JP5122384B2

JP5122384B2 - Gear support structure

Info

Publication number: JP5122384B2
Application number: JP2008169584A
Authority: JP
Inventors: 博野村; 孝治萩原
Original assignee: Hoya Corp
Current assignee: Hoya Corp
Priority date: 2008-06-27
Filing date: 2008-06-27
Publication date: 2013-01-16
Anticipated expiration: 2028-06-27
Also published as: JP2010007799A

Description

本発明は、駆動力伝達用ギヤ列の構成ギヤの支持構造に関する。 The present invention relates to a support structure for a component gear of a driving force transmission gear train.

モータなどの駆動源に設けた回転出力軸の回転を軸方向移動に変換して駆動対象を移動させる駆動機構では、回転出力軸にリードスクリュー（送りねじ）を直結させるタイプと、回転出力軸からギヤ列を介して別設のリードスクリューに回転力を伝達するタイプが知られている。前者のタイプは、駆動機構が回転出力軸の軸線方向に長くなりがちで、軸方向での薄型化を狙った機器には不向きである。後者のギヤ列を用いたタイプは、モータなどの駆動源とリードスクリューを並べて（重ねて）配置できるので、駆動機構を薄型化することができる。但し、ギヤ列を用いた場合、回転出力軸側の原動ギヤとリードスクリュー側の従動ギヤに加えて、その間に位置される中間ギヤにおける支持安定性に留意する必要が生じる。例えば、撮像装置のＡＦ（オートフォーカス）機構では、モータの高速な間欠駆動が行われるため、中間ギヤの支持部に余分な遊びがあると、ギヤのがたつきや異音が生じやすい。このようなギヤ列の中間ギヤを安定保持する構造として、例えば特許文献１がある。
特開２００７−１１４５３０号公報 In a drive mechanism that converts the rotation of a rotary output shaft provided in a drive source such as a motor into an axial movement to move the object to be driven, a type in which a lead screw (feed screw) is directly connected to the rotary output shaft, and a rotary output shaft A type is known in which rotational force is transmitted to a separate lead screw via a gear train. In the former type, the drive mechanism tends to be long in the axial direction of the rotation output shaft, and is not suitable for a device aiming at thinning in the axial direction. In the type using the latter gear train, a drive source such as a motor and a lead screw can be arranged (stacked) side by side, so that the drive mechanism can be thinned. However, when the gear train is used, it is necessary to pay attention to the support stability in the intermediate gear positioned between the driving gear on the rotation output shaft side and the driven gear on the lead screw side. For example, in the AF (autofocus) mechanism of the image pickup apparatus, high-speed intermittent driving of the motor is performed. Therefore, if there is extra play in the support portion of the intermediate gear, gear rattling or abnormal noise is likely to occur. For example, Patent Document 1 discloses a structure for stably holding the intermediate gear of such a gear train.
JP 2007-114530 A

特許文献１では、ギヤ列の中間ギヤを構成する平歯ギヤの一端部と、この平歯ギヤの回転軸を支持する支持部材との間にスプリングワッシャ（皿ばね）を挿入し、該スプリングワッシャの付勢力によって平歯ギヤを安定させている。一般に、このタイプの付勢部材は、サイズ（支点から着力点までの距離）が小さいほど、単位変位量あたりの弾性力の変化（荷重変動）が大きくなるため、個々の部品寸法誤差を考慮した場合、安定した付勢力を得るためには、付勢部材のサイズは大きいことが好ましい。特許文献１のスプリングワッシャは、円形、楕円形、長方形などの外形形状が提案されており、このような形状のスプリングワッシャにおいてサイズの大型化を図った場合、スプリングワッシャとの干渉を避けるために、中間ギヤとその前後のギヤとのギヤ軸間隔を大きくする必要があり、ギヤ機構が大型化する原因となる。 In Patent Document 1, a spring washer (disc spring) is inserted between one end of a spur gear that constitutes an intermediate gear of a gear train and a support member that supports the rotation shaft of the spur gear, and the spring washer The spur gear is stabilized by the biasing force. In general, the smaller the size (distance from the fulcrum to the applied force point) of this type of urging member, the greater the change in elastic force per unit displacement (load fluctuation). In this case, in order to obtain a stable urging force, the size of the urging member is preferably large. The spring washer of Patent Document 1 has been proposed to have an outer shape such as a circle, an ellipse, and a rectangle. When the size of the spring washer having such a shape is increased, interference with the spring washer is avoided. In addition, it is necessary to increase the gear shaft interval between the intermediate gear and the front and rear gears, which causes an increase in the size of the gear mechanism.

本発明は、以上の問題点に鑑みてなされたもので、コンパクトでスペース効率に優れ、中間ギヤを高精度に保持することが可能なギヤ支持構造を提供することを目的とする。 The present invention has been made in view of the above problems, and an object thereof is to provide a gear support structure that is compact and excellent in space efficiency, and that can hold an intermediate gear with high accuracy.

本発明は、２つのギヤと、該２つのギヤに噛合して回転伝達を行う中間ギヤの支持構造において、中間ギヤのギヤ軸を支持するギヤ軸支持部材と、ギヤ軸支持部材と中間ギヤの間に挿入されるばね部材とを備え、このばね部材が、中間ギヤに当接するギヤ当接部と、該ギヤ当接部を中心とする放射方向に延出されてギヤ軸支持部材に当接する弾性変形可能な少なくとも３つの弾性支持脚とを備えており、該弾性支持脚をそれぞれ弾性変形させて中間ギヤをギヤ軸の軸線方向に付勢すること；及び、中間ギヤが噛合する２つのギヤのそれぞれの少なくとも一部が、中間ギヤのギヤ軸の軸線に沿う方向から見て、ばね部材の弾性支持脚にそれぞれ挟まれる少なくとも３つの脚間空間のうち異なる２つの脚間空間に位置しており、かつ中間ギヤのギヤ軸の軸線と直交する方向から見て、２つのギヤをそれぞれ支持するギヤ軸が２つの脚間空間に位置していること；を特徴としている。 The present invention relates to two gears and a support structure for an intermediate gear that meshes with the two gears to transmit rotation, a gear shaft support member that supports the gear shaft of the intermediate gear, a gear shaft support member, and an intermediate gear. A spring member inserted between the gear contact portion and a gear contact portion that contacts the intermediate gear, and extends in a radial direction around the gear contact portion and contacts the gear shaft support member. And at least three elastic support legs that can be elastically deformed, each of the elastic support legs is elastically deformed to urge the intermediate gear in the axial direction of the gear shaft; and two gears meshed with the intermediate gear each at least partially, when viewed from a direction along the axis of the gear shaft of the intermediate gear, located in two different inter-leg spaces of the at least three legs between the space sandwiched respectively elastically supporting leg of the spring member Gear and intermediate gear It is characterized in; as viewed from a direction perpendicular to the axis of the shaft, the gear shaft supporting the two gears each to be located at two inter-leg spaces.

ばね部材に設けられる３つの弾性支持脚は、ギヤ当接部から先端まで略同じ長さであり、かつ略等角度間隔で配置されていることが好ましい。 Three elastic support leg provided on the spring member is substantially the same length from the gear contact portion to the tip, and it is preferably disposed at a substantially uniform angular intervals.

ギヤ軸支持部材には、弾性支持脚に係合してばね部材の回転を規制する回転規制部を設けることが好ましい。例えば、ギヤ軸支持部材が中間ギヤを格納する筒状凹部を有しており、この筒状凹部の内壁面に形成された凹部によって回転規制部を形成することができる。 The gear shaft support member is preferably provided with a rotation restricting portion that engages with the elastic support leg to restrict the rotation of the spring member. For example, the gear shaft support member has a cylindrical recess for storing the intermediate gear, and the rotation restricting portion can be formed by the recess formed on the inner wall surface of the cylindrical recess.

ギヤ軸支持部材として、中間ギヤのギヤ軸が突出形成されたギヤ軸形成部材と、該ギヤ軸形成部材に固定されてギヤ軸の先端を支持し、ギヤ軸に対し中間ギヤを抜け止めさせる抜止部材とを有する態様では、ばね部材は、ギヤ軸形成部材と中間ギヤの間、あるいは抜止部材と中間ギヤの間に選択して挿入することができる。 As a gear shaft support member, a gear shaft forming member from which the gear shaft of the intermediate gear is formed to be protruded, and a retaining member that is fixed to the gear shaft forming member and supports the tip of the gear shaft and prevents the intermediate gear from coming off from the gear shaft. In the aspect having the member, the spring member can be selectively inserted between the gear shaft forming member and the intermediate gear or between the retaining member and the intermediate gear.

ばね部材のギヤ当接部には、中間ギヤのギヤ軸を挿通させる開口を形成してもよい。 An opening through which the gear shaft of the intermediate gear is inserted may be formed in the gear contact portion of the spring member.

本発明は、様々な機器のギヤ機構に適用が可能であり、例えば、撮像装置のＡＦレンズ駆動用のギヤ機構に特に好適である。 The present invention can be applied to a gear mechanism of various devices, and is particularly suitable for, for example, a gear mechanism for driving an AF lens of an imaging apparatus.

以上の本発明によれば、中間ギヤに噛合する前後のギヤ及びそのギヤ軸に対してばね部材の弾性支持脚が干渉しない位置にあるため、各ギヤとばね部材をスペース効率良く配置することができる。そして、ばね部材の弾性支持脚の長さが前後のギヤとの関係による制限を受けず、弾性支持脚の長さを自由に選択して任意のばねサイズ及び付勢力に設定できるため、製品誤差による付勢力の変動を抑制して中間ギヤを高精度に安定して支持することができる。また、小型のばね部材で精度管理を厳しくして製品ごとの付勢力の変動を少なくしていくという方向性に比べて、本発明を適用した場合、ばね部材の製造コストを抑えることができる。 According to the present invention described above, since the elastic support legs of the spring member do not interfere with the front and rear gears meshed with the intermediate gear and the gear shaft, the gears and the spring members can be arranged in a space-efficient manner. it can. The length of the elastic support leg of the spring member is not limited by the relationship with the front and rear gears, and the length of the elastic support leg can be freely selected and set to an arbitrary spring size and biasing force. It is possible to stably support the intermediate gear with high accuracy by suppressing the fluctuation of the urging force due to. Further, when the present invention is applied, the manufacturing cost of the spring member can be suppressed as compared with the direction in which the precision control is strictly controlled by a small spring member and the fluctuation of the urging force for each product is reduced.

図１から図４を参照して、本発明によるギヤ支持構造を備えたズームレンズ鏡筒７０の概略構造を説明する。このズームレンズ鏡筒７０の撮像光学系は、物体（被写体）側から順に第１レンズ群ＬＧ１、第２レンズ群ＬＧ２、絞り兼用のシャッタ羽根Ｓ、第３レンズ群ＬＧ３、ローパスフィルタ２５及び撮像素子７１を備えており、以下の説明中で光軸方向とは、この撮影光学系の光軸Ｏと平行な方向を意味する。 A schematic structure of a zoom lens barrel 70 having a gear support structure according to the present invention will be described with reference to FIGS. The imaging optical system of the zoom lens barrel 70 includes, in order from the object (subject) side, a first lens group LG1, a second lens group LG2, a shutter blade S that also serves as an aperture, a third lens group LG3, a low-pass filter 25, and an imaging element. In the following description, the optical axis direction means a direction parallel to the optical axis O of the photographing optical system.

ローパスフィルタ２５と撮像素子７１はユニット化されて撮像素子ホルダ２３に固定され、撮像素子ホルダ２３がハウジング２２の後部に固定される。ハウジング２２の外側には、ズームモータ１５０とＡＦモータ１６０が支持されている。 The low-pass filter 25 and the image sensor 71 are unitized and fixed to the image sensor holder 23, and the image sensor holder 23 is fixed to the rear portion of the housing 22. A zoom motor 150 and an AF motor 160 are supported outside the housing 22.

第３レンズ群ＬＧ３を保持する３群レンズ枠５１は、ハウジング２２に対して光軸方向に移動可能に支持されていて、ＡＦモータ１６０によって駆動される。 The third group lens frame 51 that holds the third lens group LG3 is supported so as to be movable in the optical axis direction with respect to the housing 22, and is driven by the AF motor 160.

ハウジング２２の内側にはカム環１１が支持されている。カム環１１は、ズームモータ１５０の駆動力によって回転され、鏡筒収納状態（図３）から撮影状態（図４）になるまでの間は、回転しながら光軸方向に移動し、撮影状態におけるズーム域（図４上半のワイド端と図４下半のテレ端の間）では、光軸方向には定位置で回転される。 A cam ring 11 is supported inside the housing 22. The cam ring 11 is rotated by the driving force of the zoom motor 150 and moves in the optical axis direction while rotating from the lens barrel storage state (FIG. 3) to the photographing state (FIG. 4). In the zoom range (between the wide end in the upper half of FIG. 4 and the tele end in the lower half of FIG. 4), it is rotated at a fixed position in the optical axis direction.

カム環１１を挟んで第１繰出筒１３と直進案内環１０が支持されている。第１繰出筒１３と直進案内環１０はそれぞれハウジング２２に対して光軸方向に直進案内されており、かつカム環１１に対しては、相対回転は可能で光軸方向に共に移動するように結合されている。 The first feed cylinder 13 and the straight guide ring 10 are supported with the cam ring 11 in between. The first feeding cylinder 13 and the rectilinear guide ring 10 are each guided in a straight line with respect to the housing 22 in the optical axis direction, and can be relatively rotated with respect to the cam ring 11 and move together in the optical axis direction. Are combined.

直進案内環１０は、２群レンズ移動枠８を光軸方向へ相対移動可能に直進案内している。２群レンズ移動枠８の内部には、第２レンズ群ＬＧ２を保持する２群レンズ保持枠２、シャッタ羽根Ｓを保持するシャッタブロック１００が支持されている。また、ハウジング２２に対して光軸方向に直進案内された第１繰出筒１３はさらに、第２繰出筒１２を光軸方向へ相対移動可能に直進案内している。第２繰出筒１２の内部には、１群レンズ保持枠１を介して第１レンズ群ＬＧ１が支持されている。 The rectilinear guide ring 10 guides the second group lens moving frame 8 so that it can move relative to the optical axis. Inside the second group lens moving frame 8, a second group lens holding frame 2 that holds the second lens group LG2 and a shutter block 100 that holds the shutter blades S are supported. Further, the first feeding cylinder 13 guided linearly in the optical axis direction with respect to the housing 22 further guides the second feeding cylinder 12 so as to be relatively movable in the optical axis direction. A first lens group LG <b> 1 is supported inside the second feeding cylinder 12 via a first group lens holding frame 1.

第２繰出筒１２は内径方向に突出する１群用カムフォロアＣＦ１を有し、この１群用カムフォロアＣＦ１が、カム環１１の外周面に形成した１群制御カム溝ＣＧ１に摺動可能に嵌合している。第２繰出筒１２は第１繰出筒１３を介して光軸方向に直進案内されているため、カム環１１が回転すると、１群制御カム溝ＣＧ１の形状に従って、第２繰出筒１２すなわち第１レンズ群ＬＧ１が光軸方向へ所定の軌跡で移動する。 The second feeding cylinder 12 has a first group cam follower CF1 protruding in the inner diameter direction, and the first group cam follower CF1 is slidably fitted in a first group control cam groove CG1 formed on the outer peripheral surface of the cam ring 11. doing. Since the second feeding cylinder 12 is guided linearly in the direction of the optical axis via the first feeding cylinder 13, when the cam ring 11 rotates, the second feeding cylinder 12, i.e., the first feeding cylinder 12, according to the shape of the first group control cam groove CG1. The lens group LG1 moves along a predetermined locus in the optical axis direction.

カム環１１の内周面に形成した２群制御カム溝ＣＧ２に対し、２群レンズ移動枠８の外周面に設けた２群用カムフォロアＣＦ２が係合している。２群レンズ移動枠８は直進案内環１０を介して光軸方向に直進案内されているため、カム環１１が回転すると、２群制御カム溝ＣＧ２の形状に従って、２群レンズ移動枠８すなわち第２レンズ群ＬＧ２が光軸方向へ所定の軌跡で移動する。 The second group cam follower CF2 provided on the outer peripheral surface of the second group lens moving frame 8 is engaged with the second group control cam groove CG2 formed on the inner peripheral surface of the cam ring 11. Since the second group lens moving frame 8 is linearly guided in the optical axis direction via the straight guide ring 10, when the cam ring 11 rotates, the second group lens moving frame 8, i.e., the first group moving frame 8 according to the shape of the second group control cam groove CG2. The two lens group LG2 moves along a predetermined locus in the optical axis direction.

２群レンズ移動枠８と第２繰出筒１２の間には、圧縮ばねからなる群間付勢ばね２７が挿入されており、２群レンズ移動枠８と第２繰出筒１２は互いに離間する方向に付勢されている。 A group biasing spring 27 made of a compression spring is inserted between the second group lens moving frame 8 and the second feeding cylinder 12, and the second group lens moving frame 8 and the second feeding cylinder 12 are separated from each other. Is being energized.

以上の構造からなるズームレンズ鏡筒７０は次のように動作する。図１及び図３に示す鏡筒収納状態では、図２及び図４に示す撮影状態よりも光軸方向の光学系の長さ（第１レンズ群ＬＧ１の物体側の面から撮像素子７１の撮像面までの距離）が短くなっている。この鏡筒収納状態において撮影状態への移行信号（例えば、ズームレンズ鏡筒７０が搭載されるカメラに設けたメインスイッチのオン）が入力されると、ズームモータ１５０が鏡筒繰出方向に駆動され、カム環１１が回転しながら光軸方向前方へ繰り出される。直進案内環１０と第１繰出筒１３は、カム環１１と共に前方に直進移動する。カム環１１が回転すると、その内側では、直進案内環１０を介して直進案内された２群レンズ移動枠８が、２群用カムフォロアＣＦ２と２群制御カム溝ＣＧ２の関係によって光軸方向に所定の軌跡で移動される。また、カム環１１が回転すると、該カム環１１の外側では、第１繰出筒１３を介して直進案内された第２繰出筒１２が、１群用カムフォロアＣＦ１と１群制御カム溝ＣＧ１の関係によって光軸方向に所定の軌跡で移動される。 The zoom lens barrel 70 having the above structure operates as follows. In the lens barrel storage state shown in FIGS. 1 and 3, the length of the optical system in the optical axis direction compared to the imaging state shown in FIGS. 2 and 4 (imaging of the image sensor 71 from the object side surface of the first lens group LG1). The distance to the surface is short. When a transition signal to the photographing state in this lens barrel storage state (for example, a main switch provided in a camera on which the zoom lens barrel 70 is mounted) is input, the zoom motor 150 is driven in the lens barrel feeding direction. The cam ring 11 is fed forward in the optical axis direction while rotating. The rectilinear guide ring 10 and the first feed cylinder 13 move forward together with the cam ring 11. When the cam ring 11 rotates, on the inner side, the second group lens moving frame 8 guided linearly through the straight guide ring 10 is predetermined in the optical axis direction due to the relationship between the second group cam follower CF2 and the second group control cam groove CG2. It is moved by the trajectory. Further, when the cam ring 11 rotates, the second feeding cylinder 12 guided linearly through the first feeding cylinder 13 on the outside of the cam ring 11 is related to the first group cam follower CF1 and the first group control cam groove CG1. Is moved along a predetermined locus in the optical axis direction.

すなわち、鏡筒収納状態からの第１レンズ群ＬＧ１と第２レンズ群ＬＧ２の繰出量はそれぞれ、前者が、ハウジング２２に対するカム環１１の前方移動量と、該カム環１１に対する第２繰出筒１２のカム繰出量との合算値として決まり、後者が、ハウジング２２に対するカム環１１の前方移動量と、該カム環１１に対する２群レンズ移動枠８のカム繰出量との合算値として決まる。ズーミングは、この第１レンズ群ＬＧ１と第２レンズ群ＬＧ２が互いの空気間隔を変化させながら撮影光軸Ｏに沿って移動することにより行われる。収納状態から鏡筒繰出を行うと、まず図４の上半断面に示すワイド端の繰出状態になり、さらにズームモータ１５０を鏡筒繰出方向に駆動させると、図４の下半断面に示すテレ端の繰出状態となる。テレ端とワイド端の間のズーム領域では、カム環１１は前述の定位置回転を行い、光軸方向へは進退しない。収納状態への移行信号（例えば、カメラのメインスイッチのオフ）が入力されると、ズームモータ１５０が鏡筒収納方向に駆動され、ズームレンズ鏡筒７０は以上の繰出動作とは逆の収納動作を行う。 That is, the first lens group LG1 and the second lens group LG2 are fed out from the lens barrel retracted state by the former moving amount of the cam ring 11 with respect to the housing 22 and the second feeding cylinder 12 with respect to the cam ring 11, respectively. The latter is determined as the sum of the amount of forward movement of the cam ring 11 relative to the housing 22 and the amount of cam extension of the second group lens moving frame 8 relative to the cam ring 11. Zooming is performed by moving the first lens group LG1 and the second lens group LG2 along the photographing optical axis O while changing the air interval between them. When the lens barrel is extended from the housed state, first, the wide end extended state shown in the upper half section of FIG. 4 is obtained. When the zoom motor 150 is further driven in the lens barrel extending direction, the telephoto section shown in the lower half section of FIG. The end is brought out. In the zoom region between the tele end and the wide end, the cam ring 11 performs the above-mentioned fixed position rotation and does not advance or retreat in the optical axis direction. When a storage state transition signal (for example, turning off the main switch of the camera) is input, the zoom motor 150 is driven in the lens barrel storage direction, and the zoom lens barrel 70 is retracted in the opposite manner to the above-described extension operation. I do.

また、第２繰出筒１２の前端部には、第１レンズ群ＬＧ１の前方を開閉可能なバリヤ羽根１０４が設けられており、鏡筒収納状態ではバリヤ羽根１０４が閉じており、撮影状態への繰り出し動作に応じてバリヤ羽根１０４が開かれる。 Further, a barrier blade 104 capable of opening and closing the front of the first lens group LG1 is provided at the front end portion of the second feeding cylinder 12, and the barrier blade 104 is closed when the lens barrel is housed, so that the shooting state is restored. The barrier blade 104 is opened according to the feeding operation.

第３レンズ群ＬＧ３を支持する３群レンズ枠５１は、以上のズームモータ１５０による第１レンズ群ＬＧ１及び第２レンズ群ＬＧ２の駆動とは独立して、ＡＦモータ１６０によって光軸方向に前後移動させることができる。そして、光学系がワイド端からテレ端までのズーム域にあるとき、測距手段によって得られた被写体距離情報に応じてＡＦモータ１６０を駆動することにより、第３レンズ群ＬＧ３が光軸方向に移動してフォーカシングが実行される。 The third lens group frame 51 that supports the third lens group LG3 is moved back and forth in the optical axis direction by the AF motor 160 independently of the driving of the first lens group LG1 and the second lens group LG2 by the zoom motor 150 described above. Can be made. When the optical system is in the zoom range from the wide end to the tele end, the third lens group LG3 is moved in the optical axis direction by driving the AF motor 160 according to the subject distance information obtained by the distance measuring means. Move to perform focusing.

図５以下に示すように、ハウジング２２と撮像素子ホルダ２３の間に撮影光軸Ｏと平行な３群ガイド軸５２が設けられ、この３群ガイド軸５２に対して、３群レンズ枠５１のガイド穴５１ａが摺動自在に挿通支持されている。３群レンズ枠５１は、撮影光軸Ｏを挟んでガイド穴５１ａと略対称の位置に設けた回転規制キー５１ｂを、ハウジング２２の回転規制溝２２ａに係合させて回転規制されており、３群ガイド軸５２に沿う光軸方向の直進移動のみ可能に案内されている。３群レンズ枠５１は、ハウジング２２の側部に支持されたトーションばね５５によって、光軸方向前方（被写体側）へ向けて付勢されており、この付勢力によって、３群レンズ枠５１のナット当付部５１ｃが、前方に位置するＡＦナット５４に当て付いている。 As shown in FIG. 5 and subsequent figures, a third group guide shaft 52 parallel to the photographing optical axis O is provided between the housing 22 and the image sensor holder 23, and the third group lens frame 51 has a third group guide shaft 52. A guide hole 51a is slidably inserted and supported. The third group lens frame 51 is restricted in rotation by engaging a rotation restricting key 51b provided at a position substantially symmetrical to the guide hole 51a with the photographing optical axis O interposed therebetween in the rotation restricting groove 22a of the housing 22. Only the linear movement in the optical axis direction along the group guide shaft 52 is guided. The third group lens frame 51 is urged toward the front in the optical axis direction (subject side) by a torsion spring 55 supported on the side of the housing 22, and the nut of the third group lens frame 51 is urged by this urging force. The abutting portion 51c is in contact with the AF nut 54 located in the front.

ＡＦナット５４はＡＦモータ１６０を駆動源とする駆動機構によって光軸方向に移動されるものである。ハウジング２２の上部には駆動機構組付部（ギヤ軸支持部材、ギヤ軸形成部材）２２ｂが形成され、ＡＦモータ１６０は駆動機構組付部２２ｂの前面側に固定され、該ＡＦモータ１６０の回転出力軸１６０ａに設けたピニオン１６０ｂが駆動機構組付部２２ｂの後面側に突出する。駆動機構組付部２２ｂの後面側には、ピニオン１６０ｂに噛合する中間ギヤ５７と、該中間ギヤ５７に噛合する従動ギヤ５６が軸支されていて、ＡＦモータ１６０の回転出力軸１６０ａの回転は、ピニオン１６０ｂと中間ギヤ５７を介して、従動ギヤ５６と同軸で一体に回転するスクリューシャフト５８に伝達される。スクリューシャフト５８は、シャフト回転軸５８ａを中心として回転自在に、ハウジング２２と撮像素子ホルダ２３の間に支持されていて、図１０や図１１に示すように、シャフト回転軸５８ａ上に形成した非円形断面の軸部と、従動ギヤ５６に形成した非円形断面穴の嵌合によって、従動ギヤ５６とスクリューシャフト５８が一体化されている。スクリューシャフト５８の外周面には螺旋状の送りねじが形成されていて、この送りねじ形成部分が、ナット当付部５１ｃに形成した貫通穴を通して該ナット当付部５１ｃの前方に突出し、ＡＦナット５４のねじ穴に螺合している。ＡＦナット５４は、３群レンズ枠５１に設けた回転規制突起５１ｄによって、光軸方向に直進案内（回転規制）されていて、スクリューシャフト５８が回転すると、その軸方向に直進移動される。 The AF nut 54 is moved in the optical axis direction by a drive mechanism using the AF motor 160 as a drive source. A drive mechanism assembly portion (gear shaft support member, gear shaft forming member) 22b is formed on the upper portion of the housing 22, and the AF motor 160 is fixed to the front side of the drive mechanism assembly portion 22b, and the AF motor 160 rotates. A pinion 160b provided on the output shaft 160a protrudes to the rear surface side of the drive mechanism assembly portion 22b. An intermediate gear 57 meshed with the pinion 160b and a driven gear 56 meshed with the intermediate gear 57 are pivotally supported on the rear surface side of the drive mechanism assembly portion 22b, and the rotation of the rotation output shaft 160a of the AF motor 160 is rotated. , The pinion 160 b and the intermediate gear 57 are transmitted to the screw shaft 58 that rotates coaxially with the driven gear 56. The screw shaft 58 is supported between the housing 22 and the image sensor holder 23 so as to be rotatable about the shaft rotation shaft 58a. As shown in FIGS. 10 and 11, the screw shaft 58 is formed on the shaft rotation shaft 58a. The driven gear 56 and the screw shaft 58 are integrated by fitting a shaft portion having a circular cross section and a non-circular cross sectional hole formed in the driven gear 56. A spiral feed screw is formed on the outer peripheral surface of the screw shaft 58, and this feed screw forming portion projects forward of the nut abutting portion 51c through a through hole formed in the nut abutting portion 51c, and an AF nut. 54 is screwed into the screw hole. The AF nut 54 is linearly guided (rotation restricted) in the optical axis direction by a rotation restricting projection 51d provided on the third group lens frame 51. When the screw shaft 58 rotates, the AF nut 54 moves straight in the axial direction.

３群レンズ枠５１は、トーションばね５５の付勢力でナット当付部５１ｃがＡＦナット５４に当て付くことによって前方への移動が規制され、３群レンズ枠５１の光軸方向での前後位置はＡＦナット５４に依存して決まる。例えば、ＡＦモータ１６０によってスクリューシャフト５８を回転させる上記の駆動機構によってＡＦナット５４を光軸方向前方に移動させると、ＡＦナット５４の移動分だけ、トーションばね５５の付勢力によって３群レンズ枠５１が追随して前方に移動する。逆に、ＡＦナット５４を光軸方向後方に移動させると、該ＡＦナット５４がナット当付部５１ｃを押し込み、３群レンズ枠５１はトーションばね５５の付勢力に抗して後方へ移動される。つまり、ＡＦナット５４の移動により、第３レンズ群ＬＧ３を保持した３群レンズ枠５１の光軸方向位置が変化する。 The third group lens frame 51 is restricted from moving forward by the nut abutting portion 51c being applied to the AF nut 54 by the urging force of the torsion spring 55, and the front / rear position of the third group lens frame 51 in the optical axis direction is It depends on the AF nut 54. For example, when the AF nut 54 is moved forward in the optical axis direction by the drive mechanism that rotates the screw shaft 58 by the AF motor 160, the third group lens frame 51 is moved by the urging force of the torsion spring 55 by the amount of movement of the AF nut 54. Follows and moves forward. Conversely, when the AF nut 54 is moved rearward in the optical axis direction, the AF nut 54 pushes the nut abutting portion 51 c, and the third group lens frame 51 is moved rearward against the urging force of the torsion spring 55. . That is, the movement of the AF nut 54 changes the position in the optical axis direction of the third group lens frame 51 holding the third lens group LG3.

図１２に示すように、ハウジング２２における駆動機構組付部２２ｂの後面側には、ピニオン１６０ｂを格納するピニオン格納穴２２ｃと、中間ギヤ５７を格納する中間ギヤ格納凹部（筒状凹部）２２ｄと、従動ギヤ５６及びスクリューシャフト５８を格納するスクリューシャフト格納空間２２ｅが形成されている。スクリューシャフト格納空間２２ｅの前端部には、スクリューシャフト５８のシャフト回転軸５８ａの前端部を回転可能に軸支する軸穴２２ｆが形成されている。ピニオン格納穴２２ｃは、ＡＦモータ１６０の回転出力軸１６０ａを挿通させるために光軸方向に貫通しているのに対し、中間ギヤ格納凹部２２ｄは底面２２ｄ-１を有する筒状の有底穴となっている。そして、この有底の中間ギヤ格納凹部２２ｄの略中央に、光軸方向後方へ向けて突出し、中間ギヤ５７を軸支するギヤ軸突起２２ｇが設けられている。図７、図８、図１３及び図１４に示すように、中間ギヤ５７は、ピニオン１６０ｂに噛み合う大径ギヤ部５７ａと、従動ギヤ５６に噛み合う小径ギヤ部５７ｂが同軸上に位置する二段平歯ギヤであり、その中心を軸方向に貫通する軸穴５７ｃが形成されている。ギヤ軸突起２２ｇは、この軸穴５７ｃに対応する内径サイズの大径中間部２２ｇ-１と、大径中間部２２ｇ-１よりも小径の小径先端部２２ｇ-２と、中間ギヤ格納凹部２２ｄの底面２２ｄ-１上に位置し大径中間部２２ｇ-１よりも大径の円板状の基部２２ｇ-３を有している。中間ギヤ５７の大径ギヤ部５７ａと小径ギヤ部５７ｂには、ギヤ軸突起２２ｇに軸支された状態で、ギヤ軸突起２２ｇの軸線と直交する軸直交端面５７ｄ、５７ｅが形成されている。 As shown in FIG. 12, on the rear surface side of the drive mechanism assembly portion 22b in the housing 22, a pinion storage hole 22c for storing the pinion 160b, an intermediate gear storage recess (tubular recess) 22d for storing the intermediate gear 57, and A screw shaft storage space 22e for storing the driven gear 56 and the screw shaft 58 is formed. A shaft hole 22f that rotatably supports the front end portion of the shaft rotation shaft 58a of the screw shaft 58 is formed in the front end portion of the screw shaft storage space 22e. The pinion storage hole 22c penetrates in the optical axis direction so as to allow the rotation output shaft 160a of the AF motor 160 to pass therethrough, whereas the intermediate gear storage recess 22d has a cylindrical bottomed hole having a bottom surface 22d-1. It has become. A gear shaft projection 22g that protrudes rearward in the optical axis direction and supports the intermediate gear 57 is provided at the approximate center of the bottomed intermediate gear storage recess 22d. As shown in FIGS. 7, 8, 13, and 14, the intermediate gear 57 is a two-stage spur gear in which a large-diameter gear portion 57 a that meshes with the pinion 160 b and a small-diameter gear portion 57 b that meshes with the driven gear 56 are positioned coaxially. A shaft hole 57c that is a gear and penetrates the center in the axial direction is formed. The gear shaft protrusion 22g includes a large-diameter intermediate portion 22g-1 having an inner diameter corresponding to the shaft hole 57c, a small-diameter tip portion 22g-2 having a smaller diameter than the large-diameter intermediate portion 22g-1, and an intermediate gear storage recess 22d. It has a disk-like base portion 22g-3 which is located on the bottom surface 22d-1 and has a larger diameter than the large diameter intermediate portion 22g-1. The large-diameter gear portion 57a and the small-diameter gear portion 57b of the intermediate gear 57 are formed with axial orthogonal end surfaces 57d and 57e orthogonal to the axis of the gear shaft protrusion 22g while being supported by the gear shaft protrusion 22g.

撮像素子ホルダ２３は駆動機構組付部２２ｂに対向するギヤ列抜止部（ギヤ軸支持部材、抜止部材）２３ａを有し、図５に示すように、このギヤ列抜止部２３ａには、ＡＦモータ１６０の回転出力軸１６０ａの先端部を回転可能に支持する軸穴２３ｂと、ギヤ軸突起２２ｇの小径先端部２２ｇ-２が嵌合する軸固定穴２３ｃと、スクリューシャフト５８のシャフト回転軸５８ａの後端部を回転可能に支持する軸穴２３ｄが形成されている。 The image sensor holder 23 has a gear train retaining portion (gear shaft support member, retaining member) 23a facing the drive mechanism assembly portion 22b. As shown in FIG. 5, the gear train retaining portion 23a includes an AF motor. The shaft hole 23b that rotatably supports the tip of the rotation output shaft 160a of 160, the shaft fixing hole 23c into which the small-diameter tip 22g-2 of the gear shaft protrusion 22g is fitted, and the shaft rotation shaft 58a of the screw shaft 58 A shaft hole 23d for rotatably supporting the rear end portion is formed.

よって、撮像素子ホルダ２３をハウジング２２の後部に取り付けた状態では、ピニオン１６０ｂ、中間ギヤ５７、従動ギヤ５６及びスクリューシャフト５８がそれぞれ、駆動機構組付部２２ｂとギヤ列抜止部２３ａの間で回転可能に保持される。このとき、ピニオン１６０ｂの回転中心であるＡＦモータ１６０の回転出力軸１６０ａと、中間ギヤ５７の回転中心であるギヤ軸突起２２ｇと、従動ギヤ５６及びスクリューシャフト５８の回転中心であるシャフト回転軸５８ａは、それぞれの軸線が撮影光軸Ｏと略平行となる。 Therefore, in a state where the image sensor holder 23 is attached to the rear portion of the housing 22, the pinion 160b, the intermediate gear 57, the driven gear 56, and the screw shaft 58 are rotated between the drive mechanism assembly portion 22b and the gear train retaining portion 23a, respectively. Held possible. At this time, the rotation output shaft 160a of the AF motor 160 that is the rotation center of the pinion 160b, the gear shaft protrusion 22g that is the rotation center of the intermediate gear 57, and the shaft rotation shaft 58a that is the rotation center of the driven gear 56 and the screw shaft 58. Each axis is substantially parallel to the photographing optical axis O.

ギヤ列を構成する中間ギヤ５７は、中間ギヤ付勢ばね（ばね部材）５０によってギヤ軸突起２２ｇの軸線方向へ付勢されることにより、駆動機構組付部２２ｂとギヤ列抜止部２３ａの間で安定保持されている。中間ギヤ付勢ばね５０は、薄い金属製の板状体からなり、ギヤ軸突起２２ｇの大径中間部２２ｇ-１が挿通される円形穴（開口）５０ａを有する環状の中心座部（ギヤ当接部）５０ｂと、この中心座部５０ｂを中心とする放射方向に延出された３つの弾性支持脚部５０ｃとを有している。 The intermediate gear 57 constituting the gear train is urged in the axial direction of the gear shaft projection 22g by an intermediate gear urging spring (spring member) 50, whereby between the drive mechanism assembly portion 22b and the gear train retaining portion 23a. And is held stable. The intermediate gear biasing spring 50 is made of a thin metal plate, and has an annular center seat (gear contact) having a circular hole (opening) 50a through which the large diameter intermediate portion 22g-1 of the gear shaft projection 22g is inserted. Contact portion) 50b and three elastic support legs 50c extending in a radial direction centering on the central seat portion 50b.

図１１や図１２のようにギヤ軸突起２２ｇの軸線に沿う方向（軸線延長上）から見て、中間ギヤ付勢ばね５０における３つの弾性支持脚部５０ｃは、それぞれが略同じ長さで略同じ形状をしており、中心座部５０ｂを中心とする周方向に略等角度間隔で配置されている。また、図１３及び図１４に示すように、中心座部５０ｂはギヤ軸突起２２ｇの軸線と略直交する平面内に位置しており、それぞれの弾性支持脚部５０ｃは、中心座部５０ｂから離れるにつれて徐々に中間ギヤ格納凹部２２ｄの底面２２ｄ-１に接近する傾斜部５０ｃ-１と、中間ギヤ格納凹部２２ｄの底面２２ｄ-１に当接される５０ｃ-２先端当接部５０ｃ-２とを有している。 As shown in FIGS. 11 and 12, when viewed from the direction along the axis of the gear shaft protrusion 22g (on the extension of the axis), the three elastic support legs 50c of the intermediate gear biasing spring 50 are each substantially the same length and substantially the same. It has the same shape and is arranged at substantially equal angular intervals in the circumferential direction centering on the central seat portion 50b. As shown in FIGS. 13 and 14, the center seat portion 50b is located in a plane substantially orthogonal to the axis of the gear shaft projection 22g, and each elastic support leg portion 50c is separated from the center seat portion 50b. As shown, an inclined portion 50c-1 that gradually approaches the bottom surface 22d-1 of the intermediate gear storage recess 22d and a 50c-2 tip contact portion 50c-2 that contacts the bottom surface 22d-1 of the intermediate gear storage recess 22d. Have.

図１２に示すように、ハウジング２２の駆動機構組付部２２ｂには、３つの回転規制凹部（回転規制部）２２ｈが、中間ギヤ格納凹部２２ｄの内壁面に臨ませて形成されている。これら３つの回転規制凹部２２ｈは、中間ギヤ格納凹部２２ｄに隣接するピニオン格納穴２２ｃやスクリューシャフト格納空間２２ｅとは重ならない位置に、周方向へ略等間隔で形成されており、中間ギヤ付勢ばね５０の３つの弾性支持脚部５０ｃの先端当接部５０ｃ-２を係合させて、その回転を規制するものである。詳細には、駆動機構組付部２２ｂには、ギヤ列抜止部２３ａ側の位置決め穴２３ｅ（図５）に係合する位置決めボス２２ｉが突設されており、回転規制凹部２２ｈは、ギヤ軸突起２２ｇを中心として、該位置決めボス２２ｉとピニオン格納穴２２ｃの間、該位置決めボス２２ｉとスクリューシャフト格納空間２２ｅの間、ピニオン格納穴２２ｃとスクリューシャフト格納空間２２ｅの間の３つの位置に形成されている。 As shown in FIG. 12, in the drive mechanism assembly portion 22b of the housing 22, three rotation restricting recesses (rotation restricting portions) 22h are formed so as to face the inner wall surface of the intermediate gear storage recess 22d. These three rotation restricting recesses 22h are formed at substantially equal intervals in the circumferential direction at positions that do not overlap with the pinion storage hole 22c adjacent to the intermediate gear storage recess 22d and the screw shaft storage space 22e. The front end contact portions 50c-2 of the three elastic support legs 50c of the spring 50 are engaged to restrict the rotation thereof. Specifically, a positioning boss 22i that engages with a positioning hole 23e (FIG. 5) on the gear train retaining portion 23a side protrudes from the drive mechanism assembling portion 22b, and the rotation restricting recess 22h includes a gear shaft protrusion. Centering on 22g, it is formed at three positions between the positioning boss 22i and the pinion storage hole 22c, between the positioning boss 22i and the screw shaft storage space 22e, and between the pinion storage hole 22c and the screw shaft storage space 22e. Yes.

図１２から図１４に示すように、中間ギヤ付勢ばね５０は、中間ギヤ５７を組み付ける前にギヤ軸突起２２ｇに対して円形穴５０ａを挿通させ、３つの弾性支持脚部５０ｃをそれぞれ回転規制凹部２２ｈに係合させて、中間ギヤ格納凹部２２ｄ内に取り付けられる。３つの弾性支持脚部５０ｃと３つの回転規制凹部２２ｈはそれぞれ、ギヤ軸突起２２ｇを中心として等角度（１２０°間隔）で設けられており、かつそれぞれの弾性支持脚部５０ｃの長さと形状が同じであるため、いずれの弾性支持脚部５０ｃをいずれの回転規制凹部２２ｈに対して係合させてもよい。すなわち、中間ギヤ付勢ばね５０は、周方向に３箇所存在する任意の角度位置で組み付けることができる。 As shown in FIG. 12 to FIG. 14, the intermediate gear biasing spring 50 inserts the circular hole 50 a into the gear shaft protrusion 22 g before assembling the intermediate gear 57 and restricts the three elastic support legs 50 c respectively. It is engaged with the recess 22h and attached in the intermediate gear storage recess 22d. The three elastic support legs 50c and the three rotation restricting recesses 22h are provided at equal angles (at intervals of 120 °) around the gear shaft protrusion 22g, and the length and shape of each elastic support leg 50c are the same. Since they are the same, any elastic support leg 50c may be engaged with any rotation restricting recess 22h. That is, the intermediate gear biasing spring 50 can be assembled at arbitrary angular positions that exist in three locations in the circumferential direction.

図１３に示す中間ギヤ付勢ばね５０の自由状態では、中間ギヤ格納凹部２２ｄの底面２２ｄ-１に対する弾性支持脚部５０ｃの傾斜部５０ｃ-１の立ち上がり角度が大きくなっており、中心座部５０ｂは中間ギヤ格納凹部２２ｄの底面２２ｄ-１から大きく離間している。このとき、弾性支持脚部５０ｃの先端当接部５０ｃ-２は中心座部５０ｂと略平行をなしている。続いて、大径ギヤ部５７ａ側を先頭にして中間ギヤ５７の軸穴５７ｃをギヤ軸突起２２ｇに挿通させると、軸直交端面５７ｄが中心座部５０ｂに当接して支持される。このとき小径ギヤ部５７ｂ側の軸直交端面５７ｅは、ギヤ軸突起２２ｇにおける大径中間部２２ｇ-１と小径先端部２２ｇ-２の境界部よりも後方（図１３の上方）に位置している。そして、撮像素子ホルダ２３をハウジング２２に固定すると、図１４のように、ギヤ軸突起２２ｇの小径先端部２２ｇ-２が軸固定穴２３ｃに挿入され、ギヤ列抜止部２３ａの前面が軸直交端面５７ｅを押圧し、中間ギヤ付勢ばね５０の各弾性支持脚５０ｃを中間ギヤ格納凹部２２ｄの底面２２ｄ-１に接近させる方向に弾性変形させながら、中間ギヤ５７が押し込まれる。 In the free state of the intermediate gear biasing spring 50 shown in FIG. 13, the rising angle of the inclined portion 50c-1 of the elastic support leg portion 50c with respect to the bottom surface 22d-1 of the intermediate gear storage recess 22d is large, and the center seat portion 50b. Is far away from the bottom surface 22d-1 of the intermediate gear storage recess 22d. At this time, the tip contact portion 50c-2 of the elastic support leg portion 50c is substantially parallel to the central seat portion 50b. Subsequently, when the shaft hole 57c of the intermediate gear 57 is inserted through the gear shaft projection 22g with the large-diameter gear portion 57a side as the head, the shaft orthogonal end surface 57d is in contact with and supported by the center seat portion 50b. At this time, the shaft orthogonal end surface 57e on the small-diameter gear portion 57b side is located behind (upward in FIG. 13) the boundary between the large-diameter intermediate portion 22g-1 and the small-diameter tip portion 22g-2 in the gear shaft protrusion 22g. . When the image sensor holder 23 is fixed to the housing 22, as shown in FIG. 14, the small-diameter tip 22g-2 of the gear shaft projection 22g is inserted into the shaft fixing hole 23c, and the front surface of the gear train retaining portion 23a is the axis orthogonal end surface. The intermediate gear 57 is pushed in while pressing each elastic support leg 50c of the intermediate gear biasing spring 50 in a direction to approach the bottom surface 22d-1 of the intermediate gear storage recess 22d.

ギヤ軸突起２２ｇの大径中間部２２ｇ-１の軸方向長さは、同方向への中間ギヤ５７の軸穴５７ｃよりも長く、図１４のように中間ギヤ５７が押し込まれた状態で、大径ギヤ部５７ａ側の軸直交端面５７ｄは、ギヤ軸突起２２ｇの基部２２ｇ-３や中間ギヤ格納凹部２２ｄの底面２２ｄ-１には当て付いておらず、中間ギヤ５７は若干の軸方向移動が許容されている。そして、中間ギヤ付勢ばね５０の３つの弾性支持脚部５０ｃが弾性変形から復元しようとする力によって、中間ギヤ５７は、小径ギヤ部５７ｂ側の軸直交端面５７ｅをギヤ列抜止部２３ａに当て付ける方向に付勢されるため、その軸方向位置が安定する。つまり、中間ギヤ付勢ばね５０の付勢力によって中間ギヤ５７のがたつき、ばたつきが防がれ、ＡＦモータ１６０の駆動時における異音の発生を抑制することができる。 The axial length of the large-diameter intermediate portion 22g-1 of the gear shaft protrusion 22g is longer than the shaft hole 57c of the intermediate gear 57 in the same direction, and is large when the intermediate gear 57 is pushed in as shown in FIG. The shaft orthogonal end surface 57d on the diameter gear portion 57a side does not contact the base portion 22g-3 of the gear shaft protrusion 22g and the bottom surface 22d-1 of the intermediate gear storage recess 22d, and the intermediate gear 57 is slightly moved in the axial direction. Is allowed. Then, due to the force that the three elastic support legs 50c of the intermediate gear biasing spring 50 attempt to recover from the elastic deformation, the intermediate gear 57 applies the axis orthogonal end surface 57e on the small-diameter gear portion 57b side to the gear train retaining portion 23a. Since it is biased in the attaching direction, its axial position is stabilized. That is, rattling and fluttering of the intermediate gear 57 are prevented by the biasing force of the middle gear biasing spring 50, and the generation of abnormal noise when the AF motor 160 is driven can be suppressed.

中間ギヤ付勢ばね５０においては、中心座部５０ｂから放射状に延出した３つの弾性支持脚部５０ｃの間に、ＡＦモータ１６０の回転出力軸１６０ａとピニオン１６０ｂ、従動ギヤ５６とスクリューシャフト５８、といった他の回転部材やその軸を配しているため、これらの回転部材との干渉を生じることなく、スペース効率に優れたばね配置が可能となっている。詳細には、図１１のようにギヤ軸突起２２ｇの軸線方向に沿って正面視したとき、ギヤ機構における原動側のギヤであるピニオン１６０ｂの一部とその回転中心である回転出力軸１６０ａは、中間ギヤ付勢ばね５０の３つの弾性支持脚部５０ｃ-Ａ、５０ｃ-Ｂ及び５０ｃ-Ｃの先端を結んだギヤ軸突起２２ｇを中心とする先端円Ｒと、隣り合う一対の弾性支持脚部５０ｃ-Ａ、５０ｃ-Ｂとに囲まれる脚間空間内に位置している。同様に、ギヤ機構における従動側のギヤである従動ギヤ５６の一部とスクリューシャフト５８の一部は、上記先端円Ｒと、一対の弾性支持脚部５０ｃ-Ｂ、５０ｃ-Ｃとに囲まれた脚間空間内に位置している。ピニオン１６０ｂを支持する回転出力軸１６０ａや、従動ギヤ５６を支持するギヤ軸は、中間ギヤ５７を挟む駆動機構組付部２２ｂとギヤ列抜止部２３ａのうち駆動機構組付部２２ｂ側から突出し、図１３や図１４のようにギヤ軸突起２２ｇの軸線と直交する方向から見て、弾性支持脚部５０ｃ-Ａと弾性支持脚部５０ｃ-Ｂの間や、弾性支持脚部５０ｃ-Ｂと弾性支持脚部５０ｃ-Ｃの間を通って中間ギヤ５７の側方へ延設されている。 In the intermediate gear biasing spring 50, the rotation output shaft 160a and pinion 160b of the AF motor 160, the driven gear 56 and the screw shaft 58 are interposed between three elastic support legs 50c extending radially from the center seat 50b. Since other rotating members such as, and their shafts are arranged, spring arrangement with excellent space efficiency is possible without causing interference with these rotating members. Specifically, when viewed from the front along the axial direction of the gear shaft protrusion 22g as shown in FIG. 11, a part of the pinion 160b which is the driving side gear in the gear mechanism and the rotation output shaft 160a which is the rotation center thereof are: A tip circle R centering on the gear shaft projection 22g connecting the tips of the three elastic support legs 50c-A, 50c-B and 50c-C of the intermediate gear biasing spring 50 and a pair of adjacent elastic support legs It is located in the space between legs surrounded by 50c-A and 50c-B. Similarly, a part of the driven gear 56 that is a driven side gear in the gear mechanism and a part of the screw shaft 58 are surrounded by the tip circle R and the pair of elastic support legs 50c-B and 50c-C. Located in the space between the legs. The rotation output shaft 160a that supports the pinion 160b and the gear shaft that supports the driven gear 56 protrude from the drive mechanism assembly portion 22b side of the drive mechanism assembly portion 22b and the gear train retaining portion 23a sandwiching the intermediate gear 57, 13 and 14, when viewed from the direction orthogonal to the axis of the gear shaft projection 22g, the elastic support leg 50c-A and the elastic support leg 50c-B, or between the elastic support leg 50c-B and the elasticity It extends to the side of the intermediate gear 57 through between the support legs 50c-C.

例えば、本実施形態とは異なり、中間ギヤ付勢ばね５０に代えて、図１１の先端円Ｒを外形とした円形のスプリングワッシャを付勢部材として用いることを想定すると、このスプリングワッシャとの干渉を避けるため、先端円Ｒよりも外側の（ギヤ軸突起２２ｇから遠い）位置にピニオン１６０ｂや従動ギヤ５６を配置しなければならず、本実施形態のようなコンパクトなギヤ配置にすることができない。コンパクトなギヤ配置にするためにスプリングワッシャを小径なものに代えると、前述の通り、ばね部材は小さくなるほど単位変位量あたりの荷重変動が大きくなるため、部品の寸法誤差を小さくするための厳密な精度管理が要求されるようになり、製造コストが高くなってしまう。 For example, unlike this embodiment, assuming that a circular spring washer having an outer shape of the tip circle R in FIG. 11 is used as the urging member instead of the intermediate gear urging spring 50, interference with the spring washer is assumed. Therefore, the pinion 160b and the driven gear 56 must be disposed outside the tip circle R (distant from the gear shaft protrusion 22g), and a compact gear arrangement as in this embodiment cannot be achieved. . If the spring washer is replaced with a smaller one in order to achieve a compact gear arrangement, as described above, the smaller the spring member, the greater the load fluctuation per unit displacement amount. Precision management is required, and the manufacturing cost is increased.

これに対し本実施形態の中間ギヤ付勢ばね５０では、ピニオン１６０ｂや従動ギヤ５６などとの干渉を生じることなく、弾性支持脚部５０ｃの長さや付勢力を自由に設定することができる。よって、製品ごとの荷重変動を抑制するために弾性支持脚部５０ｃを長くした場合でも、ピニオン１６０ｂや従動ギヤ５６の位置を変更する必要がなく、コンパクトな構造を維持しつつ、中間ギヤ５７に対する付勢力の安定性を得ることができる。そして、弾性支持脚部５０ｃを長くすることによって荷重変動が抑制された中間ギヤ付勢ばね５０は、精度管理が容易となり安価な供給が可能となる。 On the other hand, in the intermediate gear biasing spring 50 of the present embodiment, the length and biasing force of the elastic support leg 50c can be freely set without causing interference with the pinion 160b, the driven gear 56, and the like. Therefore, even when the elastic support leg 50c is lengthened in order to suppress the load fluctuation for each product, it is not necessary to change the positions of the pinion 160b and the driven gear 56, and the intermediate gear 57 is maintained while maintaining a compact structure. The stability of the urging force can be obtained. The intermediate gear biasing spring 50, in which the load variation is suppressed by elongating the elastic support leg 50c, is easy to manage with accuracy and can be supplied at a low cost.

また、中間ギヤ付勢ばね５０は、ハウジング２２側の回転規制凹部２２ｈとの係合により回転が規制されているため、中間ギヤ５７の回転時に連れ回りすることがなく、ピニオン１６０ｂや従動ギヤ５６などとの干渉を確実に防ぐことができる。 Further, since the rotation of the intermediate gear biasing spring 50 is restricted by the engagement with the rotation restricting recess 22 h on the housing 22 side, the intermediate gear urging spring 50 does not rotate when the intermediate gear 57 rotates, and the pinion 160 b and the driven gear 56 are not rotated. Can be reliably prevented.

以上、図示実施形態に基づき本発明を説明したが、本発明は、この実施形態に限定されるものではない。例えば、支持安定性とスペース効率の両立という観点からは、実施形態のように中間ギヤ付勢ばね５０に３つの弾性支持脚部５０ｃを設けることが好ましいが、弾性支持脚部を４つ以上の数にすることも可能である。 As mentioned above, although this invention was demonstrated based on illustration embodiment, this invention is not limited to this embodiment. For example, from the viewpoint of achieving both support stability and space efficiency, it is preferable to provide the intermediate gear biasing spring 50 with three elastic support legs 50c as in the embodiment, but the number of elastic support legs is four or more. It can also be a number.

また、前述のように、中間ギヤ付勢ばね５０に設ける複数の弾性支持脚部５０ｃを、同じ長さ及び形状にして等角度間隔で配することで、組み付け性の自由度を高くすることができるが、弾性支持脚部に関するこれらの諸条件を異ならせることも可能である。例えば、隣り合う弾性支持脚部の長さが異なる場合には、短い方の弾性支持脚部よりも内側（短い弾性支持脚部の先端を通る、中間ギヤのギヤ軸を中心とした円よりも内側）の脚間領域まで、中間ギヤの前後ギヤの少なくとも一部を進入させて配置することで、前述したコンパクト化の効果を得ることができる。 Further, as described above, by arranging the plurality of elastic support legs 50c provided on the intermediate gear biasing spring 50 with the same length and shape at equal angular intervals, the degree of freedom in assembling can be increased. However, it is possible to vary these conditions for the elastic support legs. For example, when the lengths of the adjacent elastic support legs are different, the inner side of the shorter elastic support leg (rather than the circle passing through the tip of the short elastic support leg and centering on the gear shaft of the intermediate gear) By arranging at least a part of the front and rear gears of the intermediate gear up to the inner (inter) leg region, the above-described compacting effect can be obtained.

また、実施形態の中間ギヤ付勢ばね５０の中心座部５０ｂは、ギヤ軸突起２２ｇの大径中間部２２ｇ-１を挿通させる円形穴５０ａを有する円形環状をしているが、ばね部材におけるギヤ当接部の形状はこれに限定されず、例えばＣ字状などにすることも可能である。 Further, the center seat portion 50b of the intermediate gear biasing spring 50 of the embodiment has a circular ring shape having a circular hole 50a through which the large diameter intermediate portion 22g-1 of the gear shaft projection 22g is inserted. The shape of the contact portion is not limited to this, and may be a C-shape, for example.

また、実施形態では、ハウジング２２の駆動機構組付部２２ｂにギヤ軸突起２２ｇが突出形成され、このギヤ軸突起２２ｇの先端部が、撮像素子ホルダ２３のギヤ列抜止部２３ａに形成した軸固定穴２３ｃに対して挿入固定された構造となっており、駆動機構組付部２２ｂとギヤ列抜止部２３ａが、ギヤ軸突起２２ｇの両端部を支持するギヤ軸支持部材を構成している。本発明においては、この実施形態とは別に、ギヤ軸の端部を支持する軸穴を、駆動機構組付部２２ｂとギヤ列抜止部２３ａにそれぞれ形成し、この軸穴に支持されるギヤ軸を、中間ギヤ５７に一体形成したギヤ軸、あるいは中間ギヤ５７とは別体の独立したギヤ軸によって構成することも可能である。すなわち、本発明では、ギヤ軸支持部材と中間ギヤのギヤ軸との具体的態様を限定するものではなく、実施形態のように、ギヤ軸が一体に形成された部材（駆動機構組付部２２ｂ）と抜止部材（ギヤ列抜止部２３ａ）の組み合わせによってギヤ軸支持部材を構成してもよいし、それぞれがギヤ軸端部支持用の軸穴を有する一対の軸穴形成部材でギヤ軸支持部材を構成してもよい。 In the embodiment, a gear shaft projection 22 g is formed to protrude from the drive mechanism assembly portion 22 b of the housing 22, and a tip end portion of the gear shaft projection 22 g is fixed to the gear row retaining portion 23 a of the image sensor holder 23. The drive mechanism assembly portion 22b and the gear train retaining portion 23a constitute a gear shaft support member that supports both ends of the gear shaft protrusion 22g. In the present invention, apart from this embodiment, a shaft hole for supporting the end of the gear shaft is formed in each of the drive mechanism assembly portion 22b and the gear train retaining portion 23a, and the gear shaft supported by this shaft hole. Can be constituted by a gear shaft integrally formed with the intermediate gear 57 or an independent gear shaft separate from the intermediate gear 57. That is, in the present invention, the specific mode of the gear shaft support member and the gear shaft of the intermediate gear is not limited, and a member (drive mechanism assembly portion 22b) in which the gear shaft is integrally formed as in the embodiment. ) And a retaining member (gear train retaining portion 23a) may constitute a gear shaft supporting member, or each of them is a pair of shaft hole forming members each having a shaft hole for supporting a gear shaft end portion. May be configured.

また、実施形態では、ハウジング２２の駆動機構組付部２２ｂと中間ギヤ５７の間に中間ギヤ付勢ばね５０を設け、中間ギヤ５７がギヤ列抜止部２３ａへの接近方向に付勢されているが、中間ギヤ付勢ばね５０の配置と付勢方向を逆にし、ギヤ列抜止部２３ａと中間ギヤ５７の間に中間ギヤ付勢ばね５０を設け、駆動機構組付部２２ｂへの接近方向へ中間ギヤ５７を付勢するような構成も可能である。この場合、ピニオン１６０ｂを支持する回転出力軸１６０ａや、従動ギヤ５６を支持するギヤ軸は、駆動機構組付部２２ｂ側ではなくギヤ列抜止部２３ａ側から突出して、中間ギヤ付勢ばね５０に設けた弾性支持脚部５０ｃの間を通って中間ギヤ５７の側方へ延設される。
In the embodiment, the intermediate gear urging spring 50 is provided between the drive mechanism assembly portion 22b of the housing 22 and the intermediate gear 57, and the intermediate gear 57 is urged in the approaching direction to the gear train retaining portion 23a. However, the arrangement and the urging direction of the intermediate gear urging spring 50 are reversed, the intermediate gear urging spring 50 is provided between the gear train retaining portion 23a and the intermediate gear 57, and in the direction toward the drive mechanism assembling portion 22b. A configuration in which the intermediate gear 57 is biased is also possible. In this case, the rotation output shaft 160a that supports the pinion 160b and the gear shaft that supports the driven gear 56 protrude from the gear train retaining portion 23a side, not the drive mechanism assembly portion 22b side, to the intermediate gear biasing spring 50. It extends between the provided elastic support legs 50c to the side of the intermediate gear 57.

また、本発明は、実施形態におけるＡＦレンズ群の駆動機構のように、高速で間欠的に駆動されるタイプのギヤ機構に特に適しているが、それ以外の駆動機構のギヤ支持構造としても適用が可能である。 Further, the present invention is particularly suitable for a gear mechanism that is intermittently driven at a high speed, such as the AF lens group driving mechanism in the embodiment, but is also applicable to a gear support structure for other driving mechanisms. Is possible.

本発明を適用したズームレンズ鏡筒の収納状態の外観斜視図である。It is an external appearance perspective view of the storage state of the zoom lens barrel to which the present invention is applied. 同ズームレンズ鏡筒の撮影状態の外観斜視図である。It is an external appearance perspective view of the photographing state of the zoom lens barrel. 同ズームレンズ鏡筒の収納状態の断面図である。It is sectional drawing of the accommodation state of the zoom lens barrel. 同ズームレンズ鏡筒の撮影状態の断面図である。It is sectional drawing of the imaging state of the zoom lens barrel. ３群レンズ枠の駆動機構の前方分解斜視図である。It is a front exploded perspective view of the drive mechanism of a 3 group lens frame. ３群レンズ枠の駆動機構の後方分解斜視図である。It is a back disassembled perspective view of the drive mechanism of a 3 group lens frame. ３群レンズ枠の駆動機構を構成する中間ギヤと中間ギヤ付勢ばねの前方斜視図である。FIG. 6 is a front perspective view of an intermediate gear and an intermediate gear biasing spring that constitute a drive mechanism for a third group lens frame. ３群レンズ枠の駆動機構を構成する中間ギヤと中間ギヤ付勢ばねの後方斜視図である。FIG. 6 is a rear perspective view of an intermediate gear and an intermediate gear biasing spring that constitute a drive mechanism for the third group lens frame. ３群レンズ枠とその駆動機構を主として示した、ズームレンズ鏡筒の正面図である。3 is a front view of a zoom lens barrel mainly showing a third group lens frame and a driving mechanism thereof. FIG. ３群レンズ枠とその駆動機構を主として示した、ズームレンズ鏡筒の背面図である。It is a rear view of a zoom lens barrel mainly showing a third group lens frame and its driving mechanism. 図１０における３群レンズ枠の駆動機構付近を拡大した図である。It is the figure which expanded the drive mechanism vicinity of the 3 group lens frame in FIG. ハウジングの駆動機構組付部に対して中間ギヤ付勢ばねのみを組み付けた状態の拡大図である。FIG. 5 is an enlarged view of a state where only an intermediate gear biasing spring is assembled to the drive mechanism assembly portion of the housing. 中間ギヤの組み付け前における、ハウジングの駆動機構組付部、撮像素子ホルダのギヤ列抜止部、中間ギヤ及び中間ギヤ付勢ばねの関係を示す、ギヤ軸突起の軸線に沿う方向の断面図である。It is sectional drawing in the direction along the axis line of a gear shaft protrusion which shows the relationship between the drive-mechanism assembly | attachment part of a housing, the gear train locking part of an image pick-up element holder, an intermediate | middle gear, and an intermediate | middle gear biasing spring before the assembly | attachment of an intermediate | middle gear. . 中間ギヤの組み付け完了状態における、ハウジングの駆動機構組付部、撮像素子ホルダのギヤ列抜止部、中間ギヤ及び中間ギヤ付勢ばねの関係を示す、ギヤ軸突起の軸線に沿う方向の断面図である。FIG. 6 is a cross-sectional view in the direction along the axis of the gear shaft projection showing the relationship between the drive mechanism assembly portion of the housing, the gear train retaining portion of the image sensor holder, the intermediate gear, and the intermediate gear biasing spring in the state where the intermediate gear is assembled. is there.

符号の説明Explanation of symbols

１１群レンズ保持枠
２２群レンズ保持枠
８２群レンズ移動枠
１０直進案内環
１１カム環
１２第２繰出筒
１３第１繰出筒
２２ハウジング
２２ａ回転規制溝
２２ｂ駆動機構組付部（ギヤ軸支持部材、ギヤ軸形成部材）
２２ｃピニオン格納穴
２２ｄ中間ギヤ格納凹部（筒状凹部）
２２ｄ-１中間ギヤ格納凹部の底面
２２ｅスクリューシャフト格納空間
２２ｆ軸穴
２２ｇギヤ軸突起
２２ｇ-１大径中間部
２２ｇ-２小径先端部
２２ｇ-３基部
２２ｈ回転規制凹部（回転規制部）
２２ｉ位置決めボス
２３撮像素子ホルダ
２３ａギヤ列抜止部（ギヤ軸支持部材、抜止部材）
２３ｂ２３ｄ軸穴
２３ｃ軸固定穴
２３ｅ位置決め穴
２５ローパスフィルタ
２７群間付勢ばね
５０中間ギヤ付勢ばね（ばね部材）
５０ａ円形穴（開口）
５０ｂ中心座部（ギヤ当接部）
５０ｃ弾性支持脚部
５０ｃ-１傾斜部
５０ｃ-２先端当接部
５１３群レンズ枠
５１ａガイド穴
５１ｂ回転規制キー
５１ｃナット当付部
５１ｄ回転規制突起
５２３群ガイド軸
５４ＡＦナット
５５トーションばね
５６従動ギヤ
５７中間ギヤ
５８スクリューシャフト
５８ａシャフト回転軸
７０ズームレンズ鏡筒
７１撮像素子
１００シャッタブロック
１０４バリヤ羽根
１５０ズームモータ
１６０ＡＦモータ
１６０ａ回転出力軸
１６０ｂピニオン
ＣＦ１１群用カムフォロア
ＣＦ２２群用カムフォロア
ＣＧ１１群制御カム溝
ＣＧ２２群制御カム溝
ＬＧ１第１レンズ群
ＬＧ２第２レンズ群
ＬＧ３第３レンズ群
Ｏ撮影光学系の光軸
Ｓシャッタ羽根 DESCRIPTION OF SYMBOLS 1 1st group lens holding frame 2 2nd group lens holding frame 8 2nd group lens moving frame 10 Straight guide ring 11 Cam ring 12 2nd delivery cylinder 13 1st delivery cylinder 22 Housing 22a Rotation restriction groove 22b Drive mechanism assembly part (gear shaft) Support member, gear shaft forming member)
22c Pinion storage hole 22d Intermediate gear storage recess (cylindrical recess)
22d-1 Bottom surface of intermediate gear storage recess 22e Screw shaft storage space 22f Shaft hole 22g Gear shaft projection 22g-1 Large diameter intermediate portion 22g-2 Small diameter tip 22g-3 Base 22h Rotation restricting recess (rotation restricting portion)
22i Positioning boss 23 Image sensor holder 23a Gear train retaining portion (gear shaft support member, retaining member)
23b 23d Shaft hole 23c Shaft fixing hole 23e Positioning hole 25 Low pass filter 27 Inter-group bias spring 50 Intermediate gear bias spring (spring member)
50a Circular hole (opening)
50b Center seat (gear contact part)
50c Elastic support leg portion 50c-1 Inclined portion 50c-2 Tip contact portion 51 Third group lens frame 51a Guide hole 51b Rotation restriction key 51c Nut abutting portion 51d Rotation restriction projection 52 Third group guide shaft 54 AF nut 55 Torsion spring 56 Drive gear 57 Intermediate gear 58 Screw shaft 58a Shaft rotation shaft 70 Zoom lens barrel 71 Image sensor 100 Shutter block 104 Barrier blade 150 Zoom motor 160 AF motor 160a Rotation output shaft 160b Pinion CF1 Group 1 cam follower CF2 Group 2 cam follower CG1 1 Group control cam groove CG2 Second group control cam groove LG1 First lens group LG2 Second lens group LG3 Third lens group O Optical axis S of photographing optical system Shutter blade

Claims

２つのギヤと、該２つのギヤに噛合して回転伝達を行う中間ギヤの支持構造において、
上記中間ギヤのギヤ軸を支持するギヤ軸支持部材と；
上記ギヤ軸支持部材と中間ギヤの間に挿入されるばね部材と；
を備え、
上記ばね部材は、上記中間ギヤに当接するギヤ当接部と、該ギヤ当接部を中心とする放射方向に延出されてギヤ軸支持部材に当接する弾性変形可能な少なくとも３つの弾性支持脚とを備えており、上記弾性支持脚をそれぞれ弾性変形させて中間ギヤを上記ギヤ軸の軸線方向に付勢すること；及び
上記中間ギヤのギヤ軸の軸線に沿う方向から見て、上記２つのギヤのそれぞれの少なくとも一部が、上記ばね部材の上記弾性支持脚にそれぞれ挟まれる少なくとも３つの脚間空間のうち異なる２つの脚間空間に位置しており、かつ上記中間ギヤのギヤ軸の軸線と直交する方向から見て、上記２つのギヤをそれぞれ支持するギヤ軸が上記２つの脚間空間に位置していること；
を特徴とするギヤ支持構造。 In a support structure for two gears and an intermediate gear that meshes with the two gears and transmits rotation,
A gear shaft support member for supporting the gear shaft of the intermediate gear;
A spring member inserted between the gear shaft support member and the intermediate gear;
With
The spring member includes a gear abutting portion that abuts on the intermediate gear, and at least three elastic support legs that extend in a radial direction around the gear abutting portion and abut against the gear shaft support member. includes bets, the elastic supporting legs were respectively elastically deformed it urges the intermediate gear in the axial direction of the gear shaft; when viewed from a direction along the axis of and the gear shaft of the intermediate gear, the two At least a part of each gear is located in two different leg spaces among at least three leg spaces sandwiched between the elastic support legs of the spring member , and the axis of the gear shaft of the intermediate gear The gear shafts supporting the two gears are located in the space between the two legs as viewed from the direction orthogonal to the two ;
Gear support structure characterized by

請求項１記載のギヤ支持構造において、上記ばね部材は３つの上記弾性支持脚を有し、該３つの上記弾性支持脚は、上記ギヤ当接部から先端まで略同じ長さであり、かつ略等角度間隔で配置されているギヤ支持構造。 In the gear support structure according to claim 1, wherein said spring member has three of said elastic support legs, said three of the elastic supporting legs is substantially the same length to the tip from the gear contact portion, and a substantially Gear support structure arranged at equiangular intervals.

請求項１または２記載のギヤ支持構造において、上記ギヤ軸支持部材は、上記弾性支持脚に係合してばね部材の回転を規制する回転規制部を有しているギヤ支持構造。 3. The gear support structure according to claim 1, wherein the gear shaft support member has a rotation restricting portion that engages with the elastic support leg to restrict the rotation of the spring member.

請求項３記載のギヤ支持構造において、上記ギヤ軸支持部材は、中間ギヤを格納する筒状凹部を有し、上記回転規制部は、該筒状凹部の内壁面に形成された凹部からなるギヤ支持構造。 4. The gear support structure according to claim 3, wherein the gear shaft support member has a cylindrical recess for storing an intermediate gear, and the rotation restricting portion is a gear including a recess formed on an inner wall surface of the cylindrical recess. Support structure.

請求項１から４のいずれか１項に記載のギヤ支持構造において、上記ギヤ軸支持部材は、
上記中間ギヤのギヤ軸が突出形成されたギヤ軸形成部材と；
該ギヤ軸形成部材に固定されてギヤ軸の先端を支持し、ギヤ軸に対し中間ギヤを抜け止めさせる抜止部材と；
を有し、
上記ばね部材は、ギヤ軸形成部材または抜止部材と中間ギヤとの間に挿入されているギヤ支持構造。 The gear support structure according to any one of claims 1 to 4, wherein the gear shaft support member includes:
A gear shaft forming member from which the gear shaft of the intermediate gear protrudes;
A retaining member that is fixed to the gear shaft forming member, supports the tip of the gear shaft, and prevents the intermediate gear from coming off from the gear shaft;
Have
A gear support structure in which the spring member is inserted between a gear shaft forming member or a retaining member and an intermediate gear.

請求項１から５のいずれか１項に記載のギヤ支持構造において、上記ばね部材のギヤ当接部は、上記ギヤ軸を挿通させる開口を有する環状をなしているギヤ支持構造。 The gear support structure according to any one of claims 1 to 5, wherein the gear contact portion of the spring member has an annular shape having an opening through which the gear shaft is inserted.

請求項１から６のいずれか１項に記載のギヤ支持構造において、上記２つのギヤと中間ギヤは、撮像装置のＡＦレンズ駆動用のギヤ機構を構成しているギヤ支持構造。 The gear support structure according to any one of claims 1 to 6, wherein the two gears and the intermediate gear constitute a gear mechanism for driving an AF lens of the imaging apparatus.