JP2007033983A

JP2007033983A - Lens module

Info

Publication number: JP2007033983A
Application number: JP2005218557A
Authority: JP
Inventors: Shuji Aizawa; 周二相澤; Tomohiro Yonezawa; 友浩米澤; Yukio Nishinomiya; 幸雄西宮; Kazunori Honda; 和徳本多; Akihiro Isomura; 明宏磯村
Original assignee: NEC Tokin Corp
Current assignee: Tokin Corp
Priority date: 2005-07-28
Filing date: 2005-07-28
Publication date: 2007-02-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable lens module which is simple in its structure and has a large drive torque with a small footprint. <P>SOLUTION: This lens module has piezoelectric elements 12 having polarizing axes parallel with the pole surface to make shearing deformations following the applied voltage, a drive element having a substrate 13 and a drive plate 14, a case 22 which has a contact surface parallel with the pole surface and rotates by the drive power generated by the deformations, a cylindrical case 23 for holding the optical lens 26, and a motion conversion-transmission mechanism which converts the rotation of the case 22 into a motion in the direction of the optical axis 27 and transmit it to the case 23. It drives the case 23 by converting the rotating motion of the case 22 turned by the drive power generated by applying drive pulses to the piezoelectric elements 12 into the motion in the direction of the optical axis 27 by the above motion conversion-transmission mechanism, and moves the optical lens 26 in the direction of the optical axis. Further, the piezoelectric elements 12 are arranged along the periphery, and the center axis of the whole drive element is on the optical axis 27. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、所定の方向に移動する光学レンズを備えるレンズモジュールに係り、特に、デジタルビデオカメラ、デジタルカメラあるいは携帯電話のカメラに用いて好適なレンズモジュールに関し、さらに詳しくは、オートフォーカスおよびズーム機構を有する光学機器に好適なレンズモジュールに関する。 The present invention relates to a lens module including an optical lens that moves in a predetermined direction, and more particularly to a lens module suitable for use in a digital video camera, digital camera, or mobile phone camera, and more particularly, an autofocus and zoom mechanism. The present invention relates to a lens module suitable for an optical apparatus having

カメラにオートフォーカスやズーム機能を持たせるためには、光軸に沿って光学レンズを移動させる機構が必要であり、従来から電磁式のモータを用いた方法が知られている。近年、デジタルカメラやカメラ付き携帯電話にみられるように、機器の小型化が急速に進み、それに伴って電磁式のモータから、圧電素子に代表される電気−機械変換素子によるレンズ移動の方法が提案されている。例えば、特許文献１には、圧電素子を用いて光学レンズを保持する円筒状の筐体を回転させることによって、光学レンズを移動させる構造が開示されている。 In order to provide the camera with an autofocus or zoom function, a mechanism for moving the optical lens along the optical axis is necessary, and a method using an electromagnetic motor has been conventionally known. In recent years, as seen in digital cameras and camera-equipped mobile phones, the miniaturization of devices has rapidly progressed. Accordingly, there is a method of moving a lens from an electromagnetic motor to an electro-mechanical conversion element represented by a piezoelectric element. Proposed. For example, Patent Document 1 discloses a structure in which an optical lens is moved by rotating a cylindrical housing that holds the optical lens using a piezoelectric element.

特開２００４−３１２８１４号公報JP 2004-31814 A

しかし、特許文献１に開示されている方法では、圧電素子を、レンズを保持する筐体の外部に設置し、筐体を回転させる構造をとっているため、レンズモジュールの設置面積（床面積）が大きくなるという問題がある。また、圧電素子による駆動力を伝達する接触部の面積が小さく、駆動トルクを大きくすることが容易でないという問題あるいは機械的衝撃力に対する信頼性を確保するのが容易でないという問題がある。 However, in the method disclosed in Patent Document 1, since the piezoelectric element is installed outside the housing that holds the lens and rotates the housing, the installation area (floor area) of the lens module is adopted. There is a problem that becomes larger. In addition, there is a problem that the area of the contact portion for transmitting the driving force by the piezoelectric element is small and it is not easy to increase the driving torque, or that it is not easy to ensure the reliability against the mechanical impact force.

この状況にあって、本発明の課題は、単純な構造を持ち、設置面積が小さく、駆動トルクが大きく、高信頼性のレンズモジュールを提供することにある。 In this situation, an object of the present invention is to provide a highly reliable lens module having a simple structure, a small installation area, a large driving torque.

上記課題を解決するために本発明のレンズモジュールは、電極面に対し平行方向に分極軸を有し、駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子と、前記電極面と略平行に形成された接触面を有し、前記せん断変形により発生する駆動力を前記接触面で受けて回転する筒状または円柱状の回転体と、光学レンズを保持した筒状筐体と、前記回転体の回転運動を所定方向の運動に変換して前記筒状筐体に伝える運動変換伝達機構とを備えることを特徴とする。 In order to solve the above problems, the lens module of the present invention includes an electro-mechanical conversion element having a polarization axis parallel to the electrode surface and shearing in the polarization axis direction according to a driving voltage, and the electrode surface. A cylindrical or cylindrical rotating body that has a contact surface formed substantially in parallel and rotates by receiving the driving force generated by the shear deformation at the contact surface; and a cylindrical housing holding an optical lens; It is provided with a motion conversion transmission mechanism that converts the rotational motion of the rotating body into motion in a predetermined direction and transmits the motion to the cylindrical housing.

前記電気−機械変換素子は、電極面に対し平行方向に分極軸を有し駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子の要素が円周に沿って複数個配置されてなるとよい。 The electro-mechanical conversion element has a plurality of electro-mechanical conversion element elements arranged along a circumference having a polarization axis parallel to the electrode surface and shearing in the polarization axis direction according to a driving voltage. It ’s good.

前記電気−機械変換素子と、前記回転体および筒状筐体とが、前記光学レンズの光軸に沿って、同軸に配設されるとよい。 The electro-mechanical conversion element, the rotating body, and the cylindrical housing may be arranged coaxially along the optical axis of the optical lens.

前記電気−機械変換素子の中心部には開口が設けられるとよい。 An opening may be provided at the center of the electromechanical conversion element.

前記電気−機械変換素子の２種類が同軸に配設され、各々、前記光学レンズを保持した筒状筐体を互いに独立に移動させるとよい。 Two types of the electro-mechanical conversion elements are coaxially arranged, and each of the cylindrical housings holding the optical lens may be moved independently of each other.

前記電気−機械変換素子に、昇圧速度と降圧速度が異なるパルス電圧を印加することで、前記回転体を回転させるとよい。 The rotating body may be rotated by applying to the electro-mechanical conversion element a pulse voltage having a different step-up speed and step-down speed.

前記運動変換伝達機構はリードスクリューであり、前記回転体および筒状筐体は前記リードスクリューによって機械的に結合されるとよい。 The motion conversion transmission mechanism may be a lead screw, and the rotating body and the cylindrical housing may be mechanically coupled by the lead screw.

本発明においては、駆動素子として、駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子を用いており、さらに、電気−機械変換素子と、この電気−機械変換素子の駆動力により回転可能な筐体とが光学レンズの光軸上に同軸に配列してなる構造をとっているため、回転可能な筐体とほぼ同じ面積の床面積でレンズモジュールを形成することができる。また、複数のレンズを独立で移動させることが可能なため、オートフォーカスとズーム機能が求められる小型カメラのアクチュエータとして利用できる。 In the present invention, an electro-mechanical conversion element that shears and deforms in the direction of the polarization axis in accordance with the drive voltage is used as the drive element. Furthermore, the electro-mechanical conversion element and the driving force of the electro-mechanical conversion element Since the rotatable casing and the optical axis of the optical lens are arranged coaxially, the lens module can be formed with a floor area substantially the same as the rotatable casing. In addition, since a plurality of lenses can be moved independently, they can be used as actuators for small cameras that require autofocus and zoom functions.

さらに、本発明のレンズモジュールは、電気−機械変換素子とレンズの光軸を同軸に配置しない場合にも、構造が単純で部品点数も少なく面接触により電気−機械変換素子の回転駆動力を伝達するので、低コストで製造が可能であるだけでなく、高トルクであり、機械的衝撃力に対して高信頼である。 Furthermore, the lens module of the present invention transmits the rotational driving force of the electro-mechanical conversion element by surface contact even when the electro-mechanical conversion element and the optical axis of the lens are not arranged coaxially with a simple structure and a small number of parts. Therefore, not only can it be manufactured at low cost, but also high torque and high reliability against mechanical impact force.

以下、本発明の実施の形態について詳細に説明する。図４は、筒状筐体を回転させる駆動素子の構造の一例を斜視図で示している。この駆動素子は、複数の圧電素子１２を基板１３に接着し、また、駆動面１５を有する駆動板１４が圧電素子１２に接着している。なお、図４においては、圧電素子１２の連接構造が分かりやすいように、駆動板１４の接着前の状態を示している。基板１３と駆動板１４の材質は、特に限定しないが、圧電素子１２の電極としての機能を有することが望ましいため、ステンレスやアルミなどの金属材料が好適である。この圧電素子１２は、図５に斜視図で示すように、あらかじめ分極処理が施されている。その圧電素子１２の、分極方向１１と垂直方向に電圧を印加すると、図６に断面図で示すように、印加する電圧の大きさに比例してせん断変形が発生する。ここで、図６は、圧電素子１２の断面図である。また、電圧の極性を反転すると、せん断変形の方向は逆方向になる。この関係は、（１）式で表すことができる。 Hereinafter, embodiments of the present invention will be described in detail. FIG. 4 is a perspective view showing an example of the structure of the drive element that rotates the cylindrical housing. In this driving element, a plurality of piezoelectric elements 12 are bonded to a substrate 13, and a driving plate 14 having a driving surface 15 is bonded to the piezoelectric elements 12. FIG. 4 shows a state before the drive plate 14 is bonded so that the connecting structure of the piezoelectric elements 12 can be easily understood. The material of the substrate 13 and the drive plate 14 is not particularly limited, but a metal material such as stainless steel or aluminum is preferable because it preferably has a function as an electrode of the piezoelectric element 12. As shown in the perspective view of FIG. 5, the piezoelectric element 12 has been previously polarized. When a voltage is applied to the piezoelectric element 12 in a direction perpendicular to the polarization direction 11, shear deformation is generated in proportion to the magnitude of the applied voltage, as shown in a sectional view in FIG. Here, FIG. 6 is a cross-sectional view of the piezoelectric element 12. Further, when the polarity of the voltage is reversed, the direction of shear deformation is reversed. This relationship can be expressed by equation (1).

δ＝ｄ₁₅×Ｖ・・・・・（１）
ここで、δはせん断変形の変位、Ｖは印加電圧、ｄ₁₅は圧電素子１２の圧電定数である。（１）式から、δは圧電素子１２の寸法には依存せず、材料定数と印加電圧のみで決定されることが分かる。 δ = d ₁₅ × V (1)
Here, δ is a displacement of shear deformation, V is an applied voltage, and d ₁₅ is a piezoelectric constant of the piezoelectric element 12. From equation (1), it can be seen that δ does not depend on the dimensions of the piezoelectric element 12 and is determined only by the material constant and the applied voltage.

この変形を図４の駆動素子で考えると、基板１３を電気的にグランドとして、駆動板１４に電圧を印加すると、駆動面１５が基板１３に対して、（１）式できまる量だけ回転することが分かる。この駆動素子の駆動面１５上に、図７で概念的斜視図で示すように回転可能なロータ１６を設置し、電圧を急速に印加するとロータ１６は回転せず、電圧を低速で印加するとロータ１６が回転する。すなわち、電圧を急速に印加し、ゆっくりと落とすというパルス電圧を交流で印加すると、ロータ１６は連続的に回転する。また、電圧の極性を反転する、あるいは、電圧をゆっくり印加し、急速に落とすことで逆回転が可能である。 Considering this deformation in the drive element of FIG. 4, when a voltage is applied to the drive plate 14 with the substrate 13 being electrically grounded, the drive surface 15 rotates with respect to the substrate 13 by an amount determined by the expression (1). I understand that. As shown in a conceptual perspective view in FIG. 7, a rotatable rotor 16 is installed on the drive surface 15 of this drive element. When a voltage is applied rapidly, the rotor 16 does not rotate, and when a voltage is applied at a low speed, the rotor 16 rotates. 16 rotates. That is, when a pulse voltage of applying a voltage rapidly and dropping it slowly is applied with an alternating current, the rotor 16 rotates continuously. Further, reverse rotation is possible by reversing the polarity of the voltage, or by applying the voltage slowly and dropping it rapidly.

圧電素子１２の材質はジルコン酸チタン酸鉛（Ｐｂ（Ｚｒ・Ｔｉ）Ｏ_３）を主成分とする圧電セラミクスであることが好適であるが、他に、ビスマス層状セラミクス、ニオブ酸カリウムあるいはニオブ酸ナトリウムを主成分とするセラミクスなどの、非鉛材料なども使用可能である。また、ニオブ酸リチウムなどの単結晶材料も使用可能である。 The material of the piezoelectric element 12 is preferably a piezoelectric ceramic mainly composed of lead zirconate titanate (Pb (Zr · Ti) O ₃ ). Lead-free materials such as ceramics mainly composed of sodium can also be used. A single crystal material such as lithium niobate can also be used.

ジルコン酸チタン酸鉛（Ｐｂ（Ｚｒ・Ｔｉ）Ｏ_３）を主成分とする圧電セラミクスによる圧電素子の作製については、一般的な圧電セラミクスの製法により、焼結体を製造し、機械加工などにより所定の形状とした後、銀などを用いて仮電極を形成後、図５に示す方向に分極処理を施す。その後、仮電極を機械的に取り除き、基板１３と駆動板１４に接着する面にスパッタなどで外部電極を形成し、基板１３および駆動板１４を接着することで、駆動素子を製造する。このようにして、電極面に対し平行方向に分極軸を有し駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子を製造する。 For the production of piezoelectric elements using piezoelectric ceramics containing lead zirconate titanate (Pb (Zr · Ti) O ₃ ) as the main component, a sintered body is manufactured by a general method of manufacturing piezoelectric ceramics, and is processed by machining. After forming a predetermined shape, a temporary electrode is formed using silver or the like, and then a polarization treatment is performed in the direction shown in FIG. Thereafter, the temporary electrode is mechanically removed, an external electrode is formed on the surface to be bonded to the substrate 13 and the drive plate 14 by sputtering or the like, and the drive element is manufactured by bonding the substrate 13 and the drive plate 14 together. In this way, an electro-mechanical transducer having a polarization axis parallel to the electrode surface and shearing deformed in the polarization axis direction according to the driving voltage is manufactured.

前述のように圧電素子１２の変形は、圧電素子１２の形状によらないため、圧電素子１２の寸法は自由に設定することができる。例えば、圧電素子１２として、矩形形状のものを用い、分極方向を周方向にそろえて同心円状に配列しても良い。ただし、ロータ１６を円滑に回転させるためには、図４に示したように、円筒形状の圧電セラミクスを複数に切断し、周方向に沿って分極することが好適であり、また、圧電素子１２の個数を減らすこともできる。 Since the deformation of the piezoelectric element 12 does not depend on the shape of the piezoelectric element 12 as described above, the dimensions of the piezoelectric element 12 can be freely set. For example, the piezoelectric elements 12 may be rectangular and may be arranged concentrically with their polarization directions aligned in the circumferential direction. However, in order to rotate the rotor 16 smoothly, as shown in FIG. 4, it is preferable to cut the cylindrical piezoelectric ceramic into a plurality of pieces and to polarize them along the circumferential direction. The number of can also be reduced.

この駆動素子を用いた、本発明の一実施の形態でのレンズモジュールを図１に斜視図で示す。また、図２にその断面図を示す。本実施の形態のレンズモジュールは、圧電素子１２、基板１３、駆動板１４からなる駆動素子と、ベース２８と、光軸２７を中心軸として回転可能な筐体（回転体）２２、光学レンズ２６を保持する筐体（筒状筐体）２３、回転可能な筐体２２に押圧力を加えるガイド２４、筐体２３の移動を光軸２７方向に拘束するロッド２５、および光学レンズ２６からなる。ここで、筐体２２に作用するガイド２４は、筐体２２の水平方向に対するガイドが目的であって、筐体２２の回転を抑制しない程度の押さえ力で、駆動素子の駆動面１５（図４参照）に筐体２２を押し付けている。 A lens module according to an embodiment of the present invention using this driving element is shown in a perspective view in FIG. FIG. 2 shows a cross-sectional view thereof. The lens module according to the present embodiment includes a driving element including a piezoelectric element 12, a substrate 13, and a driving plate 14, a base 28, a casing (rotating body) 22 that can rotate around an optical axis 27, and an optical lens 26. A guide 24 for applying a pressing force to the rotatable housing 22, a rod 25 for restraining the movement of the housing 23 in the direction of the optical axis 27, and an optical lens 26. Here, the guide 24 acting on the housing 22 is intended to guide the housing 22 in the horizontal direction, and the driving surface 15 of the drive element (FIG. 4) with a pressing force that does not suppress the rotation of the housing 22. The casing 22 is pressed against the reference).

回転可能な筐体２２と、光学レンズ２６を保持する筐体２３の材質は特に限定されないが、デジタルカメラやカメラ付き携帯電話のカメラモジュールとして考えた場合、プラスチックなどの樹脂を用いるのが一般的である。また、これらの寸法は、光学レンズ２６の寸法に依存するが、大略、外形８〜１５ｍｍ、高さ７〜２０ｍｍ程度である。 The material of the casing 22 that can rotate and the casing 23 that holds the optical lens 26 is not particularly limited, but when considered as a camera module of a digital camera or a camera-equipped mobile phone, a resin such as plastic is generally used. It is. Moreover, although these dimensions depend on the dimension of the optical lens 26, they are roughly about 8 to 15 mm in outer shape and about 7 to 20 mm in height.

光学レンズの種類と枚数、および、位置関係は、レンズモジュールの使用目的によって異なるため、図１および図２においては、オートフォーカスやズームに用いられる光学レンズ２６のみを載せ、他の固定レンズについては省略した。また、複数のレンズを独立で移動させることも容易であるが、簡略化のために、１個の可動レンズの場合について示した。 Since the type and number of optical lenses and the positional relationship differ depending on the purpose of use of the lens module, only the optical lens 26 used for autofocus and zoom is mounted in FIGS. 1 and 2, and other fixed lenses are used. Omitted. Although it is easy to move a plurality of lenses independently, the case of one movable lens is shown for the sake of simplicity.

回転可能な筐体２２と、光学レンズ２６を保持する筐体２３とは、図示しないリードスクリュー（たとえば、雄ねじの山または雌ねじの谷に相当するらせん状の部位と略直線方向に運動方向を拘束された部位とが組み合わされ、らせん状の部位の回転運動を略直線方向の運動に変換して伝えるスクリュー）によって機械的に結合しており、光学レンズ２６を保持する筐体２３は回転しないようにロッド２５によって保持されている。 The rotatable housing 22 and the housing 23 holding the optical lens 26 are constrained in the direction of movement in a substantially linear direction with a lead screw (not shown) (for example, a spiral portion corresponding to a male screw thread or a female screw valley). And the housing 23 that holds the optical lens 26 is prevented from rotating. The screw 23 is mechanically coupled by a screw that converts the rotational motion of the spiral portion into a substantially linear motion and transmits the motion. Is held by a rod 25.

その駆動素子の電極に駆動パルス電圧を印加することで回転可能な筐体２２が回転し、リードスクリューを介して、光学レンズ２６を保持する筐体２３が光軸２７に沿って直進移動する。この直進移動により、光学レンズ２６が光軸２７に沿って移動する。光学レンズ２６を保持する筐体２３の移動量と移動速度は、オートフォーカスやズームなどの使用目的に適合するよう適宜決定し、リードスクリューの構造や駆動電圧と駆動周波数を選定する。 By applying a drive pulse voltage to the electrode of the drive element, the rotatable housing 22 rotates, and the housing 23 holding the optical lens 26 moves straight along the optical axis 27 via the lead screw. By this linear movement, the optical lens 26 moves along the optical axis 27. The amount and speed of movement of the housing 23 that holds the optical lens 26 are determined as appropriate to suit the purpose of use such as autofocus and zoom, and the structure, drive voltage, and drive frequency of the lead screw are selected.

以上説明したように、本発明においては、電極面に対し平行方向に分極軸を有し、駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子からなる駆動素子と、その駆動力により回転可能な筐体２２とが、光学レンズ２６の光軸２７に沿って同軸に配列されているため、回転可能な筐体２２とほぼ同じ面積の床面積（設置面積）でレンズモジュールを形成することができた。 As described above, in the present invention, a driving element comprising an electro-mechanical conversion element having a polarization axis parallel to the electrode surface and shearing in the polarization axis direction according to the driving voltage, and its driving force Since the rotatable casing 22 is coaxially arranged along the optical axis 27 of the optical lens 26, a lens module is formed with a floor area (installation area) of substantially the same area as the rotatable casing 22. We were able to.

以上、１個の可動レンズを制御する場合について説明したが、たとえば、オートフォーカスとズームのために、複数の可動レンズを制御する場合についても、図４のような中心部に開口を有する電気−機械変換素子を２種類用いると、第１の電気−機械変換素子の開口に合わせて第２の電気−機械変換素子を同軸に配置し、各々、光学レンズを保持した筒状筐体を互いに独立に移動させることができ、さらに実用性が高められる。 The case where one movable lens is controlled has been described above. However, for example, in the case where a plurality of movable lenses are controlled for autofocusing and zooming, an electric circuit having an opening at the center as shown in FIG. When two types of mechanical conversion elements are used, the second electro-mechanical conversion elements are arranged coaxially in accordance with the openings of the first electro-mechanical conversion elements, and the cylindrical housings holding the optical lenses are independent of each other. It can be moved to the position and the practicality is further improved.

図３に、本発明の他の実施の形態でのレンズモジュールを部分断面図で示す。ハッチングで指示した部分は切断面であり、リードスクリュー３２はねじ類の慣例に従い断面図とはせず、それを回転駆動する駆動素子についても断面図ではなく正面図で描いた。 FIG. 3 is a partial cross-sectional view showing a lens module according to another embodiment of the present invention. The portion indicated by hatching is a cut surface, and the lead screw 32 is not a cross-sectional view according to the convention of screws, and the drive element for rotationally driving it is not a cross-sectional view but a front view.

図４で説明したものと同じ構造の駆動素子を用いて、リードスクリュー３２を回転させる。光学レンズ３３は２本のロッド３５によって保持されるとともに、リードスクリュー３２の回転によって光軸３６に沿って直進移動する。図３に示した、本実施の形態では、駆動素子が光軸３６と同軸には配置されていないため、図１の実施の形態に比較すると床面積は増加するものの、構造をさらに単純化し、薄型とすることができる。 The lead screw 32 is rotated using a drive element having the same structure as that described with reference to FIG. The optical lens 33 is held by the two rods 35 and moves linearly along the optical axis 36 by the rotation of the lead screw 32. In the present embodiment shown in FIG. 3, since the drive element is not arranged coaxially with the optical axis 36, the floor area increases compared to the embodiment of FIG. 1, but the structure is further simplified, It can be thin.

以上のように、本発明では、電極面に対し平行方向に分極軸を有し、駆動電圧に応じて分極軸方向にせん断変形する電気−機械変換素子（圧電素子）を用いたので、電力損失が少なく、また面接触により回転駆動力を伝達するので、強いトルクが得られる。さらに、同軸構造または単純な薄型構造を採用したので、機械的衝撃に対して高信頼性のレンズモジュールが得られる。 As described above, in the present invention, since an electro-mechanical conversion element (piezoelectric element) having a polarization axis parallel to the electrode surface and shearing deformed in the polarization axis direction according to the drive voltage is used, power loss Since the rotational driving force is transmitted by surface contact, a strong torque can be obtained. Furthermore, since a coaxial structure or a simple thin structure is adopted, a lens module with high reliability against mechanical impact can be obtained.

本発明の一実施の形態でのレンズモジュールを示す斜視図。The perspective view which shows the lens module in one embodiment of this invention. 本発明の一実施の形態でのレンズモジュールを示す断面図。Sectional drawing which shows the lens module in one embodiment of this invention. 本発明の他の実施の形態でのレンズモジュールを示す部分断面図。The fragmentary sectional view which shows the lens module in other embodiment of this invention. 本発明に係る駆動素子の一例を示す概念的な斜視図。The conceptual perspective view which shows an example of the drive element which concerns on this invention. 本発明に係る圧電素子の分極方向を示す斜視図。The perspective view which shows the polarization direction of the piezoelectric element which concerns on this invention. 本発明に係る圧電素子のせん断変形を説明する断面図。Sectional drawing explaining the shear deformation of the piezoelectric element which concerns on this invention. 本発明における回転駆動の原理を説明する概念的な斜視図。The conceptual perspective view explaining the principle of the rotational drive in this invention.

Explanation of symbols

１１分極方向
１２圧電素子
１３基板
１４駆動板
１５駆動面
１６ロータ
２２筐体（回転体）
２３筐体（筒状筐体）
２４ガイド
２５，３５ロッド
２６，３３光学レンズ
２７，３６光軸
２８，３７ベース
３２リードスクリュー
δ せん断変形の変位 11 Polarization direction 12 Piezoelectric element 13 Substrate 14 Drive plate 15 Drive surface 16 Rotor 22 Housing (rotating body)
23 Housing (tubular housing)
24 Guide 25, 35 Rod 26, 33 Optical lens 27, 36 Optical axis 28, 37 Base 32 Lead screw δ Displacement of shear deformation

Claims

An electromechanical transducer having a polarization axis parallel to the electrode surface and shearing deformed in the polarization axis direction in accordance with a driving voltage; and a contact surface formed substantially parallel to the electrode surface; A cylindrical or columnar rotating body that rotates by receiving a driving force generated by deformation on the contact surface, a cylindrical housing that holds an optical lens, and a rotational motion of the rotating body is converted into a motion in a predetermined direction. And a motion conversion transmission mechanism that transmits the movement to the cylindrical housing.

The electro-mechanical conversion element has a plurality of electro-mechanical conversion element elements arranged along a circumference having a polarization axis parallel to the electrode surface and shearing in the polarization axis direction according to a driving voltage. The lens module according to claim 1, wherein:

3. The lens module according to claim 1, wherein the electro-mechanical conversion element, the rotating body, and the cylindrical housing are arranged coaxially along an optical axis of the optical lens.

The lens module according to claim 3, wherein an opening is provided in a central portion of the electromechanical conversion element.

The lens module according to claim 4, wherein two types of the electro-mechanical conversion elements are coaxially arranged, and each moves a cylindrical housing holding the optical lens independently of each other.

6. The lens module according to claim 1, wherein the rotating body is rotated by applying to the electro-mechanical conversion element a pulse voltage having a step-up speed and a step-down speed different from each other.

The lens according to any one of claims 1 to 6, wherein the motion conversion transmission mechanism is a lead screw, and the rotating body and the cylindrical housing are mechanically coupled by the lead screw. module.