JP3352245B2 - Zoom lens - Google Patents

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明は写真用カメラやビデオカ
メラ、そしてＳＶカメラ等に好適なズームレンズ及びそ
れを用いたカメラに関し、特に負の屈折力のレンズ群が
先行する全体として２つのレンズ群を有し、これら２つ
のレンズ群のレンズ構成を適切に設定することによりレ
ンズ系全体の小型化を図った撮影画角５８°〜３３°、
変倍比２程度のズームレンズ及びそれを用いたカメラに
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens suitable for a photographic camera, a video camera, an SV camera and the like and a camera using the zoom lens. A photographing angle of view of 58 ° to 33 °, in which the entire lens system is miniaturized by appropriately setting the lens configurations of these two lens groups.
The present invention relates to a zoom lens having a zoom ratio of about 2, and a camera using the same.

【０００２】[0002]

【従来の技術】従来より負の屈折力のレンズ群が先行す
る所謂ネガティブリード型のズームレンズは長いバック
フォーカスが容易に得られ、しかも広画角化が比較的容
易であるため一眼レフカメラ用の標準型のズームレンズ
に多く用いられている。2. Description of the Related Art A so-called negative lead type zoom lens in which a lens unit having a negative refractive power precedes the conventional one can easily obtain a long back focus and relatively easily widen the angle of view, so that it is used for a single-lens reflex camera. Is widely used for standard zoom lenses.

【０００３】例えば特開昭５７−２０７１３号公報，特
公昭６０−４６６８８号公報，特公昭６１−４２２４６
号公報、そして特開平５−８８０８４号公報等では、物
体側より順に負の屈折力の第１群と正の屈折力の第２群
の２つのレンズ群を有し、双方のレンズ群間隔を変えて
変倍を行ったズームレンズが提案されている。このうち
特開昭５７−２０７１３号公報では、第１群を負レンズ
と正レンズの２枚のレンズと１つの非球面を用いること
により、標準ズームレンズとして全変倍範囲にわたり高
い光学性能を得ている。For example, JP-A-57-20713, JP-B-60-46688, and JP-B-61-42246.
In JP-A-5-88084 and the like, there are two lens groups, a first group having a negative refractive power and a second group having a positive refractive power, in order from the object side. There has been proposed a zoom lens in which the magnification is changed. In Japanese Patent Application Laid-Open No. 57-20713, high optical performance is obtained as a standard zoom lens over the entire zoom range by using two lenses, a negative lens and a positive lens, and one aspheric surface in the first group. ing.

【０００４】特公昭６０−４６６８８号公報と特開平５
−８８０８４号公報では第１群を負レンズと正レンズの
２枚のレンズ、第２群を正レンズ，正レンズ，負レン
ズ、そして正レンズの４つのレンズより構成した小型の
ズームレンズを提案している。特公昭６１−４２２４６
号公報では第１群を負レンズと正レンズの２枚のレン
ズ、第２群を４枚又は５枚のレンズより構成したズーム
レンズを提案している。Japanese Patent Publication No. 60-46888 and Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 88084 proposes a small zoom lens in which the first group includes two lenses, a negative lens and a positive lens, and the second group includes four lenses, a positive lens, a positive lens, a negative lens, and a positive lens. ing. Tokiko Sho 61-42246
The publication proposes a zoom lens in which the first group includes two lenses, a negative lens and a positive lens, and the second group includes four or five lenses.

【０００５】[0005]

【発明が解決しようとする課題】一般に負の屈折力の第
１群と正の屈折力の第２群の２つのレンズ群より成るネ
ガティブリード型のズームレンズは広画角化が比較的容
易であり、また所定のバックフォーカスが容易に得られ
るという特長がある。しかしながら、レンズ系全体を５
〜６枚程度の少ないレンズ枚数で構成し、かつ良好なる
光学性能を得るには、各レンズ群の屈折力配置やレンズ
形状等を適切に設定する必要がある。各レンズ群の屈折
力配置やレンズ構成が不適切であるとレンズ枚数を増加
させても変倍に伴う収差変動が大きくなり、全変倍範囲
にわたり高い光学性能を得るのが難しくなってくる。Generally, a negative lead type zoom lens comprising a first lens unit having a negative refractive power and a second lens unit having a positive refractive power has a relatively wide angle of view. There is a feature that a predetermined back focus can be easily obtained. However, the whole lens system
In order to configure the optical system with a small number of lenses of about 6 and to obtain good optical performance, it is necessary to appropriately set the refractive power arrangement, lens shape, and the like of each lens group. If the refractive power arrangement or the lens configuration of each lens group is inappropriate, even if the number of lenses is increased, the aberration variation accompanying zooming becomes large, and it becomes difficult to obtain high optical performance over the entire zoom range.

【０００６】例えば所定の変倍比を確保しつつレンズ全
長の短縮化を図るために、各レンズ群の屈折力を強める
と広角側での画面周辺部の劣化、即ち収差で言い換える
と像面弯曲、非点隔差、及び歪曲の発生が著しく多くな
ってくる。For example, in order to shorten the overall length of the lens while maintaining a predetermined zoom ratio, if the refractive power of each lens unit is increased, deterioration of the peripheral portion of the image on the wide-angle side, that is, in other words, aberration, in other words, curvature of field. , Astigmatism and distortion are significantly increased.

【０００７】本発明は、負の屈折力のレンズ群が先行す
るネガティブリード型の２つのレンズ群より成るズーム
レンズにおいて、各レンズ群のレンズ構成を適切に設定
することにより、全体として６枚という少ないレンズ枚
数で所定のバックフォーカスを有しつつ、撮影画角５８
°〜３３°、Ｆナンバー４．３〜５．８、変倍比２程度
の全変倍範囲にわたり高い光学性能を有し、レンズ系全
体の小型化を図ったズームレンズ及びそれを用いたカメ
ラの提供を目的とする。The present invention is directed to a zoom lens composed of two negative-lead type lens groups which are preceded by a lens group having a negative refractive power. By appropriately setting the lens configuration of each lens group, the total number of the six lenses can be reduced. While having a predetermined back focus with a small number of lenses,
A zoom lens having high optical performance over the entire zoom range of about ° to 33 °, an F-number of 4.3 to 5.8, and a zoom ratio of about 2, and a compact lens system, and a camera using the same. The purpose is to provide.

【０００８】請求項１の発明のズームレンズは、物体側
より順に負の屈折力の第１群と正の屈折力の第２群の２
つのレンズ群より成り、広角端から望遠端への変倍を該
第１群を像面側に凸状の軌跡を有して移動させ、該第２
群を該第１群との間隔が減少するように物体側へ移動さ
せて行い、該第１群は物体側に凸面を向けたメニスカス
状の負の第１１レンズと物体側に凸面を向けたメニスカ
ス状の正の第１２レンズより成り、該第２群は、正の第
２１レンズと正の第２２レンズより成る正の第２１成
分、負の第２３レンズより成る負の第２２成分、そして
正の第２４レンズより成る正の第２３成分の３つの成分
を有し、第ｉ群の焦点距離をｆｉ、全系の広角端の焦点
距離をｆｗ、該第１２レンズの物体側と像面側のレンズ
面の曲率半径を各々Ｒ１２ａ，Ｒ１２ｂ、該第１１レン
ズのレンズ厚をＤ１１、該第１１レンズと第１２レンズ
との空気間隔をＤ１１，１２、広角端におけるバックフ
ォーカスをＢｆｗ、望遠端における第１レンズ面から最
終レンズ面までの長さをＴＤＴ、該第１１レンズの材質
のアッベ数をν１１、該第２１レンズの材質の屈折率を
Ｎ２１としたとき[0008] The zoom lens according to the first aspect of the present invention is composed of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power.
The first lens unit is moved from the wide-angle end to the telephoto end by moving the first unit with a locus convex toward the image plane side.
The group is moved to the object side so as to reduce the distance between the first group and the first group. The first group has a meniscus negative eleventh lens having a convex surface facing the object side and a convex surface facing the object side. The second group includes a positive twelfth lens having a meniscus shape,
A positive twenty-first component comprising a twenty-first lens and a positive twenty-second lens
Minute, a negative 22nd component comprising a negative 23rd lens, and
The three components of the positive twenty-third component comprising the positive twenty-fourth lens
Has a focal length of the i group fi, the entire system of the focal length fw at the wide-angle end, said 12 lens on the object side and the lens surface on the image side curvature radius respectively R12a, R12b, said 11 The lens thickness of the lens is D11, the air gap between the eleventh lens and the twelfth lens is D11 and 12, the back focus at the wide angle end is Bfw, the length from the first lens surface to the last lens surface at the telephoto end is TDT , Material of the eleventh lens
Is the Abbe number of ν11 and the refractive index of the material of the 21st lens is
When N21

【数３】 ５２＜ν１１ ・・・（９） １．６５＜Ｎ２１ ・・・（１０） なる条件を満足することを特徴としている。(Equation 3) 52 <ν11 (9) 1.65 <N21 (10)

【０００９】[0009]

【数３】 なる条件を満足することを特徴としている。(Equation 3) It is characterized by satisfying certain conditions.

【００１０】[0010]

【実施例】図１〜図５は各々本発明の数値実施例１〜５
のレンズ断面図である。レンズ断面図において、（Ａ）
は広角端、（Ｂ）は中間、（Ｃ）は望遠端のズーム位置
を示している。図中、Ｌ１は負の屈折力の第１群、Ｌ２
は正の屈折力の第２群、ＳＰは絞り、ＦＰは固定のフレ
アーカット絞り、ＩＰは像面である。矢印は広角端から
望遠端への変倍における各レンズ群の移動軌跡を示して
おり、同図では両レンズ群の間隔を減少させながら第１
群Ｌ１は像面側へ凸状の軌跡を有しつつ、第２群Ｌ２は
物体側へ各々移動している。第１群は変倍に伴う像面変
動を補正しており、第２群は変倍作用を有している。1 to 5 show numerical examples 1 to 5 of the present invention, respectively.
It is a lens sectional view of. In the lens sectional view, (A)
Indicates the zoom position at the wide-angle end, (B) indicates the middle position, and (C) indicates the zoom position at the telephoto end. In the figure, L1 is the first group of negative refractive power, L2
Denotes a second group having a positive refractive power, SP denotes an aperture, FP denotes a fixed flare cut aperture, and IP denotes an image plane. Arrows indicate the movement trajectories of the respective lens units during zooming from the wide-angle end to the telephoto end. In FIG.
The second group L2 moves toward the object side while the group L1 has a locus convex toward the image plane. The first lens unit corrects the image plane fluctuation caused by zooming, and the second lens unit has zooming action.

【００１１】第１群Ｌ１は物体側に凸面を向けたメニス
カス状の負の第１１レンズと物体側に凸面を向けたメニ
スカス状の正の第１２レンズの２つのレンズより構成
し、これにより第１群全体の諸収差の発生を少なくして
いる。The first lens unit L1 is composed of two lenses: a negative meniscus eleventh lens having a convex surface facing the object side and a positive meniscus twelfth lens having a convex surface facing the object side. The occurrence of various aberrations in the entire first group is reduced.

【００１２】第２群Ｌ２においてＬ２１は正の第２１成
分であり、両レンズ面が凸面の正の第２１レンズと正の
第２２レンズの２つのレンズより成っている。Ｌ２２は
負の第２２成分であり、両レンズ面が凹面の単一の負の
第２３レンズより成っている。Ｌ２３は正の第２３成分
であり、像面側に凸面を向けたメニスカス状の正の第２
４レンズより成っている。In the second lens unit L2, L21 is a positive twenty-first component, and has two lenses, a positive twenty-first lens and a positive twenty-second lens, both lens surfaces of which are convex. L22 is a negative twenty-second component, and both lens surfaces are composed of a single negative twenty-third lens having a concave surface. L23 is a positive 23rd component, which is a meniscus-shaped positive second component having a convex surface facing the image surface side.
It consists of four lenses.

【００１３】第２群Ｌ２を以上のように構成することに
より変倍に伴う諸収差の変動を良好に補正している。絞
りＳＰは第２１レンズと第２２レンズとの間に設けてお
り変倍と共に第２群と一体的に移動している。これによ
り前玉径の増大を防止し、レンズ系全体の小型化を図っ
ている。By configuring the second lens unit L2 as described above, fluctuations of various aberrations due to zooming are corrected well. The stop SP is provided between the 21st lens and the 22nd lens, and moves together with the second unit with zooming. This prevents an increase in the diameter of the front lens and reduces the size of the entire lens system.

【００１４】本実施例ではフレアーカット絞りＦＰは変
倍に際して固定にしているが、第２群と一体的に又は独
立に移動させても良い。これによれば収差補正の自由度
を増加させることができる。尚、フォーカスは第１群又
は第２群又は全系を移動させて行っている。In this embodiment, the flare cut aperture FP is fixed at the time of zooming, but it may be moved integrally or independently of the second lens unit. According to this, the degree of freedom of aberration correction can be increased. Focusing is performed by moving the first group, the second group, or the entire system.

【００１５】本発明では以上のように各レンズ群のレン
ズ構成を特定すると共に条件式（１）〜（７）を満足さ
せることにより全変倍範囲にわたり又画面全体にわたり
良好なる光学性能を得ている。In the present invention, as described above, by specifying the lens configuration of each lens group and satisfying conditional expressions (1) to (7), good optical performance can be obtained over the entire zoom range and over the entire screen. I have.

【００１６】次に前述の各条件式の技術的意味について
説明する。Next, the technical meaning of each of the above conditional expressions will be described.

【００１７】条件式（１）は第１群の屈折力に関し、主
にレンズ系全体の小型化を図りつつ広角側における歪曲
収差を良好に補正するためのものである。条件式（１）
の上限値を越えると負の歪曲収差の発生は小さくなる
が、前玉径が大型化してくる。また下限値を越えると負
の歪曲収差が増大してくるので良くない。Conditional expression (1) relates to the refractive power of the first lens unit, and is intended to favorably correct distortion on the wide-angle side while mainly reducing the size of the entire lens system. Conditional expression (1)
If the upper limit is exceeded, the occurrence of negative distortion becomes small, but the diameter of the front lens becomes large. On the other hand, when the value exceeds the lower limit, negative distortion increases, which is not preferable.

【００１８】条件式（２）は第１群と第２群の屈折力の
比に関し、主に前玉レンズ径の小型化を図りつつ、広角
端での像面特性と望遠端での球面収差を良好に補正する
ためのものである。条件式（２）の上限値を越えると広
角側において第１群と第２群の間隔を長くしなければな
らなくなり、前玉径の大型化や変倍のための各レンズ群
の移動量が増加しレンズ全長が長くなってくる。また下
限値を越えると広角側での像面弯曲や望遠側での球面収
差の補正が困難となる。Conditional expression (2) relates to the ratio of the refracting power of the first lens unit and the second lens unit. The image surface characteristic at the wide-angle end and the spherical aberration at the telephoto end are mainly determined while reducing the diameter of the front lens. Is to be corrected favorably. If the upper limit of conditional expression (2) is exceeded, the distance between the first and second lens units must be increased on the wide-angle side, and the amount of movement of each lens unit for increasing the diameter of the front lens and changing the magnification is reduced. The total length of the lens increases. If the lower limit is exceeded, it becomes difficult to correct curvature of field on the wide-angle side and spherical aberration on the telephoto side.

【００１９】条件式（３）は正の第１２レンズのレンズ
形状（シェイプファクター）に関し、主に球面収差と歪
曲収差をバランス良く補正するためのものである。条件
式（３）の上限値を越えると広角端での負の歪曲収差は
小さくなるが、望遠側で正の球面収差が多く発生してく
る。また下限値を越えると広角端での負の歪曲収差が多
く発生し、これを補正するのが難しくなってくる。Conditional expression (3) relates to the lens shape (shape factor) of the positive twelfth lens, and is mainly for correcting spherical aberration and distortion in a well-balanced manner. When the value exceeds the upper limit of conditional expression (3), the negative distortion at the wide-angle end decreases, but a large amount of positive spherical aberration occurs on the telephoto side. If the lower limit value is exceeded, a large amount of negative distortion occurs at the wide-angle end, and it becomes difficult to correct this.

【００２０】条件式（４）はメニスカス状の負の第１１
レンズの光軸上のレンズ厚を適切に設定したものであ
る。上限値を越えると外径が大型化し、又重量が増加し
てくる。又下限値を越えるとレンズとしての耐久強度が
落ちるので良くない。Condition (4) is a negative meniscus eleventh condition.
The lens thickness on the optical axis of the lens is set appropriately. Exceeding the upper limit will increase the outer diameter and increase the weight. On the other hand, when the value exceeds the lower limit, the durability of the lens decreases, which is not good.

【００２１】本発明に係る２群ズームレンズにおいて、
第１群と第２群の屈折力を各々φ１，φ２、第１群と第
２群の主点間隔をｅとしたとき、全系の屈折力φは φ＝φ１＋φ２−ｅφ１φ２ ‥‥‥（ａ） となる。ここで屈折力φは正、φ１とφ２は異符号であ
る。この為屈折力φが一定の時主点間隔ｅを大にすると
φ１を大にするかφ２を小にする必要がある。又主点間
隔ｅを小にするとその逆となる。In the two-unit zoom lens according to the present invention,
When the refractive powers of the first and second groups are φ1 and φ2, respectively, and the distance between the principal points of the first and second groups is e, the refractive power φ of the entire system is φ = φ1 + φ2-eφ1φ2 ‥‥‥ (a ). Here, the refractive power φ is positive, and φ1 and φ2 have different signs. Therefore, when the principal point interval e is increased when the refractive power φ is constant, it is necessary to increase φ1 or decrease φ2. The opposite is true when the principal point interval e is reduced.

【００２２】前者の場合、各レンズ群内の諸収差を小と
する為に、第１群の光学系を高屈折率、第２群の光学系
を低屈折率の硝材で構成すると良い。ところが光学用の
硝材は高屈折率高分散、低屈折率低分散の分布を持って
いるので上記のような硝材を選択すると色収差の補正が
困難となる。In the former case, in order to reduce various aberrations in each lens group, it is preferable that the first group of optical systems is made of a glass material having a high refractive index and the second group of optical systems is made of a glass material having a low refractive index. However, since optical glass materials have a distribution of high refractive index and high dispersion and low refractive index and low dispersion, it is difficult to correct chromatic aberration if the above glass materials are selected.

【００２３】一方後者の場合、硝材の選択には有利であ
るが、軸上光束のマージナル光線が第１群の光学系と第
２群の光学系を通過する高さの変化が小となる。この為
特に望遠端において球面収差の補正が困難となる。On the other hand, in the latter case, although the selection of the glass material is advantageous, the change in the height at which the marginal ray of the axial light beam passes through the first and second optical systems becomes small. For this reason, it becomes difficult to correct spherical aberration particularly at the telephoto end.

【００２４】条件式（５）は以上の点を鑑みて第１群の
メニスカス状の負の第１１レンズとメニスカス状の正の
第１２レンズの間隔Ｄ１１を適切に設定したものであ
り、条件式（５）の上限値又は下限値を越えると色収差
及び望遠側での球面収差の補正が難しくなってくる。In view of the above points, the conditional expression (5) appropriately sets the distance D11 between the meniscus negative eleventh lens and the meniscus positive twelfth lens of the first group. If the value exceeds the upper limit or the lower limit of (5), it becomes difficult to correct chromatic aberration and spherical aberration on the telephoto side.

【００２５】本発明に係る２群ズームレンズにおいてバ
ックフォーカスを長く設定しすぎると第１群と第２群の
屈折力が強くなってきて、諸収差をバランス良く補正す
るには各レンズ群のレンズ枚数を増加させる必要があ
り、この結果レンズ系全体の小型化を図るのが難しくな
ってくる。In the two-unit zoom lens system according to the present invention, if the back focus is set too long, the refractive power of the first and second units will increase, and the lenses of each lens unit will be corrected in a well-balanced manner. It is necessary to increase the number of lenses, and as a result, it is difficult to reduce the size of the entire lens system.

【００２６】条件式（６）は２群ズームレンズとして、
例えば一眼レフカメラ等にも適用できる長さのバックフ
ォーカスを有するように広角端でのバックフォーカスを
適切に設定しつつ、諸収差を良好に補正する為のもので
ある。Conditional expression (6) is used as a two-unit zoom lens.
For example, this is for properly correcting various aberrations while appropriately setting the back focus at the wide-angle end so as to have a back focus of a length applicable to a single-lens reflex camera or the like.

【００２７】本発明に係る２群ズームレンズの場合、望
遠端でレンズ全厚（第１レンズ面から最終レンズ面まで
の長さ）が最小となる。このレンズ全厚は空気間隔も含
んでいるが、それぞれのレンズの軸上厚によるところが
大である。一般にレンズの軸上厚が大となれば強度は増
すが、重量が増加し、又大型化してくる。逆に軸上厚が
小となると製造が困難となる。In the case of the two-unit zoom lens according to the present invention, the total lens thickness (the length from the first lens surface to the last lens surface) becomes minimum at the telephoto end. Although the total thickness of the lens includes the air gap, it largely depends on the axial thickness of each lens. Generally, as the axial thickness of the lens increases, the strength increases, but the weight increases and the size increases. Conversely, when the axial thickness is small, manufacturing becomes difficult.

【００２８】条件式（７）は上記を鑑みて望遠端でのレ
ンズ全厚を適切に設定し、レンズ系全体の小型化を効果
的に図ったものである。In view of the above, the conditional expression (7) appropriately sets the total thickness of the lens at the telephoto end and effectively reduces the size of the entire lens system.

【００２９】条件式（９）は第１１レンズの材質のアッ
ベ数を適切に設定し、変倍に伴う軸上及び倍率色収差を
良好に補正するためのものであり、条件式（９）を外れ
るとこれらの色収差を良好に補正するのが難しくなって
くる。条件式（１０）は第２１レンズの材質の屈折率を
適切に設定し、主に変倍範囲中の像面湾曲を良好に補正
するためのものである。条件式（１０）を外れるとペッ
ツバール和が大きくなり、中間から望遠端への変倍範囲
において像面湾曲が増大すると共に望遠側での非点隔差
が大きくなってくるので良くない。本発明では以上のよ
うに第１群と第２群のレンズ構成を適切に設定すること
により、変倍比２程度の広画角を含む簡易な構成のズー
ムレンズを得ているが、更に全変倍範囲にわたり、且つ
画面全体にわたり高い光学性能を有したズームレンズを
得るには、次の項目のうち少なくとも１つを満足させる
のが良い。 Conditional expression (9) is an expression for the material of the eleventh lens.
Set the number of beams appropriately to reduce axial and lateral chromatic aberrations associated with
This is for good correction and deviates from conditional expression (9).
This makes it difficult to correct these chromatic aberrations properly.
come. Conditional expression (10) defines the refractive index of the material of the twenty-first lens.
Appropriately set, good correction of field curvature mainly in the zoom range
It is for doing. If conditional expression (10) is not satisfied,
The Tuvalu sum increases and the zoom range from the middle to the telephoto end
Field curvature increases and the astigmatic difference at the telephoto side
Is not good because it gets bigger. In the present invention,
The lens configuration of the first and second groups appropriately
Zoom with a simple configuration including a wide angle of view with a zoom ratio of about 2.
Lens, but over the entire zoom range, and
A zoom lens with high optical performance over the entire screen
To obtain, satisfy at least one of the following items
Is good.

【００３０】[0030]

【数４】 本発明では以上のように第１群と第２群のレンズ構成を
適切に設定することにより、変倍比２程度の広画角を含
む簡易な構成のズームレンズを得ているが、更に全変倍
範囲にわたり、且つ画面全体にわたり高い光学性能を有
したズームレンズを得るには、次の項目のうち少なくと
も１つを満足させるのが良い。(Equation 4) In the present invention, a zoom lens having a simple configuration including a wide angle of view with a zoom ratio of about 2 is obtained by appropriately setting the lens configurations of the first and second groups as described above. In order to obtain a zoom lens having high optical performance over the zoom range and over the entire screen, at least one of the following items should be satisfied.

【００３１】◎前記第２２レンズと第２３レンズとの空
気間隔をＤ２２,２３としたとき Ｄ２２，２３／ｆｗ＜０．０３ ・・・（８） なる条件を満足することである。[0031] ◎ is to satisfy D22,23 / fw <0.03 ··· (8 ) becomes a condition when the D22,23 the air gap between the first lens 22 and the 23 lens.

【００３２】本発明に係るズームレンズでは第２群を
正，負そして正の成分より成る所謂トリプレットタイプ
の屈折力配置を用いている。ここで第２群の光束入射
面、つまり正の第２１成分に注目すると広角端から望遠
端まで全域において軸上光束のマージナル光線位置が高
く、急激に光線を屈折させると特に球面収差の補正が困
難となる。そこで正の第２１成分を２枚の正レンズに分
けることにより、無理のない屈折を達成している。又こ
れ以上レンズ枚数を増やすとペッツバール和の減少によ
る像面弯曲を良好に補正するのが難しくなる。The zoom lens according to the present invention uses a so-called triplet type refractive power arrangement in which the second lens unit includes positive, negative and positive components. Here, when focusing on the light-incident surface of the second group, that is, the positive 21st component, the position of the marginal ray of the axial ray is high in the entire region from the wide-angle end to the telephoto end. It will be difficult. Therefore, by dividing the positive 21st component into two positive lenses, reasonable refraction is achieved. Further, if the number of lenses is further increased, it becomes difficult to satisfactorily correct the field curvature due to the decrease in Petzval sum.

【００３３】又第２群中の正の第２１成分と負の第２２
成分との空気間隔はピント面の移動敏感度が非常に高い
ので位置精度が得やすい、所謂マージナルコンタクトと
するのが望ましい。The positive 21st component and the negative 22nd component in the second lens unit
The air gap between the components is preferably a so-called marginal contact, in which the position sensitivity is easily obtained because the sensitivity of movement of the focus surface is very high.

【００３４】条件式（８）は上記の点を鑑みて正の第２
１成分と負の第２２成分との空気間隔を適切に設定した
ものであり、この条件を外れるとマージナルコンタクト
径が増大し、レンズが大型化するので良くない。尚収差
補正上、条件式（８）の数値条件を次の如く設定するの
が更に好ましい。In view of the above, conditional expression (8)
The air gap between the first component and the negative twenty-second component is appropriately set, and if this condition is not satisfied, the marginal contact diameter increases and the size of the lens increases, which is not good. In terms of aberration correction, it is more preferable to set the numerical condition of conditional expression (8) as follows.

【００３５】 Ｄ２２，２３／ｆｗ＜０．０２ ・・・（８ａ）D22,23 / fw <0.02 (8a)

【００３６】[0036]

【００３７】[0037]

【００３８】[0038]

【００３９】◎前記第２４レンズは像面側に凸面を向け
たメニスカス形状より成り、該第２４レンズの物体側と
像面側のレンズ面の曲率半径を各々Ｒ２４ａ，Ｒ２４ｂ
としたときThe twenty-fourth lens has a meniscus shape with the convex surface facing the image surface side, and the radii of curvature of the object-side and image-side lens surfaces of the twenty-fourth lens are R24a and R24b, respectively.
And when

【００４０】[0040]

【数５】 なる条件を満足することである。(Equation 5) Satisfying the following conditions.

【００４１】本発明に係る負の屈折力のレンズ群が先行
する２群ズームレンズにおいては、第１群を負の第１１
レンズと正の第１２レンズの２つのレンズより構成して
いる。このため２群ズームレンズの第１群を負、負そし
て正レンズの３つのレンズより構成した場合に比べて負
の第１１レンズの負担が多くなり、広角端での負の歪曲
収差の発生が多くなってくる。In the two-unit zoom lens system according to the present invention, which is preceded by a lens unit having a negative refractive power, the first unit is a negative eleventh lens unit.
It consists of two lenses, a lens and a positive twelfth lens. For this reason, the load on the negative eleventh lens is increased as compared with the case where the first group of the two-unit zoom lens is constituted by three lenses of negative, negative and positive lenses, and negative distortion occurs at the wide-angle end. More and more.

【００４２】一般には第１１レンズを物体側に凸面を向
けたメニスカス状の負レンズとし、軸外収差、特に広角
側における負の歪曲収差の発生量を少なくしているが、
無理に歪曲収差を良好に補正しようとすると、球面収差
及び倍率色収差等に悪影響を及ぼす。そこで本発明では
第２群の最も像面側の正の第２４レンズを条件式（１
１）を満足させるようなレンズ形状にして、このときの
歪曲収差を良好に補正している。Generally, the eleventh lens is a meniscus negative lens having a convex surface facing the object side to reduce the amount of off-axis aberrations, particularly negative distortion on the wide-angle side.
Forcibly trying to satisfactorily correct distortion has a bad influence on spherical aberration, lateral chromatic aberration and the like. Therefore, in the present invention, the positive 24th lens closest to the image plane in the second group is set to the conditional expression (1).
By making the lens shape satisfying 1), the distortion at this time is favorably corrected.

【００４３】一般に歪曲収差は軸外光束が光軸から離れ
た位置を通過するレンズにおいて多く発生しやすい。本
発明のレンズタイプの場合、第２群の最も像面側の第２
４レンズにおいて軸外光束が最も光軸から離れた位置を
通過する。この第２４レンズを条件式（１１）を満足す
る形状の正レンズとして第１群で補正不足となった歪曲
収差を良好に補正している。条件式（１１）の上限値を
越えると負の歪曲収差が補正不足となり、また下限値を
越えると球面収差が補正過剰となってくるので良くな
い。In general, distortion is likely to occur more frequently in a lens where an off-axis light beam passes through a position distant from the optical axis. In the case of the lens type of the present invention, the second lens unit closest to the image plane in the second unit
In the four lenses, the off-axis light beam passes through the position farthest from the optical axis. This twenty-fourth lens is a positive lens having a shape satisfying conditional expression (11), and the distortion which is insufficiently corrected in the first lens group is satisfactorily corrected. If the upper limit of conditional expression (11) is exceeded, negative distortion will be insufficiently corrected. If the lower limit is exceeded, spherical aberration will be overcorrected.

【００４４】尚収差補正上、条件式（１１）の数値条件
を次の如く設定するのが更に好ましい。For aberration correction, it is more preferable to set the numerical condition of the conditional expression (11) as follows.

【００４５】[0045]

【数６】 次に本発明の数値実施例を示す。数値実施例においてＲ
ｉは物体側より順に第ｉ番目のレンズ面の曲率半径、Ｄ
ｉは物体側より第ｉ番目のレンズ厚及び空気間隔、Ｎｉ
とνｉは各々物体側より順に第ｉ番目のレンズのガラス
の屈折率とアッベ数である。又、前述の各条件式と数値
実施例における諸数値との関係を表−１に示す。 （数値実施例１） f= 39.33 〜73.34 Fno=4.32 〜5.88 2ω= 57.6°〜32.9° R 1= 116.40 D 1= 1.50 N 1=1.63853 ν 1= 55.4 R 2= 19.42 D 2= 6.63 R 3= 21.34 D 3= 2.20 N 2=1.74076 ν 2= 27.8 R 4= 27.44 D 4= 可変 R 5= 28.72 D 5= 2.35 N 3=1.71999 ν 3= 50.3 R 6=-144.60 D 6= 1.85 R 7= 絞り D 7= 3.27 R 8= 26.03 D 8= 2.69 N 4=1.62299 ν 4= 58.1 R 9=-400.64 D 9= 0.50 R10= -41.11 D10= 2.88 N 5=1.80518 ν 5= 25.4 R11= 22.80 D11= 3.69 R12= -65.52 D12= 1.65 N 6=1.76182 ν 6= 26.5 R13= -23.40 D13= 可変 R14=∞(フレアーカット絞り) (Equation 6) Next, numerical examples of the present invention will be described. In the numerical examples, R
i is the radius of curvature of the i-th lens surface in order from the object side, D
i is the i-th lens thickness and air gap from the object side, Ni
And νi are the refractive index and Abbe number of the glass of the i-th lens in order from the object side. Table 1 shows the relationship between the above-described conditional expressions and various numerical values in the numerical examples. (Numerical Example 1) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 116.40 D 1 = 1.50 N 1 = 1.63853 ν 1 = 55.4 R 2 = 19.42 D 2 = 6.63 R 3 = 21.34 D 3 = 2.20 N 2 = 1.74076 ν 2 = 27.8 R 4 = 27.44 D 4 = Variable R 5 = 28.72 D 5 = 2.35 N 3 = 1.71999 ν 3 = 50.3 R 6 = -144.60 D 6 = 1.85 R 7 = Aperture D 7 = 3.27 R 8 = 26.03 D 8 = 2.69 N 4 = 1.62299 ν 4 = 58.1 R 9 = -400.64 D 9 = 0.50 R10 = -41.11 D10 = 2.88 N 5 = 1.80518 ν 5 = 25.4 R11 = 22.80 D11 = 3.69 R12 = -65.52 D12 = 1.65 N 6 = 1.76182 ν 6 = 26.5 R13 = -23.40 D13 = Variable R14 = ∞ (flare cut aperture)

【００４６】[0046]

【表１】 （数値実施例２） f= 39.33 〜73.34 Fno=4.32 〜5.88 2ω= 57.6°〜32.9° R 1= 140.29 D 1= 1.50 N 1=1.62299 ν 1= 58.1 R 2= 19.35 D 2= 6.31 R 3= 21.43 D 3= 2.20 N 2=1.76181 ν 2= 26.6 R 4= 27.74 D 4= 可変 R 5= 27.90 D 5= 2.35 N 3=1.71299 ν 3= 53.8 R 6=-131.57 D 6= 1.85 R 7= 絞り D 7= 2.74 R 8= 24.97 D 8= 2.43 N 4=1.62299 ν 4= 58.1 R 9=-70659.3 D 9= 0.51 R10= -44.71 D10= 2.89 N 5=1.80518 ν 5= 25.4 R11= 21.74 D11= 4.01 R12= -66.78 D12= 1.65 N 6=1.78471 ν 6= 25.7 R13= -24.32 D13= 可変 R14=∞(フレアーカット絞り) [Table 1] (Numerical Example 2) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 140.29 D 1 = 1.50 N 1 = 1.62299 ν 1 = 58.1 R 2 = 19.35 D 2 = 6.31 R 3 = 21.43 D 3 = 2.20 N 2 = 1.76181 ν 2 = 26.6 R 4 = 27.74 D 4 = Variable R 5 = 27.90 D 5 = 2.35 N 3 = 1.71299 ν 3 = 53.8 R 6 = -131.57 D 6 = 1.85 R 7 = Aperture D 7 = 2.74 R 8 = 24.97 D 8 = 2.43 N 4 = 1.62299 ν 4 = 58.1 R 9 = -70659.3 D 9 = 0.51 R10 = -44.71 D10 = 2.89 N 5 = 1.80518 ν 5 = 25.4 R11 = 21.74 D11 = 4.01 R12 = -66.78 D12 = 1.65 N 6 = 1.78471 ν 6 = 25.7 R13 = -24.32 D13 = Variable R14 = ∞ (flare cut aperture)

【００４７】[0047]

【表２】 （数値実施例３） f= 39.33 〜73.34 Fno=4.32 〜5.88 2ω= 57.6°〜32.9° R 1= 147.18 D 1= 1.50 N 1=1.60311 ν 1= 60.7 R 2= 19.43 D 2= 6.66 R 3= 21.33 D 3= 2.20 N 2=1.72824 ν 2= 28.5 R 4= 27.32 D 4= 可変 R 5= 28.40 D 5= 2.40 N 3=1.71299 ν 3= 53.8 R 6=-126.88 D 6= 1.90 R 7= 絞り D 7= 1.81 R 8= 22.94 D 8= 2.85 N 4=1.60562 ν 4= 43.7 R 9=2446.23 D 9= 0.46 R10= -51.41 D10= 2.95 N 5=1.80518 ν 5= 25.4 R11= 20.09 D11= 4.60 R12= -76.64 D12= 1.65 N 6=1.69894 ν 6= 30.1 R13= -24.23 D13= 可変 R14=∞(フレアーカット絞り) [Table 2] (Numerical Example 3) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 147.18 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.43 D 2 = 6.66 R 3 = 21.33 D 3 = 2.20 N 2 = 1.72824 ν 2 = 28.5 R 4 = 27.32 D 4 = Variable R 5 = 28.40 D 5 = 2.40 N 3 = 1.71299 ν 3 = 53.8 R 6 = -126.88 D 6 = 1.90 R 7 = Aperture D 7 = 1.81 R 8 = 22.94 D 8 = 2.85 N 4 = 1.60562 ν 4 = 43.7 R 9 = 2446.23 D 9 = 0.46 R10 = -51.41 D10 = 2.95 N 5 = 1.80518 ν 5 = 25.4 R11 = 20.09 D11 = 4.60 R12 = -76.64 D12 = 1.65 N 6 = 1.69894 ν 6 = 30.1 R13 = -24.23 D13 = Variable R14 = ∞ (Flare cut aperture)

【００４８】[0048]

【表３】 （数値実施例４） f= 39.33 〜73.34 Fno=4.31 〜5.88 2ω= 57.6°〜32.8° R 1= 137.26 D 1= 1.50 N 1=1.60311 ν 1= 60.7 R 2= 19.86 D 2= 7.76 R 3= 21.47 D 3= 2.20 N 2=1.63979 ν 2= 34.5 R 4= 27.20 D 4= 可変 R 5= 28.40 D 5= 2.45 N 3=1.70153 ν 3= 41.2 R 6=-116.31 D 6= 2.20 R 7= 絞り D 7= 2.38 R 8= 25.40 D 8= 2.20 N 4=1.62299 ν 4= 58.1 R 9=-122.99 D 9= 0.43 R10= -37.93 D10= 2.60 N 5=1.80518 ν 5= 25.4 R11= 22.03 D11= 4.70 R12= -47.70 D12= 1.65 N 6=1.74076 ν 6= 27.8 R13= -21.56 D13= 可変 R14=∞(フレアーカット絞り) [Table 3] (Numerical Example 4) f = 39.33 to 73.34 Fno = 4.31 to 5.88 2ω = 57.6 ° to 32.8 ° R 1 = 137.26 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.86 D 2 = 7.76 R 3 = 21.47 D 3 = 2.20 N 2 = 1.63979 ν 2 = 34.5 R 4 = 27.20 D 4 = Variable R 5 = 28.40 D 5 = 2.45 N 3 = 1.70153 ν 3 = 41.2 R 6 = -116.31 D 6 = 2.20 R 7 = Aperture D 7 = 2.38 R 8 = 25.40 D 8 = 2.20 N 4 = 1.62299 ν 4 = 58.1 R 9 = -122.99 D 9 = 0.43 R10 = -37.93 D10 = 2.60 N 5 = 1.80518 ν 5 = 25.4 R11 = 22.03 D11 = 4.70 R12 = -47.70 D12 = 1.65 N 6 = 1.74076 ν 6 = 27.8 R13 = -21.56 D13 = Variable R14 = ∞ (flare cut aperture)

【００４９】[0049]

【表４】 （数値実施例５） f= 39.30 〜73.70 Fno=4.27 〜5.88 2ω= 57.7°〜32.7° R 1= 136.35 D 1= 1.50 N 1=1.60311 ν 1= 60.7 R 2= 19.56 D 2= 7.58 R 3= 21.26 D 3= 2.20 N 2=1.67270 ν 2= 32.1 R 4= 26.90 D 4= 可変 R 5= 27.79 D 5= 2.50 N 3=1.70153 ν 3= 41.2 R 6=-115.11 D 6= 1.39 R 7= 絞り D 7= 1.25 R 8= 21.89 D 8= 3.00 N 4=1.60311 ν 4= 60.7 R 9=-239.55 D 9= 0.44 R10= -48.88 D10= 3.00 N 5=1.76182 ν 5= 26.5 R11= 17.82 D11= 4.64 R12= -48.06 D12= 1.80 N 6=1.69894 ν 6= 30.1 R13= -22.42 D13= 可変 R14=∞(フレアーカット絞り) [Table 4] (Numerical Example 5) f = 39.30 to 73.70 Fno = 4.27 to 5.88 2ω = 57.7 ° to 32.7 ° R 1 = 136.35 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.56 D 2 = 7.58 R 3 = 21.26 D 3 = 2.20 N 2 = 1.67270 ν 2 = 32.1 R 4 = 26.90 D 4 = Variable R 5 = 27.79 D 5 = 2.50 N 3 = 1.70153 ν 3 = 41.2 R 6 = -115.11 D 6 = 1.39 R 7 = Aperture D 7 = 1.25 R 8 = 21.89 D 8 = 3.00 N 4 = 1.60311 ν 4 = 60.7 R 9 = -239.55 D 9 = 0.44 R10 = -48.88 D10 = 3.00 N 5 = 1.76182 ν 5 = 26.5 R11 = 17.82 D11 = 4.64 R12 = -48.06 D12 = 1.80 N 6 = 1.69894 ν 6 = 30.1 R13 = -22.42 D13 = Variable R14 = ∞ (flare cut aperture)

【００５０】[0050]

【表５】 [Table 5]

【００５１】[0051]

【表６】 [Table 6]

【００５２】[0052]

【発明の効果】本発明によれば以上のように、負の屈折
力のレンズ群が先行するネガティブリード型の２つのレ
ンズ群より成るズームレンズにおいて、各レンズ群のレ
ンズ構成を適切に設定することにより、全体として６枚
という少ないレンズ枚数で所定のバックフォーカスを有
しつつ、撮影画角５８°〜３３°、Ｆナンバー４．３〜
５．８、変倍比２程度の全変倍範囲にわたり高い光学性
能を有し、レンズ系全体の小型化を図ったズームレンズ
及びそれを用いたカメラを達成することができる。As described above, according to the present invention, in a zoom lens composed of two negative-lead type lens groups which are preceded by a lens group having a negative refractive power, the lens configuration of each lens group is appropriately set. Accordingly, while having a predetermined back focus with a small number of lenses such as 6 as a whole, a shooting angle of view of 58 ° to 33 °, and an F-number of 4.3 to
It is possible to achieve a zoom lens having high optical performance over the entire zoom range of about 5.8 and a zoom ratio of about 2, and miniaturizing the entire lens system, and a camera using the same.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の数値実施例１のレンズ断面図FIG. 1 is a sectional view of a lens according to a numerical example 1 of the present invention.

【図２】本発明の数値実施例２のレンズ断面図FIG. 2 is a sectional view of a lens according to a numerical example 2 of the present invention.

【図３】本発明の数値実施例３のレンズ断面図FIG. 3 is a sectional view of a lens according to a numerical example 3 of the present invention.

【図４】本発明の数値実施例４のレンズ断面図FIG. 4 is a sectional view of a lens according to a numerical example 4 of the present invention.

【図５】本発明の数値実施例５のレンズ断面図FIG. 5 is a sectional view of a lens according to a numerical example 5 of the present invention.

【図６】本発明の数値実施例１の広角端の収差図FIG. 6 is an aberration diagram at a wide-angle end according to Numerical Embodiment 1 of the present invention.

【図７】本発明の数値実施例１の中間の収差図FIG. 7 is an intermediate aberration diagram of the numerical example 1 of the present invention.

【図８】本発明の数値実施例１の望遠端の収差図FIG. 8 is an aberration diagram at a telephoto end in Numerical Example 1 of the present invention;

【図９】本発明の数値実施例２の広角端の収差図FIG. 9 is an aberration diagram at a wide-angle end according to Numerical Example 2 of the present invention.

【図１０】本発明の数値実施例２の中間の収差図FIG. 10 is a diagram showing aberrations in the middle of the numerical example 2 of the present invention.

【図１１】本発明の数値実施例２の望遠端の収差図FIG. 11 is an aberration diagram at a telephoto end in Numerical Example 2 of the present invention.

【図１２】本発明の数値実施例３の広角端の収差図FIG. 12 is an aberration diagram at a wide angle end according to Numerical Example 3 of the present invention.

【図１３】本発明の数値実施例３の中間の収差図FIG. 13 is an intermediate aberration diagram of the numerical example 3 of the present invention.

【図１４】本発明の数値実施例３の望遠端の収差図FIG. 14 is an aberration diagram at a telephoto end in Numerical Example 3 of the present invention.

【図１５】本発明の数値実施例４の広角端の収差図FIG. 15 is an aberration diagram at a wide angle end according to Numerical Example 4 of the present invention.

【図１６】本発明の数値実施例４の中間の収差図FIG. 16 is an intermediate aberration diagram of the numerical example 4 of the present invention.

【図１７】本発明の数値実施例４の望遠端の収差図FIG. 17 is an aberration diagram at a telephoto end in Numerical Example 4 of the present invention.

【図１８】本発明の数値実施例５の広角端の収差図FIG. 18 is an aberration diagram at a wide angle end according to Numerical Example 5 of the present invention.

【図１９】本発明の数値実施例５の中間の収差図FIG. 19 is an intermediate aberration diagram of the numerical example 5 of the present invention.

【図２０】本発明の数値実施例５の望遠端の収差図FIG. 20 is an aberration diagram at a telephoto end in Numerical Example 5 of the present invention.

【符号の説明】[Explanation of symbols]

Ｌ１ 第１群 Ｌ２ 第２群 ＳＰ 絞り ＦＰ フレアーカット絞り ＩＰ 像面 ｄ ｄ線 ｇ ｇ線 Ｓ サジタル像面 Ｍ メリディオナル像面 Ｓ．Ｃ 正弦条件 L1 First lens group L2 Second lens group SP stop FP flare cut stop IP image plane dd line gg line S sagittal image plane M meridional image plane C sine condition

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.⁷，ＤＢ名) G02B 15/16 ──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 15/16

Claims (4)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 物体側より順に負の屈折力の第１群と正
の屈折力の第２群の２つのレンズ群より成り、広角端か
ら望遠端への変倍を該第１群を像面側に凸状の軌跡を有
して移動させ、該第２群を該第１群との間隔が減少する
ように物体側へ移動させて行い、該第１群は物体側に凸
面を向けたメニスカス状の負の第１１レンズと物体側に
凸面を向けたメニスカス状の正の第１２レンズより成
り、該第２群は、正の第２１レンズと正の第２２レンズ
より成る正の第２１成分、負の第２３レンズより成る負
の第２２成分、そして正の第２４レンズより成る正の第
２３成分の３つの成分を有し、第ｉ群の焦点距離をｆ
ｉ、全系の広角端の焦点距離をｆｗ、該第１２レンズの
物体側と像面側のレンズ面の曲率半径を各々Ｒ１２ａ，
Ｒ１２ｂ、該第１１レンズのレンズ厚をＤ１１、該第１
１レンズと第１２レンズとの空気間隔をＤ１１，１２、
広角端におけるバックフォーカスをＢｆｗ、望遠端にお
ける第１レンズ面から最終レンズ面までの長さをＴＤ
Ｔ、該第１１レンズの材質のアッベ数をν１１、該第２
１レンズの材質の屈折率をＮ２１としたとき 【数１】 ５２＜ν１１ １．６５＜Ｎ２１ なる条件を満足することを特徴とするズームレンズ。1. A lens system comprising, in order from the object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The second group is moved toward the object side such that the distance from the first group is reduced, and the first group is directed toward the object side. The second group includes a positive eleventh lens and a positive twenty- second lens, and comprises a negative meniscus eleventh lens and a positive meniscus twelfth lens having a convex surface facing the object side.
A positive 21st component consisting of a negative 23rd lens
A positive twenty-second component comprising a positive twenty-fourth lens
It has three components of 23 components, and the focal length of the ith group is f
i, the focal length at the wide-angle end of the entire system is fw, the radii of curvature of the lens surfaces of the twelfth lens on the object side and the image plane side are R12a,
R12b, the lens thickness of the eleventh lens is D11, the first lens is
The air gap between the first lens and the twelfth lens is D11, 12,
The back focus at the wide-angle end is Bfw, and the length from the first lens surface to the final lens surface at the telephoto end is TD.
T , the Abbe number of the material of the eleventh lens is ν11;
When the refractive index of the material of one lens is N21 A zoom lens characterized by satisfying the following condition: 52 <ν11 1.65 <N21 . 【請求項２】 前記第２２レンズと第２３レンズとの空
気間隔をＤ２２，２３としたとき Ｄ２２，２３／ｆｗ＜０．０３ なる条件を満足することを特徴とする請求項１のズーム
レンズ。2. The space between the 22nd lens and the 23rd lens.
2. The zoom lens according to claim 1, wherein a condition of D22,23 / fw <0.03 is satisfied when the air gap is D22,23 . 【請求項３】 前記第２４レンズは像面側に凸面を向け
たメニスカス形状より成り、該第２４レンズの物体側と
像面側のレンズ面の曲率半径を各々Ｒ２４ａ，Ｒ２４ｂ
としたとき 【数２】 なる条件を満足することを特徴とする請求項１又は２の
いずれか１項のズームレンズ。3. The twenty-fourth lens has a meniscus shape having a convex surface facing the image surface side, and the object surfaces and the image surface side of the twenty-fourth lens have curvature radii of R24a and R24b, respectively.
[Equation 2] 3. The zoom lens according to claim 1 , wherein the following condition is satisfied. 【請求項４】 請求項１乃至３のいずれか１項のズーム
レンズを有することを特徴とするカメラ。4. A camera comprising the zoom lens according to claim 1.