーズ・ジャーナル・オブ・アプライド・フィジックス（Japanese Journal of Applied Physics）、応用物理学会（The Japan Society of Applied Physics）、２００４年、Ｖｏｌ．４３、Ｎｏ．５Ｂ、ｐ．２８７９‐２８８３ However, when pressurizing the rotating body or the moving body, a relatively large circumferential tensile stress acts on the inside of the hole. Therefore, for example, when a piezoelectric ceramic such as PZT is used for the vibration generating member, a strong pressing force cannot be applied to the rotating body or the like from the vibrator because the tensile strength of the piezoelectric ceramic is weak. When the pressing force is weak, the frictional force between the vibrator and the rotating body is reduced, and the driving force cannot be increased.
JP-A-11-275878 Takahiro Masuda and two others, “Piezoelectric Linear Motor Uzing (R, 1)-((1,1)) Mode Disc Equiped With Tee Type Support Jigs For Realizing It Fine Performance (Piezoelectric Linear Motor Using (R, 1)-((1,1)) Mode Disk Equipped with T-Type Support Jigs for Realizing its Fine Performance), Japanese Journal of・ Applied Physics, The Japan Society of Applied Physics, 2004, Vol. 43, no. 5B, p. 2879-2883

したがって、本発明では、引張り応力に強く、かつ、伸縮する両端において互いに反対方向の楕円運動を発生する振動子の提供を目的とする。 Accordingly, an object of the present invention is to provide a vibrator that is resistant to tensile stress and generates elliptical motions in opposite directions at both ends that expand and contract.

本発明の振動子は、振動子の中央から第１方向に沿って両側に延び最先端において第１方向と垂直な第２方向に平行な辺部を有する第１、第２突出部と、中央から第２方向に沿って両側に延びる第３、第４突出部とを備え、第１、第２電極にそれぞれ位相の異なる交流電圧を印加することにより、振動することを特徴としている。このような構成によれば、振動子に孔を設けることなく、第１、第２突出部を互いに反対方向に楕円運動させることが可能である。 The vibrator according to the present invention includes first and second protrusions having sides parallel to a second direction perpendicular to the first direction extending from the center of the vibrator to both sides along the first direction. The third and fourth protrusions extending on both sides along the second direction from the first to the second electrodes, and are vibrated by applying alternating voltages having different phases to the first and second electrodes, respectively. According to such a configuration, the first and second protrusions can be elliptically moved in directions opposite to each other without providing a hole in the vibrator.

また、第１、第２電極の間にさらに電極が設けられることが好ましい。 Moreover, it is preferable that an electrode is further provided between the first and second electrodes.

また、第３、第４突出部が中央から第２方向にそって延びるにつれて幅が小さくなることが好ましい。また、第１突出部が辺部と第１方向に平行な２つの辺によって形成されることが好ましい。更に、第１突出部の先端部と第２突出部の先端部との間隔より第３突出部の先端部と第４突出部の先端部との間隔の方が短いことが好ましい。このような構成により、振動子の第２方向の寸法及び後述するように支持部材を含めた第２方向の寸法を小さくすることが出来る。 Moreover, it is preferable that a width | variety becomes small as a 3rd, 4th protrusion part extends along a 2nd direction from the center. Moreover, it is preferable that a 1st protrusion part is formed of two sides parallel to a side part and a 1st direction. Furthermore, it is preferable that the distance between the tip of the third protrusion and the tip of the fourth protrusion is shorter than the distance between the tip of the first protrusion and the tip of the second protrusion. With such a configuration, it is possible to reduce the size in the second direction of the vibrator and the size in the second direction including the support member as described later.

また、第１、第２電極の間に第３電極を備え、前記第３電極に前記第１、第２電極のいずれか一方に印加される交流電圧とは位相が９０°、他方に印加される交流電圧とは位相が−９０°異なる交流電圧が印加されることが好ましい。このような構成により、第１の振動モードを中央の電極である第３電極で駆動し、第２の振動モードを最も外側にある２つの電極、第１、第２電極で駆動することによりそれぞれの電極を簡単な回路で構成することが可能になる。 Further, a third electrode is provided between the first and second electrodes, and the phase of the AC voltage applied to one of the first and second electrodes is 90 ° and the other is applied to the other. It is preferable to apply an AC voltage whose phase is -90 ° different from that of the AC voltage. With such a configuration, the first vibration mode is driven by the third electrode as the center electrode, and the second vibration mode is driven by the two outermost electrodes, the first and second electrodes, respectively. These electrodes can be configured with a simple circuit.

また、第３、第４突出部のそれぞれが圧電体振動子が備えられる圧電体振動子支持体に圧電体振動子を支持するための第１、第２支持部材を有し、第１支持部材には圧電体振動子と第１支持部材とを連結する第１連結点が圧電体振動子の第２方向への振動が最も大きくなる点である振動中心を通る直線であって第２方向に平行な直線から外れる位置に設けられ、第２支持部材には圧電体振動子と第２支持部材とを連結する第２連結点が、振動中心を通る第２方向に平行な直線から外れる位置に設けられることが好ましい。 Each of the third and fourth protrusions includes first and second support members for supporting the piezoelectric vibrator on a piezoelectric vibrator support body provided with the piezoelectric vibrator, and the first support member The first connecting point for connecting the piezoelectric vibrator and the first support member is a straight line passing through the vibration center, which is the point where the vibration in the second direction of the piezoelectric vibrator is the largest, and in the second direction. Provided at a position deviating from the parallel straight line, the second support member connecting the piezoelectric vibrator and the second support member to the second support member at a position deviating from the straight line parallel to the second direction passing through the vibration center. It is preferable to be provided.

また、第１、第２突出部と第１、第２電極とを有し交流電圧を印加することにより振動する板状の振動体と、振動体と密着し第１方向に沿って第１、第２突出部より外側に延びる調整部を有する弾性板部材とを備えることが好ましく、弾性板部材の第１方向に沿った両端が第２方向と平行に形成されることが好ましい。さらに、弾性板部材には、第１方向に沿った両端から外側に突出する接触部が設けられることが好ましい。 Further, a plate-like vibrating body having first and second projecting portions and first and second electrodes and vibrating by applying an AC voltage, and a first and It is preferable to provide an elastic plate member having an adjustment portion extending outward from the second protrusion, and it is preferable that both ends of the elastic plate member along the first direction are formed in parallel with the second direction. Furthermore, the elastic plate member is preferably provided with a contact portion that protrudes outward from both ends along the first direction.

また、第１〜第４突出部を有する弾性板部材と、第１方向の長さが第２方向の幅より長く形成され弾性板部材に密着し第１、第２電極を有し交流電圧を印加することにより振動する板状の振動体とを備えることが好ましい。このような構成により、第１方向への伸縮振動の振幅を大きくすることが可能になる。 In addition, the elastic plate member having the first to fourth projecting portions, the length in the first direction is longer than the width in the second direction, the first and second electrodes are in close contact with the elastic plate member, and an AC voltage is applied. It is preferable to include a plate-like vibrating body that vibrates when applied. With such a configuration, it is possible to increase the amplitude of the stretching vibration in the first direction.

さらに、振動体が第１方向及び第２方向に平行な辺を有する矩形であることが好ましい。 Furthermore, the vibrating body is preferably a rectangle having sides parallel to the first direction and the second direction.

また、本発明の振動子の共振周波数調整方法は、振動子における弾性板部材の第1方向に沿った両端の一方或いは両方の一部を除去することを特徴としている。さらに、弾性板部材の第１方向に沿った両端の一方或いは両方の一部が第２方向と平行に除去されることが好ましい。 In addition, the resonance frequency adjusting method for a vibrator according to the present invention is characterized in that one or both of both ends along the first direction of the elastic plate member in the vibrator are removed. Furthermore, it is preferable that one or both of both ends along the first direction of the elastic plate member are removed in parallel with the second direction.

本発明によれば、低次数の振動モードで振動する圧電体振動子において、孔を設けることなく中心から延びる両端部において互いに反対方向の楕円運動を大きな駆動力で発生させることが可能となる。 According to the present invention, in a piezoelectric vibrator that vibrates in a low-order vibration mode, elliptical motions in opposite directions can be generated with a large driving force at both ends extending from the center without providing a hole.

以下、本発明の実施形態について図面を参照して説明する。
図１は、本発明の第１の実施形態を適用した圧電体振動子の正面図である。図２は圧電体振動子の側面図である。圧電体振動子１０は、板状の圧電素子２０、２０、及び金属板であるシム３０により構成される。シム３０は、厚さ方向に分極した板状の圧電素子２０、２０により挟持される。 Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a front view of a piezoelectric vibrator to which the first embodiment of the present invention is applied. FIG. 2 is a side view of the piezoelectric vibrator. The piezoelectric vibrator 10 includes plate-like piezoelectric elements 20 and 20 and a shim 30 that is a metal plate. The shim 30 is sandwiched between plate-like piezoelectric elements 20 and 20 polarized in the thickness direction.

圧電素子２０、２０には、圧電素子２０、２０の中央から面上の第１方向Ｄ１に沿って両側に延びる第１突出部２１ａ、及び第２突出部２１ｂが形成される。第１突出部２１ａ、及び第２突出部２１ｂは、第１方向Ｄ１に平行な２辺、及び第１方向Ｄ１に垂直な第２方向Ｄ２に平行な辺部２２によって矩形に形成される。辺部２２は圧電素子２０、２０の中央から第１方向Ｄ１に沿った最先端に位置する。 The piezoelectric elements 20 and 20 are formed with a first protrusion 21a and a second protrusion 21b that extend from the center of the piezoelectric elements 20 and 20 to both sides along a first direction D1 on the surface. The first protrusion 21a and the second protrusion 21b are formed in a rectangular shape by two sides parallel to the first direction D1 and a side 22 parallel to the second direction D2 perpendicular to the first direction D1. The side portion 22 is located at the forefront along the first direction D1 from the center of the piezoelectric elements 20 and 20.

圧電素子２０、２０には、第２方向Ｄ２に沿って両側に延びる第３突出部２１ｃ、及び第４突出部２１ｄが形成される。第３、第４突出部２１ｃ、２１ｄは、第２方向Ｄ２に沿って外側に延びるにつれて幅がテーパ状に小さくなるように形成される。圧電素子２０、２０は第１方向Ｄ１、及び第２方向Ｄ２に線対称である。テーパの長さや角度を調整することにより、周波数の調節が可能となる。 The piezoelectric elements 20 and 20 are formed with a third protrusion 21c and a fourth protrusion 21d that extend on both sides along the second direction D2. The third and fourth protrusions 21c and 21d are formed such that the width decreases in a tapered shape as they extend outward along the second direction D2. The piezoelectric elements 20 and 20 are line symmetric with respect to the first direction D1 and the second direction D2. The frequency can be adjusted by adjusting the length and angle of the taper.

圧電素子２０、２０の表面には、電極が設けられる。電極は第２方向Ｄ２に沿って２つに分割され、第１電極２３ａ、及び第２電極２３ｂが形成される。第１、第２電極２３ａ、２３ｂには位相の異なる交流電圧が印加される。 Electrodes are provided on the surfaces of the piezoelectric elements 20 and 20. The electrode is divided into two along the second direction D2, and the first electrode 23a and the second electrode 23b are formed. AC voltages having different phases are applied to the first and second electrodes 23a and 23b.

シム３０には、第１接触部３１ａ、第２接触部３１ｂ、第１支持部３２ａ、及び第２支持部３２ｂが形成される。第１接触部３１ａ、第２接触部３１ｂはそれぞれ第１突出部２１ａ、第２突出部２１ｂから更に第１方向Ｄ１に沿って外側に延ばされる。 The shim 30 includes a first contact portion 31a, a second contact portion 31b, a first support portion 32a, and a second support portion 32b. The 1st contact part 31a and the 2nd contact part 31b are further extended outside along the 1st direction D1 from the 1st protrusion part 21a and the 2nd protrusion part 21b, respectively.

圧電素子２０、２０、及びシム３０は、それぞれ第１、第２方向Ｄ１、Ｄ２に略対称となるように形成される。従って、圧電体振動子１０全体として、第１、第２方向Ｄ１、Ｄ２に略対称となる。このような形状によれば、安定した振動を発生させることが可能となる。 The piezoelectric elements 20, 20 and the shim 30 are formed so as to be substantially symmetric in the first and second directions D1 and D2, respectively. Accordingly, the piezoelectric vibrator 10 as a whole is substantially symmetric in the first and second directions D1 and D2. According to such a shape, it becomes possible to generate a stable vibration.

一例として、上述の圧電体振動子１０において、シム３０をステンレス鋼、圧電素子２０をＰＺＴとした場合、第１突出部２１ａ先端から第２突出部２１ｂ先端までの幅（図１符号Ｅ参照）、第３突出部２１ｃ先端から第４突出部２１ｄ先端までの幅（図１符号Ａ参照）、第１、第２突出部２１ａ、２１ｂの先端の幅（図１符号Ｂ参照）、第３、第４突出部２１ｃ、２１ｄの先端の幅（図１符号Ｆ参照）をそれぞれ８．１：８：４：１．７の比となるように形成することにより、２つのモードの共振周波数を一致させることが可能である。 As an example, when the shim 30 is stainless steel and the piezoelectric element 20 is PZT in the piezoelectric vibrator 10 described above, the width from the tip of the first protrusion 21a to the tip of the second protrusion 21b (see E in FIG. 1). , The width from the tip of the third protrusion 21c to the tip of the fourth protrusion 21d (see FIG. 1 reference A), the width of the tip of the first and second protrusions 21a and 21b (see reference B of FIG. 1), third, The widths of the tips of the fourth protrusions 21c and 21d (see reference numeral F in FIG. 1) are formed so as to have a ratio of 8.1: 8: 4: 1.7, respectively, thereby matching the resonance frequencies of the two modes. It is possible to make it.

図３は、本実施形態の圧電体振動子を備えた超音波モータ５０の断面を示す図である。図３に示すように、第１、第２接触部３１ａ、３１ｂがそれぞれロータ５２、５２に当接される。このような構成により、圧電素子が直接ロータ５２、５２に当接する事を防ぎ、圧電体振動子全体の耐久性が向上する。 FIG. 3 is a view showing a cross section of an ultrasonic motor 50 including the piezoelectric vibrator of the present embodiment. As shown in FIG. 3, the first and second contact portions 31a and 31b are in contact with the rotors 52 and 52, respectively. With such a configuration, the piezoelectric element is prevented from coming into direct contact with the rotors 52 and 52, and the durability of the entire piezoelectric vibrator is improved.

第１、第２支持部３２ａ、３２ｂは、腕部３３と脚部３４を有するＴ字形に形成される。脚部３４は第２方向Ｄ２と平行で、第３、第４突出部２１ｃ、２１ｄから外側に延び、腕部３３は第１方向Ｄ１に平行となるように配置される。腕部３３には、圧電体振動子１０の厚さ方向に孔が設けられる。孔に雄螺子を挿通して、圧電体振動子が備えられる圧電体振動子支持体である超音波モータ５０に、螺着することにより、圧電体振動子１０は超音波モータ５０に支持される。 The first and second support portions 32 a and 32 b are formed in a T shape having an arm portion 33 and a leg portion 34. The leg portion 34 is parallel to the second direction D2, extends outward from the third and fourth projecting portions 21c, 21d, and the arm portion 33 is arranged to be parallel to the first direction D1. A hole is provided in the arm portion 33 in the thickness direction of the piezoelectric vibrator 10. The piezoelectric vibrator 10 is supported by the ultrasonic motor 50 by inserting the male screw into the hole and screwing the male screw into the ultrasonic motor 50 that is a piezoelectric vibrator support body provided with the piezoelectric vibrator. .

図１に示すように、第１支持部３２ａに設けられる孔３５ａ（第１連結点）、及び第２支持部３２ｂに設けられる孔３５ｂ（第２連結点）は、後述する第２方向Ｄ２への屈曲振動が最も大きくなる振動中心Ｃを通り第２方向Ｄ２に平行な直線から外れる位置に設けられる。 As shown in FIG. 1, a hole 35a (first connection point) provided in the first support part 32a and a hole 35b (second connection point) provided in the second support part 32b are in a second direction D2 to be described later. Is provided at a position that deviates from a straight line that passes through the vibration center C where the bending vibration is the largest and is parallel to the second direction D2.

圧電体振動子１０と、第１、第２支持部３２ａ、３２ｂの第２方向Ｄ２への剛性の和との比の平方根を２×πで除した値が印加される交流電圧の周波数に一致させるように、腕部３３の長さが定められる。 The value obtained by dividing the square root of the ratio of the piezoelectric vibrator 10 and the sum of the rigidity of the first and second support portions 32a and 32b in the second direction D2 by 2 × π matches the frequency of the applied AC voltage. Thus, the length of the arm portion 33 is determined.

上述のように腕部３３の長さを定めることにより、印加される交流電圧の周波数における第１、第２支持部３２ａ、３２ｂの第２方向への剛性が十分小さくなり、圧電体振動子１０の共振が第１、第２支持部３２ａ、３２ｂによって損なわれることを防止することが可能である。 By determining the length of the arm portion 33 as described above, the rigidity in the second direction of the first and second support portions 32a and 32b at the frequency of the applied AC voltage becomes sufficiently small, and the piezoelectric vibrator 10 Can be prevented from being damaged by the first and second support portions 32a and 32b.

図４は第１の実施形態を適用した圧電体振動子１０を駆動する駆動回路を示すブロック図である。駆動回路４０は、発振部４１、移相部Ｌ４２、移相部Ｆ４３、第１増幅部４４ａ、第２増幅部４４ｂ、第１加算部４５ａ、及び第２加算部４５ｂによって構成される。 FIG. 4 is a block diagram showing a drive circuit for driving the piezoelectric vibrator 10 to which the first embodiment is applied. The drive circuit 40 includes an oscillation unit 41, a phase shift unit L42, a phase shift unit F43, a first amplification unit 44a, a second amplification unit 44b, a first addition unit 45a, and a second addition unit 45b.

発振部４１は移相部Ｌ４２、及び移相部Ｆ４３に接続される。移相部Ｌ４２は第１増幅部４４ａに、移相部Ｆ４３は第２増幅部４４ｂに接続される。第１加算部４５ａ、及び第２加算部４５ｂは、ともに第１増幅部４４ａ、及び第２増幅部４４ｂに接続される。第１加算部４５ａは圧電体振動子１０の第１電極２３ａに、第２加算部４５ｂは第２電極２３ｂに接続される。 The oscillation unit 41 is connected to the phase shift unit L42 and the phase shift unit F43. The phase shifter L42 is connected to the first amplifier 44a, and the phase shifter F43 is connected to the second amplifier 44b. Both the first addition unit 45a and the second addition unit 45b are connected to the first amplification unit 44a and the second amplification unit 44b. The first adder 45a is connected to the first electrode 23a of the piezoelectric vibrator 10, and the second adder 45b is connected to the second electrode 23b.

発振部４１において交流電圧が発生して、移相部Ｌ４２、及び移相部Ｆ４３に印加される。発振部４１において発生した交流電圧の位相は、移相部Ｌ４２において第１方向Ｄ１に圧電体振動子１０を伸縮振動させるための信号となるように変えられ、その電圧はｓｉｎωｔとなる。また、発振部４１において発生した交流電圧の位相は、移相部Ｆ４３において第２方向Ｄ２に圧電体振動子を屈曲振動させるための信号となるように変えられ、電圧はｃｏｓωｔとなる。 An alternating voltage is generated in the oscillating unit 41 and applied to the phase shift unit L42 and the phase shift unit F43. The phase of the AC voltage generated in the oscillating unit 41 is changed to become a signal for causing the piezoelectric vibrator 10 to expand and contract in the first direction D1 in the phase shift unit L42, and the voltage becomes sin ωt. The phase of the AC voltage generated in the oscillating unit 41 is changed to be a signal for bending and vibrating the piezoelectric vibrator in the second direction D2 in the phase shift unit F43, and the voltage becomes cos ωt.

移相部Ｌ４２、及び移相部Ｆ４３の出力端におけるそれぞれの電圧ｓｉｎωｔ、ｃｏｓωｔは第１増幅部４４ａ、及び第２増幅部４４ｂにより所定の増幅率Ａ、Ｂにより増幅され、Ａｓｉｎωｔ、Ｂｃｏｓωｔとなる。なお、第１増幅部４４ａ、及び第２増幅部４４ｂはそれぞれ振幅制御部４６に接続され、振幅制御部４６により増幅率Ａ、Ｂの設定が行われる。 The voltages sinωt and cosωt at the output terminals of the phase shift unit L42 and the phase shift unit F43 are amplified by predetermined amplification factors A and B by the first amplification unit 44a and the second amplification unit 44b, and become Asinωt and Bcosωt. . The first amplifying unit 44a and the second amplifying unit 44b are respectively connected to the amplitude control unit 46, and the amplification factors A and B are set by the amplitude control unit 46.

第１加算部４５ａでは、第１増幅部４４ａの出力端の電圧Ａｓｉｎωｔを加算し、第２増幅部４４ｂの出力端の電圧Ｂｃｏｓωｔを減算して、Ａｓｉｎωｔ−Ｂｃｏｓωｔの電圧を第１電極２３ａに印加する。 The first adder 45a adds the voltage Asinωt at the output terminal of the first amplifier 44a, subtracts the voltage Bcosωt at the output terminal of the second amplifier 44b, and applies the voltage of Asinωt−Bcosωt to the first electrode 23a. To do.

第２加算部４５ｂでは、第１増幅部４４ａの出力端の電圧Ａｓｉｎωｔを加算し、第２増幅部４４ｂの出力端の電圧Ｂｃｏｓωｔを加算して、Ａｓｉｎωｔ＋Ｂｃｏｓωｔの電圧を第２電極２３ｂに印加する。 The second adder 45b adds the voltage Asinωt at the output terminal of the first amplifier 44a, adds the voltage Bcosωt at the output terminal of the second amplifier 44b, and applies the voltage Asinωt + Bcosωt to the second electrode 23b.

以上のような、回路構成によって印加される電圧による圧電体振動子１０の振動について図１、及び図５〜図８を用いて説明する。 The vibration of the piezoelectric vibrator 10 due to the voltage applied by the circuit configuration as described above will be described with reference to FIGS. 1 and 5 to 8.

図１は第１電極２３ａ、及び第２電極２３ｂに電圧が印加されない状態における圧電体振動子の外観を示す図である。電圧が印加されない状態においては、圧電素子は変形を起こさず静止している。圧電体振動子１０は、正の電圧が印加される部分が膨張し、負の電圧が印加される部分が収縮する。例えば、第１電極２３ａに正の電圧を印加すると第１電極２３ａにおける圧電素子が膨張し、第２電極２３ｂに負の電圧を印加すると第２電極２３ｂにおける圧電素子が収縮していく。 FIG. 1 is a view showing the appearance of the piezoelectric vibrator in a state where no voltage is applied to the first electrode 23a and the second electrode 23b. In a state where no voltage is applied, the piezoelectric element does not deform and remains stationary. In the piezoelectric vibrator 10, a portion to which a positive voltage is applied expands, and a portion to which a negative voltage is applied contracts. For example, when a positive voltage is applied to the first electrode 23a, the piezoelectric element in the first electrode 23a expands, and when a negative voltage is applied to the second electrode 23b, the piezoelectric element in the second electrode 23b contracts.

図５は、印加電圧の位相がωｔ＝０のときの圧電体振動子１０の状態を示した図である。この時、第1電極２３ａには負の電圧−Ｂ、第２電極２３ｂには正の電圧＋Ｂが印加される。従って、第１電極２３ａにおける圧電素子が収縮し、第２電極２３ｂにおける圧電素子が膨張していく。第１電極２３ａにおける圧電素子の収縮、及び第２電極２３ｂにおける圧電素子の膨張が最大となる第１状態まで圧電体振動子１０は第２方向Ｄ２に沿って屈曲する。両端自由の屈曲１次モード振動であるため、圧電体振動子１０の中心Ｃは第１、第２接触部３１ａ、３１ｂと第２方向Ｄ２に沿って反対方向に変位する。 FIG. 5 is a diagram showing a state of the piezoelectric vibrator 10 when the phase of the applied voltage is ωt = 0. At this time, a negative voltage −B is applied to the first electrode 23a, and a positive voltage + B is applied to the second electrode 23b. Accordingly, the piezoelectric element in the first electrode 23a contracts and the piezoelectric element in the second electrode 23b expands. The piezoelectric vibrator 10 bends in the second direction D2 until the first state in which the piezoelectric element contracts in the first electrode 23a and the piezoelectric element expands in the second electrode 23b is maximized. Since the bending primary mode vibration is free at both ends, the center C of the piezoelectric vibrator 10 is displaced in the opposite direction along the first and second contact portions 31a and 31b and the second direction D2.

図６は、印加電圧の位相がωｔ＝π／２のときの圧電体振動子１０の状態を示した図である。この時、両電極２３ａ、２３ｂともに正の電圧＋Ａが印加される。従って、第１電極２３ａにおける圧電素子、及び第２電極２３ｂにおける圧電素子の伸縮は静止状態から、圧電素子２０、２０が第１方向Ｄ１に沿って膨張していく。圧電素子２０、２０の膨張が最大となる第２状態まで圧電体振動子１０は第１方向Ｄ１に膨張する。 FIG. 6 is a diagram illustrating the state of the piezoelectric vibrator 10 when the phase of the applied voltage is ωt = π / 2. At this time, a positive voltage + A is applied to both electrodes 23a and 23b. Therefore, the expansion and contraction of the piezoelectric element in the first electrode 23a and the piezoelectric element in the second electrode 23b expands along the first direction D1 from the stationary state. The piezoelectric vibrator 10 expands in the first direction D1 until the second state where the expansion of the piezoelectric elements 20 and 20 is maximized.

この時、圧電体振動子１０は第１方向Ｄ１に伸びるが、第３、第４突出部２１ｃ、２１ｄの多くの部分は第２方向の内側に変位する。この振動モードは正方形板における輪郭すべりモードに相当するモードであり、第１、第２接触部３１ａ、３１ｂの間の長さが伸縮する最も低次のモードである。 At this time, the piezoelectric vibrator 10 extends in the first direction D1, but most of the third and fourth projecting portions 21c and 21d are displaced inward in the second direction. This vibration mode is a mode corresponding to the contour sliding mode in the square plate, and is the lowest order mode in which the length between the first and second contact portions 31a and 31b expands and contracts.

図７は、印加電圧の位相がωｔ＝πのときの圧電体振動子１０の状態を示した図である。この時、第１電極２３ａには正の電圧＋Ｂが印加される一方、第２電極２３ｂには負の電圧−Ｂが印加される。従って、第２電極２３ｂにおける圧電素子が収縮し、及び第１電極２３ａにおける圧電素子が膨張していく。第２電極２３ｂにおける圧電素子の収縮、及び第１電極２３ａにおける圧電素子の膨張が最大となる第３状態まで圧電体振動子１０は第２方向Ｄ２に沿って屈曲する。両端自由の屈曲１次モード振動であるため、圧電体振動子１０の中心Ｃは第１、第２接触部３１ａ、３１ｂと第２方向Ｄ２に沿って反対方向に変位する。 FIG. 7 is a diagram showing a state of the piezoelectric vibrator 10 when the phase of the applied voltage is ωt = π. At this time, a positive voltage + B is applied to the first electrode 23a, while a negative voltage -B is applied to the second electrode 23b. Accordingly, the piezoelectric element in the second electrode 23b contracts and the piezoelectric element in the first electrode 23a expands. The piezoelectric vibrator 10 bends in the second direction D2 until the third state in which the contraction of the piezoelectric element in the second electrode 23b and the expansion of the piezoelectric element in the first electrode 23a are maximized. Since the bending primary mode vibration is free at both ends, the center C of the piezoelectric vibrator 10 is displaced in the opposite direction along the first and second contact portions 31a and 31b and the second direction D2.

図８は、印加電圧の位相がωｔ＝（３／２）πのときの圧電体振動子１０の状態を示した図である。この時、両電極２３ａ、２３ｂには、ともに負の電圧−Ａが印加される。従って、第１電極２３ａにおける圧電素子、及び第２電極２３ｂにおける圧電素子の伸縮は静止状態から、圧電素子２０、２０が第１方向Ｄ１に沿って縮小していく。圧電素子２０、２０の収縮が最大となる第４状態まで圧電体振動子１０は第１方向Ｄ１に収縮する。この時、圧電体振動子１０は第１方向Ｄ１に収縮するが第３、第４突出部２１ｃ、２１ｄの多くの部分は第２方向Ｄ２の外側に変位する。 FIG. 8 is a diagram illustrating a state of the piezoelectric vibrator 10 when the phase of the applied voltage is ωt = (3/2) π. At this time, a negative voltage −A is applied to both electrodes 23a and 23b. Therefore, the expansion and contraction of the piezoelectric element in the first electrode 23a and the piezoelectric element in the second electrode 23b is reduced from the stationary state in the first direction D1. The piezoelectric vibrator 10 contracts in the first direction D1 until the fourth state where the contraction of the piezoelectric elements 20 and 20 is maximized. At this time, the piezoelectric vibrator 10 contracts in the first direction D1, but most of the third and fourth projecting portions 21c and 21d are displaced outward in the second direction D2.

圧電体振動子１０は、第４状態から第１状態まで変化し、以後、第２状態、第３状態、第４状態、第１状態、・・・となるように周期的に循環変形する。このように圧電体振動子１０の外形が変化すると、辺部２２の任意の一点は楕円運動を行う。 The piezoelectric vibrator 10 changes from the fourth state to the first state, and thereafter cyclically deforms in a second state, a third state, a fourth state, a first state, and so on. When the outer shape of the piezoelectric vibrator 10 changes in this way, an arbitrary point on the side portion 22 performs an elliptical motion.

以上のような構成によれば、第１方向Ｄ１、及び第２方向Ｄ２にそれぞれ伸縮１次モード、屈曲１次モードの振動を発生させることが可能であって、第１突出部の辺部２２、及び第２突出部の辺部２２において互いに反対方向であり屈曲方向への駆動力の大きな楕円運動を発生させることが可能である。 According to the configuration as described above, it is possible to generate vibrations in the expansion / contraction primary mode and the bending primary mode in the first direction D1 and the second direction D2, respectively, and the side portion 22 of the first protrusion portion. In addition, it is possible to generate an elliptical motion having a large driving force in opposite directions and in the bending direction at the side portion 22 of the second projecting portion.

図９に本発明の第２の実施形態を示す。本実施形態は圧電素子の表面に設けられる電極の配置、及びそれぞれの電極に印加される電圧が第１の実施形態と異なる。本実施形態においては、電極は第２方向Ｄ２に沿って３つに分割され、両側に第１電極２３ａ、第２電極２３ｂ、真ん中に第３電極２３ｃが形成される。 FIG. 9 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in the arrangement of electrodes provided on the surface of the piezoelectric element and the voltage applied to each electrode. In the present embodiment, the electrode is divided into three along the second direction D2, and the first electrode 23a and the second electrode 23b are formed on both sides, and the third electrode 23c is formed in the middle.

第１〜第３電極２３ａ、２３ｂ、２３ｃには、それぞれ位相の異なる交流電圧が印加される。後述するように第１、第２電極２３ａ、２３ｂに印加される交流電圧の極性は互いに反転しており、第３電極２３ｃには、第１、第２電極２３ａ、２３ｂのいずれか一方に印加される交流電圧とは位相が９０°異なり、他方に印加される交流電圧とは位相が９０°異なる交流電圧が印加される。 AC voltages having different phases are applied to the first to third electrodes 23a, 23b, and 23c. As will be described later, the polarities of the AC voltages applied to the first and second electrodes 23a and 23b are reversed, and the third electrode 23c is applied to one of the first and second electrodes 23a and 23b. The AC voltage is 90 ° different in phase from the AC voltage applied, and the AC voltage applied is 90 ° different in phase from the AC voltage applied to the other.

図１０は第２の実施形態を適用した圧電体振動子１００を駆動する駆動回路を示すブロック図である。駆動回路４００は、発振部４１、移相部Ｌ４２、移相部Ｆ４３、第１増幅部４４ａ、第２増幅部４４ｂ、第１加算部４５ａ、及び第２加算部４５ｂによって構成される。 FIG. 10 is a block diagram showing a drive circuit for driving the piezoelectric vibrator 100 to which the second embodiment is applied. The drive circuit 400 includes an oscillation unit 41, a phase shift unit L42, a phase shift unit F43, a first amplification unit 44a, a second amplification unit 44b, a first addition unit 45a, and a second addition unit 45b.

発振部４１は、移相部Ｌ４２、及び移相部Ｆ４３に接続される。移相部Ｌ４２は第１増幅部４４ａに、移相部Ｆ４３は第２増幅部４４ｂに接続される。第１増幅部４４ａは第３電極２３ｃに接続される。第２増幅部４４ｂは第１加算部４５ａ、及び第２加算部４５ｂに接続される。第１加算部４５ａは圧電体振動子１０の第１電極２３ａに、第２加算部４５ｂは第２電極２３ｂに接続される。 The oscillating unit 41 is connected to the phase shift unit L42 and the phase shift unit F43. The phase shifter L42 is connected to the first amplifier 44a, and the phase shifter F43 is connected to the second amplifier 44b. The first amplification unit 44a is connected to the third electrode 23c. The second amplification unit 44b is connected to the first addition unit 45a and the second addition unit 45b. The first adder 45a is connected to the first electrode 23a of the piezoelectric vibrator 10, and the second adder 45b is connected to the second electrode 23b.

発振部４１において交流電圧が発生し、移相部Ｌ４２、及び移相部Ｆ４３に印加される。発振部４１において発生した交流電圧の位相は、移相部Ｌ４２において第１方向Ｄ１に圧電体振動子１０を伸縮振動させるための信号となるように変えられ、その電圧はｓｉｎωｔとなる。また、発振部４１において発生した交流電圧の位相は、移相部Ｆ４３において第２方向Ｄ２に圧電体振動子を屈曲振動させるための信号となるように変えられ、その電圧はｃｏｓωｔとなる。 An alternating voltage is generated in the oscillating unit 41 and is applied to the phase shift unit L42 and the phase shift unit F43. The phase of the AC voltage generated in the oscillating unit 41 is changed to become a signal for causing the piezoelectric vibrator 10 to expand and contract in the first direction D1 in the phase shift unit L42, and the voltage becomes sin ωt. The phase of the AC voltage generated in the oscillating unit 41 is changed to be a signal for bending and vibrating the piezoelectric vibrator in the second direction D2 in the phase shift unit F43, and the voltage becomes cos ωt.

第１増幅部４４ａにおいて増幅された電圧Ａｓｉｎωｔは、第３電極２３ｃに印加される。第１加算部４５ａでは、第１増幅部４４ａの出力端の電圧Ｂｃｏｓωｔを減算して、−Ｂｃｏｓωｔの電圧が第１電極２３ａに印加される。第２加算部４５ｂでは、第２増幅部４４ｂの出力端の電圧Ｂｃｏｓωｔを加算して、＋Ｂｃｏｓωｔの電圧が第２電極２３ｂに印加される。 The voltage Asinωt amplified in the first amplifying unit 44a is applied to the third electrode 23c. In the first adder 45a, the voltage Bcosωt at the output terminal of the first amplifier 44a is subtracted, and a voltage of −Bcosωt is applied to the first electrode 23a. In the second adder 45b, the voltage Bcosωt at the output terminal of the second amplifier 44b is added, and a voltage of + Bcosωt is applied to the second electrode 23b.

以上のような、第２の実施形態を適用した圧電体振動子において第１電極２３ａ、及び第２電極２３ｂにおける圧電素子の伸縮により第２方向Ｄ２に沿った屈曲振動を発生させ、第３電極２３ｃにおける圧電素子の伸縮により第１方向Ｄ１に沿った伸縮振動を発生させることが可能であり、これらの振動の組合わせにより辺部に楕円運動を行わせることが可能である。 In the piezoelectric vibrator to which the second embodiment is applied as described above, bending vibration along the second direction D2 is generated by expansion and contraction of the piezoelectric elements in the first electrode 23a and the second electrode 23b, and the third electrode The expansion and contraction vibration along the first direction D1 can be generated by expansion and contraction of the piezoelectric element in 23c, and an elliptical motion can be performed on the side portion by combining these vibrations.

図１１は、本発明の第３の実施形態を適用した振動子を示す。本実施形態は圧電体振動子を構成する圧電素子及びシムの形状が第１の実施形態と異なる。 FIG. 11 shows a vibrator to which the third embodiment of the present invention is applied. This embodiment is different from the first embodiment in the shape of a piezoelectric element and a shim constituting a piezoelectric vibrator.

シム３００（弾性板部材）には、シム３００の中央から面上の第１方向Ｄ１に沿って両側に延びる第１突出部３６ａ、及び第２突出部３６ｂが形成される。第１突出部３６ａ、及び第２突出部３６ｂは、第１方向Ｄ１に平行な２辺、及び第１方向Ｄ１に垂直な第２方向Ｄ２に平行な辺によって矩形に形成される。 The shim 300 (elastic plate member) is formed with a first protrusion 36a and a second protrusion 36b extending from the center of the shim 300 to both sides along the first direction D1 on the surface. The first protrusion 36a and the second protrusion 36b are formed in a rectangular shape by two sides parallel to the first direction D1 and a side parallel to the second direction D2 perpendicular to the first direction D1.

シム３００には、第２方向Ｄ２に沿って両側に延びる第３突出部３６ｃ、及び第４突出部３６ｄが形成される。第３、第４突出部３６ｃ、３６ｄは、第２方向Ｄ２に沿って外側に延びるにつれて幅がテーパ状に小さくなるように形成される。シム３００は第１方向Ｄ１及び第２方向Ｄ２に線対称である。テーパの長さや角度を調整することにより、周波数の調節が可能となる。 The shim 300 is formed with a third projecting portion 36c and a fourth projecting portion 36d that extend on both sides along the second direction D2. The third and fourth protrusions 36c and 36d are formed such that the width decreases in a tapered shape as they extend outward along the second direction D2. The shim 300 is line symmetric with respect to the first direction D1 and the second direction D2. The frequency can be adjusted by adjusting the length and angle of the taper.

シム３００に形成される第１、第２接触部３１ａ、３１ｂは、第１、第２突出部３６ａ、３６ｂから更に第１方向Ｄ１に沿って外側に伸ばされる。シム３００に形成される第１、第２支持部３２ａ、３２ｂの構成及び機能は第１の実施形態と同じである。 The first and second contact portions 31a and 31b formed on the shim 300 are further extended outward along the first direction D1 from the first and second projecting portions 36a and 36b. The configurations and functions of the first and second support portions 32a and 32b formed in the shim 300 are the same as those in the first embodiment.

圧電素子２００、２００（振動体）は、第１方向Ｄ１に沿った２辺及び第２方向Ｄ２に沿った２辺を外縁とする矩形に形成される。また、圧電素子２００、２００は、第１方向Ｄ１の長さが第２方向Ｄ２の幅に比べて長くなるように形成される。圧電素子２００、２００の表面に、第１、第２電極２３０ａ、２３０ｂが設けられる構成は第１の実施形態と同じである。 The piezoelectric elements 200 and 200 (vibrating bodies) are formed in a rectangular shape having two sides along the first direction D1 and two sides along the second direction D2 as outer edges. The piezoelectric elements 200 and 200 are formed so that the length in the first direction D1 is longer than the width in the second direction D2. The configuration in which the first and second electrodes 230a and 230b are provided on the surfaces of the piezoelectric elements 200 and 200 is the same as that in the first embodiment.

以上のような本実施形態の圧電体振動子１０１においても、駆動回路４０を用いて第１方向Ｄ１、及び第２方向Ｄ２にそれぞれ伸縮１次モード、屈曲１次モードの振動を発生させることが可能であって、第１突出部３６ａ、及び第２突出部３６ｂにおいて互いに反対方向であり屈曲方向への駆動力の大きな楕円運動を発生させることが可能である。 Also in the piezoelectric vibrator 101 of the present embodiment as described above, the vibration of the expansion / contraction primary mode and the bending primary mode can be generated in the first direction D1 and the second direction D2 using the drive circuit 40, respectively. It is possible, and it is possible to generate an elliptical motion with a large driving force in the bending direction in the first protruding portion 36a and the second protruding portion 36b in opposite directions.

圧電体振動子の第１方向Ｄ１の伸縮振動の共振周波数、及び第２方向Ｄ２の共振周波数は、圧電体振動子全体の形状によって定まり、圧電素子の形状だけでなく、シムの形状を前述のように形成することによっても、目的に応じた振動が可能な振動子が得られる。 The resonance frequency of the stretching vibration in the first direction D1 and the resonance frequency in the second direction D2 of the piezoelectric vibrator are determined by the shape of the entire piezoelectric vibrator, and not only the shape of the piezoelectric element but also the shape of the shim described above. By forming in this way, a vibrator capable of vibrating according to the purpose can be obtained.

また、本実施形態においては、第１、第２実施形態の圧電体振動子に比べて、第１方向Ｄ１への伸縮振動の振幅を大きくすることが可能である。第１、第２の実施形態において用いられる圧電素子が有する第３、第４突出部２１ｃ、２１ｄのように第２方向に沿って中央から両側に延びる突出部がなく、第１方向Ｄ１に伸縮しやすくなるためである。 In this embodiment, the amplitude of the stretching vibration in the first direction D1 can be increased as compared with the piezoelectric vibrators of the first and second embodiments. Like the third and fourth projecting portions 21c and 21d of the piezoelectric elements used in the first and second embodiments, there is no projecting portion extending from the center to both sides along the second direction, and it expands and contracts in the first direction D1. It is because it becomes easy to do.

なお、本実施形態において、圧電素子２００、２００の形状は、矩形であるが、第１方向Ｄ１に延びる形状であって、第１方向Ｄ１の長さが、第２方向Ｄ２の幅より長ければよく、例えば、楕円形であってもよい。 In the present embodiment, the shape of the piezoelectric elements 200 and 200 is rectangular, but the shape extends in the first direction D1, and the length in the first direction D1 is longer than the width in the second direction D2. For example, it may be oval.

第１〜第３の実施形態では、電極が第２方向Ｄ２に沿って、２或いは３に分割される構成であるが、第２方向Ｄ２に沿って２以上に分割される構成、すなわち第２方向Ｄ２に沿って複数の電極が並べられる構成であれば同様の効果が得られる。また、３以上に分割される場合は、第１、第２電極の間にさらに電極が設けられる構成が好ましい。すなわち、第２方向Ｄ２に沿って最も外側にある２つの電極にそれぞれ位相の異なる交流電圧が入力されることになる。 In the first to third embodiments, the electrode is divided into two or three along the second direction D2, but is divided into two or more along the second direction D2, that is, second. A similar effect can be obtained if a plurality of electrodes are arranged along the direction D2. Moreover, when dividing | segmenting into 3 or more, the structure in which an electrode is further provided between the 1st, 2nd electrode is preferable. That is, AC voltages having different phases are input to the two outermost electrodes along the second direction D2.

また、第１〜第３の実施形態では、金属製のシムを用いたが、弾性を有する板部材であれば、本実施形態と同様の効果を生じる。 Further, in the first to third embodiments, the metal shim is used, but if it is a plate member having elasticity, the same effect as that of the present embodiment is produced.

第１、第２の実施形態では、圧電体振動子を８角形の対向する２辺から外側に矩形の突出部を設ける形状としたが、図１２に示すように８角形に形成した圧電素子２０１によっても、孔を開けることなく、伸縮の１次モードと屈曲の１次モードの共振周波数を一致させることが可能である。或いは、第３の実施形態におけるシムを圧電素子２０１と同様に８角形に形成しても同様の効果が得られる。 In the first and second embodiments, the piezoelectric vibrator has a shape in which a rectangular protrusion is provided on the outer side from two opposite sides of the octagon. However, as shown in FIG. 12, the piezoelectric element 201 formed in an octagon. Therefore, the resonance frequency of the primary mode of expansion and contraction and the primary mode of bending can be matched without opening a hole. Alternatively, the same effect can be obtained even when the shim in the third embodiment is formed in an octagon like the piezoelectric element 201.

更には、中央から第１、第２方向Ｄ１、Ｄ２に沿って両側に突出部を有し、少なくとも１組の対向する突出部の先端に辺部が設けられる形状の振動子であれば、上述の効果が得られる。 Furthermore, if the vibrator has a shape having protrusions on both sides along the first and second directions D1 and D2 from the center, and a side portion is provided at the tip of at least one pair of opposite protrusions, The effect is obtained.

また、第１〜第３の実施形態では、振動子を加振させるのに圧電素子を用いたが、電歪素子等の交流電圧を印加することにより振動する素子（振動体）を用いても上述の効果が得られる。 In the first to third embodiments, the piezoelectric element is used to vibrate the vibrator. However, an element (vibrating body) that vibrates by applying an AC voltage such as an electrostrictive element may be used. The effects described above can be obtained.

次に、第１〜第３の実施形態におけるシムの変形例を図１３に示す。本変形例において、弾性を有するシム３０１（弾性板部材）は板状に形成される。シム３０１の板状の表面と、圧電素子２０の板状の表面とが結合される。 Next, a modification of the shim in the first to third embodiments is shown in FIG. In this modification, the shim 301 (elastic plate member) having elasticity is formed in a plate shape. The plate-like surface of the shim 301 and the plate-like surface of the piezoelectric element 20 are combined.

シム３０１は、圧電素子２０、２０と結合された状態において、第１方向Ｄ１に沿って、第１、第２突出部２１ａ、２１ｂを越えて外側に延びるように形成される。また、シム３０１は、第１方向Ｄ１に沿った両端３７、３７が第２方向Ｄ２に平行となるように、形成される。また、シム３０１において第１、第２接触部３１ａ、３１ｂは、シム３０１の第１方向Ｄ１に沿った両端３７、３７を越えて外側に突出するように形成される。なお、圧電素子２０、２０の構成及び機能は第１の実施形態と同じとする。 The shim 301 is formed to extend outwardly beyond the first and second projecting portions 21 a and 21 b along the first direction D <b> 1 in a state where the shim 301 is coupled to the piezoelectric elements 20 and 20. Further, the shim 301 is formed such that both ends 37 and 37 along the first direction D1 are parallel to the second direction D2. In the shim 301, the first and second contact portions 31a and 31b are formed so as to protrude outward beyond both ends 37 and 37 along the first direction D1 of the shim 301. The configurations and functions of the piezoelectric elements 20 and 20 are the same as those in the first embodiment.

以上のような、シム３０１を適用した振動子１０２の第１方向Ｄ１の共振周波数と第２方向Ｄ２の共振周波数は、シム３０１の第１方向Ｄ１に沿った両端３７、３７の一方或いは両方の削除する大きさに応じて、異なる割合で変化する。即ち、形成後の振動子に対して、シム３０１の第１方向Ｄ１に沿った両端３７、３７の一方或いは両方を適当に除去することにより、第１、第２方向Ｄ１、Ｄ２それぞれの共振周波数を一致させることが可能となる。 As described above, the resonance frequency in the first direction D1 and the resonance frequency in the second direction D2 of the vibrator 102 to which the shim 301 is applied are equal to one or both of the both ends 37, 37 along the first direction D1 of the shim 301. It changes at a different rate depending on the size to be deleted. That is, by appropriately removing one or both of the both ends 37 and 37 along the first direction D1 of the shim 301 with respect to the formed vibrator, the resonance frequencies of the first and second directions D1 and D2 are respectively removed. Can be matched.

形成後の振動子において圧電素子の大きさを変えることは難しく、圧電素子の形成誤差により第１、第２方向Ｄ１、Ｄ２の共振周波数がずれる場合に、共振周波数を一致させるための微調整は難しい。しかし、切削可能な部材により形成されたシムを用いた振動子によれば、共振周波数を一致させるための微調整が容易になる。 In the vibrator after formation, it is difficult to change the size of the piezoelectric element, and when the resonance frequency in the first and second directions D1 and D2 shifts due to the formation error of the piezoelectric element, fine adjustment to match the resonance frequency is difficult. However, according to the vibrator using the shim formed of a member that can be cut, fine adjustment for matching the resonance frequency is facilitated.

なお、両端３７、３７の第２方向Ｄ２に平行にした切削量に対する振動子１０２の第１、第２方向Ｄ１、Ｄ２の共振周波数の変化量を予め測定しておくことが望ましい。形成後の振動子の第１、第２方向Ｄ１、Ｄ２の共振周波数のずれに対して、測定された変化量に基づきシム３０１の両端３７、３７を第２方向Ｄ２に平行に除去することにより、微調整がより容易となる。 In addition, it is desirable to measure in advance the amount of change in the resonance frequency of the vibrator 102 in the first and second directions D1 and D2 with respect to the cutting amount parallel to the second direction D2 of both ends 37 and 37. By removing both ends 37 and 37 of the shim 301 in parallel with the second direction D2 based on the measured variation with respect to the resonance frequency shift in the first and second directions D1 and D2 of the formed vibrator. Fine adjustment becomes easier.

なお、本変形例においてシム３０１は、第１方向Ｄ１に沿って両側に延びるが、第２方向Ｄ２に沿って両側に延びる構成であってもよい。ただし、第２方向Ｄ２に添って延びる構成では、第１方向Ｄ１に沿って延びる構成に比べて、両端の切削量に対する共振周波数の変化の感度が小さい。従って、圧電素子の形成精度が相対的に高く、共振周波数の微調整が小さい場合は、第２方向Ｄ２に延びる構成であっても十分な効果が得られる。 In this modification, the shim 301 extends on both sides along the first direction D1, but may have a configuration extending on both sides along the second direction D2. However, the configuration extending along the second direction D2 is less sensitive to the change in the resonance frequency with respect to the cutting amount at both ends than the configuration extending along the first direction D1. Therefore, when the formation accuracy of the piezoelectric element is relatively high and the fine adjustment of the resonance frequency is small, a sufficient effect can be obtained even with the configuration extending in the second direction D2.

本発明の第１の実施形態を適用した圧電体振動子の正面図である。1 is a front view of a piezoelectric vibrator to which a first embodiment of the present invention is applied. 第１の実施形態を適用した圧電体振動子の側面図である。1 is a side view of a piezoelectric vibrator to which a first embodiment is applied. 第１の実施形態を適用した圧電体振動子を備えた超音波モータの断面図である。It is sectional drawing of the ultrasonic motor provided with the piezoelectric material vibrator to which 1st Embodiment is applied. 第１の実施形態を適用した圧電体振動子の電極に接続される駆動回路のブロック図である。It is a block diagram of the drive circuit connected to the electrode of the piezoelectric vibrator to which the first embodiment is applied. 圧電体振動子の第２方向への屈曲状態を示す図である。It is a figure which shows the bending state to the 2nd direction of a piezoelectric material vibrator. 圧電体振動子の第１方向への伸張状態を示す図である。It is a figure which shows the expansion | extension state to the 1st direction of a piezoelectric vibrator. 圧電体振動子の第２方向への屈曲状態を示す図である。It is a figure which shows the bending state to the 2nd direction of a piezoelectric material vibrator. 圧電体振動子の第１方向への収縮状態を示す図である。It is a figure which shows the contraction state to the 1st direction of a piezoelectric vibrator. 本発明の第２の実施形態を適用した圧電体振動子の正面図である。It is a front view of the piezoelectric vibrator to which the 2nd Embodiment of this invention is applied. 第２の実施形態を適用した圧電体振動子の電極に接続される駆動回路のブロック図である。It is a block diagram of a drive circuit connected to an electrode of a piezoelectric vibrator to which a second embodiment is applied. 本発明の第３の実施形態を適用した圧電体振動子の正面図である。It is a front view of the piezoelectric vibrator to which the third embodiment of the present invention is applied. 第１、第２の実施形態を適用した圧電体振動子の外観形状の変形例を示す図である。It is a figure which shows the modification of the external shape of the piezoelectric material vibrator to which the 1st, 2nd embodiment is applied. シムの変形例を示す図である。It is a figure which shows the modification of a shim.

符号の説明Explanation of symbols

１０、１００、１０１、１０２圧電体振動子
２０、２００、２０１圧電素子
２１ａ〜２１ｄ第１〜第４突出部
２２辺部
２３ａ、２３０ａ第１電極
２３ｂ、２３０ｂ第２電極
２３ｃ第３電極
３０、３００、３０１シム
３１ａ、３１ｂ第１、第２接触部
３２ａ、３２ｂ第１、第２支持部
３６ａ、３６ｂ第１、第２突出部
４０、４００駆動回路
４１発振部
４２移相部Ｌ
４３移相部Ｆ
４４ａ、４４ｂ第１、第２増幅部
４５ａ、４５ｂ第１、第２加算部
Ｃ振動中心
Ｄ１第１方向
Ｄ２第２方向 10, 100, 101, 102 Piezoelectric vibrators 20, 200, 201 Piezoelectric elements 21a-21d First to fourth protrusions 22 Sides 23a, 230a First electrodes 23b, 230b Second electrodes 23c Third electrodes 30, 300 , 301 Shims 31a, 31b First and second contact portions 32a, 32b First and second support portions 36a, 36b First and second protrusions 40, 400 Drive circuit 41 Oscillating portion 42 Phase shift portion L
43 Phase shift part F
44a, 44b First and second amplifiers 45a, 45b First and second adders C Center of vibration D1 First direction D2 Second direction

Claims

前記振動子の中央から第１方向に沿って両側に延び、最先端において前記第１方向と垂直な第２方向に平行な辺部を有する第１、第２突出部と、
前記中央から、前記第２方向に沿って両側に延びる第３、第４突出部と、
前記第２方向に沿って並ぶ第１、第２電極とを備え、
前記第１、第２電極にそれぞれ位相の異なる交流電圧を印加することにより、振動する
ことを特徴とする振動子。 First and second protrusions extending from the center of the vibrator to both sides along a first direction and having sides parallel to a second direction perpendicular to the first direction at the forefront;
Third and fourth protrusions extending from the center to both sides along the second direction;
First and second electrodes arranged along the second direction,
Vibrating by applying alternating voltages having different phases to the first and second electrodes, respectively.

前記第１、第２電極の間にさらに電極が設けられることを特徴とする請求項１に記載の振動子。 The vibrator according to claim 1, wherein an electrode is further provided between the first and second electrodes.

前記第３、第４突出部が前記中央から前記第２方向に沿って延びるにつれて幅が小さくなることを特徴とする請求項１に記載の振動子。 2. The vibrator according to claim 1, wherein the width decreases as the third and fourth protrusions extend from the center along the second direction.

前記第１突出部が、前記辺部と前記第１方向に平行な２つの辺によって形成されることを特徴とする請求項１に記載の振動子。 The vibrator according to claim 1, wherein the first protrusion is formed by the side and two sides parallel to the first direction.

前記第１突出部の先端部と前記第２突出部の先端部との間隔より前記第３突出部の先端部と前記第４突出部の先端部との間隔の方が短いことを特徴とする請求項１に記載の振動子。 The distance between the tip of the third protrusion and the tip of the fourth protrusion is shorter than the distance between the tip of the first protrusion and the tip of the second protrusion. The vibrator according to claim 1.

前記第１、第２電極の間に第３電極を備え、前記第３電極に前記第１、第２電極のいずれか一方に印加される交流電圧とは位相が９０°、他方に印加される交流電圧とは位相が−９０°異なる交流電圧が印加されることを特徴とする請求項１に記載の振動子。 A third electrode is provided between the first and second electrodes, the phase of the AC voltage applied to one of the first and second electrodes to the third electrode is 90 °, and the other is applied to the other. The vibrator according to claim 1, wherein an AC voltage having a phase different from that of the AC voltage by −90 ° is applied.

前記振動子が、前記第１方向、及び前記第２方向に略対称であることを特徴とする請求項１に記載の振動子。 The vibrator according to claim 1, wherein the vibrator is substantially symmetrical with respect to the first direction and the second direction.

前記第３、第４突出部のそれぞれが、前記振動子が備えられる振動子支持体に、前記振動子を支持するための第１、第２支持部材を有し、
前記第１支持部材には、前記振動子と前記第１支持部材とを連結する第１連結点が、前記振動子の前記第２方向への振動が最も大きくなる点である振動中心を通る直線であって前記第２方向に平行な直線から外れる位置に設けられ、
前記第２支持部材には、前記振動子と前記第２支持部材とを連結する第２連結点が、前記振動中心を通る前記第２方向に平行な直線から外れる位置に設けられる
ことを特徴とする請求項１に記載の振動子。 Each of the third and fourth protrusions has first and second support members for supporting the vibrator on a vibrator support provided with the vibrator,
In the first support member, a straight line passing through a vibration center where a first connection point connecting the vibrator and the first support member is a point where the vibration in the second direction of the vibrator is the largest. And provided at a position deviating from a straight line parallel to the second direction,
The second support member is provided with a second connection point for connecting the vibrator and the second support member at a position deviating from a straight line passing through the vibration center and parallel to the second direction. The vibrator according to claim 1.

前記第１、第２突出部と、前記第１、第２電極とを有し、交流電圧を印加することにより振動する板状の振動体と、
前記振動体と密着し、前記第１方向に沿って前記第１、第２突出部より外側に延びる調整部を有する弾性板部材とを備える
ことを特徴とする請求項１に記載の振動子。 A plate-like vibrating body having the first and second protrusions and the first and second electrodes, and vibrating by applying an alternating voltage;
2. The vibrator according to claim 1, further comprising: an elastic plate member that is in close contact with the vibrating body and has an adjustment portion that extends outward from the first and second projecting portions along the first direction.

前記弾性板部材の前記第１方向に沿った両端が、前記第２方向と平行に形成されることを特徴とする請求項９に記載の振動子。 The vibrator according to claim 9, wherein both ends of the elastic plate member along the first direction are formed in parallel with the second direction.

前記弾性板部材には、前記第１方向に沿った両端から外側に突出する接触部が設けられることを特徴とする請求項１０に記載の振動子。 The vibrator according to claim 10, wherein the elastic plate member is provided with a contact portion that protrudes outward from both ends along the first direction.

前記第１〜第４突出部を有する弾性板部材と、
前記第１方向の長さが前記第２方向の幅より長く形成され、前記弾性板部材に密着し、前記第１、第２電極を有し、交流電圧を印加することにより振動する板状の振動体とを備える
ことを特徴とする請求項１に記載の振動子。 An elastic plate member having the first to fourth protrusions;
The length of the first direction is longer than the width of the second direction, is in close contact with the elastic plate member, has the first and second electrodes, and vibrates by applying an AC voltage. The vibrator according to claim 1, further comprising: a vibrating body.

前記振動体が、前記第１方向及び前記第２方向に平行な辺を有する矩形であることを特徴とする請求項１２に記載の振動子。 The vibrator according to claim 12, wherein the vibrating body is a rectangle having sides parallel to the first direction and the second direction.

請求項１０に記載の振動子における、前記弾性板部材の前記第１方向に沿った両端の一方、或いは両方の一部を除去することを特徴とする振動子の共振周波数調整方法。 11. The method for adjusting a resonance frequency of a vibrator according to claim 10, wherein one or both of both ends along the first direction of the elastic plate member are removed.

前記弾性板部材の前記第１方向に沿った両端の一方、或いは両方の一部が、前記第２方向と平行に除去されることを特徴とする請求項１４に記載の振動子の共振周波数調整方法。

15. The resonance frequency adjustment of the vibrator according to claim 14, wherein one or both of both ends of the elastic plate member along the first direction are removed in parallel with the second direction. Method.