JP2007017638A - Zoom lens - Google Patents

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Publication number
JP2007017638A
JP2007017638A JP2005198100A JP2005198100A JP2007017638A JP 2007017638 A JP2007017638 A JP 2007017638A JP 2005198100 A JP2005198100 A JP 2005198100A JP 2005198100 A JP2005198100 A JP 2005198100A JP 2007017638 A JP2007017638 A JP 2007017638A
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lens
lens group
positive
negative
focal length
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JP2007017638A5 (en
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Daiyu Ri
大勇 李
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Tamron Co Ltd
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Tamron Co Ltd
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/143—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only
    • G02B15/1435—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being negative
    • G02B15/143507—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being negative arranged -++

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive high-performance loom lens having a variable power ratio of about 3 which is short in the total length both at the time of photographing and the time it is collapsed. <P>SOLUTION: The zoom lens is composed in such a manner that a first lens group 110 having negative refractive power, a second lens group 120 having positive refractive power, and a third lens group 130 having positive refractive power are disposed in this order from an object side. The first lens group 110 is composed in such a way that a negative lens 111 in which a compound aspheric surface is formed on an image plane 150 side, and a positive lens 112 are disposed in this order from the object side. The second lens group 120 is composed in such a way that a positive lens 121 of which both surfaces are convex, and a cemented lens 122 formed of a positive lens and a negative lens disposed in this order from the object side. The third lens group 130 is composed of one positive lens 131. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

この発明は、ＣＣＤなどの撮像素子を備えたデジタルカメラやビデオカメラなどに搭載されるズームレンズに関し、特に３倍程度の変倍比を有するズームレンズに関する。   The present invention relates to a zoom lens mounted on a digital camera or video camera equipped with an image sensor such as a CCD, and more particularly to a zoom lens having a zoom ratio of about 3 times.

一般に、３成分の沈胴型ズームレンズは、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群とを含み構成されている。近年では、リアフォーカス方式を採用し、フォーカシングの高速化、光学系の小型化、諸収差の良好な補正が図られた、高性能な沈胴型ズームレンズが提案されている（たとえば、特許文献１〜３を参照。）。   In general, a three-component retractable zoom lens includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. ing. In recent years, a high-performance collapsible zoom lens has been proposed that employs a rear focus method to achieve high-speed focusing, a compact optical system, and good correction of various aberrations (for example, Patent Document 1). See ~ 3).

特開２００３−１４００４６号公報Japanese Patent Laid-Open No. 2003-140046 特開２００４−６１６７５号公報JP 2004-61675 A 特開２００４−９３６４７号公報JP 2004-93647 A

上記各特許文献に開示されている従来技術は、いずれも負正正の３成分でレンズ６枚５群からなる変倍比３倍の沈胴型ズームレンズである。そして、このズームレンズの第１レンズ群に含まれる負レンズは外径が大きく、材質はガラスである。さらに、レンズ面には非球面が形成されている。   The prior arts disclosed in the above-mentioned patent documents are all retractable zoom lenses having three components of negative positive and positive and consisting of five groups of six lenses and a zoom ratio of 3 times. The negative lens included in the first lens group of the zoom lens has a large outer diameter and is made of glass. Furthermore, an aspherical surface is formed on the lens surface.

一般に、ガラス材の加工は容易ではないため、製造コストが高くなる傾向にある。特に、上記従来技術では、ガラス材からなる負レンズのレンズ面に非球面が形成されているため、製造コストは相当高くなる。加えて、非球面が形成されたレンズは外径が大きいことから更なるコスト高が見込まれる。   In general, the processing of glass materials is not easy, and thus the manufacturing cost tends to increase. In particular, in the above prior art, since the aspherical surface is formed on the lens surface of the negative lens made of a glass material, the manufacturing cost is considerably increased. In addition, a lens having an aspherical surface has a large outer diameter, so that further cost increases are expected.

また、上記従来技術は、撮影時、光学系の全長が長いため、沈胴時であってもあまり全長が短くなっていない。さらに、第２レンズ群の移動量が大きく、鏡筒構成も複雑であるため、製造コストがかさむ。   Further, the above-described prior art has a long total length of the optical system at the time of photographing, so the total length is not so short even when retracted. Furthermore, since the movement amount of the second lens group is large and the lens barrel configuration is complicated, the manufacturing cost is increased.

さらに、第１レンズ群に含まれる、負レンズと正レンズとの間隔が大きく、負レンズの曲率半径が小さいため、デジタルカメラなどに搭載した際には、シャッタと干渉しやすく、光学系の全長の短縮化には著しく不利であるという問題もある。   Furthermore, since the distance between the negative lens and the positive lens included in the first lens group is large and the radius of curvature of the negative lens is small, when mounted on a digital camera or the like, it easily interferes with the shutter, and the entire length of the optical system. There is also a problem in that it is extremely disadvantageous for shortening.

この発明は、上述した従来技術による問題点を解消するため、撮影時、沈胴時を問わず全長が短く、３倍程度の変倍比を備えた、安価で高性能なズームレンズを提供することを目的とする。   The present invention provides an inexpensive and high-performance zoom lens that has a short overall length regardless of whether it is photographed or retracted, and has a zoom ratio of about 3 times, in order to eliminate the above-mentioned problems caused by the prior art. With the goal.

上述した課題を解決し、目的を達成するため、この発明の請求項１にかかるズームレンズは、物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群と、を含み構成されており、前記第１レンズ群は、複合非球面が形成された１枚の負レンズと、１枚の正レンズを含む少なくとも２枚のレンズで構成され、前記第２レンズ群は、両面が凸面の正レンズと、正レンズと負レンズとの接合レンズを含む少なくとも３枚のレンズで構成され、前記第３レンズ群は、正レンズを含む少なくとも１枚のレンズで構成され、前記第２レンズ群の光軸に沿う方向の移動量を抑制して、前記各レンズ群の間隔を変化させて変倍を行うことを特徴とする。   In order to solve the above-described problems and achieve the object, a zoom lens according to a first aspect of the present invention includes a first lens group having negative refractive power arranged in order from the object side, and positive refractive power. And a third lens group having a positive refractive power. The first lens group includes one negative lens having a composite aspherical surface and one negative lens. The second lens group is composed of at least three lenses including a positive lens having a convex surface on both sides and a cemented lens of a positive lens and a negative lens. The three lens groups are composed of at least one lens including a positive lens, and the amount of movement in the direction along the optical axis of the second lens group is suppressed, and the distance between the lens groups is changed to change the magnification. It is characterized by performing.

また、この発明の請求項２にかかるズームレンズは、物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群と、を含み構成されており、前記第１レンズ群は、１枚の負レンズと、非球面が形成された１枚の正レンズを含む少なくとも２枚のレンズで構成され、前記第２レンズ群は、両面が凸面の正レンズと、正レンズと負レンズとの接合レンズを含む少なくとも３枚のレンズで構成され、前記第３レンズ群は、正レンズを含む少なくとも１枚のレンズで構成され、前記第２レンズ群の光軸に沿う方向の移動量を抑制して、前記各レンズ群の間隔を変化させて変倍を行うことを特徴とする。   A zoom lens according to a second aspect of the present invention includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a positive refractive power, which are arranged in order from the object side. The first lens group includes at least two lenses including one negative lens and one positive lens on which an aspherical surface is formed. The second lens group includes at least three lenses including a positive lens having both convex surfaces and a cemented lens of a positive lens and a negative lens, and the third lens group includes at least one lens including a positive lens. The second lens group is controlled to move in the direction along the optical axis, and the zooming is performed by changing the distance between the lens groups.

また、この発明の請求項３にかかるズームレンズは、請求項１または２に記載の発明において、前記第３レンズ群に含まれる正レンズはプラスチック材で構成され、当該正レンズのいずれかの面には非球面が形成されていることを特徴とする。   A zoom lens according to a third aspect of the present invention is the zoom lens according to the first or second aspect, wherein the positive lens included in the third lens group is made of a plastic material, and any surface of the positive lens is used. Is characterized in that an aspherical surface is formed.

また、この発明の請求項４にかかるズームレンズは、請求項１〜３のいずれか一つに記載の発明において、前記第１レンズ群に含まれる正レンズの像側面の曲率半径が大きくなるようにして、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔を短くするとともに、前記第１レンズ群に含まれる、負レンズと正レンズの焦点距離のバランスを保ち、前記第１レンズ群全体の屈折力が弱くなるようにしたことを特徴とする。   According to a fourth aspect of the present invention, in the zoom lens according to any one of the first to third aspects, the radius of curvature of the image side surface of the positive lens included in the first lens group is increased. Thus, the distance between the negative lens and the positive lens included in the first lens group is shortened, the focal length of the negative lens and the positive lens included in the first lens group is kept balanced, and the first lens group is The refracting power of the entire lens group is weakened.

また、この発明の請求項５にかかるズームレンズは、請求項１〜４のいずれか一つに記載の発明において、前記第１レンズ群の第３面および前記第２レンズ群の第１面には、非球面が形成されていることを特徴とする。   According to a fifth aspect of the present invention, in the zoom lens according to any one of the first to fourth aspects, the third surface of the first lens group and the first surface of the second lens group. Is characterized in that an aspheric surface is formed.

また、この発明の請求項６にかかるズームレンズは、請求項１〜５のいずれか一つに記載の発明において、前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とする。 A zoom lens according to a sixth aspect of the present invention is the zoom lens according to any one of the first to fifth aspects, wherein the focal length of the first lens group is F1, and the focal length of the second lens group is the same. F2, when the focal length at the wide-angle end of the entire system is Fw,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
It is characterized by satisfying.

また、この発明の請求項７にかかるズームレンズは、請求項１〜６のいずれか一つに記載の発明において、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とする。 A zoom lens according to a seventh aspect of the present invention is the zoom lens according to any one of the first to sixth aspects, wherein the radius of curvature of the image side surface of the positive lens included in the first lens group is R, The distance between the negative lens and the positive lens included in the first lens group is D, the focal length of the negative lens included in the first lens group is f1, and the focal length of the positive lens included in the first lens group is f2. And when
R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
It is characterized by satisfying.

また、この発明の請求項８にかかるズームレンズは、請求項１または２に記載の発明において、前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗ、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
かつ
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とする。 A zoom lens according to an eighth aspect of the present invention is the zoom lens according to the first or second aspect, wherein the focal length of the first lens group is F1, the focal length of the second lens group is F2, and The focal length at the wide-angle end is Fw, the radius of curvature of the image side surface of the positive lens included in the first lens group is R, the distance between the negative lens and the positive lens included in the first lens group is D, and the first When the focal length of the negative lens included in the lens group is f1, and the focal length of the positive lens included in the first lens group is f2,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
And R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
It is characterized by satisfying.

また、この発明の請求項９にかかるズームレンズは、物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とする。 A zoom lens according to a ninth aspect of the present invention includes a first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side. When the focal length of the first lens group is F1, the focal length of the second lens group is F2, and the focal length at the wide angle end of the entire system is Fw,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
It is characterized by satisfying.

また、この発明の請求項１０にかかるズームレンズは、物体側から順に配置された、１枚の負レンズと１枚の正レンズを含む少なくとも２枚のレンズで構成され全体として負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
Ｒ／Ｄ≧１６
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とする。 A zoom lens according to a tenth aspect of the present invention is composed of at least two lenses including one negative lens and one positive lens arranged in order from the object side, and has a negative refractive power as a whole. A first lens group having a positive refractive power, and a radius of curvature of an image side surface of the positive lens included in the first lens group being R, and the first lens group having a first lens group having a positive refractive power. , The distance between the negative lens and the positive lens is D, the focal length of the second lens group is F2, and the focal length at the wide angle end of the entire system is Fw.
R / D ≧ 16
And 1.5 <F2 / Fw <1.75
It is characterized by satisfying.

また、この発明の請求項１１にかかるズームレンズは、物体側から順に配置された、１枚の負レンズと１枚の正レンズを含む少なくとも２枚のレンズで構成され全体として負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗ、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
かつ
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とする。 A zoom lens according to an eleventh aspect of the present invention is composed of at least two lenses including one negative lens and one positive lens arranged in order from the object side, and has a negative refractive power as a whole. And a second lens group having a positive refractive power, the focal length of the first lens group is F1, the focal length of the second lens group is F2, and the entire system Fw is the focal length at the wide-angle end, R is the radius of curvature of the image side surface of the positive lens included in the first lens group, D is the distance between the negative lens and positive lens included in the first lens group, and When the focal length of the negative lens included in one lens group is f1, and the focal length of the positive lens included in the first lens group is f2,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
And R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
It is characterized by satisfying.

この発明によれば、撮影時、沈胴時を問わず全長が短く、３倍程度の変倍比を備えた、安価で高性能なズームレンズを提供することができるという効果を奏する。   According to the present invention, there is an effect that it is possible to provide an inexpensive and high-performance zoom lens having a short overall length regardless of whether it is taken or retracted, and having a zoom ratio of about 3 times.

以下、添付図面を参照して、この発明にかかるズームレンズの好適な実施の形態を詳細に説明する。   Preferred embodiments of a zoom lens according to the present invention will be described below in detail with reference to the accompanying drawings.

この発明の実施の形態にかかるズームレンズは、物体側から順に配置された、負の屈折力を有する第１レンズ群、正の屈折力を有する第２レンズ群、および正の屈折力を有する第３レンズ群を含み構成される。第１レンズ群は、１枚の負レンズと１枚の正レンズで構成される。第２レンズ群は、両面が凸面の正レンズ、および正レンズと負レンズとの接合レンズの３枚のレンズで構成される。第３レンズ群は、１枚の正レンズで構成される。   A zoom lens according to an embodiment of the present invention includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a first lens having a positive refractive power, which are arranged in order from the object side. It includes 3 lens groups. The first lens group is composed of one negative lens and one positive lens. The second lens group includes three lenses, a positive lens having convex surfaces on both sides and a cemented lens of a positive lens and a negative lens. The third lens group is composed of one positive lens.

このズームレンズは、近距離撮影時に第３レンズ群を物体側へ移動させてフォーカシングを行う。また、広角端での変倍は、第２レンズ群を像側へ移動させるとともに、第３レンズ群を物体側へ移動させることによって行われる。中間端での変倍は、第１レンズ群を像側へ移動させるとともに、第２レンズ群および第３レンズ群を中間位置に移動させることによって行う。望遠端での変倍は、第２レンズ群を物体側へ移動させるとともに、第３レンズ群を像側へ移動させることによって行う。   This zoom lens performs focusing by moving the third lens unit to the object side during close-up shooting. Further, zooming at the wide-angle end is performed by moving the second lens group to the image side and moving the third lens group to the object side. The zooming at the intermediate end is performed by moving the first lens group to the image side and moving the second lens group and the third lens group to an intermediate position. The zooming at the telephoto end is performed by moving the second lens group to the object side and moving the third lens group to the image side.

この発明は、コンパクトなデジタルカメラやビデオカメラなどに用いることができるズームレンズを提供することを目的としている。このためには、レンズのコンパクト化はもとより、小型で画素数の多い撮像素子の性能に合った高い光学性能を備えることが必要になる。   An object of the present invention is to provide a zoom lens that can be used in a compact digital camera, video camera, or the like. For this purpose, it is necessary not only to make the lens compact, but also to provide high optical performance that matches the performance of a small image sensor with a large number of pixels.

そこで、まず、第１レンズ群の焦点距離をＦ１、第２レンズ群の焦点距離をＦ２とするとき、次の条件式を満足することが好ましい。
１．４＜｜Ｆ１｜／Ｆ２＜１．５１ ・・・（１） Therefore, first, when the focal length of the first lens group is F1 and the focal length of the second lens group is F2, it is preferable that the following conditional expression is satisfied.
1.4 <| F1 | / F2 <1.51 (1)

この条件式（１）は、第１レンズ群の焦点距離と第２レンズ群の焦点距離との比を規定し、光学系の全長を決定するための式である。｜Ｆ１｜／Ｆ２の値が１．４以下になると、第１レンズ群のレンズの肉厚が厚くなるため、沈胴長さが長くなり、サイズも大きくなる。一方、｜Ｆ１｜／Ｆ２の値が１．５１以上になると、第１レンズ群のパワー（ＰＷ）が強すぎるため、収差や解像度が悪化して、良好な特性が得られにくくなる。また、第１レンズ群内の公差や誤差の影響を受けやすくなり、製造時の生産性も悪くなる。   Conditional expression (1) defines the ratio of the focal length of the first lens group and the focal length of the second lens group and determines the total length of the optical system. When the value of | F1 | / F2 is 1.4 or less, the thickness of the lens of the first lens group becomes thick, so that the retractable length becomes long and the size becomes large. On the other hand, if the value of | F1 | / F2 is 1.51 or more, the power (PW) of the first lens group is too strong, so that aberration and resolution are deteriorated and it is difficult to obtain good characteristics. In addition, it becomes susceptible to tolerances and errors in the first lens group, and the productivity at the time of manufacture also deteriorates.

さらに、このズームレンズ全系の広角端における焦点距離をＦｗとするとき、次の条件式を満足することが好ましい。
１．５＜Ｆ２／Ｆｗ＜１．７５ ・・・（２） Furthermore, when the focal length at the wide angle end of the entire zoom lens system is Fw, it is preferable that the following conditional expression is satisfied.
1.5 <F2 / Fw <1.75 (2)

この条件式（２）は、このズームレンズの第２レンズ群の焦点距離とズームレンズ全系の広角端における焦点距離との比を規定し、第２レンズ群の移動量を決定するための式である。Ｆ２／Ｆｗの値が１．５以下になると、第２レンズ群のレンズの肉厚が厚くなるため、沈胴長さが長くなり、サイズも大きくなる。一方、Ｆ２／Ｆｗの値が１．７５以上になると、第２レンズ群のパワー（ＰＷ）が強すぎるため、収差や解像度が悪化して、良好な特性が得られにくくなる。また、第１レンズ群内の公差や誤差の影響を受けやすくなり、製造時の生産性も悪くなる。   Conditional expression (2) defines the ratio between the focal length of the second lens group of the zoom lens and the focal length at the wide-angle end of the entire zoom lens system, and determines the amount of movement of the second lens group. It is. When the value of F2 / Fw is 1.5 or less, the thickness of the lens of the second lens group becomes thick, so that the retractable length becomes long and the size becomes large. On the other hand, when the value of F2 / Fw is 1.75 or more, since the power (PW) of the second lens group is too strong, aberration and resolution are deteriorated, and it is difficult to obtain good characteristics. In addition, it becomes susceptible to tolerances and errors in the first lens group, and the productivity at the time of manufacture also deteriorates.

この実施の形態のズームレンズは、上記条件式（１），（２）を満足することで、第１レンズ群の屈折力を弱く、第２レンズ群の屈折力を強くすることができる。この結果、第２レンズ群の光軸に沿う方向の移動量を抑え、撮影時の光学系の全長を短くすることができ、光学系のコンパクト化を達成できる。加えて、諸収差の発生を抑制することができ、良好な光学性能が得られる。   The zoom lens according to this embodiment satisfies the conditional expressions (1) and (2), so that the refractive power of the first lens group can be weakened and the refractive power of the second lens group can be strengthened. As a result, the amount of movement of the second lens group in the direction along the optical axis can be suppressed, the total length of the optical system during shooting can be shortened, and the optical system can be made compact. In addition, the occurrence of various aberrations can be suppressed, and good optical performance can be obtained.

また、この実施の形態のズームレンズでは、第１レンズ群を、複合非球面が形成された１枚の負レンズと１枚の正レンズ、または１枚の負レンズと非球面が形成された１枚の正レンズで構成するとよい。さらに、第２レンズ群の両面が凸面の正レンズ、および第３レンズ群の正レンズに非球面を形成するとよい。このようにすることで、さらに諸収差の補正が容易になる。特に、広角端における球面収差、非点収差、歪曲収差、倍率の色収差などを良好に補正できるようになる。   In the zoom lens according to the present embodiment, the first lens group is composed of one negative lens and one positive lens on which a composite aspheric surface is formed, or one negative lens and an aspheric surface on which one is formed. It may be composed of a single positive lens. Further, it is preferable to form aspherical surfaces on the positive lens whose convex surfaces are the second lens group and the positive lens of the third lens group. This makes it easier to correct various aberrations. In particular, spherical aberration, astigmatism, distortion, magnification chromatic aberration, and the like at the wide-angle end can be corrected satisfactorily.

また、この実施の形態にかかるズームレンズでは、第３レンズ群は像側に近い位置に配置されるため、温度変化の影響を受けにくい。したがって、コストの低減を図るために、第３レンズ群を構成する正レンズをプラスチック材で成形するとよい。   Further, in the zoom lens according to this embodiment, the third lens group is disposed at a position close to the image side, and thus is not easily affected by temperature changes. Therefore, in order to reduce the cost, the positive lens constituting the third lens group may be molded from a plastic material.

また、沈胴時の光学系の全長を短くするには、ズームレンズを構成するレンズの枚数、形状、間隔が重要な要素になる。そこで、まず、第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤとするとき、次の条件式を満足することが好ましい。
Ｒ／Ｄ≧１６ ・・・（３） Further, in order to shorten the overall length of the optical system when retracted, the number, shape, and interval of lenses constituting the zoom lens are important factors. Therefore, when the radius of curvature of the image side surface of the positive lens included in the first lens group is R and the distance between the negative lens and the positive lens included in the first lens group is D, the following conditional expression is satisfied. It is preferable to do.
R / D ≧ 16 (3)

この条件式（３）は、このズームレンズの第１レンズ群に含まれる正レンズの像側面の曲率半径と、第１レンズ群に含まれる、負レンズと正レンズとの間隔との比を規定し、沈胴時の光学系の全長を決定するための式である。この条件式（３）を満足することで、第１レンズ群に含まれる正レンズの像側面の曲率半径を大きくして、第１レンズ群に含まれる、負レンズと正レンズとの間隔を短くすることができる。この結果、沈胴時の光学系の全長を短くすることができる。Ｒ／Ｄの値が１６未満になると、第１レンズ群と第２レンズ群との間隔が狭くなりすぎて、シャッタや絞り機構を設けることが困難になる。   Conditional expression (3) defines the ratio between the radius of curvature of the image side surface of the positive lens included in the first lens group of the zoom lens and the distance between the negative lens and the positive lens included in the first lens group. And an expression for determining the total length of the optical system when retracted. By satisfying this conditional expression (3), the radius of curvature of the image side surface of the positive lens included in the first lens group is increased, and the distance between the negative lens and the positive lens included in the first lens group is shortened. can do. As a result, the total length of the optical system when retracted can be shortened. If the R / D value is less than 16, the distance between the first lens group and the second lens group becomes too narrow, making it difficult to provide a shutter and a diaphragm mechanism.

さらに、第１レンズ群に含まれる負レンズの焦点距離をｆ１、第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、次の条件式を満足することが好ましい。
０．４３＜｜ｆ１｜／ｆ２＜０．５１ ・・・（４） Furthermore, when the focal length of the negative lens included in the first lens group is f1, and the focal length of the positive lens included in the first lens group is f2, it is preferable that the following conditional expression is satisfied.
0.43 <| f1 | / f2 <0.51 (4)

この条件式（４）は、第１レンズ群に含まれる、負レンズの焦点距離と正レンズの焦点距離との比を規定し、第１レンズ群の全長を決定するための式である。この条件式（４）を満足することで、第１レンズ群に含まれる、負レンズおよび正レンズの焦点距離の一方が長くなりすぎるといったようなことはなく、両レンズの焦点距離のバランスを保ち、第１レンズ群全体の屈折力を弱く設定することができる。この結果、第１レンズ群に含まれる、負レンズおよび正レンズの肉厚を薄くすることができ、光学系の全長も短くすることができる。ここで、｜ｆ１｜／ｆ２の値が０．４３以下になると、第１レンズ群に含まれる負レンズおよび正レンズの肉厚が厚くなるため、沈胴長さが長くなり、サイズも大きくなる。一方、｜ｆ１｜／ｆ２の値が０．５１以上になると、第１レンズ群のパワー（ＰＷ）が強すぎるため、収差や解像度が悪化して、良好な特性が得られにくくなる。また、第１レンズ群内の公差や誤差の影響を受けやすくなり、製造時の生産性も悪くなる。   Conditional expression (4) is an expression for determining the total length of the first lens group by defining the ratio between the focal length of the negative lens and the focal length of the positive lens included in the first lens group. By satisfying this conditional expression (4), one of the focal lengths of the negative lens and the positive lens included in the first lens group will not be too long, and the focal length balance of both lenses will be maintained. The refractive power of the entire first lens group can be set weak. As a result, the thickness of the negative lens and the positive lens included in the first lens group can be reduced, and the overall length of the optical system can be shortened. Here, when the value of | f1 | / f2 is 0.43 or less, the thickness of the negative lens and the positive lens included in the first lens group is increased, so that the retractable length is increased and the size is also increased. On the other hand, if the value of | f1 | / f2 is 0.51 or more, since the power (PW) of the first lens group is too strong, aberrations and resolution deteriorate, and it is difficult to obtain good characteristics. In addition, it becomes susceptible to tolerances and errors in the first lens group, and the productivity at the time of manufacture also deteriorates.

また、この実施の形態にかかるズームレンズは、上記各条件式（１）〜（４）を満足しさえすれば、第１レンズ群と第２レンズ群で構成しても、前述したこの発明の目的は達成できる。   In addition, the zoom lens according to this embodiment can be configured by the first lens group and the second lens group as long as the conditional expressions (1) to (4) are satisfied. The goal can be achieved.

以下、この発明の実施例を示す。   Examples of the present invention will be described below.

（実施例１）
図１は、この発明の実施例１にかかるズームレンズの構成を示す光軸に沿う断面図である。このズームレンズは、図示しない物体側から順に、負の屈折力を有する第１レンズ群１１０、正の屈折力を有する第２レンズ群１２０、および正の屈折力を有する第３レンズ群１３０が配置されて構成される。また、第１レンズ群１１０と第２レンズ群１２０との間には絞り１４０が配置されている。第３レンズ群１３０と像面１５０との間には、カバーガラス１６０が配置されている。 Example 1
FIG. 1 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 1 of the present invention. In this zoom lens, a first lens group 110 having a negative refractive power, a second lens group 120 having a positive refractive power, and a third lens group 130 having a positive refractive power are arranged in this order from the object side (not shown). Configured. A stop 140 is disposed between the first lens group 110 and the second lens group 120. A cover glass 160 is disposed between the third lens group 130 and the image plane 150.

第１レンズ群１１０は、物体側から順に、像面１５０側に複合非球面が形成された負レンズ１１１と、正レンズ１１２が配置されて構成される。第２レンズ群１２０は、物体側から順に、両面が凸面の正レンズ１２１と、正レンズと負レンズとで形成された接合レンズ１２２が配置されて構成される。第３レンズ群１３０は、１枚の正レンズ１３１で構成される。この正レンズ１３１はプラスチック材で成形するとよい。   The first lens group 110 includes, in order from the object side, a negative lens 111 having a composite aspheric surface formed on the image plane 150 side and a positive lens 112. The second lens group 120 includes, in order from the object side, a positive lens 121 having convex surfaces and a cemented lens 122 formed of a positive lens and a negative lens. The third lens group 130 includes a single positive lens 131. The positive lens 131 may be molded from a plastic material.

以下、実施例１にかかるズームレンズに関する各種数値データを示す。   Various numerical data related to the zoom lens according to Example 1 will be described below.

実施例１のズームレンズ全系の焦点距離＝6.43(広角端)〜10.94(中間端)〜18.50（望遠端）
Ｆナンバ＝2.87(広角端)〜3.9(中間端)〜5.34（望遠端）
入射画角（２ω）＝60.5°(広角端)〜37.84°(中間端)〜22.9°（望遠端）
第１レンズ群１１０の焦点距離（Ｆ１）＝-16.0280
第２レンズ群１２０の焦点距離（Ｆ２）＝10.9940
第１レンズ群１１０に含まれる負レンズ１１１の焦点距離（ｆ１）＝-6.8826
第１レンズ群１１０に含まれる正レンズ１１２の焦点距離（ｆ２）＝13.9718
｜Ｆ１｜／Ｆ２＝1.458
Ｆ２／Ｆｗ＝1.71
Ｒ／Ｄ＝32.93
｜ｆ１｜／ｆ２＝0.4926 Focal length of the entire zoom lens system of Example 1 = 6.43 (wide-angle end) to 10.94 (intermediate end) to 18.50 (telephoto end)
F number = 2.87 (wide-angle end) to 3.9 (intermediate end) to 5.34 (telephoto end)
Incident angle of view (2ω) = 60.5 ° (wide-angle end) to 37.84 ° (intermediate end) to 22.9 ° (telephoto end)
Focal length (F1) of the first lens group 110 = -16.0280
Focal length (F2) of the second lens group 120 = 10.9940
Focal length (f1) of negative lens 111 included in first lens group 110 = −6.8826
Focal length (f2) of positive lens 112 included in first lens group 110 = 13.9718
| F1 | /F2=1.458
F2 / Fw = 1.71
R / D = 32.93
| F1 | /f2=0.4926

ｒ1＝-76.463
ｄ1＝0.800 ｎｄ1＝1.773 νｄ1＝49.600
ｒ2＝6.378
ｄ2＝0.200 ｎｄ2＝1.536 νｄ2＝41.200
ｒ3＝5.572（非球面）
ｄ3＝1.280
ｒ4＝9.107
ｄ4＝1.780 ｎｄ3＝1.806 νｄ3＝33.300
ｒ5＝42.150
ｄ5＝12.778(広角端)〜5.63(中間端)〜1.266（望遠端）
ｒ6＝∞（絞り）
ｄ6＝0.500
ｒ7＝5.800（非球面）
ｄ7＝1.640 ｎｄ4＝1.694 νｄ4＝53.300
ｒ8＝-19.997（非球面）
ｄ8＝0.430
ｒ9＝17.050
ｄ9＝1.530 ｎｄ5＝1.834 νｄ5＝37.300
ｒ10＝-5.562
ｄ10＝0.500 ｎｄ6＝1.717 νｄ6＝29.500
ｒ11＝3.807
ｄ11＝4.452(広角端)〜9.638(中間端)〜17.134（望遠端）
ｒ12＝28.971（非球面）
ｄ12＝1.900 ｎｄ7＝1.525 νｄ7＝56.200
ｒ13＝-12.289（非球面）
ｄ13＝2.97(広角端) 〜2.426(中間端)〜1.800（望遠端）
ｒ14＝∞
ｄ14＝0.440 ｎｄ8＝1.517 νｄ8＝64.200
ｒ15＝∞
ｄ15＝0.500
ｒ16＝∞
ｄ16＝0.500 ｎｄ9＝1.569 νｄ9＝56.000
ｒ17＝∞
ｄ17＝0.800 r 1 = -76.463
d 1 = 0.800 nd 1 = 1.773 νd 1 = 49.600
r 2 = 6.378
d 2 = 0.200 nd 2 = 1.536 νd 2 = 41.200
r 3 = 5.572 (aspherical surface)
d 3 = 1.280
r 4 = 9.107
d 4 = 1.780 nd 3 = 1.806 νd 3 = 33.300
r 5 = 42.150
d 5 = 12.778 (wide-angle end) to 5.63 (intermediate end) to 1.266 (telephoto end)
r 6 = ∞ (aperture)
d 6 = 0.500
r 7 = 5.800 (aspherical surface)
d 7 = 1.640 nd 4 = 1.694 νd 4 = 53.300
r 8 = -19.997 (aspherical surface)
d 8 = 0.430
r 9 = 17.050
d 9 = 1.530 nd 5 = 1.834 νd 5 = 37.300
r 10 = -5.562
d 10 = 0.500 nd 6 = 1.717 νd 6 = 29.500
r 11 = 3.807
d 11 = 4.452 (wide-angle end) to 9.638 (intermediate end) to 17.134 (telephoto end)
r 12 = 28.971 (aspherical surface)
d 12 = 1.900 nd 7 = 1.525 νd 7 = 56.200
r 13 = -12.289 (aspherical surface)
d 13 = 2.97 (wide-angle end) to 2.426 (intermediate end) to 1.800 (telephoto end)
r 14 = ∞
d 14 = 0.440 nd 8 = 1.517 νd 8 = 64.200
r 15 = ∞
d 15 = 0.500
r 16 = ∞
d 16 = 0.500 nd 9 = 1.569 νd 9 = 56.000
r 17 = ∞
d 17 = 0.800

円錐係数（Ｋ）および非球面係数（Ａ4，Ａ6，Ａ8，Ａ10）
第３面
Ｋ＝0
Ａ4＝-0.732611×10-3， Ａ6＝-0.856036×10-5，
Ａ8＝-0.168875×10-6， Ａ10＝-0.174717×10-7
第７面
Ｋ＝0
Ａ4＝-0.765452×10-3， Ａ6＝-0.933398×10-6，
Ａ8＝-0.424009×10-5， Ａ10＝0.317546×10-6
第８面
Ｋ＝0
Ａ4＝0.456009×10-3， Ａ6＝0.461507×10-5，
Ａ8＝-0.501465×10-5， Ａ10＝0.521392×10-6
第１２面
Ｋ＝31.066237
Ａ4＝0.681593×10-3， Ａ6＝-0.575966×10-4，
Ａ8＝-0.122290×10-5， Ａ10＝0.892887×10-7
第１３面
Ｋ＝0
Ａ4＝0.125154×10-2， Ａ6＝-0.272436×10-4，
Ａ8＝-0.463785×10-5， Ａ10＝0.187543×10-6 Conic coefficient (K) and aspheric coefficient (A 4 , A 6 , A 8 , A 10 )
Third side K = 0
A 4 = -0.732611 × 10 -3 , A 6 = -0.856036 × 10 -5 ,
A 8 = -0.168875 × 10 -6 , A 10 = -0.174717 × 10 -7
7th surface K = 0
A 4 = -0.765452 × 10 -3 , A 6 = -0.933398 × 10 -6 ,
A 8 = -0.424009 × 10 -5 , A 10 = 0.317546 × 10 -6
8th surface K = 0
A 4 = 0.456009 × 10 −3 , A 6 = 0.461507 × 10 −5 ,
A 8 = -0.501465 × 10 -5 , A 10 = 0.521392 × 10 -6
12th surface K = 31.066237
A 4 = 0.681593 × 10 −3 , A 6 = −0.575966 × 10 −4 ,
A 8 = -0.122290 × 10 -5 , A 10 = 0.892887 × 10 -7
13th surface K = 0
A 4 = 0.125154 × 10 −2 , A 6 = −0.272436 × 10 −4 ,
A 8 = -0.463785 × 10 -5 , A 10 = 0.187543 × 10 -6

また、図２は、実施例１にかかるズームレンズの広角端における収差図である。図３は、実施例１にかかるズームレンズの中間端における収差図である。図４は、実施例１にかかるズームレンズの望遠端における収差図である。   FIG. 2 is an aberration diagram at the wide-angle end of the zoom lens according to Example 1. FIG. 3 is an aberration diagram at an intermediate end of the zoom lens according to the first example. FIG. 4 is an aberration diagram at the telephoto end of the zoom lens according to the first example.

（実施例２）
図５は、この発明の実施例２にかかるズームレンズの構成を示す光軸に沿う断面図である。このズームレンズは、図示しない物体側から順に、負の屈折力を有する第１レンズ群２１０、正の屈折力を有する第２レンズ群２２０、および正の屈折力を有する第３レンズ群２３０が配置されて構成される。また、第１レンズ群２１０と第２レンズ群２２０との間には絞り２４０が配置されている。第３レンズ群２３０と像面２５０との間には、カバーガラス２６０が配置されている。 (Example 2)
FIG. 5 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 2 of the present invention. In this zoom lens, a first lens group 210 having a negative refractive power, a second lens group 220 having a positive refractive power, and a third lens group 230 having a positive refractive power are arranged in this order from the object side (not shown). Configured. In addition, a diaphragm 240 is disposed between the first lens group 210 and the second lens group 220. A cover glass 260 is disposed between the third lens group 230 and the image plane 250.

第１レンズ群２１０は、物体側から順に、像面２５０側に複合非球面が形成された負レンズ２１１と、正レンズ２１２が配置されて構成される。第２レンズ群２２０は、物体側から順に、両面が凸面の正レンズ２２１と、正レンズと負レンズとで形成された接合レンズ２２２が配置されて構成される。第３レンズ群２３０は、１枚の正レンズ２３１で構成される。この正レンズ２３１はプラスチック材で成形するとよい。   The first lens group 210 includes a negative lens 211 having a composite aspheric surface formed on the image plane 250 side and a positive lens 212 in order from the object side. The second lens group 220 includes, in order from the object side, a positive lens 221 having convex surfaces and a cemented lens 222 formed of a positive lens and a negative lens. The third lens group 230 includes a single positive lens 231. The positive lens 231 may be molded from a plastic material.

以下、実施例２にかかるズームレンズに関する各種数値データを示す。   Various numerical data related to the zoom lens according to Example 2 will be described below.

実施例２のズームレンズ全系の焦点距離＝6.43(広角端)〜10.94(中間端)〜18.50（望遠端）
Ｆナンバ＝2.87(広角端)〜3.9(中間端)〜5.34（望遠端）
入射画角（２ω）＝60.5°(広角端)〜37.84°(中間端)〜22.9°（望遠端）
第１レンズ群２１０の焦点距離（Ｆ１）＝-15.9680
第２レンズ群２２０の焦点距離（Ｆ２）＝10.6750
第１レンズ群２１０に含まれる負レンズ２１１の焦点距離（ｆ１）＝-7.225
第１レンズ群２１０に含まれる正レンズ２１２の焦点距離（ｆ２）＝14.3141
｜Ｆ１｜／Ｆ２＝1.496
Ｆ２／Ｆｗ＝1.66
Ｒ／Ｄ＝17.7
｜ｆ１｜／ｆ２＝0.5047 Focal length of the entire zoom lens system of Example 2 = 6.43 (wide-angle end) to 10.94 (intermediate end) to 18.50 (telephoto end)
F number = 2.87 (wide-angle end) to 3.9 (intermediate end) to 5.34 (telephoto end)
Incident angle of view (2ω) = 60.5 ° (wide-angle end) to 37.84 ° (intermediate end) to 22.9 ° (telephoto end)
Focal length (F1) of the first lens group 210 = -15.9680
Focal length (F2) of the second lens group 220 = 10.6750
Focal length (f1) of negative lens 211 included in first lens group 210 = −7.225
Focal length (f2) of positive lens 212 included in first lens group 210 = 14.3141
| F1 | /F2=1.498
F2 / Fw = 1.66
R / D = 17.7
| F1 | /f2=0.5047

ｒ1＝325.858
ｄ1＝0.7 ｎｄ1＝1.7725 νｄ1＝49.62
ｒ2＝6.050
ｄ2＝0.2 ｎｄ2＝1.5361 νｄ2＝41.20
ｒ3＝5.325（非球面）
ｄ3＝1.13
ｒ4＝7.630
ｄ4＝1.7 ｎｄ3＝1.8061 νｄ3＝33.27
ｒ5＝20.000
ｄ5＝12.737(広角端)〜5.651(中間端)〜1.481（望遠端）
ｒ6＝∞（絞り）
ｄ6＝0.7
ｒ7＝5.950（非球面）
ｄ7＝1.55 ｎｄ4＝1.6935 νｄ4＝53.34
ｒ8＝-23.473（非球面）
ｄ8＝0.4
ｒ9＝12.330
ｄ9＝1.6 ｎｄ5＝1.8340 νｄ5＝37.35
ｒ10＝-7.900
ｄ10＝0.55 ｎｄ6＝1.7283 νｄ6＝28.32
ｒ11＝3.780
ｄ11＝4.179(広角端)〜9.057(中間端)〜16.442（望遠端）
ｒ12＝38.670（非球面）
ｄ12＝1.9 ｎｄ7＝1.5248 νｄ7＝58.00
ｒ13＝-10.833（非球面）
ｄ13＝2.614(広角端) 〜2.229(中間端)〜1.600（望遠端）
ｒ14＝∞
ｄ14＝0.44 ｎｄ8＝1.5523 νｄ8＝63.42
ｒ15＝∞
ｄ15＝1
ｒ16＝∞
ｄ16＝0.5 ｎｄ9＝1.5168 νｄ9＝64.20
ｒ17＝∞
ｄ17＝0.6 r 1 = 325.858
d 1 = 0.7 nd 1 = 1.7725 νd 1 = 49.62
r 2 = 6.050
d 2 = 0.2 nd 2 = 1.5361 νd 2 = 41.20
r 3 = 5.325 (aspherical surface)
d 3 = 1.13
r 4 = 7.630
d 4 = 1.7 nd 3 = 1.8061 νd 3 = 33.27
r 5 = 20.000
d 5 = 12.737 (wide-angle end) to 5.651 (intermediate end) to 1.481 (telephoto end)
r 6 = ∞ (aperture)
d 6 = 0.7
r 7 = 5.950 (aspherical surface)
d 7 = 1.55 nd 4 = 1.6935 νd 4 = 53.34
r 8 = -23.473 (aspherical surface)
d 8 = 0.4
r 9 = 12.330
d 9 = 1.6 nd 5 = 1.8340 νd 5 = 37.35
r 10 = -7.900
d 10 = 0.55 nd 6 = 1.7283 νd 6 = 28.32
r 11 = 3.780
d 11 = 4.179 (wide-angle end) to 9.057 (intermediate end) to 16.442 (telephoto end)
r 12 = 38.670 (aspherical surface)
d 12 = 1.9 nd 7 = 1.5248 νd 7 = 58.00
r 13 = -10.833 (aspherical surface)
d 13 = 2.614 (wide-angle end) ～2.229 (middle end) ～1.600 (telephoto end)
r 14 = ∞
d 14 = 0.44 nd 8 = 1.5523 νd 8 = 63.42
r 15 = ∞
d 15 = 1
r 16 = ∞
d 16 = 0.5 nd 9 = 1.5168 νd 9 = 64.20
r 17 = ∞
d 17 = 0.6

円錐係数（Ｋ）および非球面係数（Ａ4，Ａ6，Ａ8，Ａ10）
第３面
Ｋ＝0
Ａ4＝-0.570789×10-3， Ａ6＝-0.790883×10-5，
Ａ8＝-0.193511×10-6， Ａ10＝-0.281154×10-7
第７面
Ｋ＝0
Ａ4＝-0.506901×10-3， Ａ6＝-0.123533×10-3，
Ａ8＝0.229594×10-4， Ａ10＝-0.168228×10-5
第８面
Ｋ＝0
Ａ4＝0.527440×10-3， Ａ6＝-0.162694×10-3，
Ａ8＝0.347268×10-4， Ａ10＝-0.265876×10-5
第１２面
Ｋ＝0
Ａ4＝0.587404×10-3， Ａ6＝-0.383154×10-4，
Ａ8＝0.181466×10-5， Ａ10＝-0.494647×10-7
第１３面
Ｋ＝0
Ａ4＝0.115941×10-2， Ａ6＝-0.440723×10-4，
Ａ8＝0.132371×10-5， Ａ10＝-0.319703×10-7 Conic coefficient (K) and aspheric coefficient (A 4 , A 6 , A 8 , A 10 )
Third side K = 0
A 4 = -0.570789 × 10 -3 , A 6 = -0.790883 × 10 -5 ,
A 8 = -0.193511 × 10 -6 , A 10 = -0.281154 × 10 -7
7th surface K = 0
A 4 = -0.506901 × 10 -3 , A 6 = -0.123533 × 10 -3 ,
A 8 = 0.229594 × 10 −4 , A 10 = −0.168228 × 10 −5
8th surface K = 0
A 4 = 0.527440 × 10 −3 , A 6 = −0.162694 × 10 −3 ,
A 8 = 0.347268 × 10 −4 , A 10 = −0.265876 × 10 −5
12th surface K = 0
A 4 = 0.587404 × 10 −3 , A 6 = −0.383154 × 10 −4 ,
A 8 = 0.181466 × 10 −5 , A 10 = −0.494647 × 10 −7
13th surface K = 0
A 4 = 0.115941 × 10 −2 , A 6 = −0.440723 × 10 −4 ,
A 8 = 0.132371 × 10 −5 , A 10 = −0.319703 × 10 −7

また、図６は、実施例２にかかるズームレンズの広角端における収差図である。図７は、実施例２にかかるズームレンズの中間端における収差図である。図８は、実施例２にかかるズームレンズの望遠端における収差図である。   FIG. 6 is an aberration diagram at the wide-angle end of the zoom lens according to Example 2. FIG. 7 is an aberration diagram at an intermediate end of the zoom lens according to the second example. FIG. 8 is an aberration diagram of the zoom lens according to Example 2 at the telephoto end.

（実施例３）
図９は、この発明の実施例３にかかるズームレンズの構成を示す光軸に沿う断面図である。このズームレンズは、図示しない物体側から順に、負の屈折力を有する第１レンズ群３１０、正の屈折力を有する第２レンズ群３２０、および正の屈折力を有する第３レンズ群３３０が配置されて構成される。また、第１レンズ群３１０と第２レンズ群３２０との間には絞り３４０が配置されている。第３レンズ群３３０と像面３５０との間には、カバーガラス３６０が配置されている。 (Example 3)
FIG. 9 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 3 of the present invention. In this zoom lens, a first lens group 310 having a negative refractive power, a second lens group 320 having a positive refractive power, and a third lens group 330 having a positive refractive power are arranged in this order from the object side (not shown). Configured. A stop 340 is disposed between the first lens group 310 and the second lens group 320. A cover glass 360 is disposed between the third lens group 330 and the image plane 350.

第１レンズ群３１０は、物体側から順に、負レンズ３１１と、非球面が形成された正レンズ３１２が配置されて構成される。第２レンズ群３２０は、物体側から順に、両面が凸面の正レンズ３２１と、正レンズと負レンズとで形成された接合レンズ３２２が配置されて構成される。第３レンズ群３３０は、１枚の正レンズ３３１で構成される。この正レンズ３３１はプラスチック材で成形するとよい。   The first lens group 310 includes, in order from the object side, a negative lens 311 and a positive lens 312 having an aspheric surface. The second lens group 320 includes, in order from the object side, a positive lens 321 having convex surfaces on both sides and a cemented lens 322 formed of a positive lens and a negative lens. The third lens group 330 includes a single positive lens 331. The positive lens 331 may be molded from a plastic material.

以下、実施例３にかかるズームレンズに関する各種数値データを示す。   Various numerical data relating to the zoom lens according to Example 3 will be described below.

実施例３のズームレンズ全系の焦点距離＝6.43(広角端)〜10.94(中間端)〜18.50（望遠端）
Ｆナンバ＝2.87(広角端)〜3.9(中間端)〜5.34（望遠端）
入射画角（２ω）＝60.5°(広角端)〜37.84°(中間端)〜22.9°（望遠端）
第１レンズ群３１０の焦点距離（Ｆ１）＝-14.1020
第２レンズ群３２０の焦点距離（Ｆ２）＝9.9140
第１レンズ群３１０に含まれる負レンズ３１１の焦点距離（ｆ１）＝-7.408
第１レンズ群３１０に含まれる正レンズ３１２の焦点距離（ｆ２）＝17.1006
｜Ｆ１｜／Ｆ２＝1.422
Ｆ２／Ｆｗ＝1.54
Ｒ／Ｄ＝20
｜ｆ１｜／ｆ２＝0.4332 Focal length of the entire zoom lens system of Example 3 = 6.43 (wide-angle end) to 10.94 (intermediate end) to 18.50 (telephoto end)
F number = 2.87 (wide-angle end) to 3.9 (intermediate end) to 5.34 (telephoto end)
Incident angle of view (2ω) = 60.5 ° (wide-angle end) to 37.84 ° (intermediate end) to 22.9 ° (telephoto end)
Focal length (F1) of the first lens group 310 = -14.1020
Focal length (F2) of second lens group 320 = 9.9140
Focal length (f1) of negative lens 311 included in first lens group 310 = −7.408
Focal length (f2) of positive lens 312 included in first lens group 310 = 17.1006
| F1 | /F2=1.422
F2 / Fw = 1.54
R / D = 20
| F1 | /f2=0.4332

ｒ1＝198.440
ｄ1＝1 ｎｄ1＝1.7725 νｄ1＝49.62
ｒ2＝5.576
ｄ2＝1.22
ｒ3＝8.443（非球面）
ｄ3＝1.68 ｎｄ2＝1.71736 νｄ2＝29.5
ｒ4＝24.396（非球面）
ｄ4＝11.0(広角端)〜5.131(中間端)〜1.397（望遠端）
ｒ5＝∞（絞り）
ｄ5＝0.5
ｒ6＝5.368（非球面）
ｄ6＝1.7 ｎｄ3＝1.7292 νｄ3＝54.67
ｒ7＝-21.999（非球面）
ｄ7＝0.1
ｒ8＝20.243
ｄ8＝1.5 ｎｄ4＝1.7859 νｄ4＝43.93
ｒ9＝-5.704
ｄ9＝0.7 ｎｄ5＝1.6727 νｄ5＝32.17
ｒ10＝3.631
ｄ10＝4.482(広角端)〜9.59(中間端)〜16.818（望遠端）
ｒ11＝91.770（非球面）
ｄ11＝1.8 ｎｄ6＝1.52 νｄ6＝56
ｒ12＝-9.418（非球面）
ｄ12＝2.752(広角端)〜2.14(中間端)〜1.70（望遠端）
ｒ13＝∞
ｄ13＝0.44 ｎｄ7＝1.5168 νｄ7＝64.17
ｒ14＝∞
ｄ14＝0.5
ｒ15＝∞
ｄ15＝0.5 ｎｄ8＝1.5688 νｄ8＝56.04
ｒ16＝∞
ｄ16＝0.79 r 1 = 198.440
d 1 = 1 nd 1 = 1.7725 νd 1 = 49.62
r 2 = 5.576
d 2 = 1.22
r 3 = 8.443 (aspherical surface)
d 3 = 1.68 nd 2 = 1.71736 νd 2 = 29.5
r 4 = 24.396 (aspherical surface)
d 4 = 11.0 (wide-angle end) to 5.131 (intermediate end) to 1.397 (telephoto end)
r 5 = ∞ (aperture)
d 5 = 0.5
r 6 = 5.368 (aspherical surface)
d 6 = 1.7 nd 3 = 1.7292 νd 3 = 54.67
r 7 = -21.999 (aspherical surface)
d 7 = 0.1
r 8 = 20.243
d 8 = 1.5 nd 4 = 1.7859 νd 4 = 43.93
r 9 = -5.704
d 9 = 0.7 nd 5 = 1.6727 νd 5 = 32.17
r 10 = 3.631
d 10 = 4.482 (wide-angle end) to 9.59 (intermediate end) to 16.818 (telephoto end)
r 11 = 91.770 (aspherical surface)
d 11 = 1.8 nd 6 = 1.52 νd 6 = 56
r 12 = -9.418 (aspherical surface)
d 12 = 2.752 (wide-angle end) to 2.14 (intermediate end) to 1.70 (telephoto end)
r 13 = ∞
d 13 = 0.44 nd 7 = 1.5168 νd 7 = 64.17
r 14 = ∞
d 14 = 0.5
r 15 = ∞
d 15 = 0.5 nd 8 = 1.5688 νd 8 = 56.04
r 16 = ∞
d 16 = 0.79

円錐係数（Ｋ）および非球面係数（Ａ4，Ａ6，Ａ8，Ａ10）
第３面
Ｋ＝0.648446
Ａ4＝0.307154×10-4， Ａ6＝-0.885616×10-5，
Ａ8＝0.116641×10-5， Ａ10＝-0.305120×10-7
第４面
Ｋ＝-11.675684
Ａ4＝-0.133579×10-3， Ａ6＝0，
Ａ8＝0， Ａ10＝0
第６面
Ｋ＝0
Ａ4＝-0.564667×10-3， Ａ6＝0.417915×10-4，
Ａ8＝-0.590464×10-5， Ａ10＝0.107592×10-5
第７面
Ｋ＝0
Ａ4＝0.103297×10-2， Ａ6＝0.442306×10-4，
Ａ8＝-0.486985×10-5， Ａ10＝0.147821×10-5
第１１面
Ｋ＝0
Ａ4＝0.243849×10-4， Ａ6＝0.121526×10-4，
Ａ8＝0， Ａ10＝0
第１２面
Ｋ＝0
Ａ4＝0.704611×10-3， Ａ6＝-0.176681×10-4，
Ａ8＝0.171116×10-5， Ａ10＝-0.392563×10-7 Conic coefficient (K) and aspheric coefficient (A 4 , A 6 , A 8 , A 10 )
Third side K = 0.648446
A 4 = 0.307154 × 10 −4 , A 6 = −0.885616 × 10 −5 ,
A 8 = 0.116641 × 10 −5 , A 10 = −0.305120 × 10 −7
4th surface K = -11.675684
A 4 = -0.133579 × 10 -3 , A 6 = 0,
A 8 = 0, A 10 = 0
6th surface K = 0
A 4 = -0.564667 × 10 -3 , A 6 = 0.417915 × 10 -4 ,
A 8 = -0.590464 × 10 -5 , A 10 = 0.107592 × 10 -5
7th surface K = 0
A 4 = 0.103297 × 10 -2 , A 6 = 0.442306 × 10 -4 ,
A 8 = -0.486985 × 10 -5 , A 10 = 0.147821 × 10 -5
11th surface K = 0
A 4 = 0.243849 × 10 −4 , A 6 = 0.121526 × 10 −4 ,
A 8 = 0, A 10 = 0
12th surface K = 0
A 4 = 0.704611 × 10 −3 , A 6 = −0.176681 × 10 −4 ,
A 8 = 0.171116 × 10 −5 , A 10 = −0.392563 × 10 −7

また、図１０は、実施例３にかかるズームレンズの広角端における収差図である。図１１は、実施例３にかかるズームレンズの中間端における収差図である。図１２は、実施例３にかかるズームレンズの望遠端における収差図である。   FIG. 10 is an aberration diagram at the wide-angle end of the zoom lens according to the third example. FIG. 11 is an aberration diagram at an intermediate end of the zoom lens according to the third example. FIG. 12 is an aberration diagram at the telephoto end of the zoom lens according to the third example.

なお、上記数値データにおいて、ｒ1，ｒ2，・・・・は各レンズ、絞り面などの曲率半径、ｄ1，ｄ2，・・・・は各レンズ、絞りなどの肉厚またはそれらの面間隔、ｎｄ1，ｎｄ2，・・・・は各レンズなどのｄ線の屈折率、νｄ1，νｄ2，・・・・は各レンズなどのアッベ数を示している。 In the above numerical data, r 1, r 2, · · · · each lens, the curvature of such diaphragm surface radius, d 1, d 2, · · · · each lens, such as a diaphragm thickness or their The distance between the surfaces, nd 1 , nd 2 ,... Indicates the refractive index of the d-line of each lens, and νd 1 , νd 2 ,.

また、上記各非球面形状は、光軸方向にｚ軸、光軸と垂直方向にｙ軸をとり、光の進行方向を正とするとき、以下に示す式により表される。   Each of the aspherical shapes is expressed by the following equation when the z-axis is taken in the optical axis direction, the y-axis is taken in the direction perpendicular to the optical axis, and the light traveling direction is positive.

Figure 2007017638
Figure 2007017638

ただし、ｒは近軸曲率半径、Ｋは円錐係数、Ａ4，Ａ6，Ａ8，Ａ10はそれぞれ４次，６次，８次，１０次の非球面係数である。 Here, r is a paraxial radius of curvature, K is a conical coefficient, and A 4 , A 6 , A 8 , and A 10 are fourth-order, sixth-order, eighth-order, and tenth-order aspheric coefficients, respectively.

以上説明したように、この実施例のズームレンズは、第１レンズ群を負レンズに複合非球面が形成されている負レンズか、非球面が形成された正レンズを用いて構成し、さらに、第３レンズ群をプラスチック材で成形された正レンズで構成しているため、全体を６枚のレンズで構成でき、製造コストの低減を図ることができる。   As described above, in the zoom lens of this embodiment, the first lens group is configured using a negative lens in which a composite aspheric surface is formed as a negative lens, or a positive lens in which an aspheric surface is formed. Since the third lens group is composed of a positive lens molded of a plastic material, the entire lens group can be composed of six lenses, and the manufacturing cost can be reduced.

また、第１レンズ群の屈折力が弱く、第２レンズ群の屈折力が強くなるようにしたことにより、第２レンズ群の光軸に沿う方向の移動量を抑え、撮影時の光学系の全長を短くすることができ、光学系のコンパクト化を達成できる。   In addition, since the refractive power of the first lens group is weak and the refractive power of the second lens group is increased, the movement amount of the second lens group in the direction along the optical axis is suppressed, and the optical system at the time of photographing is reduced. The overall length can be shortened, and the optical system can be made compact.

また、第１レンズ群に含まれる正レンズの像側面の曲率半径が大きくなるようにして、第１レンズ群に含まれる、負レンズと正レンズとの間隔を短くしたことにより、沈胴時の光学系の全長を短くすることができる。   Further, the radius of curvature of the image side surface of the positive lens included in the first lens group is increased, and the distance between the negative lens and the positive lens included in the first lens group is shortened, so that the optical at the time of collapsing is reduced. The total length of the system can be shortened.

また、各レンズ群は非球面が形成されたレンズを含んで構成されているため、少ないレンズ枚数で、諸収差を良好に補正することができる。   In addition, since each lens group includes a lens having an aspherical surface, various aberrations can be corrected with a small number of lenses.

以上のように、この発明のズームレンズは、コンパクトなデジタルカメラやビデオカメラなどに有用であり、特に、小型で高い光学性能が要求される場合に最適である。   As described above, the zoom lens of the present invention is useful for a compact digital camera, a video camera, and the like, and is particularly suitable when a small size and high optical performance are required.

この発明の実施例１にかかるズームレンズの構成を示す光軸に沿う断面図である。It is sectional drawing which follows the optical axis which shows the structure of the zoom lens concerning Example 1 of this invention. 実施例１にかかるズームレンズの広角端における収差図である。FIG. 6 is an aberration diagram at a wide-angle end of the zoom lens according to Example 1; 実施例１にかかるズームレンズの中間端における収差図である。FIG. 6 is an aberration diagram at an intermediate end of the zoom lens according to Example 1; 実施例１にかかるズームレンズの望遠端における収差図である。FIG. 6 is an aberration diagram at a telephoto end of a zoom lens according to Example 1; この発明の実施例２にかかるズームレンズの構成を示す光軸に沿う断面図である。It is sectional drawing which follows the optical axis which shows the structure of the zoom lens concerning Example 2 of this invention. 実施例２にかかるズームレンズの広角端における収差図である。FIG. 6 is an aberration diagram at a wide angle end of a zoom lens according to Example 2; 実施例２にかかるズームレンズの中間端における収差図である。FIG. 6 is an aberration diagram at an intermediate end of the zoom lens according to Example 2; 実施例２にかかるズームレンズの望遠端における収差図である。FIG. 6 is an aberration diagram at a telephoto end of a zoom lens according to Example 2; この発明の実施例３にかかるズームレンズの構成を示す光軸に沿う断面図である。It is sectional drawing which follows the optical axis which shows the structure of the zoom lens concerning Example 3 of this invention. 実施例３にかかるズームレンズの広角端における収差図である。FIG. 6 is an aberration diagram at a wide angle end of a zoom lens according to Example 3; 実施例３にかかるズームレンズの中間端における収差図である。FIG. 6 is an aberration diagram at an intermediate end of a zoom lens according to Example 3; 実施例３にかかるズームレンズの望遠端における収差図である。FIG. 6 is an aberration diagram at a telephoto end of a zoom lens according to Example 3;

符号の説明Explanation of symbols

１１０，２１０，３１０ 第１レンズ群
１１１，２１１，３１１ 負レンズ
１１２，１２１，１３１，２１２，２２１，２３１，３１２，３２１，３３１ 正レンズ
１２０，２２０，３２０ 第２レンズ群
１２２，２２２，３２２ 接合レンズ
１３０，２３０，３３０ 第３レンズ群
１４０，２４０，３４０ 絞り
１５０，２５０，３５０ 像面
１６０，２６０，３６０ カバーガラス

110, 210, 310 First lens group 111, 211, 311 Negative lens 112, 121, 131, 212, 221, 231, 312, 321, 331 Positive lens 120, 220, 320 Second lens group 122, 222, 322 Joint Lens 130, 230, 330 Third lens group 140, 240, 340 Aperture 150, 250, 350 Image surface 160, 260, 360 Cover glass

Claims (11)

物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群と、を含み構成されており、
前記第１レンズ群は、複合非球面が形成された１枚の負レンズと、１枚の正レンズを含む少なくとも２枚のレンズで構成され、
前記第２レンズ群は、両面が凸面の正レンズと、正レンズと負レンズとの接合レンズを含む少なくとも３枚のレンズで構成され、
前記第３レンズ群は、正レンズを含む少なくとも１枚のレンズで構成され、
前記第２レンズ群の光軸に沿う方向の移動量を抑制して、前記各レンズ群の間隔を変化させて変倍を行うことを特徴とするズームレンズ。 A first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, which are arranged in order from the object side. ,
The first lens group includes at least two lenses including one negative lens having a composite aspherical surface and one positive lens,
The second lens group includes at least three lenses including a positive lens having both convex surfaces and a cemented lens of a positive lens and a negative lens;
The third lens group includes at least one lens including a positive lens,
A zoom lens, wherein zooming is performed by changing an interval between the lens groups while suppressing an amount of movement of the second lens group in the direction along the optical axis. 物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群と、を含み構成されており、
前記第１レンズ群は、１枚の負レンズと、非球面が形成された１枚の正レンズを含む少なくとも２枚のレンズで構成され、
前記第２レンズ群は、両面が凸面の正レンズと、正レンズと負レンズとの接合レンズを含む少なくとも３枚のレンズで構成され、
前記第３レンズ群は、正レンズを含む少なくとも１枚のレンズで構成され、
前記第２レンズ群の光軸に沿う方向の移動量を抑制して、前記各レンズ群の間隔を変化させて変倍を行うことを特徴とするズームレンズ。 A first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, which are arranged in order from the object side. ,
The first lens group includes at least two lenses including one negative lens and one positive lens on which an aspheric surface is formed,
The second lens group includes at least three lenses including a positive lens having both convex surfaces and a cemented lens of a positive lens and a negative lens;
The third lens group includes at least one lens including a positive lens,
A zoom lens, wherein zooming is performed by changing an interval between the lens groups while suppressing an amount of movement of the second lens group in the direction along the optical axis. 前記第３レンズ群に含まれる正レンズはプラスチック材で構成され、当該正レンズのいずれかの面には非球面が形成されていることを特徴とする請求項１または２に記載のズームレンズ。   3. The zoom lens according to claim 1, wherein a positive lens included in the third lens group is made of a plastic material, and an aspheric surface is formed on any surface of the positive lens. 前記第１レンズ群に含まれる正レンズの像側面の曲率半径が大きくなるようにして、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔を短くするとともに、前記第１レンズ群に含まれる、負レンズと正レンズの焦点距離のバランスを保ち、前記第１レンズ群全体の屈折力が弱くなるようにしたことを特徴とする請求項１〜３のいずれか一つに記載のズームレンズ。   The radius of curvature of the image side surface of the positive lens included in the first lens group is increased to shorten the interval between the negative lens and the positive lens included in the first lens group, and the first lens group. The balance of the focal length of the negative lens and the positive lens included in the lens is maintained, and the refractive power of the entire first lens group is weakened. Zoom lens. 前記第１レンズ群の第３面および前記第２レンズ群の第１面には、非球面が形成されていることを特徴とする請求項１〜４のいずれか一つに記載のズームレンズ。   The zoom lens according to claim 1, wherein an aspherical surface is formed on the third surface of the first lens group and the first surface of the second lens group. 前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とする請求項１〜５のいずれか一つに記載のズームレンズ。 When the focal length of the first lens group is F1, the focal length of the second lens group is F2, and the focal length at the wide angle end of the entire system is Fw,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
The zoom lens according to claim 1, wherein: 前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とする請求項１〜６のいずれか一つに記載のズームレンズ。 The radius of curvature of the image side surface of the positive lens included in the first lens group is R, the distance between the negative lens and the positive lens included in the first lens group is D, and the negative lens included in the first lens group is When the focal length is f1, and the focal length of the positive lens included in the first lens group is f2,
R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
The zoom lens according to claim 1, wherein the zoom lens satisfies the following. 前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗ、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
かつ
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とする請求項１または２に記載のズームレンズ。 The focal length of the first lens group is F1, the focal length of the second lens group is F2, the focal length at the wide-angle end of the entire system is Fw, and the curvature radius of the image side surface of the positive lens included in the first lens group is R, the distance between the negative lens and the positive lens included in the first lens group is D, the focal length of the negative lens included in the first lens group is f1, and the focal point of the positive lens included in the first lens group. When the distance is f2,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
And R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
The zoom lens according to claim 1, wherein the zoom lens satisfies the following. 物体側から順に配置された、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、
前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とするズームレンズ。 A first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side, and
When the focal length of the first lens group is F1, the focal length of the second lens group is F2, and the focal length at the wide angle end of the entire system is Fw,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
A zoom lens characterized by satisfying 物体側から順に配置された、１枚の負レンズと１枚の正レンズを含む少なくとも２枚のレンズで構成され全体として負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、
前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗとするとき、
Ｒ／Ｄ≧１６
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
を満足することを特徴とするズームレンズ。 A first lens group which is composed of at least two lenses including one negative lens and one positive lens arranged in order from the object side and has a negative refractive power as a whole, and a first lens group having a positive refractive power. Two lens groups, and
The radius of curvature of the image side surface of the positive lens included in the first lens group is R, the distance between the negative lens and the positive lens included in the first lens group is D, and the focal length of the second lens group is F2. When the focal length at the wide-angle end of the entire system is Fw,
R / D ≧ 16
And 1.5 <F2 / Fw <1.75
A zoom lens characterized by satisfying 物体側から順に配置された、１枚の負レンズと１枚の正レンズを含む少なくとも２枚のレンズで構成され全体として負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、を含み構成されており、
前記第１レンズ群の焦点距離をＦ１、前記第２レンズ群の焦点距離をＦ２、全系の広角端における焦点距離をＦｗ、前記第１レンズ群に含まれる正レンズの像側面の曲率半径をＲ、前記第１レンズ群に含まれる、負レンズと正レンズとの間隔をＤ、前記第１レンズ群に含まれる負レンズの焦点距離をｆ１、前記第１レンズ群に含まれる正レンズの焦点距離をｆ２とするとき、
１．４＜｜Ｆ１｜／Ｆ２＜１．５１
かつ
１．５＜Ｆ２／Ｆｗ＜１．７５
かつ
Ｒ／Ｄ≧１６
かつ
０．４３＜｜ｆ１｜／ｆ２＜０．５１
を満足することを特徴とするズームレンズ。 A first lens group which is composed of at least two lenses including one negative lens and one positive lens arranged in order from the object side and has a negative refractive power as a whole, and a first lens group having a positive refractive power. Two lens groups, and
The focal length of the first lens group is F1, the focal length of the second lens group is F2, the focal length at the wide-angle end of the entire system is Fw, and the curvature radius of the image side surface of the positive lens included in the first lens group is R, the distance between the negative lens and the positive lens included in the first lens group is D, the focal length of the negative lens included in the first lens group is f1, and the focal point of the positive lens included in the first lens group. When the distance is f2,
1.4 <| F1 | / F2 <1.51
And 1.5 <F2 / Fw <1.75
And R / D ≧ 16
And 0.43 <| f1 | / f2 <0.51
A zoom lens characterized by satisfying
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014007298A1 (en) * 2012-07-03 2014-01-09 株式会社タムロン Zoom lens
CN113448179A (en) * 2021-07-02 2021-09-28 浙江大学 Nano laser direct writing objective lens
CN114114651A (en) * 2022-01-27 2022-03-01 江西联创电子有限公司 Optical lens

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002372667A (en) * 2001-06-14 2002-12-26 Konica Corp Zoom lens
JP2003140046A (en) * 2001-10-30 2003-05-14 Nidec Copal Corp Zoom lens
JP2004061675A (en) * 2002-07-26 2004-02-26 Canon Inc Zoom lens
JP2004093917A (en) * 2002-08-30 2004-03-25 Nikon Corp Zoom lens
JP2004325975A (en) * 2003-04-28 2004-11-18 Sony Corp Zoom lens and imaging apparatus
JP2005128194A (en) * 2003-10-23 2005-05-19 Konica Minolta Opto Inc Zoom lens and imaging device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002372667A (en) * 2001-06-14 2002-12-26 Konica Corp Zoom lens
JP2003140046A (en) * 2001-10-30 2003-05-14 Nidec Copal Corp Zoom lens
JP2004061675A (en) * 2002-07-26 2004-02-26 Canon Inc Zoom lens
JP2004093917A (en) * 2002-08-30 2004-03-25 Nikon Corp Zoom lens
JP2004325975A (en) * 2003-04-28 2004-11-18 Sony Corp Zoom lens and imaging apparatus
JP2005128194A (en) * 2003-10-23 2005-05-19 Konica Minolta Opto Inc Zoom lens and imaging device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014007298A1 (en) * 2012-07-03 2014-01-09 株式会社タムロン Zoom lens
CN113448179A (en) * 2021-07-02 2021-09-28 浙江大学 Nano laser direct writing objective lens
CN113448179B (en) * 2021-07-02 2022-05-24 浙江大学 Nano laser direct writing objective lens
CN114114651A (en) * 2022-01-27 2022-03-01 江西联创电子有限公司 Optical lens

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