JP2015203736A - Super wide angle zoom lens - Google Patents

Super wide angle zoom lens Download PDF

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JP2015203736A
JP2015203736A JP2014082216A JP2014082216A JP2015203736A JP 2015203736 A JP2015203736 A JP 2015203736A JP 2014082216 A JP2014082216 A JP 2014082216A JP 2014082216 A JP2014082216 A JP 2014082216A JP 2015203736 A JP2015203736 A JP 2015203736A
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lens group
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wide
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JP6390147B2 (en
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武久 小山
Takehisa Koyama
武久 小山
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Sigma Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a wide angle zoom lens having an angle of view exceeding 120 degrees, in which a focus lens group is reduced in weight by appropriately setting power arrangement and which is suitable for inner focus with a small image height change rate.SOLUTION: The wide angle zoom lens includes, in order from the object side, a first lens group G1 having negative power, a second lens group G2 having negative power, a third lens group G3 having positive power and consisting of a single lens, a fourth lens group G4 having positive power, a fifth lens group G5 having positive power, and a sixth lens group G6 having positive power. When focusing from the object side infinity to an object at a short distance, the third lens group G3 is moved toward the image plane side. The wide angle zoom lens satisfies predetermined conditions.

Description

本発明は、スチルカメラ、ビデオカメラ等の撮像装置に用いる撮影レンズに好適な光学系に関し、オートフォーカスカメラに適したインナーフォーカス方式を採用し、またフォーカスレンズ群を光軸に沿う方向への微少な振動（ウオブリング）させた際の像高変化率が小さく、広角端での撮影画角が１２０度以上と広画角なズームレンズに関するものである。   The present invention relates to an optical system suitable for a photographic lens used in an imaging apparatus such as a still camera or a video camera, and employs an inner focus system suitable for an autofocus camera, and a focus lens group in a direction along the optical axis. The present invention relates to a zoom lens that has a small image height change rate when it is vibrated (wobbling) and has a wide field angle of 120 ° or more at the wide angle end.

ズームレンズのフォーカス方式は、物体側の第１群をそのまま繰出すフロントフォーカス方式が一般的である。しかしＡＦ化の要請から、第１群以外の比較的軽量なレンズ群でフォーカスを行うインナーフォーカス方式が望まれていた。このインナーフォーカス方式については近年数多く提案されているが、有限距離におけるズーミング時のピントずれを防ぐために補正カムを必要とし、機構が複雑になる問題を抱えていた。第１群以外のレンズ群でフォーカスを行うインナーフォーカス方式を採用した技術として特許文献１、２、３、４が開示されている。   A zoom lens focusing method is generally a front focusing method in which the first group on the object side is extended as it is. However, due to the demand for AF, an inner focus method in which focusing is performed with a relatively light lens group other than the first group has been desired. In recent years, there have been many proposals for this inner focus method, but a correction cam is required to prevent a focus shift during zooming at a finite distance, and the mechanism is complicated. Patent Documents 1, 2, 3, and 4 are disclosed as techniques that employ an inner focus method in which focusing is performed using a lens group other than the first group.

特開平４−１５６１２号公報Japanese Patent Laid-Open No. 4-15612 特開平６−２３０２８１号公報JP-A-6-230281 特開２００１−１８８１７１号公報（特許第４５１９２３２号）JP 2001-188171 A (Patent No. 4519232) 特開２０１３−１５６２１号公報JP 2013-15621 A

負の屈折力のレンズ群が先行するズームタイプは、広角ズームや超広角ズームに適したタイプである。しかし、第１レンズ群でフォーカスすることが多く、フォーカス群が重いためＡＦに支障をきたしていた。   The zoom type preceded by a lens unit having a negative refractive power is a type suitable for wide-angle zoom and ultra-wide-angle zoom. However, focusing is often performed with the first lens group, and the focus group is heavy, which hinders AF.

また、第１レンズ群の内部をフォーカスさせることにより、若干量の重量軽減を図っているものも見受けられるが、十分な軽量化はなされていない。このため、アクチュエータの縮小化や応答性・リアルタイム性の問題等を改善させるため、さらなるフォーカス群の重量軽減が必要とされていた。   Further, there are some lenses that achieve a slight weight reduction by focusing the inside of the first lens group, but the weight has not been reduced sufficiently. For this reason, in order to improve the downsizing of the actuator and the problems of responsiveness and real-time characteristics, it is necessary to further reduce the weight of the focus group.

また、近年台頭してきたミラーレス一眼カメラのオートフォーカスのように、フォーカスレンズ群を光軸に沿う方向へ微少な振動（ウオブリング）をさせ続けることで、常にフォーカス駆動方向を判断し続ける形式のインナーフォーカス方式が開発されてきた。その際、ウオブリング時の像高変化率が大きいと、鑑賞者が画面に映る被写体の倍率変動を認識し、目障りに感じてしまう。そのためフォーカス変化に対して像高変化率が小さいフォーカス形式が望まれていた。   In addition, like the auto focus of mirrorless interchangeable-lens cameras that have emerged in recent years, the focus lens group continues to be slightly oscillated (wobbling) in the direction along the optical axis, thereby constantly determining the focus drive direction. Focus methods have been developed. At that time, if the image height change rate during wobbling is large, the viewer recognizes the magnification change of the subject on the screen and feels it annoying. Therefore, a focus type having a small image height change rate with respect to the focus change has been desired.

ここで、所定の物体高を与えて、その物体に対応する合焦状態での像高をｙ、撮影距離と物体高とを変えずにフォーカスレンズ群を移動させて、ガウス像面が合焦状態の位置から光軸方向への移動をΔｓとするとΔｓ＝±０．０８ｍｍだけ移動した場合の像高をｙ′とする。Δｓ＝±０．０８ｍｍは、最小錯乱円の直径を０．０１ｍｍ、Ｆ値をＦ８とした場合の片側焦点深度に相当する。ここでは、次式で定義されるηを像高変化率と呼ぶことにする。
η＝（ｙ′−ｙ）／ｙ 参考式（１） Here, given a predetermined object height, the image height in the focused state corresponding to the object is y, the focus lens group is moved without changing the shooting distance and the object height, and the Gaussian image plane is focused. When the movement in the optical axis direction from the position of the state is Δs, the image height when moving by Δs = ± 0.08 mm is y ′. Δs = ± 0.08 mm corresponds to the one-side depth of focus when the diameter of the minimum circle of confusion is 0.01 mm and the F value is F8. Here, η defined by the following equation is called an image height change rate.
η = (y′−y) / y Reference formula (1)

また、像高変化率ηの目標値に関しては、特開２００９−１２２６２０に以下の記述があり、本件発明はこの記述を参考に像高変化率ηの目標設定を行った。上記ガウス像面の移動量をΔｓとした時、段落［００６０］、［００６２］にて
「ここで、次のようにＥを定義する。
Ｅ＝η／Δｓ
種々の実験を行い、一般的な条件下で像高変化が目立たない条件は、
｜Ｅ｜＜１／８
であり、最も厳しい条件下で像高変化が目立たない条件は、
｜Ｅ｜＜１／８０
であることがわかった。」
と開示しており、この記述からすると、Δｓ＝０．０８とした時の像高変化率ηの許容は、
｜η｜＝Ｅ×Δｓ
より、最も厳しい条件下で像高変化が目立たない条件は、
｜η｜＜０．００１（０．１％）
となり、本件発明はこの記述を参考に像高変化率ηの目標設定を行った。 Regarding the target value of the image height change rate η, Japanese Unexamined Patent Application Publication No. 2009-122620 has the following description, and the present invention sets the target of the image height change rate η with reference to this description. When the amount of movement of the Gaussian image plane is Δs, paragraphs [0060] and [0062] “Here, E is defined as follows.
E = η / Δs
Various experiments were conducted, and the conditions under which image height change was not noticeable under general conditions were
| E | <1/8
The conditions under which the change in image height is not noticeable under the most severe conditions are
| E | <1/80
I found out that "
From this description, the allowable image height change rate η when Δs = 0.08 is
| Η | = E × Δs
The conditions under which the change in image height is not noticeable under the most severe conditions are
| Η | <0.001 (0.1%)
Therefore, the present invention sets the target of the image height change rate η with reference to this description.

特許文献１で開示されているズームレンズは、負の屈折力の第１群と正の屈折力の第２群より成り、双方のレンズ群を移動させて変倍を行う２群ズームレンズにおいて第１群を負の屈折力の２つのレンズ群に分け、このうち像面側の小型軽量の負の屈折力の第１２群を光軸上移動させてフォーカスを行うことにより、合焦操作の高速化を容易にした、広角端の撮影面角が約１１３度と広画角なズームレンズを達成するとされるが、フォーカス群は複数のレンズで構成される、全体として負の屈折力を持つレンズ群であるため、フォーカスレンズ群の重量軽減が十分ではない。   The zoom lens disclosed in Patent Document 1 includes a first group having a negative refractive power and a second group having a positive refractive power, and is the first in a two-group zoom lens that performs zooming by moving both lens groups. One group is divided into two lens groups having a negative refractive power, and a small and light negative group 12 having a negative refractive power on the image plane side is moved on the optical axis to perform focusing, thereby achieving high-speed focusing operation. It is said that a zoom lens with a wide field angle of about 113 degrees at the wide-angle end that makes it easy to achieve will be achieved, but the focus group is composed of a plurality of lenses and has a negative refractive power as a whole Since it is a group, weight reduction of the focus lens group is not sufficient.

また、特許文献１の実施例１の広角端では、先に示した像高変化率ηの値は、最大像高２１．６３で０．５１％と大きく、さらに広角端の撮影画角が１１３度程しかない。   Further, at the wide angle end of Example 1 of Patent Document 1, the value of the image height change rate η described above is as large as 0.51% at the maximum image height 21.63, and the photographing field angle at the wide angle end is 113. There is only a degree.

また、特許文献２で開示されているズームレンズは、物体側より順に負の屈折力の第１群、負の屈折力の第２群、そして正の屈折力の第３群の３つのレンズ群を有し、フォーカス群は小型軽量の第２群で行うことで、オートフォーカスを容易にしているが、この技術も特許文献１と同様にフォーカス群は複数のレンズで構成される全体として負の屈折力を持つレンズ群であるため、フォーカスレンズ群の重量軽減が十分ではない。   In addition, the zoom lens disclosed in Patent Document 2 includes three lens groups of a first group having a negative refractive power, a second group having a negative refractive power, and a third group having a positive refractive power in order from the object side. In this technique, the focus group is composed of a plurality of lenses as in the case of Patent Document 1, and the focus group is a small and light second group. Since the lens group has a refractive power, weight reduction of the focus lens group is not sufficient.

また、特許文献２の実施例１では、広角端での像高変化率ηは、最大像高２１．６３で０．２０％と大きく、さらに広角端の撮影画角が９３度程しかない。   In Example 1 of Patent Document 2, the image height change rate η at the wide-angle end is as large as 0.20% at the maximum image height 21.63, and the photographing field angle at the wide-angle end is only about 93 degrees.

さらに、特許文献３で開示されているズームレンズは、物体側から順に負負正正の４群で構成し、物体距離無限遠から近距離物体へフォーカシングする際、第３レンズ群Ｌ３が像面方向へ移動し、第３群のパワー、および第３、４群の倍率を適切に設定することで、インナーフォーカスに最適な広画角なズームレンズを得ることができるが、広角端の撮影画角が７８度程しかなく、撮影画角が十分ではない。   Further, the zoom lens disclosed in Patent Document 3 includes four groups of negative, negative, positive and positive in order from the object side. When focusing from an infinite object distance to a close object, the third lens group L3 is in the image plane direction. The zoom lens with the wide angle of view that is optimal for inner focus can be obtained by appropriately setting the power of the third lens group and the magnification of the third and fourth lens groups. Is only about 78 degrees, and the angle of view is not sufficient.

また、特許文献４で開示されているレンズは、物体側より順に、負の屈折力の第１レンズ群Ｇ１、正の屈折力の第２レンズ群Ｇ２からなり、第１レンズ群Ｇ１は、負の屈折力の第１Ａレンズ群Ｇ１Ａ、負の屈折力の第１Ｂレンズ群Ｇ１Ｂで構成され、フォーカシングの際、第１Ｂレンズ群Ｇ１Ｂを物体側に移動させ、所定の条件式を満足させることにより、撮影画角が１２０度を超える超広角レンズ系でありながら、バックフォーカスが長く、イメージサークルが大きな３５ｍｍフォーマットの交換レンズに適した、フォーカシングによる収差変動が少なく、高性能な超広角レンズ系を提供している。   Further, the lens disclosed in Patent Document 4 includes, in order from the object side, a first lens group G1 having a negative refractive power and a second lens group G2 having a positive refractive power. The first A lens group G1A having a negative refractive power and the first B lens group G1B having a negative refractive power are moved to the object side during focusing, and a predetermined conditional expression is satisfied, Providing a high-performance ultra-wide-angle lens system that is suitable for 35mm format interchangeable lenses with a long back focus and a large image circle, and has a small aberration fluctuation due to focusing. doing.

しかしこの技術も特許文献１、２と同様にフォーカス群は複数のレンズで構成される全体として負の屈折力を持つレンズ群であるため、フォーカスレンズ群の重量軽減が十分ではない。   However, in this technique as well, as in Patent Documents 1 and 2, since the focus group is a lens group having a negative refractive power as a whole composed of a plurality of lenses, weight reduction of the focus lens group is not sufficient.

特許文献４の実施例１は単焦点レンズであるが、像高変化率ηは最大像高２１．６３で−０．３７％と大きい。   Example 1 of Patent Document 4 is a single focus lens, but the image height change rate η is as large as −0.37% at the maximum image height 21.63.

また、特許文献４のズームレンズである実施例２では、広角端での像高変化率ηは、最大像高２１．６３で−０．７％とさらに大きい課題がある。   In Example 2 which is a zoom lens disclosed in Patent Document 4, the image height change rate η at the wide-angle end has a larger problem of −0.7% at the maximum image height 21.63.

本発明は上述した従来技術の課題に対してなされたものであり、パワー配置を適切に設定することによりフォーカスレンズ群を軽量化し、像高変化率の小さいインナーフォーカスに最適な、画角が１２０度を超える広画角なズームレンズの提供を目的とする。   The present invention has been made to solve the above-described problems of the prior art, and by appropriately setting the power arrangement, the focus lens group can be reduced in weight, and the angle of view is optimal for inner focus with a small image height change rate. The purpose is to provide a zoom lens with a wide angle of view that exceeds 100 degrees.

上記課題を解決するために第１の発明の超広角ズームレンズでは、物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成し、物体側無限遠から近距離物体へフォーカシングする際、第３レンズ群Ｇ３が像面方向へ移動し、以下の条件を満足することとした。
（１）１０．０＜ｆ３／ｆｗ＜４０．０
（２）１．０＜１／（ＭＲＴ＾２×（Ｍ３Ｔ＾２−１））
ただし、
ｆｗ：ワイド端無限遠時の焦点距離
ｆ３：第３レンズ群の焦点距離
Ｍ３Ｔ：物体距離無限遠時の望遠端の第３レンズ群の倍率負担
ＭＲＴ：物体距離無限遠時の望遠端の第４レンズ群から第６レンズ群までの合成倍率負担 In order to solve the above problem, in the super wide-angle zoom lens according to the first aspect of the invention, a third lens including a first lens group G1 having a negative power, a second lens group G2 having a negative power, and a single lens having a positive power in order from the object side. The third lens group G3 includes a group G3, a positive power fourth lens group G4, a positive power fifth lens group G5, and a positive power sixth lens group G6. When focusing from infinity on the object side to a close object, Moved in the image plane direction, and the following conditions were satisfied.
(1) 10.0 <f3 / fw <40.0
(2) 1.0 <1 / (MRT ^ 2 × (M3T ^ 2-1))
However,
fw: focal length at the wide end infinity f3: focal length of the third lens group M3T: magnification burden of the third lens group at the telephoto end when the object distance is infinity MRT: fourth at the telephoto end at the object distance infinity Composite magnification burden from the lens group to the sixth lens group

また、第２の発明の超広角ズームレンズでは、第１の発明においてさらに、第３レンズ群Ｇ３の物体側の面を基準とし、広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置をＦｃＥｎｔｐとした時、以下の条件を満足することとした。
（３）０．１＜ＦｃＥｎｔｐ／ｆ３＜０．５
（４）２．５＜ＦｃＥｎｔｐ／ｆｗ In the super wide-angle zoom lens according to the second aspect of the invention, the surface of the third lens group G3 from the third lens group G3 at the wide-angle end to the front of the stop is further defined with reference to the object side surface of the third lens group G3. When the image position of the stop by the combining optical system is FcEntp, the following conditions are satisfied.
(3) 0.1 <FcEntp / f3 <0.5
(4) 2.5 <FcEntp / fw

また、第２の発明の超広角ズームレンズでは、第１乃至第２の発明においてさらに、変倍時において第１レンズ群Ｇ１が像面に対し固定であることとした。   In the super wide-angle zoom lens of the second invention, in the first to second inventions, the first lens group G1 is fixed with respect to the image plane at the time of zooming.

本発明によれば、パワー配置を適切に設定することによりフォーカスレンズ群を軽量化し、像高変化率の小さいインナーフォーカスに最適な、画角が１２０度を超える広画角なズームレンズの提供することができる。   According to the present invention, there is provided a zoom lens having a wide angle of view with an angle of view exceeding 120 degrees, which is optimal for inner focus with a small image height change rate by reducing the weight of the focus lens group by appropriately setting the power arrangement. be able to.

本発明の実施例１の結像光学系の広角端で無限遠合焦時のレンズ構成図である。It is a lens block diagram at the time of wide-angle end of the imaging optical system of Example 1 of this invention at the time of infinity focusing. 本発明の実施例１の無限遠物体における縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．６３ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a longitudinal aberration diagram of an object at infinity according to Example 1 of the present invention, in which a is the wide-angle end, b is the intermediate focal length (16.63 mm), and c is the telephoto end aberration diagram. 本発明の実施例１の無限遠物体における横収差図であり、ａが広角端、ｂが中間焦点距離（１６．６３ｍｍ）、ｃが望遠端の収差図である。FIG. 4 is a lateral aberration diagram for an object at infinity according to Example 1 of the present invention, where a is the wide-angle end, b is the intermediate focal length (16.63 mm), and c is the aberration diagram at the telephoto end. 本発明の実施例１の物体距離４００ｍｍにおける縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．６３ｍｍ）、ｃが望遠端の収差図である。FIG. 4 is a longitudinal aberration diagram at an object distance of 400 mm according to Example 1 of the present invention, where a is the wide-angle end, b is the intermediate focal length (16.63 mm), and c is the telephoto end aberration diagram. 本発明の実施例１の物体距離４００ｍｍにおける横収差図であり、ａが広角端、ｂが中間焦点距離（１６．６３ｍｍ）、ｃが望遠端の収差図である。FIG. 4 is a lateral aberration diagram at an object distance of 400 mm according to Example 1 of the present invention, where a is the wide-angle end, b is the intermediate focal length (16.63 mm), and c is the telephoto end aberration diagram. 本発明の実施例２の結像光学系の広角端で無限遠合焦時のレンズ構成図である。It is a lens block diagram at the time of wide-angle end of the imaging optical system of Example 2 of this invention at the time of infinity focusing. 本発明の実施例２の無限遠物体における縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．１６ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a longitudinal aberration diagram of an object at infinity according to Example 2 of the present invention, in which a is the wide-angle end, b is the intermediate focal length (16.16 mm), and c is the aberration diagram at the telephoto end. 本発明の実施例２の無限遠物体における横収差図であり、ａが広角端、ｂが中間焦点距離（１６．１６ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a lateral aberration diagram for an infinite object according to Example 2 of the present invention, in which a is the wide-angle end, b is the intermediate focal length (16.16 mm), and c is the telephoto end aberration diagram. 本発明の実施例２の物体距離４００ｍｍにおける縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．１６ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a longitudinal aberration diagram at an object distance of 400 mm in Example 2 of the present invention, where a is an aberration angle at the wide-angle end, b is an intermediate focal length (16.16 mm), and c is an aberration diagram at the telephoto end. 本発明の実施例２の物体距離４００ｍｍにおける横収差図であり、ａが広角端、ｂが中間焦点距離（１６．１６ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a lateral aberration diagram at an object distance of 400 mm according to Example 2 of the present invention, where a is the wide-angle end, b is the intermediate focal length (16.16 mm), and c is the aberration diagram at the telephoto end. 本発明の実施例３の結像光学系の広角端で無限遠合焦時のレンズ構成図である。It is a lens block diagram at the time of wide-angle end focusing on infinity at the wide angle end of Example 3 of the present invention. 本発明の実施例３の無限遠物体における縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．６９ｍｍ）、ｃが望遠端の収差図である。It is a longitudinal aberration figure in the infinite object of Example 3 of this invention, a is a wide angle end, b is an intermediate | middle focal distance (16.69 mm), c is an aberration figure of a telephoto end. 本発明の実施例３の無限遠物体における横収差図であり、ａが広角端、ｂが中間焦点距離（１６．６９ｍｍ）、ｃが望遠端の収差図である。It is a lateral aberration figure in the infinite object of Example 3 of this invention, a is a wide angle end, b is an intermediate | middle focal distance (16.69 mm), c is an aberration figure of a telephoto end. 本発明の実施例３の物体距離４００ｍｍにおける縦収差図であり、ａが広角端、ｂが中間焦点距離（１６．６９ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a longitudinal aberration diagram at an object distance of 400 mm in Example 3 of the present invention, in which a is an aberration angle at the wide angle end, b is an intermediate focal length (16.69 mm), and c is an aberration diagram at the telephoto end. 本発明の実施例３の物体距離４００ｍｍにおける横収差図であり、ａが広角端、ｂが中間焦点距離（１６．６９ｍｍ）、ｃが望遠端の収差図である。FIG. 6 is a lateral aberration diagram at an object distance of 400 mm in Example 3 of the present invention, where a is the wide-angle end, b is the intermediate focal length (16.69 mm), and c is the telephoto end aberration diagram.

本発明に係る超広角ズームレンズは、物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成され、物体側無限遠から近距離物体へフォーカシングする際、第３レンズ群Ｇ３が像面方向へ移動する構成となっている。   The super wide-angle zoom lens according to the present invention includes, in order from the object side, a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 including a single lens having a positive power, and a fourth lens having a positive power. Consists of a lens group G4, a positive power fifth lens group G5, and a positive power sixth lens group G6, and the third lens group G3 moves in the image plane direction when focusing from an infinite distance on the object side to a short distance object. It has become.

本実施形態に係る超広角ズームレンズでは、物体側無限遠から近距離物体へフォーカシングする際、単レンズである第３レンズ群Ｇ３が像面方向へ移動することで、フォーカシングに係るアクチュエータへの負荷が少なく、高速なフォーカシング動作を実現し、またフォーカシングによる像高変動を微小にすることができる。また、第３レンズ群Ｇ３を正パワーの単レンズにすることにより、フォーカシングに係るアクチュエータを小型にすることができ、全体の光学系をコンパクトにすることが可能となる。   In the super wide-angle zoom lens according to the present embodiment, when focusing from infinity on the object side to a short distance object, the third lens group G3, which is a single lens, moves in the image plane direction, so that the load on the actuator related to focusing is reduced. Therefore, it is possible to realize a high-speed focusing operation with a small amount, and to reduce the fluctuation of the image height due to the focusing. Further, by making the third lens group G3 a single lens of positive power, the focusing actuator can be made compact, and the entire optical system can be made compact.

また、高速な合焦動作、光学系の小型化を実現するため、ワイド端無限遠時の焦点距離をｆｗ、第３レンズ群の焦点距離をｆ３とした時、以下の条件式を満足することを特徴とする。
（１）１０．０＜ｆ３／ｆｗ＜４０．０
ただし、
ｆｗ：ワイド端無限遠時の焦点距離
ｆ３：第３レンズ群の焦点距離 Also, in order to realize high-speed focusing operation and downsizing of the optical system, when the focal length at the wide end infinity is fw and the focal length of the third lens group is f3, the following conditional expression is satisfied: It is characterized by.
(1) 10.0 <f3 / fw <40.0
However,
fw: focal length at wide end infinity f3: focal length of the third lens unit

また、ＡＦ合焦範囲内にフォーカスレンズ群である第３レンズ群を駆動制御するためには、第３レンズ群、および、第３レンズ群以降の倍率負担を規定することが重要になり、物体距離無限遠時の望遠端の第３レンズ群の倍率負担をＭ３Ｔ、物体距離無限遠時の望遠側の第４レンズ群から第６レンズ群までの合成倍率負担ＭＲＴとした時、以下の条件式を満足することを特徴としている。
（２）１．０＜１／（ＭＲＴ＾２×（Ｍ３Ｔ＾２−１））
ただし、
Ｍ３Ｔ： 物体距離無限遠時の望遠端の第３レンズ群の倍率負担
ＭＲＴ： 物体距離無限遠時の望遠端の第４レンズ群から第６レンズ群までの合成倍率負担 In addition, in order to drive and control the third lens group, which is the focus lens group, within the AF focusing range, it is important to define the third lens group and the magnification burden after the third lens group. When the magnification burden of the third lens group at the telephoto end at the infinite distance is M3T and the combined magnification burden MRT from the fourth lens group to the sixth lens group at the infinite object distance is MRT, the following conditional expression It is characterized by satisfying.
(2) 1.0 <1 / (MRT ^ 2 × (M3T ^ 2-1))
However,
M3T: Magnification burden of the third lens group at the telephoto end when the object distance is infinity MRT: Composite magnification burden from the fourth lens group to the sixth lens group at the telephoto end when the object distance is infinity

また、第２の発明では、ウオブリングによる像高変動を抑制することを目的としている。ウオブリングによる像高変動は、ウオブリングによる歪曲収差の変動で表すことができる。   Further, the second invention aims to suppress image height fluctuations due to wobbling. Image height variation due to wobbling can be represented by variation in distortion due to wobbling.

松居吉哉著、レンズ設計法、共立出版Ｐ８８によれば３次の歪曲収差係数Ｖは以下の式であらわされる。
Ｖ＝Ｊ・ＩＶ
これを展開すると以下になり、
Ｖ＝（Ｈ’・Ｑ’）＾３／（Ｈ・Ｑ）・Ｈ＾２・Δ（１／（ｎ・ｓ））＋Ｐ・（Ｈ’ｈ・Ｑ’）／（Ｈ・Ｑ） 参考式（２）
３次の歪曲収差係数Ｖは近軸主光線高Ｈ’の３乗に比例する。 According to Yoshiya Matsui, lens design method, Kyoritsu Shuppan P88, the third-order distortion coefficient V is expressed by the following equation.
V = J ・ IV
When expanded, it becomes the following,
V = (H ′ · Q ′) ^ 3 / (H · Q) · H ^ 2 · Δ (1 / (n · s)) + P · (H′h · Q ′) / (H · Q) Reference equation (2)
The third-order distortion coefficient V is proportional to the cube of the paraxial principal ray height H ′.

これより、ウオブリングによる歪曲収差の変動を少なくするには、ウオブリングによるフォーカスレンズ群の主光線高の変動を少なくすればよい。   Accordingly, in order to reduce the variation in distortion due to the wobbling, the variation in the principal ray height of the focus lens group due to the wobbling may be reduced.

ここで、物体距離無限遠時のフォーカスレンズ群による絞りの像の位置、およびフォーカスレンズ群である第３レンズ群の倍率負担、フォーカスレンズ群より後方のレンズ群である第４レンズ群から第６レンズ群までの合成倍率負担、およびフォーカスレンズ群における主光線高から、ウオブリングによるフォーカスレンズ群の主光線高の変動Δｈは以下の式で表される。
Δｈ＝ｈ’−ｈ＝ｈ・Δｓ／（ＦｃＥｎｔｐ×ＭＲ＾２×（Ｍ３＾２−１）） 参考式（３）
ただし、
ＦｃＥｎｔｐ：物体距離無限遠時の広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置
Δｓ：ウオブリング時の像面移動量
ｈ：物体距離無限遠時のフォーカスレンズ群における主光線高
ｈ’：ウオブリング時のフォーカスレンズ群における主光線高
Ｍ３：物体距離無限遠時の第３レンズ群の倍率負担
ＭＲ：物体距離無限遠時の第４レンズ群から第６レンズ群までの合成倍率負担 Here, the position of the aperture image by the focus lens group when the object distance is infinity, the magnification burden of the third lens group that is the focus lens group, the fourth lens group that is the lens group behind the focus lens group, and the sixth lens group. From the combined magnification burden up to the lens group and the principal ray height in the focus lens group, the fluctuation Δh of the principal ray height of the focus lens group due to wobbling is expressed by the following equation.
Δh = h′−h = h · Δs / (FcEntp × MR ^ 2 × (M3 ^ 2-1)) Reference formula (3)
However,
FcEntp: Image position of the aperture by the combining optical system of the surface from the third lens group G3 at the wide-angle end to the front of the aperture when the object distance is infinite. Δs: Image plane movement amount during wobbling. The principal ray height h ′ in the lens group: the principal ray height M3 in the focus lens group during wobbling: the magnification burden of the third lens group when the object distance is infinity MR: the fourth lens group to the sixth lens when the object distance is infinity Composite magnification burden to group

このため、主光線高の変動を少なくするには、物体距離無限遠時のフォーカスレンズ群による絞りの像の位置を大きくすればよいことがわかる。   For this reason, in order to reduce the fluctuation of the chief ray height, it is understood that the position of the aperture image by the focus lens group when the object distance is infinite may be increased.

したがって、第２の発明では、フォーカスレンズ群である第３レンズ群Ｇ３の物体側の面を基準とし、広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置をＦｃＥｎｔｐとした時、以下の条件を満足することで達成される。
（３）０．１＜ＦｃＥｎｔｐ／ｆ３＜０．５
（４）２．５＜ＦｃＥｎｔｐ／ｆｗ Therefore, in the second aspect of the invention, the image of the stop by the combining optical system of the surface from the third lens group G3 at the wide-angle end to the front of the stop with the object side surface of the third lens group G3 that is the focus lens group as a reference. This is achieved by satisfying the following conditions when the position is FcEntp.
(3) 0.1 <FcEntp / f3 <0.5
(4) 2.5 <FcEntp / fw

また、変倍時において第１レンズ群が像面に対し固定であっても、移動してもよい。   Further, at the time of zooming, the first lens group may be fixed or moved with respect to the image plane.

以下、本発明の条件式について説明する。   Hereinafter, conditional expressions of the present invention will be described.

条件式（１）は、フォーカスレンズ群である第３レンズ群の焦点距離を規定し、高速な合焦動作、光学系の小型化を実現するための条件である。条件式（１）の下限を超え第３レンズ群Ｇ３の焦点距離ｆ３が短くなると、フォーカスのための繰出し量が短くなりすぎ、正確な合焦位置でフォーカスレンズ群を停止させることが困難になる。   Conditional expression (1) defines the focal length of the third lens group, which is the focus lens group, and is a condition for realizing high-speed focusing operation and downsizing of the optical system. If the lower limit of conditional expression (1) is exceeded and the focal length f3 of the third lens group G3 is shortened, the amount of extension for focusing becomes too short, and it becomes difficult to stop the focus lens group at an accurate in-focus position. .

また条件式（１）の上限を超え第３レンズ群Ｇ３の焦点距離ｆ３が長くなると、フォーカスのための繰出し量が長くなり、第３レンズ群と第４レンズ群との間のスペース確保が困難になりズーム比がかせげない。またコンパクト化に不利なため、フィルター径が大きくなる。なお、条件式（１）について、その下限値をさらに１６に、また、上限値をさらに２１とすることで、前述の効果をより確実にすることができる。   If the upper limit of conditional expression (1) is exceeded and the focal length f3 of the third lens group G3 is increased, the amount of extension for focusing becomes longer, and it is difficult to secure a space between the third lens group and the fourth lens group. The zoom ratio is inevitable. Moreover, since it is disadvantageous for compactization, a filter diameter becomes large. In addition, regarding the conditional expression (1), the lower limit value is further set to 16 and the upper limit value is further set to 21, whereby the above-described effect can be further ensured.

条件式（２）は第３レンズ群Ｇ３がフォーカス時に移動した時の結像面の敏感度を規定する。条件式（２）の下限を超えると、フォーカスレンズ群の移動量が少なくなるため、フォーカスレンズ群の微少な動きで結像面が大きく動き、ＡＦ合焦範囲内にフォーカスレンズ群である第３レンズ群Ｇ３を駆動制御することが困難になる。なお、条件式（２）について、その下限値をさらに１．２とすることで、前述の効果をより確実にすることができる。   Conditional expression (2) defines the sensitivity of the image plane when the third lens group G3 moves during focusing. When the lower limit of conditional expression (2) is exceeded, the amount of movement of the focus lens group decreases, so that the imaging surface moves greatly due to slight movement of the focus lens group, and the third lens that is the focus lens group within the AF focusing range. It becomes difficult to drive and control the lens group G3. In addition, regarding the conditional expression (2), by further setting the lower limit value to 1.2, the above-described effect can be further ensured.

条件式（３）、（４）は、併せてウオブリング時の像高変動を抑制させるための条件である。条件式（３）の下限を超え、広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置までの距離が小さくなると、ウオブリング時のフォーカスレンズ群の主光線高の変動が大きくなるため、ウオブリング時の像高変動を抑制することが困難になる。   Conditional expressions (3) and (4) are conditions for suppressing fluctuations in image height during wobbling. When the lower limit of conditional expression (3) is exceeded and the distance from the third lens group G3 at the wide-angle end to the image position of the stop by the combining optical system on the surface before the stop becomes small, the principal ray of the focus lens group at the time of wobbling Since the fluctuation of the height becomes large, it becomes difficult to suppress the fluctuation of the image height during wobbling.

また、条件式（３）の上限を超え、広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置までの距離が大きくなると、フォーカスレンズ群から絞りまでの距離が大きくなるため、広角端の光学全長が長くなり、フィルター径の増大や周辺光量を確保することが困難になる。また第３レンズ群Ｇ３の焦点距離が短くなると、第１乃至第３レンズ群の合成系の負の屈折力が弱くなるため、バックフォーカスが短くなり、一眼レフレックスカメラに装着使用する際のクイックリターンミラーへの干渉抑制が困難になる。なお、条件式（３）について、その下限値をさらに０．１４に、また、上限値をさらに０．２２とすることで、前述の効果をより確実にすることができる。   When the distance from the third lens group G3 at the wide-angle end to the front of the stop increases beyond the upper limit of the conditional expression (3) and the image position of the stop by the combining optical system increases, the distance from the focus lens group to the stop is increased. Since the distance becomes large, the optical total length at the wide angle end becomes long, and it becomes difficult to increase the filter diameter and to secure the peripheral light amount. When the focal length of the third lens group G3 is shortened, the negative refractive power of the composite system of the first to third lens groups is weakened. Therefore, the back focus is shortened, and quick use when mounted on a single-lens reflex camera is used. It becomes difficult to suppress interference with the return mirror. Regarding conditional expression (3), the lower limit value is further set to 0.14, and the upper limit value is further set to 0.22, so that the above-described effect can be further ensured.

また、条件式（４）の下限を超え、広角端の第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置までの距離が小さくなると、ウオブリング時のフォーカスレンズ群の主光線高の変動が大きくなるため、ウオブリング時の像高変動を抑制することが困難になる。なお、条件式（４）について、その下限値をさらに２．９とすることで、前述の効果をより確実にすることができる。   If the lower limit of conditional expression (4) is exceeded and the distance from the third lens group G3 at the wide-angle end to the image position of the stop by the combining optical system on the surface before the stop decreases, the focus lens group at the time of wobbling is reduced. Since the variation in chief ray height becomes large, it becomes difficult to suppress the variation in image height during wobbling. In addition, regarding the conditional expression (4), by further setting the lower limit value to 2.9, the above-described effect can be further ensured.

次に、本発明の結像光学系に係る実施例のレンズ構成について説明する。なお、以下の説明ではレンズ構成を物体側から像側の順番で記載する。   Next, a lens configuration of an example according to the imaging optical system of the present invention will be described. In the following description, the lens configuration is described in order from the object side to the image side.

図１は、本発明の実施例１の結像光学系の広角端で無限遠合焦時のレンズ構成図である。物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成され、変倍時に第１レンズ群Ｇ１は像面に対し固定である。   FIG. 1 is a lens configuration diagram when focusing on infinity at the wide angle end of the imaging optical system according to Example 1 of the present invention. In order from the object side, the first lens group G1 with negative power, the second lens group G2 with negative power, the third lens group G3 consisting of a single lens with positive power, the fourth lens group G4 with positive power, and the fifth lens with positive power. The lens unit is composed of a group G5 and a sixth lens group G6 having positive power, and the first lens group G1 is fixed with respect to the image plane during zooming.

第１レンズ群Ｇ１は、物体側に凸面を向けた負メニスカスレンズ、物体側の面は非球面形状で物体側に凸面を向けた負メニスカスレンズから成る。   The first lens group G1 includes a negative meniscus lens having a convex surface facing the object side, and a negative meniscus lens having an aspherical surface on the object side and a convex surface facing the object side.

また、第２レンズ群Ｇ２は、物体側の面は非球面形状で物体側に凸面を向けた負メニスカスレンズ、物体側の面は非球面形状で両凹の負レンズ、物体側に凸面を向けた正メニスカスレンズから成る。   The second lens group G2 includes a negative meniscus lens having an aspheric surface on the object side and a convex surface facing the object side, a negative lens having an aspheric surface on the object side, and a convex surface facing the object side. It consists of a positive meniscus lens.

また、第３レンズ群Ｇ３は、物体側に凸面を向けた正メニスカスレンズで構成される。   The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.

また、第４レンズ群Ｇ４は、物体側に凸面を向けた正メニスカスレンズ、開口絞り、両凸レンズと両凹レンズとから成る接合の負レンズ、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズから成る。   The fourth lens group G4 includes a positive meniscus lens having a convex surface facing the object side, an aperture stop, a cemented negative lens composed of a biconvex lens and a biconcave lens, a negative meniscus lens having a biconvex lens and a concave surface facing the object side, It consists of a cemented positive lens.

また、第５レンズ群Ｇ５は、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズ、両凸レンズから成る。   The fifth lens group G5 is composed of a cemented positive lens and a biconvex lens each composed of a biconvex lens and a negative meniscus lens having a concave surface directed toward the object side.

また、第６レンズ群Ｇ６は、物体側に凸面を向けた負メニスカスレンズと物体側に凸面を向けた正メニスカスレンズとから成る接合の負レンズ、物体側に凹面を向けた正メニスカスレンズ、物体側に凹面を向け、物体側の面に樹脂の層が形成されており、その物体側の面は非球面からなる正メニスカスレンズから成る。   The sixth lens group G6 includes a negative lens cemented with a negative meniscus lens having a convex surface directed toward the object side and a positive meniscus lens having a convex surface directed toward the object side, a positive meniscus lens having a concave surface directed toward the object side, A concave surface is directed to the side, and a resin layer is formed on the object side surface. The object side surface is formed of a positive meniscus lens formed of an aspherical surface.

図６は、本発明の実施例２の結像光学系の広角端で無限遠合焦時のレンズ構成図である。物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成され、変倍時に第１レンズ群は像面に対し固定である。   FIG. 6 is a lens configuration diagram at the wide-angle end of the imaging optical system according to Example 2 of the present invention when focusing on infinity. In order from the object side, the first lens group G1 with negative power, the second lens group G2 with negative power, the third lens group G3 consisting of a single lens with positive power, the fourth lens group G4 with positive power, and the fifth lens with positive power. The lens unit is composed of a group G5 and a sixth lens group G6 having positive power, and the first lens group is fixed with respect to the image plane during zooming.

第１レンズ群Ｇ１は、物体側に凸面を向けた負メニスカスレンズ、物体側の面は非球面形状で物体側に凸面を向けた負メニスカスレンズから成る。   The first lens group G1 includes a negative meniscus lens having a convex surface facing the object side, and a negative meniscus lens having an aspherical surface on the object side and a convex surface facing the object side.

また、第２レンズ群Ｇ２は、物体側の面は非球面形状で両凹の負レンズ、物体側に凸面を向けた正メニスカスレンズから成る。   The second lens group G2 includes a negative lens having an aspheric surface on the object side and a biconcave lens, and a positive meniscus lens having a convex surface directed toward the object side.

また、第３レンズ群Ｇ３は、物体側に凸面を向けた正メニスカスレンズで構成される。   The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.

また、第４レンズ群Ｇ４は、物体側に凸面を向けた正メニスカスレンズ、開口絞り、両凸レンズと両凹レンズとから成る接合の負レンズ、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズから成る。   The fourth lens group G4 includes a positive meniscus lens having a convex surface facing the object side, an aperture stop, a cemented negative lens composed of a biconvex lens and a biconcave lens, a negative meniscus lens having a biconvex lens and a concave surface facing the object side, It consists of a cemented positive lens.

また、第５レンズ群Ｇ５は、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズ、両凸レンズから成る。   The fifth lens group G5 is composed of a cemented positive lens and a biconvex lens each composed of a biconvex lens and a negative meniscus lens having a concave surface directed toward the object side.

また、第６レンズ群Ｇ６は、物体側に凸面を向けた負メニスカスレンズと物体側に凸面を向けた正メニスカスレンズレンズとから成る接合の負レンズ、両凸レンズ、物体側に凹面を向け、その物体側の面は非球面からなる正メニスカスレンズから成る。   The sixth lens group G6 includes a cemented negative lens composed of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens lens having a convex surface facing the object side, a biconvex lens, and a concave surface facing the object side. The object side surface is composed of a positive meniscus lens made of an aspherical surface.

図１１は、本発明の実施例３の結像光学系の広角端で無限遠合焦時のレンズ構成図である。物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成され、変倍時に第１レンズ群は像面に対し固定である。   FIG. 11 is a lens configuration diagram at the wide-angle end of the imaging optical system according to Example 3 of the present invention when focusing on infinity. In order from the object side, the first lens group G1 with negative power, the second lens group G2 with negative power, the third lens group G3 consisting of a single lens with positive power, the fourth lens group G4 with positive power, and the fifth lens with positive power. The lens unit is composed of a group G5 and a sixth lens group G6 having positive power, and the first lens group is fixed with respect to the image plane during zooming.

第１レンズ群Ｇ１は、物体側に凸面を向けた負メニスカスレンズ、物体側の面は非球面形状で物体側に凸面を向けた負メニスカスレンズから成る。   The first lens group G1 includes a negative meniscus lens having a convex surface facing the object side, and a negative meniscus lens having an aspherical surface on the object side and a convex surface facing the object side.

また、第２レンズ群Ｇ２は、物体側の面は非球面形状で物体側に凸面を向けた負メニスカスレンズ、物体側の面は非球面形状で両凹の負レンズ、物体側に凸面を向けた正メニスカスレンズから成る。   The second lens group G2 includes a negative meniscus lens having an aspheric surface on the object side and a convex surface facing the object side, a negative lens having an aspheric surface on the object side, and a convex surface facing the object side. It consists of a positive meniscus lens.

また、第３レンズ群Ｇ３は、物体側に凸面を向けた正メニスカスレンズで構成される。   The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.

また、第４レンズ群Ｇ４は、物体側に凸面を向けた正メニスカスレンズ、開口絞り、両凸レンズと両凹レンズとから成る接合の負レンズ、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズから成る。   The fourth lens group G4 includes a positive meniscus lens having a convex surface facing the object side, an aperture stop, a cemented negative lens composed of a biconvex lens and a biconcave lens, a negative meniscus lens having a biconvex lens and a concave surface facing the object side, It consists of a cemented positive lens.

また、第５レンズ群Ｇ５は、両凸レンズと物体側に凹面を向けた負メニスカスレンズとから成る接合の正レンズ、両凸レンズから成る。   The fifth lens group G5 is composed of a cemented positive lens and a biconvex lens each composed of a biconvex lens and a negative meniscus lens having a concave surface directed toward the object side.

また、第６レンズ群Ｇ６は、物体側に凸面を向けた負メニスカスレンズと物体側に凸面を向けた正メニスカスレンズレンズとから成る接合の負レンズ、物体側に凹面を向けた正メニスカスレンズ、物体側に凹面を向け、物体側の面に樹脂の層が形成されており、その物体側の面は非球面からなる正メニスカスレンズから成る。   The sixth lens group G6 includes a cemented negative lens composed of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens lens having a convex surface facing the object side, a positive meniscus lens having a concave surface facing the object side, A concave surface is directed to the object side, and a resin layer is formed on the object side surface. The object side surface is composed of a positive meniscus lens formed of an aspherical surface.

なお、本発明ではフォーカスレンズ群を正の屈折力を持つ単レンズで構成しているが、そのレンズの片面あるいは両面を非球面化し球面収差、非点収差等の補正能力を上げる、あるいは回折光学素子を付加し色収差補正能力を上げることも可能である。また、フォーカスレンズ群の重量増にはなるが、フォーカス時の色収差変動の抑制を重要視する場合は、フォーカスレンズ群に負レンズを接合し色収差能力を向上させることも可能である。   In the present invention, the focus lens group is composed of a single lens having a positive refractive power. However, one or both surfaces of the lens are made aspherical to improve the correction capability for spherical aberration, astigmatism, etc., or diffractive optics. It is also possible to increase the chromatic aberration correction capability by adding an element. In addition, although the weight of the focus lens group is increased, when importance is placed on the suppression of chromatic aberration fluctuations during focusing, a negative lens can be joined to the focus lens group to improve the chromatic aberration ability.

また、フォーカスレンズを変倍時に光軸方向に移動させ、収差補正に自由度を与え、より高性能化、コンパクト化を行うことも可能である。   Further, it is possible to move the focus lens in the optical axis direction at the time of zooming to give a degree of freedom for aberration correction, and to achieve higher performance and compactness.

以下に、前述した本発明の結像光学系の各実施例の具体的な数値データを示す。   Specific numerical data of each embodiment of the imaging optical system of the present invention described above will be shown below.

［面データ］において、面番号は物体側から数えたレンズ面又は開口絞りの番号、ｒは各面の曲率半径、ｄは各面の間隔、ｎｄはｄ線（波長５８７．５６ｎｍ）に対する屈折率、ｖｄはｄ線に対するアッベ数を示している。   In [Surface data], the surface number is the number of the lens surface or aperture stop counted from the object side, r is the radius of curvature of each surface, d is the distance between the surfaces, nd is the refractive index with respect to the d-line (wavelength 587.56 nm). , Vd indicate Abbe numbers for the d line.

面番号に付した＊（アスタリスク）は、そのレンズ面形状が非球面であることを示している。また、ＢＦはバックフォーカスを表している。   The * (asterisk) attached to the surface number indicates that the lens surface shape is an aspherical surface. BF represents back focus.

面番号に付した（絞り）は、その位置に開口絞りが位置していることを示している。平面又は開口絞りに対する曲率半径には∞（無限大）を記入している。   The (diaphragm) attached to the surface number indicates that the aperture stop is located at that position. ∞ (infinity) is entered in the radius of curvature for a plane or aperture stop.

［非球面データ］には、［面データ］において＊を付したレンズ面の非球面形状を与える各係数値を示している。非球面の形状は、非球面の形状は、光軸に直行する方向への光軸からの変位をｙ、非球面と光軸の交点から光軸方向への変位（サグ量）をｚ、基準球面の曲率半径をｒ、コーニック係数をＫ、４、６、８、１０、１２次の非球面係数をそれぞれＡ４、Ａ６、Ａ８、Ａ１０、Ａ１２と置くとき、非球面の座標が以下の式で表されるものとする。   In [Aspherical data], each coefficient value giving the aspherical shape of the lens surface marked with * in [Surface data] is shown. As for the aspherical shape, the aspherical shape is y for the displacement from the optical axis in the direction perpendicular to the optical axis, z for the displacement (sag amount) in the optical axis direction from the intersection of the aspherical surface and the optical axis, and the reference When the radius of curvature of the spherical surface is r, the conic coefficient is K, 4, 6, 8, 10, and 12th order aspherical coefficients are A4, A6, A8, A10, and A12, respectively, the coordinates of the aspherical surface are given by the following equations. Shall be represented.

Figure 2015203736
Figure 2015203736

［各種データ］には、ズーム比及び各焦点距離状態における焦点距離等の値を示している。   [Various data] shows values such as the zoom ratio and the focal length in each focal length state.

［可変間隔データ］には、各焦点距離状態における、無限遠及び物体距離４００ｍｍでの可変間隔及びＢＦの値を示している。   [Variable interval data] shows the variable interval and BF values at infinity and an object distance of 400 mm in each focal length state.

［レンズ群データ］には、各レンズ群を構成する最も物体側の面番号及び群全体の合成焦点距離を示している。   [Lens Group Data] indicates the surface number of the most object side constituting each lens group and the combined focal length of the entire group.

なお、以下の全ての諸元の値において、記載している焦点距離ｆ、曲率半径ｒ、レンズ面間隔ｄ、その他の長さの単位は特記のない限りミリメートル（ｍｍ）を使用するが、光学系では比例拡大と比例縮小とにおいても同等の光学性能が得られるので、これに限られるものではない。   In all the values of the following specifications, the focal length f, the radius of curvature r, the lens surface interval d, and other length units described are in millimeters (mm) unless otherwise specified. In the system, the same optical performance can be obtained even in proportional expansion and proportional reduction, and the present invention is not limited to this.

また、これらの各実施例における条件式の対応値の一覧を示す。   In addition, a list of corresponding values of the conditional expressions in each of these examples is shown.

また、各実施例に対応する収差図において、ｄ、ｇ、Ｃはそれぞれｄ線、ｇ線、Ｃ線を表しており、△Ｓ、△Ｍはそれぞれサジタル像面、メリジオナル像面を表している。   In the aberration diagrams corresponding to each example, d, g, and C represent d-line, g-line, and C-line, respectively, and ΔS and ΔM represent sagittal image plane and meridional image plane, respectively. .

数値実施例1
単位：mm
[面データ]
面番号 r d nd vd
物面 ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.4077
3* 168.5123 2.5391 1.69350 53.20
4 25.2821 (d4)
5* 51.7926 1.5234 1.69350 53.20
6 25.5340 8.5498
7* -42.4664 1.4219 1.69350 53.20
8 38.3589 0.1523
9 35.7051 4.7917 2.00100 29.13
10 1039.8702 (d10)
11 63.9682 2.5239 1.43700 95.10
12 235.7353 (d12)
13 15.9458 1.7255 1.58144 40.89
14 150.7163 5.9312
15(絞り) ∞ 1.7855
16 39.7926 3.2069 1.43700 95.10
17 -14.3643 0.8125 2.00100 29.13
18 36.1836 1.7733
19 65.7096 3.6134 1.84666 23.78
20 -13.7749 0.8125 1.91082 35.25
21 -37.9865 (d21)
22 206.4659 4.8163 1.43700 95.10
23 -14.7911 0.8633 1.91082 35.25
24 -23.3368 0.1523
25 84.9838 3.1687 1.43700 95.10
26 -61.8089 (d26)
27 164.7696 0.9141 1.88300 40.80
28 22.6142 5.0736 1.43700 95.10
29 346.9445 0.8734
30 -147.5241 3.7568 1.43700 95.10
31 -29.8530 0.7038
32* -49.8367 0.1016 1.51840 52.09
33 -46.9696 2.5939 1.48749 70.44
34 -32.3994 (BF)
像面 ∞


[非球面データ]
3面 5面 7面 32面
K 0.0000 7.7111 0.0000 0.0000
A4 3.46332E-05 -2.26831E-05 -1.88031E-06 -7.55234E-06
A6 -1.10257E-07 2.02329E-07 -9.11501E-08 1.72487E-09
A8 2.54048E-10 -8.70540E-10 7.44318E-10 8.24363E-11
A10 -3.12951E-13 1.54887E-12 -2.24356E-12 4.76493E-15
A12 1.63423E-16 -1.02516E-15 0.00000E+00 0.00000E+00


[各種データ]
ズーム比 1.70
広角 中間 望遠
焦点距離 12.39 16.63 21.07
Fナンバー 4.60 5.24 5.83
全画角2ω 122.63 104.46 89.57
像高Y 21.63 21.63 21.63
レンズ全長 155.48 155.41 155.51


[可変間隔データ]
広角 中間 望遠
d0 ∞ ∞ ∞
d4 6.8523 10.7582 9.4709
d10 0.6982 0.8604 0.9151
d12 24.8905 10.0729 3.9829
d21 8.1179 6.8057 3.3637
d26 0.9141 12.5684 15.1640
BF 37.4906 37.8259 46.0902

広角 中間 望遠
d0 244.5205 244.5931 244.4984
d4 6.8523 10.7582 9.4709
d10 2.9100 2.8095 2.9397
d12 22.6788 8.1238 1.9583
d21 8.1179 6.8057 3.3637
d26 0.9141 12.5684 15.1640
BF 37.4905 37.8259 46.0901


[レンズ群データ]
群 始面 焦点距離
G1 1 -23.39
G2 5 -47.33
G3 11 200.00
G4 13 53.23
G5 22 46.24
G6 27 266.96

Numerical example 1
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.4077
3 * 168.5123 2.5391 1.69350 53.20
4 25.2821 (d4)
5 * 51.7926 1.5234 1.69350 53.20
6 25.5340 8.5498
7 * -42.4664 1.4219 1.69350 53.20
8 38.3589 0.1523
9 35.7051 4.7917 2.00100 29.13
10 1039.8702 (d10)
11 63.9682 2.5239 1.43700 95.10
12 235.7353 (d12)
13 15.9458 1.7255 1.58144 40.89
14 150.7163 5.9312
15 (Aperture) ∞ 1.7855
16 39.7926 3.2069 1.43700 95.10
17 -14.3643 0.8125 2.00100 29.13
18 36.1836 1.7733
19 65.7096 3.6134 1.84666 23.78
20 -13.7749 0.8125 1.91082 35.25
21 -37.9865 (d21)
22 206.4659 4.8163 1.43700 95.10
23 -14.7911 0.8633 1.91082 35.25
24 -23.3368 0.1523
25 84.9838 3.1687 1.43700 95.10
26 -61.8089 (d26)
27 164.7696 0.9141 1.88300 40.80
28 22.6142 5.0736 1.43700 95.10
29 346.9445 0.8734
30 -147.5241 3.7568 1.43700 95.10
31 -29.8530 0.7038
32 * -49.8367 0.1016 1.51840 52.09
33 -46.9696 2.5939 1.48749 70.44
34 -32.3994 (BF)
Image plane ∞


[Aspherical data]
3 surfaces 5 surfaces 7 surfaces 32 surfaces
K 0.0000 7.7111 0.0000 0.0000
A4 3.46332E-05 -2.26831E-05 -1.88031E-06 -7.55234E-06
A6 -1.10257E-07 2.02329E-07 -9.11501E-08 1.72487E-09
A8 2.54048E-10 -8.70540E-10 7.44318E-10 8.24363E-11
A10 -3.12951E-13 1.54887E-12 -2.24356E-12 4.76493E-15
A12 1.63423E-16 -1.02516E-15 0.00000E + 00 0.00000E + 00


[Various data]
Zoom ratio 1.70
Wide angle Medium telephoto Focal length 12.39 16.63 21.07
F number 4.60 5.24 5.83
Full angle 2ω 122.63 104.46 89.57
Image height Y 21.63 21.63 21.63
Total lens length 155.48 155.41 155.51


[Variable interval data]
Wide angle Medium telephoto
d0 ∞ ∞ ∞
d4 6.8523 10.7582 9.4709
d10 0.6982 0.8604 0.9151
d12 24.8905 10.0729 3.9829
d21 8.1179 6.8057 3.3637
d26 0.9141 12.5684 15.1640
BF 37.4906 37.8259 46.0902

Wide angle Medium telephoto
d0 244.5205 244.5931 244.4984
d4 6.8523 10.7582 9.4709
d10 2.9100 2.8095 2.9397
d12 22.6788 8.1238 1.9583
d21 8.1179 6.8057 3.3637
d26 0.9141 12.5684 15.1640
BF 37.4905 37.8259 46.0901


[Lens group data]
Group Start surface Focal length
G1 1 -23.39
G2 5 -47.33
G3 11 200.00
G4 13 53.23
G5 22 46.24
G6 27 266.96

数値実施例2
単位：mm
[面データ]
面番号 r d nd vd
物面 ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.6613
3* ∞ 2.5391 1.69350 53.20
4 20.5319 (d4)
5* -38.8887 1.4219 1.69350 53.20
6 29.4840 0.1523
7 29.9949 4.7917 2.00100 29.13
8 1023.8378 (d8)
9 62.2376 2.2944 1.43700 95.10
10 137.6787 (d10)
11 15.3161 1.7255 1.58144 40.89
12 52.1157 5.9312
13(絞り) ∞ 1.7855
14 28.2990 3.4073 1.43700 95.10
15 -14.2447 0.8125 2.00100 29.13
16 45.1718 1.7733
17 82.2580 3.7819 1.84666 23.78
18 -12.6823 0.8125 1.91082 35.25
19 -36.4019 (d19)
20 151.4137 4.4310 1.43700 95.10
21 -16.5266 0.8633 1.91082 35.25
22 -28.2711 0.1523
23 119.2882 3.1687 1.43700 95.10
24 -48.7338 (d24)
25 75.4361 0.9141 1.88300 40.80
26 21.3863 4.5700 1.43700 95.10
27 85.1362 0.8749
28 420.9164 3.7568 1.43700 95.10
29 -37.2907 0.7038
30* -49.8367 2.6900 1.48749 70.44
31 -32.3994 (BF)
像面


[非球面データ]
3面 5面 30面
K 0.0000 0.0000 0.0000
A4 3.73671E-05 -8.10078E-06 -7.55234E-06
A6 -9.79995E-08 8.01406E-08 1.72487E-09
A8 2.23813E-10 -2.45723E-10 8.24363E-11
A10 -2.83017E-13 3.07636E-13 4.76493E-15
A12 1.63423E-16 0.00000E+00 0.00000E+00


[各種データ]
ズーム比 1.76
広角 中間 望遠
焦点距離 12.47 16.16 21.91
Fナンバー 4.60 5.07 5.82
全画角2ω 122.35 106.78 88.43
像高Y 21.63 21.63 21.63
レンズ全長 152.00 151.97 151.99


[可変間隔データ]
広角 中間 望遠
d0 ∞ ∞ ∞
d4 16.6814 14.6025 13.3680
d8 1.0156 1.0156 1.0156
d10 21.2970 13.0721 5.1422
d19 7.9685 8.3792 3.3637
d24 0.9141 10.0516 15.8088
BF 38.1804 38.9025 47.3476

広角 中間 望遠
d0 248.0000 248.0339 248.0125
d4 16.6814 14.6025 13.3680
d8 3.8883 4.0655 4.1799
d10 18.4244 10.0223 1.9779
d19 7.9685 8.3792 3.3637
d24 0.9141 10.0516 15.8088
BF 38.1804 38.9025 47.3476


[レンズ群データ]
群 始面 焦点距離
G1 1 -18.12
G2 5 -115.76
G3 9 257.53
G4 11 55.66
G5 20 52.04
G6 25 189.69

Numerical example 2
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.6613
3 * ∞ 2.5391 1.69350 53.20
4 20.5319 (d4)
5 * -38.8887 1.4219 1.69350 53.20
6 29.4840 0.1523
7 29.9949 4.7917 2.00100 29.13
8 1023.8378 (d8)
9 62.2376 2.2944 1.43700 95.10
10 137.6787 (d10)
11 15.3161 1.7255 1.58144 40.89
12 52.1157 5.9312
13 (Aperture) ∞ 1.7855
14 28.2990 3.4073 1.43700 95.10
15 -14.2447 0.8125 2.00100 29.13
16 45.1718 1.7733
17 82.2580 3.7819 1.84666 23.78
18 -12.6823 0.8125 1.91082 35.25
19 -36.4019 (d19)
20 151.4137 4.4310 1.43700 95.10
21 -16.5266 0.8633 1.91082 35.25
22 -28.2711 0.1523
23 119.2882 3.1687 1.43700 95.10
24 -48.7338 (d24)
25 75.4361 0.9141 1.88300 40.80
26 21.3863 4.5700 1.43700 95.10
27 85.1362 0.8749
28 420.9164 3.7568 1.43700 95.10
29 -37.2907 0.7038
30 * -49.8367 2.6900 1.48749 70.44
31 -32.3994 (BF)
Image plane


[Aspherical data]
3 surfaces 5 surfaces 30 surfaces
K 0.0000 0.0000 0.0000
A4 3.73671E-05 -8.10078E-06 -7.55234E-06
A6 -9.79995E-08 8.01406E-08 1.72487E-09
A8 2.23813E-10 -2.45723E-10 8.24363E-11
A10 -2.83017E-13 3.07636E-13 4.76493E-15
A12 1.63423E-16 0.00000E + 00 0.00000E + 00


[Various data]
Zoom ratio 1.76
Wide angle Medium telephoto Focal length 12.47 16.16 21.91
F number 4.60 5.07 5.82
Full angle of view 2ω 122.35 106.78 88.43
Image height Y 21.63 21.63 21.63
Total lens length 152.00 151.97 151.99


[Variable interval data]
Wide angle Medium telephoto
d0 ∞ ∞ ∞
d4 16.6814 14.6025 13.3680
d8 1.0156 1.0156 1.0156
d10 21.2970 13.0721 5.1422
d19 7.9685 8.3792 3.3637
d24 0.9141 10.0516 15.8088
BF 38.1804 38.9025 47.3476

Wide angle Medium telephoto
d0 248.0000 248.0339 248.0125
d4 16.6814 14.6025 13.3680
d8 3.8883 4.0655 4.1799
d10 18.4244 10.0223 1.9779
d19 7.9685 8.3792 3.3637
d24 0.9141 10.0516 15.8088
BF 38.1804 38.9025 47.3476


[Lens group data]
Group Start surface Focal length
G1 1 -18.12
G2 5 -115.76
G3 9 257.53
G4 11 55.66
G5 20 52.04
G6 25 189.69

数値実施例3
単位：mm
[面データ]
面番号 r d nd vd
物面 ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.5646
3* 179.0289 2.5391 1.69350 53.20
4 25.5334 (d4)
5* 51.6581 1.5234 1.69350 53.20
6 24.8038 8.6599
7* -44.0528 1.4219 1.69350 53.20
8 28.3079 0.1523
9 29.4864 4.7917 2.00100 29.13
10 722.7940 (d10)
11 59.9512 2.4572 1.43700 95.10
12 174.9908 (d12)
13 15.8930 1.7255 1.58144 40.89
14 75.4422 6.0765
15(絞り) ∞ 1.7855
16 31.4073 3.3175 1.43700 95.10
17 -15.3420 0.8125 2.00100 29.13
18 38.8415 1.7733
19 62.3213 3.7099 1.84666 23.78
20 -13.7295 0.8125 1.91082 35.25
21 -39.6581 (d21)
22 118.1767 4.5708 1.43700 95.10
23 -15.6334 0.8633 1.91082 35.25
24 -26.7864 0.1523
25 65.7918 3.1687 1.43700 95.10
26 -67.6896 (d26)
27 100.5007 0.9141 1.88300 40.80
28 21.2695 4.6540 1.43700 95.10
29 114.9352 0.8734
30 -541.9209 3.7568 1.43700 95.10
31 -35.1203 0.7038
32* -49.8367 0.1016 1.51840 52.09
33 -46.9696 2.5939 1.48749 70.44
34 -32.3994 (BF)
像面 ∞


[非球面データ]
3面 5面 7面 32面
K 0.0000 7.7781 0.0000 0.0000
A4 3.51234E-05 -2.03898E-05 -4.84558E-06 -7.55234E-06
A6 -1.12105E-07 1.99754E-07 -5.08864E-08 1.72487E-09
A8 2.54048E-10 -8.52927E-10 4.19002E-10 8.24363E-11
A10 -3.12951E-13 1.75095E-12 -1.39703E-12 4.76493E-15
A12 1.63423E-16 -1.56581E-15 0.00000E+00 0.00000E+00


[各種データ]
ズーム比 1.71
広角 中間 望遠
焦点距離 12.33 16.69 21.13
Fナンバー 4.61 5.25 5.82
全画角2ω 122.97 105.05 90.85
像高Y 21.63 21.63 21.63
レンズ全長 153.94 153.85 153.98


[可変間隔データ]
広角 中間 望遠
d0 ∞ ∞ ∞
d4 6.6364 9.5914 8.0759
d10 1.0156 1.0156 1.0156
d12 23.5371 9.5734 3.9341
d21 8.1179 6.8057 3.3637
d26 0.9141 10.7966 11.9148
BF 37.3124 39.6644 49.2700

広角 中間 望遠
d0 246.0629 246.1498 246.0233
d4 6.6364 9.5914 8.0759
d10 3.2140 3.0159 3.1146
d12 21.3387 7.5731 1.8352
d21 8.1179 6.8057 3.3637
d26 0.9141 10.7966 11.9148
BF 37.3124 39.6644 49.2699


[レンズ群データ]
群 始面 焦点距離
G1 1 -23.37
G2 5 -44.87
G3 11 207.33
G4 13 51.61
G5 22 48.47
G6 27 343.02

Numerical example 3
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 41.7797 1.9297 1.91082 35.25
2 23.7575 10.5646
3 * 179.0289 2.5391 1.69350 53.20
4 25.5334 (d4)
5 * 51.6581 1.5234 1.69350 53.20
6 24.8038 8.6599
7 * -44.0528 1.4219 1.69350 53.20
8 28.3079 0.1523
9 29.4864 4.7917 2.00100 29.13
10 722.7940 (d10)
11 59.9512 2.4572 1.43700 95.10
12 174.9908 (d12)
13 15.8930 1.7255 1.58144 40.89
14 75.4422 6.0765
15 (Aperture) ∞ 1.7855
16 31.4073 3.3175 1.43700 95.10
17 -15.3420 0.8125 2.00100 29.13
18 38.8415 1.7733
19 62.3213 3.7099 1.84666 23.78
20 -13.7295 0.8125 1.91082 35.25
21 -39.6581 (d21)
22 118.1767 4.5708 1.43700 95.10
23 -15.6334 0.8633 1.91082 35.25
24 -26.7864 0.1523
25 65.7918 3.1687 1.43700 95.10
26 -67.6896 (d26)
27 100.5007 0.9141 1.88300 40.80
28 21.2695 4.6540 1.43700 95.10
29 114.9352 0.8734
30 -541.9209 3.7568 1.43700 95.10
31 -35.1203 0.7038
32 * -49.8367 0.1016 1.51840 52.09
33 -46.9696 2.5939 1.48749 70.44
34 -32.3994 (BF)
Image plane ∞


[Aspherical data]
3 surfaces 5 surfaces 7 surfaces 32 surfaces
K 0.0000 7.7781 0.0000 0.0000
A4 3.51234E-05 -2.03898E-05 -4.84558E-06 -7.55234E-06
A6 -1.12105E-07 1.99754E-07 -5.08864E-08 1.72487E-09
A8 2.54048E-10 -8.52927E-10 4.19002E-10 8.24363E-11
A10 -3.12951E-13 1.75095E-12 -1.39703E-12 4.76493E-15
A12 1.63423E-16 -1.56581E-15 0.00000E + 00 0.00000E + 00


[Various data]
Zoom ratio 1.71
Wide angle Medium telephoto Focal length 12.33 16.69 21.13
F number 4.61 5.25 5.82
Full angle of view 2ω 122.97 105.05 90.85
Image height Y 21.63 21.63 21.63
Total lens length 153.94 153.85 153.98


[Variable interval data]
Wide angle Medium telephoto
d0 ∞ ∞ ∞
d4 6.6364 9.5914 8.0759
d10 1.0156 1.0156 1.0156
d12 23.5371 9.5734 3.9341
d21 8.1179 6.8057 3.3637
d26 0.9141 10.7966 11.9148
BF 37.3124 39.6644 49.2700

Wide angle Medium telephoto
d0 246.0629 246.1498 246.0233
d4 6.6364 9.5914 8.0759
d10 3.2140 3.0159 3.1146
d12 21.3387 7.5731 1.8352
d21 8.1179 6.8057 3.3637
d26 0.9141 10.7966 11.9148
BF 37.3124 39.6644 49.2699


[Lens group data]
Group Start surface Focal length
G1 1 -23.37
G2 5 -44.87
G3 11 207.33
G4 13 51.61
G5 22 48.47
G6 27 343.02

[条件式対応値]
条件式／実施例 1 2 3
(1) 10.0＜f3/fw＜40.0 16.15 20.66 16.82
(2) 1.0＜1/(MRT^2×(M3T^2-1)) 1.26 1.87 1.31
(3) 0.1＜FcEntpW/f3＜0.5 0.22 0.14 0.20
(4) 2.5＜FcEntpW/fw 3.55 2.99 3.38

[Values for conditional expressions]
Conditional expression / Example 1 2 3
(1) 10.0 <f3 / fw <40.0 16.15 20.66 16.82
(2) 1.0 <1 / (MRT ^ 2 × (M3T ^ 2-1)) 1.26 1.87 1.31
(3) 0.1 <FcEntpW / f3 <0.5 0.22 0.14 0.20
(4) 2.5 <FcEntpW / fw 3.55 2.99 3.38

Ｇ１ 第１レンズ群
Ｇ２ 第２レンズ群
Ｇ３ 第３レンズ群
Ｇ４ 第４レンズ群
Ｇ５ 第５レンズ群
Ｇ６ 第６レンズ群
Ｓ 開口絞り
Ｉ 像面 G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group G6 6th lens group S Aperture stop I Image surface

Claims (3)

物体側より順に負パワーの第１レンズ群Ｇ１、負パワーの第２レンズ群Ｇ２、正パワーの単レンズからなる第３レンズ群Ｇ３、正パワーの第４レンズ群Ｇ４、正パワーの第５レンズ群Ｇ５、正パワーの第６レンズ群Ｇ６で構成され、物体側無限遠から近距離物体へフォーカシングする際、前記第３レンズ群Ｇ３が像面方向へ移動し、以下の条件を満足することを特徴とする超広角ズームレンズ。
（１）１０．０＜ｆ３／ｆｗ＜４０．０
（２）１．０＜１／（ＭＲＴ＾２×（Ｍ３Ｔ＾２−１））
ただし、
ｆｗ：ワイド端無限遠時の焦点距離
ｆ３：第３レンズ群の焦点距離
Ｍ３Ｔ：物体距離無限遠時の望遠端の第３レンズ群の倍率負担
ＭＲＴ：物体距離無限遠時の望遠端の第４レンズ群から第６レンズ群までの合成倍率負担 In order from the object side, the first lens group G1 with negative power, the second lens group G2 with negative power, the third lens group G3 consisting of a single lens with positive power, the fourth lens group G4 with positive power, and the fifth lens with positive power. The third lens group G3 is composed of a group G5 and a sixth lens group G6 having positive power, and the third lens group G3 moves in the image plane direction when focusing from an object-side infinity to a close object, and satisfies the following conditions: Super wide-angle zoom lens.
(1) 10.0 <f3 / fw <40.0
(2) 1.0 <1 / (MRT ^ 2 × (M3T ^ 2-1))
However,
fw: focal length at the wide end infinity f3: focal length of the third lens group M3T: magnification burden of the third lens group at the telephoto end when the object distance is infinity MRT: fourth at the telephoto end at the object distance infinity Composite magnification burden from the lens group to the sixth lens group 前記第３レンズ群Ｇ３の物体側の面を基準とし、広角端の前記第３レンズ群Ｇ３から絞りの前までの面の合成光学系による絞りの像位置をＦｃＥｎｔｐとした時、以下の条件を満足することを特徴とする請求項１に記載の超広角ズームレンズ。
（３）０．１＜ＦｃＥｎｔｐ／ｆ３＜０．５
（４）２．５＜ＦｃＥｎｔｐ／ｆｗ When the image position of the stop by the combining optical system of the surface from the third lens group G3 at the wide angle end to the front of the stop is defined as FcEntp using the object side surface of the third lens group G3 as a reference, the following conditions are satisfied. The super wide-angle zoom lens according to claim 1, wherein the zoom lens is satisfied.
(3) 0.1 <FcEntp / f3 <0.5
(4) 2.5 <FcEntp / fw 変倍時において前記第１レンズ群Ｇ１が像面に対し固定であることを特徴とする請求項１乃至請求項２に記載の超広角ズームレンズ。   3. The super wide-angle zoom lens according to claim 1, wherein the first lens group G1 is fixed with respect to the image plane during zooming.
JP2014082216A 2014-04-11 2014-04-11 Super wide-angle zoom lens Active JP6390147B2 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106842528A (en) * 2015-12-03 2017-06-13 佳能株式会社 Zoom lens and the image pick-up device comprising zoom lens
JP2017156604A (en) * 2016-03-03 2017-09-07 キヤノン株式会社 Zoom lens, and imaging apparatus having the same
CN108535851A (en) * 2018-06-12 2018-09-14 安徽老蛙光学科技有限公司 Nothing surpasses in reverse wide-angle zoom lens

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0415612A (en) * 1990-05-09 1992-01-21 Canon Inc Zoom lens
JP2013015621A (en) * 2011-07-01 2013-01-24 Sigma Corp Super-wide angle lens system
JP2014035459A (en) * 2012-08-09 2014-02-24 Konica Minolta Inc Projection lens having variable magnification function and projector

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0415612A (en) * 1990-05-09 1992-01-21 Canon Inc Zoom lens
JP2013015621A (en) * 2011-07-01 2013-01-24 Sigma Corp Super-wide angle lens system
JP2014035459A (en) * 2012-08-09 2014-02-24 Konica Minolta Inc Projection lens having variable magnification function and projector

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106842528A (en) * 2015-12-03 2017-06-13 佳能株式会社 Zoom lens and the image pick-up device comprising zoom lens
CN106842528B (en) * 2015-12-03 2019-11-15 佳能株式会社 Zoom lens and image pick-up device comprising zoom lens
JP2017156604A (en) * 2016-03-03 2017-09-07 キヤノン株式会社 Zoom lens, and imaging apparatus having the same
CN108535851A (en) * 2018-06-12 2018-09-14 安徽老蛙光学科技有限公司 Nothing surpasses in reverse wide-angle zoom lens
CN108535851B (en) * 2018-06-12 2023-11-10 安徽长庚光学科技有限公司 Non-reflection ultra-wide angle zoom lens

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