JPH07270683A - Wide angle zoom lens - Google Patents

Abstract

PURPOSE:To provide a zoom lens having a wide view angle on a wide angle end, a shape that the entire length of a lens on the wide angle end is short and a small number of components and being advantageous to decrease the cost and excellent in image forming performance. CONSTITUTION:In the wide angle zoom lens provided with a first lens group G1 having positive refractive power and a second lens group G2 having negative refractive power in order from the object side and varying power in such a manner that the distance between the first and second lens groups G1 and G2 is reduced, the first lens groups G1 is provided with a first lens component L1 of negative refractive power, a second lens component L2 of positive refractive power, a third lens component L3 of positive or negative refractive power and a forth lens component L4 of positive refractive power in the order from the object side and constituted so as to satisfy various kinds of conditions.

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、レンズシャッター式の
コンパクトカメラに適した小型の広角ズームレンズ、特
に７０゜程度以上の広画角を含む広角ズームレンズに関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact wide-angle zoom lens suitable for a lens shutter type compact camera, and more particularly to a wide-angle zoom lens including a wide angle of view of about 70 ° or more.

【０００２】[0002]

【従来の技術】近年、コンパクトカメラでも広角ズーム
レンズの搭載が一般的となり、正・負の２群から構成さ
れる広角ズームレンズが、例えば特開平２−７３３２２
号公報等で数多く提案されている。2. Description of the Related Art In recent years, a wide-angle zoom lens is generally mounted even in a compact camera, and a wide-angle zoom lens composed of two groups, positive and negative, is disclosed in, for example, Japanese Patent Laid-Open No. 2-73232.
It has been proposed in many publications.

【０００３】[0003]

【発明が解決しようとする課題】特開平２−７３３２２
号公報等で提案されている広角ズームレンズでは、広角
端での画角は６０゜程度であった。しかし、近年、コン
パクトカメラ用の広角ズームレンズでも、より広角化の
要求が高まっており、この要求に対し、本件と同一出願
人による特開平３−２４００１３号公報、特開平５−１
９１６６号公報、特開平５−２３２３８３号公報におい
て７０゜以上の広角域を含む広角ズームレンズを提案し
ている。[Patent Document 1] Japanese Patent Application Laid-Open No. 2-73322
In the wide-angle zoom lens proposed in Japanese Laid-Open Patent Publication No. 2003-242, the angle of view at the wide-angle end was about 60 °. However, in recent years, there has been an increasing demand for a wider-angle zoom lens for a compact camera, and in response to this demand, Japanese Patent Laid-Open Nos. 3-240013 and 5-1 of the same applicant filed this patent.
A wide-angle zoom lens including a wide-angle range of 70 ° or more is proposed in Japanese Patent No. 9166 and Japanese Patent Application Laid-Open No. 5-232383.

【０００４】しかしながら、特開平３−２４００１３号
公報の各実施例においては、構成枚数が１１枚と多いた
め低コスト化および小型化が困難であった。また、特開
平５−１９１６６号公報、特開平５−２３２３８２号公
報の各実施例においては、いずれも広角端での全長（最
も物体側のレンズ面から像面までの距離）が広角端での
焦点距離の１．９倍以上であり、小型化が十分であると
はいえなかった。However, in each of the embodiments disclosed in Japanese Patent Laid-Open No. 3-240013, it is difficult to reduce the cost and the size because the number of constituent elements is as large as 11. Further, in each of the examples of JP-A-5-19166 and JP-A-5-232382, the total length at the wide-angle end (the distance from the lens surface closest to the object side to the image plane) is at the wide-angle end. The focal length was 1.9 times or more, which was not sufficient for miniaturization.

【０００５】本発明の目的は、広角端での画角が７０°
以上であり、広角端でのレンズ全長が広角端の焦点距離
の１．８倍以下の小型な形状であり、構成枚数が７枚程
度と少なく低コスト化に有利で、かつ結像性能の優れた
広角ズームレンズを提供することにある。An object of the present invention is to have an angle of view of 70 ° at the wide-angle end.
The above is a compact shape in which the total lens length at the wide-angle end is 1.8 times or less than the focal length at the wide-angle end, the number of components is about seven, which is advantageous for cost reduction and excellent imaging performance. To provide a wide-angle zoom lens.

【０００６】[0006]

【課題を解決するための手段】本発明は、物体側より順
に、正の屈折力を持つ第１レンズ群と、負の屈折力を持
つ第２レンズ群を有し、前記第１レンズ群と前記第２レ
ンズ群との空気間隔を縮小させることにより広角端から
望遠端への変倍を行なう広角ズームレンズにおいて、前
記第１レンズ群は、物体側から順に、負屈折力の第１レ
ンズ成分と正屈折力の第２レンズ成分と正屈折力または
負屈折力の第３レンズ成分と正屈折力の第４レンズ成分
を有し、前記第１レンズ群の焦点距離をｆ1 、前記第２
レンズ成分の焦点距離をｆL2、前記第４レンズ成分の焦
点距離をｆL4、前記第１レンズ群の最も物体側のレンズ
面から最も像側のレンズ面までの軸上距離をＤとすると
き、以下の条件を満足するよう構成した広角ズームレン
ズである。The present invention has, in order from the object side, a first lens group having a positive refractive power and a second lens group having a negative refractive power, and the first lens group and In a wide-angle zoom lens that performs zooming from a wide-angle end to a telephoto end by reducing an air space between the first lens unit and the second lens unit, the first lens unit includes, in order from the object side, a first lens component having a negative refractive power. And a second lens component having a positive refracting power, a third lens component having a positive refracting power or a negative refracting power, and a fourth lens component having a positive refracting power, and a focal length of the first lens group is f1,
When the focal length of the lens component is fL2, the focal length of the fourth lens component is fL4, and the axial distance from the most object-side lens surface to the most image-side lens surface of the first lens group is D, The wide-angle zoom lens is configured to satisfy the condition of.

【０００７】０ ＜ ｆ1 ／ｆL2 ＜ ２．５ ０．５ ＜ ｆ1 ／ｆL4 ＜ ２．０ Ｄ／ｆ1 ＜ ０．８４ さらに、前記第３レンズ成分の焦点距離をｆL3とすると
き、以下の条件式を満足することが望ましい。0 <f1 / fL2 <2.5 0.5 <f1 / fL4 <2.0 D / f1 <0.84 Further, when the focal length of the third lens component is fL3, the following conditional expression It is desirable to satisfy.

【０００８】−１．５ ＜ ｆ1 ／ｆL3 ＜ １．０ また、前記第１レンズ成分の焦点距離をｆL1とすると
き、以下の条件式を満足することが望ましい。 −２．０ ＜ ｆ1 ／ｆL1 ＜ −０．４ さらに、広角ズームレンズの広角端の焦点距離をｆW 、
前記第３レンズ成分の軸上レンズ厚をＤL3とするとき、
以下の条件式を満足することが望ましい。-1.5 <f1 / fL3 <1.0 When the focal length of the first lens component is fL1, it is desirable that the following conditional expression be satisfied. -2.0 <f1 / fL1 <-0.4 Furthermore, the focal length at the wide-angle end of the wide-angle zoom lens is fW,
When the axial lens thickness of the third lens component is DL3,
It is desirable to satisfy the following conditional expressions.

【０００９】 ０．０８５ ＜ ＤL3／ｆW ＜ ０．４００ また、前記第３レンズ成分は負レンズと正レンズとの接
合レンズであることが望ましい。さらにこのとき、前記
第３レンズ成分を構成する負レンズと正レンズの屈折率
をそれぞれＮ3nとＮ3pとし、前記第３レンズ成分を構成
する負レンズと正レンズのアッベ数をそれぞれν3nとν
3pとするとき、以下の条件式を満足することがより望ま
しい。0.085 <DL3 / fw <0.400 Further, it is desirable that the third lens component is a cemented lens of a negative lens and a positive lens. Further, at this time, the refractive indices of the negative lens and the positive lens forming the third lens component are N3n and N3p, respectively, and the Abbe numbers of the negative lens and the positive lens forming the third lens component are ν3n and ν, respectively.
When 3p, it is more desirable to satisfy the following conditional expressions.

【００１０】Ｎ3n−Ｎ3p ＞ ０．２ ν3p−ν3n ＞ ４ また、前記第２レンズ成分の物体側面を非球面で構成し
てもよく、このとき、第２レンズ成分は物体側に凸面を
向けたメニスカス形状とするのが好ましい。あるいは、
前記第１レンズ成分の像側面を非球面で構成してもよ
い。N3n-N3p> 0.2 ν3p-ν3n> 4 Further, the object side surface of the second lens component may be constructed as an aspherical surface. At this time, the second lens component has a convex surface directed toward the object side. A meniscus shape is preferable. Alternatively,
The image side surface of the first lens component may be an aspherical surface.

【００１１】あるいは、前記第１レンズ成分の物体側面
を非球面で構成してもよい。あるいは、前記第４レンズ
成分の物体側面を非球面で構成してもよく、このとき、
前記第４レンズ成分は物体側に凹面を向けたメニスカス
形状とするのが好ましい。Alternatively, the object side surface of the first lens component may be aspheric. Alternatively, the object side surface of the fourth lens component may be configured as an aspherical surface, and at this time,
The fourth lens component preferably has a meniscus shape with a concave surface facing the object side.

【００１２】[0012]

【作用】正の第１レンズ群と負の第２レンズ群とから成
るズームレンズでは、負の第２レンズ群は、常に１より
大きい正の結像倍率で用いられている。このため、全系
の焦点距離をｆ、第１レンズ群の焦点距離をｆ1、第２
レンズ群の結像倍率をβ2とすると、ｆ＝ｆ1・β2の関
係が成立するので、第１レンズ群の焦点距離ｆ1は、広
角端での全系の焦点距離ｆWより短くなる。この結果、
広角化を図るために広角端での焦点距離ｆWを短くしよ
うとすると、第１レンズ群の焦点距離ｆ1は従来よりも
一層短くする必要があり、収差補正が困難となりがちで
ある。In the zoom lens composed of the positive first lens group and the negative second lens group, the negative second lens group is always used with a positive imaging magnification larger than 1. Therefore, the focal length of the entire system is f, the focal length of the first lens unit is f1,
When the image forming magnification of the lens group is β2, the relationship of f = f1 · β2 is established, and therefore the focal length f1 of the first lens group is shorter than the focal length fW of the entire system at the wide angle end. As a result,
If the focal length fW at the wide-angle end is shortened in order to achieve a wide angle, the focal length f1 of the first lens group needs to be made shorter than in the conventional case, and aberration correction tends to be difficult.

【００１３】また、バックフォーカスの制約が少ないレ
ンズシャッターカメラに用いる場合、極端にバックフォ
ーカスを短くすると第２レンズ群の最終レンズ面の有効
径が大きくなりカメラ全体の小型化が難しくなるという
欠点がある。このため、広角端においてもある程度のバ
ックフォーカスを確保せねばならない。例えば、３５ｍ
ｍ版（画面サイズ２４×３６ｍｍ）では、６ｍｍ程度の
バックフォーカスを確保するのが望ましい。Further, when used in a lens shutter camera with few restrictions on the back focus, if the back focus is extremely shortened, the effective diameter of the final lens surface of the second lens group becomes large, which makes it difficult to downsize the entire camera. is there. Therefore, it is necessary to secure a certain amount of back focus even at the wide-angle end. For example, 35m
It is desirable to secure a back focus of about 6 mm for the m plate (screen size 24 × 36 mm).

【００１４】しかしながら、前述の特開平２−７３３２
２号公報のごとき従来の正負の２群広角ズームレンズで
は、７０°程度の広画角を得ようとすると、広角端にお
けるバックフォーカスの確保と、望遠端における第１レ
ンズ群と第２レンズ群との空気間隔の確保とを同時に達
成するのが困難であった。また、広角化を図るために第
１レンズ群の焦点距離ｆ1 を短くすれば、これに伴い諸
収差が悪化し、収差補正のためには第１レンズ群を多数
のレンズを用いて複雑な構成とせねばならなかった。However, the above-mentioned Japanese Unexamined Patent Publication No. 2-7332.
In the conventional positive / negative two-group wide-angle zoom lens as disclosed in Japanese Patent Laid-Open No. 2-2, when trying to obtain a wide angle of view of about 70 °, a back focus is secured at the wide-angle end, and the first lens group and the second lens group at the telephoto end. It was difficult to simultaneously secure the air gap between and. Further, if the focal length f1 of the first lens group is shortened in order to widen the angle, various aberrations are deteriorated accordingly, and in order to correct the aberration, the first lens group has a complicated structure using a large number of lenses. I had to say.

【００１５】以上のごとく、従来の正負の２群広角ズー
ムレンズでは、レンズ系のコンパクト化を図りながら、
単純な構成で広角化を達成することは困難であった。そ
こで、本発明においては、第１レンズ群Ｇ1 の最も物体
側に、負屈折力の第１レンズ成分Ｌ1 を配置し、第１レ
ンズ群がレトロフォーカス型のレンズ群となるよう構成
する。これにより、広角端でのバックフォーカスの確保
と、望遠端での第１レンズ群Ｇ1 と第２レンズ群Ｇ2と
の空気間隔の確保とを同時に達成できる。As described above, in the conventional positive / negative two-group wide-angle zoom lens, while making the lens system compact,
It was difficult to achieve a wide angle with a simple configuration. Therefore, in the present invention, the first lens component L1 having a negative refractive power is arranged on the most object side of the first lens group G1 so that the first lens group is a retrofocus type lens group. As a result, it is possible to simultaneously secure the back focus at the wide-angle end and the air space between the first lens group G1 and the second lens group G2 at the telephoto end.

【００１６】また、最も物体側に負屈折力の第１レンズ
成分Ｌ1 を配しているために、像面湾曲、非点収差、歪
曲収差、倍率色収差等の軸外諸収差を補正することが容
易となる。これにより、第１レンズ群Ｇ1 を単純な構成
とすることが可能となり、レンズ系の小型化を達成でき
る。さらに詳しく本発明における広角ズームレンズの構
成を以下に説明する。Further, since the first lens component L1 having negative refractive power is arranged closest to the object side, off-axis various aberrations such as field curvature, astigmatism, distortion and lateral chromatic aberration can be corrected. It will be easy. As a result, the first lens group G1 can have a simple structure, and the size of the lens system can be reduced. The configuration of the wide-angle zoom lens according to the present invention will be described in more detail below.

【００１７】第１レンズ群Ｇ1 は、負屈折力の第１レン
ズ成分Ｌ1 と、正屈折力の第２レンズ成分Ｌ2 と、正屈
折力または負屈折力の第３レンズ成分Ｌ3 と、正屈折力
の第４レンズ成分Ｌ4 とからなり、前記第３レンズ成分
Ｌ3 は、負レンズＬ3nと正レンズＬ3pとの接合レンズで
ある。一方、負の第２レンズ群Ｇ2は物体側に凹面を向
けた正メニスカスレンズと物体側に凹面を向けた負メニ
スカスレンズからなる。The first lens group G1 includes a first lens component L1 having a negative refractive power, a second lens component L2 having a positive refractive power, a third lens component L3 having a positive refractive power or a negative refractive power, and a positive refractive power. No. 4 lens component L4, and the third lens component L3 is a cemented lens of a negative lens L3n and a positive lens L3p. On the other hand, the negative second lens group G2 is composed of a positive meniscus lens having a concave surface facing the object side and a negative meniscus lens having a concave surface facing the object side.

【００１８】本発明では、前述した効果を確実に達成す
るために、以下の条件（１）〜（３）を見出した。 （１） ０ ＜ ｆ1 ／ｆL2 ＜ ２．５ （２） ０．５ ＜ ｆ1 ／ｆL4 ＜ ２．０ （３） Ｄ／ｆ1 ＜ ０．８４ 但し、 ｆ1 ：前記第１レンズ群Ｇ1 の焦点距離、 ｆL2 ：前記第２レンズ成分Ｌ2 の焦点距離、 ｆL4 ：前記第４レンズ成分Ｌ4 の焦点距離、 Ｄ ：前記第１レンズ群Ｇ1 の最も物体側のレンズ面
から最も像側のレンズ面までの軸上距離である。In the present invention, the following conditions (1) to (3) have been found in order to surely achieve the above-mentioned effects. (1) 0 <f1 / fL2 <2.5 (2) 0.5 <f1 / fL4 <2.0 (3) D / f1 <0.84 where f1 is the focal length of the first lens group G1, fL2: focal length of the second lens component L2, fL4: focal length of the fourth lens component L4, D: on-axis from the most object side lens surface to the most image side lens surface of the first lens group G1 It is a distance.

【００１９】条件式（１）は第２レンズ成分Ｌ2 の最適
な焦点距離の範囲を規定するものである。第２レンズ成
分Ｌ2 を正の屈折力とすることにより、負の第１レンズ
成分Ｌ1 と正の第２レンズ成分Ｌ2 で発生する諸収差を
互いに相殺でき、良好な収差補正が可能となる。条件式
（１）の下限を越えると、第２レンズ成分Ｌ2 が負の屈
折力を持ち、第１レンズ成分Ｌ1 と第２レンズ成分Ｌ2
とで発生する諸収差を相殺することが不可能となり、収
差補正が困難となる。反対に、条件式（１）の上限を越
えると、第２レンズ成分Ｌ2 の屈折力が大きくなり、第
２レンズ成分Ｌ2 で発生する負の球面収差が過大とな
り、補正が困難となる。Conditional expression (1) defines the optimum range of the focal length of the second lens component L2. By making the second lens component L2 have a positive refracting power, various aberrations generated in the negative first lens component L1 and the positive second lens component L2 can be offset to each other, and good aberration correction can be performed. When the lower limit of conditional expression (1) is exceeded, the second lens component L2 has a negative refractive power, and the first lens component L1 and the second lens component L2
It becomes impossible to cancel various aberrations generated in and, and it becomes difficult to correct aberrations. On the contrary, if the upper limit of conditional expression (1) is exceeded, the refracting power of the second lens component L2 becomes large, and the negative spherical aberration generated in the second lens component L2 becomes excessive, which makes correction difficult.

【００２０】条件式（２）は第４レンズ成分Ｌ4 の最適
な焦点距離の範囲を規定する条件である。条件式（２）
の下限を越えると、第４レンズ成分Ｌ4 の正の屈折力が
弱くなり、第１レンズ群Ｇ1 をレトロフォーカス型の構
成とする効果が弱まる。このため、広角端でのバックフ
ォーカスの確保と、望遠端での第１レンズ群Ｇ1 と第２
レンズ群Ｇ2 との空気間隔の確保とを同時に達成するこ
とが困難となる。反対に、条件式（２）の上限を越える
と、第４レンズ成分Ｌ4の屈折力が大きくなり、第４レ
ンズ成分Ｌ4 で発生する負の球面収差が過大となり、補
正が困難となる。Conditional expression (2) defines the optimum range of the focal length of the fourth lens component L4. Conditional expression (2)
Beyond the lower limit of, the positive refractive power of the fourth lens component L4 becomes weak and the effect of making the first lens group G1 a retrofocus type structure becomes weak. Therefore, the back focus is secured at the wide-angle end, and the first lens group G1 and the second lens group at the telephoto end are used.
At the same time, it becomes difficult to secure an air gap with the lens group G2. On the other hand, if the upper limit of conditional expression (2) is exceeded, the refracting power of the fourth lens component L4 will increase, and the negative spherical aberration generated by the fourth lens component L4 will become excessive, making correction difficult.

【００２１】条件式（３）は第１レンズ群Ｇ1 の軸上レ
ンズ厚を規定する条件である。条件式（３）の上限を越
えると、第１レンズ群Ｇ1 が大型化し、レンズ全長の大
型化を招き好ましくない。さらに好ましい条件として、
以下の条件式（４）〜（６）を見出した。 （４） −１．５ ＜ ｆ1 ／ｆL3 ＜ １．０ （５） −２．０ ＜ ｆ1 ／ｆL1 ＜ −０．４ （６） ０．０８５ ＜ ＤL3／ｆW ＜ ０．４
００ 但し、 ｆL3 ：前記第３レンズ成分Ｌ3 の焦点距離、 ｆL1 ：前記第１レンズ成分Ｌ1 の焦点距離、 ＤL3 ：前記第３レンズ成分Ｌ3の軸上レンズ厚、 ｆW ：広角ズームレンズの広角端の焦点距離である。Conditional expression (3) defines the axial lens thickness of the first lens group G1. If the upper limit of conditional expression (3) is exceeded, the size of the first lens group G1 becomes large, which undesirably increases the total lens length. More preferable conditions are
The following conditional expressions (4) to (6) were found. (4) -1.5 <f1 / fL3 <1.0 (5) -2.0 <f1 / fL1 <-0.4 (6) 0.085 <DL3 / fw <0.4
Where fL3 is the focal length of the third lens component L3, fL1 is the focal length of the first lens component L1, DL3 is the axial lens thickness of the third lens component L3, and fW is the wide-angle end of the wide-angle zoom lens. The focal length.

【００２２】条件式（４）は第３レンズ成分Ｌ3 の適切
な焦点距離範囲を規定する条件であり、条件式（４）の
上限、下限いずれを越えても、第３レンズ成分Ｌ3 の屈
折力が大きくなり、第１レンズ群Ｇ1 内部の各レンズ成
分の偏心公差が厳しくなり、好ましくない。条件式
（５）は第１レンズ成分Ｌ1 の適切な焦点距離範囲を規
定している。条件式（５）の下限を越えると、第１レン
ズ成分Ｌ1 で発生するコマ収差、倍率色収差等が過大と
なり、補正が困難となる。反対に、条件式（５）の上限
を越えると、第１レンズ成分Ｌ1 の負の屈折力が小さく
なり、第１レンズ群Ｇ1 をレトロフォーカス型の構成と
する効果が弱まる。このため、広角端でのバックフォー
カスの確保と、望遠端での第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 との空気間隔の確保とを同時に達成することが
困難となる。Conditional expression (4) is a condition for defining an appropriate focal length range of the third lens component L3. Even if either the upper limit or the lower limit of the conditional expression (4) is exceeded, the refractive power of the third lens component L3. Is large and the eccentricity tolerance of each lens component inside the first lens group G1 becomes strict, which is not preferable. Conditional expression (5) defines an appropriate focal length range of the first lens component L1. If the lower limit of conditional expression (5) is exceeded, coma, chromatic aberration of magnification, etc. generated in the first lens component L1 will become excessive and correction will be difficult. On the other hand, if the upper limit of conditional expression (5) is exceeded, the negative refractive power of the first lens component L1 will become small, and the effect of making the first lens group G1 of the retrofocus type will be weakened. For this reason, it is difficult to simultaneously secure the back focus at the wide-angle end and the air space between the first lens group G1 and the second lens group G2 at the telephoto end.

【００２３】条件式（６）は第３レンズ成分Ｌ3 の軸上
レンズ厚を規定している。条件式（６）の下限をこえる
と、第３レンズ成分Ｌ3の軸上レンズ厚が薄くなり、像
面湾曲、および歪曲収差を適切に補正するのが困難とな
る。反対に、条件式（６）の上限を越えると、第３レン
ズ成分Ｌ3 の軸上レンズ厚が大きくなり、第１レンズ群
Ｇ1 の大型化をまねき好ましくない。Conditional expression (6) defines the axial lens thickness of the third lens component L3. If the lower limit of conditional expression (6) is exceeded, the axial lens thickness of the third lens component L3 becomes thin, and it becomes difficult to properly correct field curvature and distortion. On the other hand, if the upper limit of conditional expression (6) is exceeded, the axial lens thickness of the third lens component L3 becomes large, which is not preferable because the first lens group G1 becomes large.

【００２４】さらに、球面収差、および色収差を良好に
補正するためには、第３レンズ成分Ｌ3 を、負レンズＬ
3nと正レンズＬ3pとの接合レンズとするのが望ましい。
このとき、以下の条件式（７）、（８）を満足するのが
望ましい。 （７） Ｎ3n−Ｎ3p ＞ ０．２ （８） ν3p−ν3n ＞ ４ 但し、 Ｎ3n ：前記第３レンズ成分Ｌ3 を構成する負レンズＬ
3nの屈折率、 Ｎ3p ：前記第３レンズ成分Ｌ3 を構成する正レンズＬ
3pの屈折率、 ν3n ：前記第３レンズ成分Ｌ3 を構成する負レンズＬ
3nのアッベ数、 ν3p ：前記第３レンズ成分Ｌ3を構成する正レンズＬ3p
のアッベ数である。 条件式（７）の下限を越えると、第１レンズ群Ｇ1 で発
生しがちな負の球面収差の補正が困難になり、好ましく
ない。Further, in order to satisfactorily correct spherical aberration and chromatic aberration, the third lens component L3 is replaced by the negative lens L
It is desirable to use a cemented lens of 3n and the positive lens L3p.
At this time, it is desirable to satisfy the following conditional expressions (7) and (8). (7) N3n-N3p> 0.2 (8) ν3p-ν3n> 4 However, N3n: Negative lens L constituting the third lens component L3
Refractive index of 3n, N3p: Positive lens L constituting the third lens component L3
Refractive index of 3p, ν3n: Negative lens L constituting the third lens component L3
Abbe number of 3n, ν3p: Positive lens L3p constituting the third lens component L3
Is the Abbe number. If the lower limit of conditional expression (7) is exceeded, it becomes difficult to correct the negative spherical aberration that tends to occur in the first lens group G1, which is not preferable.

【００２５】条件式（８）の下限を越えると、広角ズー
ムレンズの広角端から望遠端にわたって、軸上色収差お
よび倍率色収差をともに補正するのが困難となる。ま
た、広角ズームレンズの小型化に関連して、第１レンズ
群Ｇ1 を小型に構成するには、第１レンズ群Ｇ1 中に非
球面を設けるのが望ましい。その際、第２レンズ成分Ｌ
2 の物体側面、または、第１レンズ成分Ｌ1 の像側面、
または、第１レンズ成分Ｌ1 の物体側面、または、第４
レンズ成分Ｌ4 の物体側面を非球面とするのが望まし
い。If the lower limit of conditional expression (8) is exceeded, it becomes difficult to correct both axial chromatic aberration and lateral chromatic aberration from the wide-angle end to the telephoto end of the wide-angle zoom lens. Further, in order to make the first lens group G1 small in association with the miniaturization of the wide-angle zoom lens, it is desirable to provide an aspherical surface in the first lens group G1. At that time, the second lens component L
2, the object side surface, or the image side surface of the first lens component L1,
Alternatively, the object side surface of the first lens component L1 or the fourth lens component L1
It is desirable that the object side surface of the lens component L4 be an aspherical surface.

【００２６】なお、第２レンズ成分Ｌ2 の物体側面を非
球面とする場合には、第２レンズ成分Ｌ2 を物体側に凸
面を向けたメニスカス形状とするのが収差補正上望まし
い。また、第４レンズ成分Ｌ4 の物体側面を非球面とす
る場合には、第４レンズ成分Ｌ4 を物体側に凹面を向け
たメニスカス形状とするのが収差補正上望ましい。When the object side surface of the second lens component L2 is an aspherical surface, it is desirable for aberration correction that the second lens component L2 has a meniscus shape with its convex surface facing the object side. When the object side surface of the fourth lens component L4 is an aspherical surface, it is desirable for aberration correction that the fourth lens component L4 has a meniscus shape with a concave surface facing the object side.

【００２７】[0027]

【実施例】以下に、図を参照しながら本発明による各実
施例について具体的に説明する。 〔実施例１〕実施例１の各レンズ群の具体的なレンズ構
成を図１に示す。図１に示される如く、正屈折力の第１
レンズ群Ｇ1 は、物体側から順に、負屈折力を有し両凹
形状の第１レンズ成分Ｌ1 と、正屈折力を有し物体側に
凸面を向けたメニスカス形状の第２レンズ成分Ｌ2 と、
正屈折力を有し両凸形状の第３レンズ成分Ｌ3 と、正屈
折力を有し両凸形状の第４レンズ成分Ｌ4 とからなり、
第１レンズ成分乃至第４レンズ成分の間は空気間隔であ
る。そして、前記第２レンズ成分Ｌ2 の物体側面は非球
面であり、前記第３レンズ成分Ｌ3 は、物体側より順
に、物体側に凸面を向けた負メニスカスレンズＬ3nと、
両凸正レンズＬ3pとの接合レンズである。一方、負屈折
力の第２レンズ群Ｇ2は、物体側から順に、正屈折力を
有し物体側に凹面を向けたメニスカス形状の第５レンズ
成分Ｌ5 と、負屈折力を有し物体側に凹面を向けたメニ
スカス形状の第６レンズ成分Ｌ6 とからなり、第５レン
ズ成分Ｌ5 の物体側面は非球面である。また、絞りＳは
第１レンズ群Ｇ1 と第２レンズ群Ｇ2 の間に位置し、ズ
ーミングに際しては第１レンズ群Ｇ1 と一体で移動す
る。Embodiments Embodiments of the present invention will be specifically described below with reference to the drawings. Example 1 FIG. 1 shows a specific lens configuration of each lens group of Example 1. As shown in FIG. 1, the first
The lens group G1 includes, in order from the object side, a biconcave first lens component L1 having negative refractive power, and a meniscus second lens component L2 having positive refractive power and having a convex surface directed toward the object side.
A biconvex third lens component L3 having positive refracting power and a biconvex fourth lens component L4 having positive refracting power,
There is an air gap between the first lens component to the fourth lens component. The object side surface of the second lens component L2 is an aspherical surface, and the third lens component L3 includes, in order from the object side, a negative meniscus lens L3n having a convex surface directed toward the object side.
It is a cemented lens with a biconvex positive lens L3p. On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a meniscus-shaped fifth lens component L5 having a positive refractive power and a concave surface facing the object side, and a negative refractive power to the object side. It is composed of a meniscus sixth lens component L6 having a concave surface, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００２８】以下の表１に、本発明の実施例１の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。In Table 1 below, the values of the specifications and the numerical values corresponding to the conditions of Example 1 of the present invention are listed. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００２９】[0029]

【表１】 実施例１の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．１〜７．９ ２ω＝
７６．６〜４４．０゜ （第３面非球面係数） ｋ＝-0.1345 ×10 Ｃ4 ＝-0.8849 ×10^-4 Ｃ6 ＝-
0.8754 ×10^-6 Ｃ8 ＝-0.5813 ×10^-8 Ｃ10＝-0.1178 ×10^-9 （第１１面非球面係数） ｋ＝0.1967×10 Ｃ4 ＝0.3937×10^-4 Ｃ6 ＝0.17
69×10^-6 Ｃ8 ＝-0.5888 ×10^-9 Ｃ10＝0.2974×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3789 40.2433 54.8684 d10 13.2148 7.2156 3.3907 B.f 6.7130 20.6181 37.7588 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝0.139 （２）ｆ1 ／ｆL4＝1.16 （３）Ｄ／ｆ1 ＝0.750 （４）ｆ1 ／ｆL3＝0.518 （５）ｆ1 ／ｆL1＝-1.10 （６）ＤL3／ｆW ＝0.279 （７）Ｎ3n−Ｎ3p＝0.23593 （８）ν3p−ν3n＝32.2 〔実施例２〕実施例２の各レンズ群の具体的なレンズ構
成を図２に示す。Table 1 Specifications of Example 1 f = 28.4 to 54.9 F = 4.1 to 7.9 2ω =
76.6-44.0 ° (Third surface aspherical surface coefficient) k = -0.1345 x10 C4 = -0.8849 x10 ^-4 C6 =-
0.8754 × 10 ^-6 C8 = -0.5813 × 10 ^-8 C10 = -0.1178 × 10 ^-9 (11th surface aspherical surface coefficient) k = 0.1967 × 10 C4 = 0.3937 × 10 ^-4 C6 = 0.17
69 × 10 ^-6 C8 = -0.5888 × 10 ^-9 C10 = 0.2974 × 10 ^{-10 The} following shows the change in the interval during zooming. f 28.3789 40.2433 54.8684 d10 13.2148 7.2156 3.3907 Bf 6.7130 20.6181 37.7588 The conditions corresponding numerical values are shown below. (1) f1 / fL2 = 0.139 (2) f1 / fL4 = 1.16 (3) D / f1 = 0.750 (4) f1 / fL3 = 0.518 (5) f1 / fL1 = -1.10 (6) DL3 / fw = 0.279 ( 7) N3n-N3p = 0.23593 (8) ν3p-ν3n = 32.2 [Example 2] FIG. 2 shows a specific lens configuration of each lens group of Example 2.

【００３０】図２に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し両凹形状
の第１レンズ成分Ｌ1 と、正屈折力を有し両凸形状の第
２レンズ成分Ｌ2 と、負屈折力を有し物体側に凹面を向
けたメニスカス形状の第３レンズ成分Ｌ3 と、正屈折力
を有し両凸形状の第４レンズ成分Ｌ4 とからなり、第１
レンズ成分乃至第４レンズ成分の間は空気間隔である。
そして、前記第１レンズ成分Ｌ1 の像側面は非球面であ
り、前記第３レンズ成分Ｌ3 は、物体側より順に、両凹
負レンズＬ3nと、両凸正レンズＬ3pとの接合レンズであ
る。As shown in FIG. 2, the first lens group G1 having positive refracting power has, in order from the object side, the first lens component L1 having negative refracting power and having a biconcave shape, and both having positive refracting power. From the second lens component L2 having a convex shape, the third lens component L3 having a negative refractive power and having a concave surface facing the object side, and the fourth lens component L4 having a positive refractive power and having a biconvex shape. Become, first
There is an air space between the lens component and the fourth lens component.
The image side surface of the first lens component L1 is an aspherical surface, and the third lens component L3 is a cemented lens of a biconcave negative lens L3n and a biconvex positive lens L3p in order from the object side.

【００３１】一方、負屈折力の第２レンズ群Ｇ2は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a fifth meniscus lens component L5 having a positive refractive power and a concave surface facing the object side, and a negative refractive power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００３２】以下の表２に、本発明の実施例２の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。In Table 2 below, the values of specifications and the numerical values corresponding to the conditions of the second embodiment of the present invention are listed. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００３３】[0033]

【表２】 実施例２の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．８ ２ω＝
７６．９〜４４．０゜ （第２面非球面係数） ｋ＝0.9573×10 Ｃ4 ＝0.8933×10^-4 Ｃ6 ＝0.2611
×10^-6 Ｃ8 ＝0.4354×10^-8 Ｃ10＝0.8326×10^-11 （第１１面非球面係数） ｋ＝0.2633×10 Ｃ4 ＝0.4186×10^-4 Ｃ6 ＝0.1830×
10^-6 Ｃ8 ＝0.3808×10^-10 Ｃ10＝0.2219×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3808 40.1850 54.8774 d10 11.8149 6.1549 2.5115 B.f 7.5957 21.5919 39.0127 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝0.940 （２）ｆ1 ／ｆL4＝1.15 （３）Ｄ／ｆ1 ＝0.637 （４）ｆ1 ／ｆL3＝-0.498 （５）ｆ1 ／ｆL1＝-0.924 （６）ＤL3／ｆW ＝0.128 （７）Ｎ3n−Ｎ3p＝0.31635 （８）ν3p−ν3n＝36.3 〔実施例３〕実施例３の各レンズ群の具体的なレンズ構
成を図３に示す。Table 2 Specifications of Example 2 f = 28.4 to 54.9 F = 4.0 to 7.8 2ω =
76.9 to 44.0 ° (Second surface aspherical coefficient) k = 0.9573 × 10 C4 = 0.8933 × 10 ⁻⁴ C6 = 0.261
× 10 ^-6 C8 = 0.4354 × 10 ^-8 C10 = 0.8326 × 10 ^-11 (11th surface aspherical coefficient) k = 0.2633 × 10 C4 = 0.4186 × 10 ^-4 C6 = 0.1830 ×
The change of the interval at the magnification change of 10 ⁻⁶ C 8 = 0.3808 × 10 ⁻¹⁰ C 10 = 0.2219 × 10 ⁻¹⁰ is shown below. f 28.3808 40.1850 54.8774 d10 11.8149 6.1549 2.5115 Bf 7.5957 21.5919 39.0127 The numerical values corresponding to the conditions are shown below. (1) f1 / fL2 = 0.940 (2) f1 / fL4 = 1.15 (3) D / f1 = 0.637 (4) f1 / fL3 = -0.498 (5) f1 / fL1 = -0.924 (6) DL3 / fW = 0.128 (7) N3n-N3p = 0.31635 (8) ν3p-ν3n = 36.3 [Example 3] FIG. 3 shows a specific lens configuration of each lens group of Example 3.

【００３４】図３に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し両凹形状
の第１レンズ成分Ｌ1 と、正屈折力を有し両凸形状の第
２レンズ成分Ｌ2 と、負屈折力を有し物体側に凹面を向
けたメニスカス形状の第３レンズ成分Ｌ3 と、正屈折力
を有し両凸形状の第４レンズ成分Ｌ4 とからなり、第１
レンズ成分乃至第４レンズ成分の間は空気間隔である。
そして、前記第１レンズ成分Ｌ1 の像側面は非球面であ
り、前記第３レンズ成分Ｌ3 は、物体側より順に、両凹
負レンズＬ3nと、両凸正レンズＬ3pとの接合レンズであ
る。As shown in FIG. 3, the first lens group G1 having positive refracting power has, in order from the object side, the first lens component L1 having negative refracting power and having a biconcave shape, and the first lens component L1 having positive refracting power. From the second lens component L2 having a convex shape, the third lens component L3 having a negative refractive power and having a concave surface facing the object side, and the fourth lens component L4 having a positive refractive power and having a biconvex shape. Become, first
There is an air space between the lens component and the fourth lens component.
The image side surface of the first lens component L1 is an aspherical surface, and the third lens component L3 is a cemented lens of a biconcave negative lens L3n and a biconvex positive lens L3p in order from the object side.

【００３５】一方、負屈折力の第２レンズ群Ｇ2は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a positive meniscus fifth lens component L5 having a meniscus shape with a concave surface facing the object side, and a negative refractive power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００３６】以下の表３に、本発明の実施例３の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。In Table 3 below, the values of specifications and the numerical values corresponding to the conditions of Example 3 of the present invention are listed. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００３７】[0037]

【表３】 実施例３の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．８ ２ω＝
７６．９〜４３．９゜ （第２面非球面係数） ｋ＝0.1185×10² Ｃ4 ＝0.8629×10^-4 Ｃ6 ＝0.5315×
10^-6 Ｃ8 ＝-0.6674 ×10^-8 Ｃ10＝0.2603×10^-9 （第１１面非球面係数） ｋ＝0.2729×10 Ｃ4 ＝0.4247×10^-4 Ｃ6 ＝0.8959
×10^-7 Ｃ8 ＝0.1758×10^-8 Ｃ10＝0.1048×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3813 40.1860 54.8791 d10 11.7219 6.1185 2.5116 B.f 7.3009 21.0225 38.1014 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝0.916 （２）ｆ1 ／ｆL4＝1.20 （３）Ｄ／ｆ1 ＝0.631 （４）ｆ1 ／ｆL3＝-0.531 （５）ｆ1 ／ｆL1＝-0.912 （６）ＤL3／ｆW ＝0.133 （７）Ｎ3n−Ｎ3p＝0.31635 （８）ν3p−ν3n＝36.3 〔実施例４〕実施例４の各レンズ群の具体的なレンズ構
成を図４に示す。Table 3 Specifications of Example 3 f = 28.4 to 54.9 F = 4.0 to 7.8 2ω =
76.9 to 43.9 ° (Second surface aspherical coefficient) k = 0.1185 × 10 ² C4 ＝ 0.8629 × 10 ^-4 C6 ＝ 0.5315 ×
10 ^-6 C8 = -0.6674 × 10 ^-8 C10 = 0.2603 × 10 ^-9 (11th surface aspherical coefficient) k = 0.2729 × 10 C4 = 0.4247 × 10 ^-4 C6 = 0.8959
× 10 ^-7 C8 = 0.1758 × 10 ^-8 C10 = 0.1048 × 10 ^{-10 The} following shows the change in the interval during zooming. f 28.3813 40.1860 54.8791 d10 11.7219 6.1185 2.5116 Bf 7.3009 21.0225 38.1014 The numerical values corresponding to the conditions are shown below. (1) f1 / fL2 = 0.916 (2) f1 / fL4 = 1.20 (3) D / f1 = 0.631 (4) f1 / fL3 = -0.531 (5) f1 / fL1 = -0.912 (6) DL3 / fw = 0.133 (7) N3n-N3p = 0.31635 (8) ν3p-ν3n = 36.3 [Example 4] FIG. 4 shows a specific lens configuration of each lens group of Example 4.

【００３８】図４に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し少なくと
も光軸近傍において両凹形状の第１レンズ成分Ｌ1 と、
正屈折力を有し両凸形状の第２レンズ成分Ｌ2 と、負屈
折力を有し物体側に凹面を向けたメニスカス形状の第３
レンズ成分Ｌ3 と、正屈折力を有し両凸形状の第４レン
ズ成分Ｌ4 とからなり、第１レンズ成分乃至第４レンズ
成分の間は空気間隔である。そして、前記第１レンズ成
分Ｌ1 の物体側面と像側面はともに非球面であり、前記
第３レンズ成分Ｌ3 は、物体側より順に、両凹負レンズ
Ｌ3nと、両凸正レンズＬ3pとの接合レンズである。As shown in FIG. 4, the first lens group G1 having a positive refracting power has, in order from the object side, a first lens component L1 having a negative refracting power and having a biconcave shape at least near the optical axis,
A biconvex second lens component L2 having a positive refractive power and a meniscus third lens component L2 having a negative refractive power and having a concave surface facing the object side.
It is composed of a lens component L3 and a biconvex fourth lens component L4 having a positive refractive power, and there is an air gap between the first lens component to the fourth lens component. The object side surface and the image side surface of the first lens component L1 are aspherical surfaces, and the third lens component L3 is a cemented lens of a biconcave negative lens L3n and a biconvex positive lens L3p in order from the object side. Is.

【００３９】一方、負屈折力の第２レンズ群Ｇ2 は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a fifth meniscus lens component L5 having a positive refractive power and having a concave surface facing the object side, and a negative refractive power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００４０】以下の表４に、本発明の実施例４の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。In Table 4 below, the values of the parameters and the numerical values corresponding to the conditions of Example 4 of the present invention are listed. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００４１】[0041]

【表４】 実施例４の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．８ ２ω＝
７６．５〜４３．８゜ （第１面非球面係数） ｋ＝-0.9900 ×10² Ｃ4 ＝0.7634×10^-4 Ｃ6 ＝-0.5
937 ×10^-6 Ｃ8 ＝-0.7162 ×10^-8 Ｃ10＝0.1393×10^-9 （第２面非球面係数） ｋ＝0.9927×10 Ｃ4 ＝0.1441×10^-3 Ｃ6 ＝-0.1
408 ×10^-7 Ｃ8 ＝-0.2213 ×10^-7 Ｃ10＝-0.1571 ×10^-9 （第１１面非球面係数） ｋ＝-0.5380 ×10 Ｃ4 ＝0.4378×10^-4 Ｃ6 ＝0.21
81×10^-6 Ｃ8 ＝0.7409×10^-9 Ｃ10＝0.2559×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3809 40.1857 54.8780 d10 10.7184 6.0346 3.0198 B.f 6.7654 19.1990 34.6740 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝1.12 （２）ｆ1 ／ｆL4＝1.09 （３）Ｄ／ｆ1 ＝0.706 （４）ｆ1 ／ｆL3＝-0.717 （５）ｆ1 ／ｆL1＝-0.786 （６）ＤL3／ｆW ＝0.155 （７）Ｎ3n−Ｎ3p＝0.31635 （８）ν3p−ν3n＝36.3 〔実施例５〕実施例５の各レンズ群の具体的なレンズ構
成を図５に示す。Table 4 Specifications of Example 4 f = 28.4 to 54.9 F = 4.0 to 7.8 2ω =
76.5 to 43.8 ° (First surface aspherical coefficient) k = -0.9900 × 10 ² C4 = 0.7634 × 10 ^-4 C6 = -0.5
937 × 10 ^-6 C8 = -0.7162 × 10 ^-8 C10 = 0.1393 × 10 ^-9 (second surface aspherical coefficient) k = 0.9927 × 10 C4 = 0.1441 × 10 ^-3 C6 = -0.1
408 × 10 ^-7 C8 = -0.2213 × 10 ^-7 C10 = -0.1571 × 10 ^-9 (11th surface aspherical coefficient) k = -0.5380 × 10 C4 = 0.4378 × 10 ^-4 C6 = 0.21
81 × 10 ⁻⁶ C8 = 0.7409 × 10 ⁻⁹ C10 = 0.2559 × 10 ^{−10 The} following shows the change in the interval during zooming. f 28.3809 40.1857 54.8780 d10 10.7184 6.0346 3.0198 Bf 6.7654 19.1990 34.6740 The numerical values corresponding to the conditions are shown below. (1) f1 / fL2 = 1.12 (2) f1 / fL4 = 1.09 (3) D / f1 = 0.706 (4) f1 / fL3 = -0.717 (5) f1 / fL1 = -0.786 (6) DL3 / fW = 0.155 (7) N3n-N3p = 0.31635 (8) ν3p-ν3n = 36.3 [Example 5] FIG. 5 shows a specific lens configuration of each lens group of Example 5.

【００４２】図５に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し少なくと
も光軸近傍において両凹形状の第１レンズ成分Ｌ1 と、
正屈折力を有し両凸形状の第２レンズ成分Ｌ2 と、負屈
折力を有し物体側に凹面を向けたメニスカス形状の第３
レンズ成分Ｌ3 と、正屈折力を有し両凸形状の第４レン
ズ成分Ｌ4 とからなり、第１レンズ成分乃至第４レンズ
成分の間は空気間隔である。そして、前記第１レンズ成
分Ｌ1 の物体側面と像側面はともに非球面であり、前記
第３レンズ成分Ｌ3 は、物体側より順に、両凹負レンズ
Ｌ3nと、両凸正レンズＬ3pとの接合レンズである。As shown in FIG. 5, the first lens group G1 having a positive refracting power has, in order from the object side, a first lens component L1 having a negative refracting power and having a biconcave shape at least near the optical axis.
A biconvex second lens component L2 having a positive refractive power and a meniscus third lens component L2 having a negative refractive power and having a concave surface facing the object side.
It is composed of a lens component L3 and a biconvex fourth lens component L4 having a positive refractive power, and there is an air gap between the first lens component to the fourth lens component. The object side surface and the image side surface of the first lens component L1 are aspherical surfaces, and the third lens component L3 is a cemented lens of a biconcave negative lens L3n and a biconvex positive lens L3p in order from the object side. Is.

【００４３】一方、負屈折力の第２レンズ群Ｇ2 は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a positive meniscus fifth lens component L5 having a meniscus shape with a concave surface facing the object side, and a negative refractive power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００４４】以下の表５に、本発明の実施例５の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。Table 5 below shows the values of specifications and the numerical values corresponding to the conditions of the fifth embodiment of the present invention. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００４５】[0045]

【表５】 実施例５の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．８ ２ω＝
７７．０〜４３．９゜ （第１面非球面係数） ｋ＝-0.8987 ×10³ Ｃ4 ＝0.1354×10^-4 Ｃ6 ＝0.20
47×10^-6 Ｃ8 ＝-0.7638 ×10^-8 Ｃ10＝0.7882×10^-10 （第２面非球面係数） ｋ＝0.1213×10² Ｃ4 ＝0.8422×10^-4 Ｃ6 ＝0.50
91×10^-6 Ｃ8 ＝-0.1451 ×10^-7 Ｃ10＝0.1213×10^-9 （第１１面非球面係数） ｋ＝-0.6527 ×10 Ｃ4 ＝0.4368×10^-4 Ｃ6 ＝0.
2725×10^-6 Ｃ8 ＝0.7977×10^-10 Ｃ10＝0.2741×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3818 40.1871 54.8810 d10 10.6697 6.0156 3.0198 B.f 6.7117 19.0783 34.4708 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝1.01 （２）ｆ1 ／ｆL4＝1.04 （３）Ｄ／ｆ1 ＝0.712 （４）ｆ1 ／ｆL3＝-0.617 （５）ｆ1 ／ｆL1＝-0.712 （６）ＤL3／ｆW ＝0.155 （７）Ｎ3n−Ｎ3p＝0.22883 （８）ν3p−ν3n＝7.7 〔実施例６〕実施例６の各レンズ群の具体的なレンズ構
成を図６に示す。Table 5 Specifications of Example 5 f = 28.4 to 54.9 F = 4.0 to 7.8 2ω =
77.0 to 43.9 ° (1st surface aspherical surface coefficient) k = -0.8987 × 10 ³ C4 = 0.1354 × 10 ^-4 C6 = 0.20
47 x 10 ^-6 C8 = -0.7638 x 10 ^-8 C10 = 0.7882 x 10 ^-10 (second surface aspherical coefficient) k = 0.1213 x 10 ² C4 = 0.842 ² x 10 ^-4 C6 = 0.50
91 x 10 ^-6 C8 = -0.1451 x 10 ^-7 C10 = 0.1213 x 10 ^-9 (11th surface aspherical coefficient) k = -0.6527 x10 C4 = 0.4368 x 10 ^-4 C6 = 0.
2725 × 10 ^-6 C 8 = 0.7977 × 10 ^-10 C 10 = 0.2741 × 10 ^{-10 The} following shows the change in the interval during zooming. f 28.3818 40.1871 54.8810 d10 10.6697 6.0156 3.0198 Bf 6.7117 19.0783 34.4708 The numerical values corresponding to the conditions are shown below. (1) f1 / fL2 = 1.01 (2) f1 / fL4 = 1.04 (3) D / f1 = 0.712 (4) f1 / fL3 = -0.617 (5) f1 / fL1 = -0.712 (6) DL3 / fw = 0.155 (7) N3n-N3p = 0.22883 (8) ν3p-ν3n = 7.7 [Example 6] FIG. 6 shows a specific lens configuration of each lens group of Example 6.

【００４６】図６に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し少なくと
も光軸近傍において両凹形状の第１レンズ成分Ｌ1 と、
正屈折力を有し両凸形状の第２レンズ成分Ｌ2 と、負屈
折力を有し物体側に凹面を向けたメニスカス形状の第３
レンズ成分Ｌ3 と、正屈折力を有し両凸形状の第４レン
ズ成分Ｌ4 とからなり、第１レンズ成分乃至第４レンズ
成分の間は空気間隔である。そして、前記第１レンズ成
分Ｌ1 の物体側面と像側面はともに非球面であり、前記
第３レンズ成分Ｌ3 は、物体側より順に、両凹負レンズ
Ｌ3nと、両凸正レンズＬ3pとの接合レンズである。As shown in FIG. 6, the first lens unit G1 having a positive refracting power has, in order from the object side, a first lens component L1 having a negative refracting power and having a biconcave shape at least near the optical axis,
A biconvex second lens component L2 having a positive refractive power and a meniscus third lens component L2 having a negative refractive power and having a concave surface facing the object side.
It is composed of a lens component L3 and a biconvex fourth lens component L4 having a positive refractive power, and there is an air gap between the first lens component to the fourth lens component. The object side surface and the image side surface of the first lens component L1 are aspherical surfaces, and the third lens component L3 is a cemented lens of a biconcave negative lens L3n and a biconvex positive lens L3p in order from the object side. Is.

【００４７】一方、負屈折力の第２レンズ群Ｇ2 は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having negative refracting power has, in order from the object side, a fifth meniscus lens component L5 having positive refracting power and a concave surface facing the object side, and negative refracting power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００４８】以下の表６に、本発明の実施例６の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。Table 6 below lists the values of specifications and the numerical values corresponding to the conditions of the sixth embodiment of the present invention. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００４９】[0049]

【表６】 実施例６の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．８ ２ω＝
７７．０〜４３．９゜ （第１面非球面係数） ｋ＝-0.4009 ×10³ Ｃ4 ＝0.6736×10^-5 Ｃ6 ＝0.51
73×10^-7 Ｃ8 ＝-0.8493 ×10^-9 Ｃ10＝0.1111×10^-10 （第２面非球面係数） ｋ＝0.1164×10² Ｃ4 ＝0.5483×10^-4 Ｃ6 ＝0.17
29×10^-6 Ｃ8 ＝-0.4906 ×10^-8 Ｃ10＝0.8360×10^-10 （第１１面非球面係数） ｋ＝-0.6775 ×10 Ｃ4 ＝0.4204×10^-4 Ｃ6 ＝0.27
86×10^-6 Ｃ8＝-0.2928 ×10^-9 Ｃ10＝0.3002×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3812 40.1844 54.8748 d10 10.8869 6.1007 3.0198 B.f 6.7264 19.2410 34.8167 条件対応数値を以下に示す。 （１）ｆ１／ｆL2＝1.43 （２）ｆ1 ／ｆL4＝1.34 （３）Ｄ／ｆ1 ＝0.770 （４）ｆ1 ／ｆL3＝-0.847 （５）ｆ1 ／ｆL1＝-0.692 （６）ＤL3／ｆW ＝0.190 （７）Ｎ3n−Ｎ3p＝0.22883 （８）ν3p−ν3n＝7.7 〔実施例７〕実施例７の各レンズ群の具体的なレンズ構
成を図７に示す。Table 6 Specifications of Example 6 f = 28.4 to 54.9 F = 4.0 to 7.8 2ω =
77.0 to 43.9 ° (First surface aspherical surface coefficient) k = -0.4009 × 10 ³ C4 = 0.6736 × 10 ^-5 C6 = 0.51
73 x 10 ^-7 C8 = -0.8493 x 10 ^-9 C10 = 0.1111 x 10 ^-10 (second surface aspherical coefficient) k = 0.1164 x 10 ² C4 = 0.5483 x 10 ^-4 C6 = 0.17
29 x 10 ^-6 C8 = -0.4906 x 10 ^-8 C10 = 0.8360 x 10 ^-10 (11th surface aspherical coefficient) k = -0.6775 x10 C4 = 0.4204 x 10 ^-4 C6 = 0.27
86 × 10 ⁻⁶ C8 = −0.2928 × 10 ⁻⁹ C10 = 0.300 × 10 ^{−10 The} following shows the change in the interval during zooming. f 28.3812 40.1844 54.8748 d10 10.8869 6.1007 3.0198 Bf 6.7264 19.2410 34.8167 The values corresponding to the conditions are shown below. (1) f1 / fL2 = 1.43 (2) f1 / fL4 = 1.34 (3) D / f1 = 0.770 (4) f1 / fL3 = -0.847 (5) f1 / fL1 = -0.692 (6) DL3 / fW = 0.190 (7) N3n−N3p = 0.22883 (8) ν3p−ν3n = 7.7 [Example 7] FIG. 7 shows a specific lens configuration of each lens group of Example 7.

【００５０】図７に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し物体側に
凸面を向けたメニスカス形状の第１レンズ成分Ｌ1 と、
正屈折力を有し両凸形状の第２レンズ成分Ｌ2 と、負屈
折力を有し物体側に凹面を向けたメニスカス形状の第３
レンズ成分Ｌ3 と、正屈折力を有し両凸形状の第４レン
ズ成分Ｌ4 とからなり、第１レンズ成分乃至第４レンズ
成分の間は空気間隔である。そして、前記第１レンズ成
分Ｌ1 の像側面は非球面であり、前記第３レンズ成分Ｌ
3 は、物体側より順に、両凹負レンズＬ3nと、両凸正レ
ンズＬ3pとの接合レンズである。As shown in FIG. 7, the first lens group G1 having a positive refractive power has, in order from the object side, a first lens component L1 having a negative refractive power and having a meniscus shape having a convex surface directed toward the object side.
A biconvex second lens component L2 having a positive refractive power and a meniscus third lens component L2 having a negative refractive power and having a concave surface facing the object side.
It is composed of a lens component L3 and a biconvex fourth lens component L4 having a positive refractive power, and there is an air gap between the first lens component to the fourth lens component. The image side surface of the first lens component L1 is an aspherical surface, and the third lens component L1
Reference numeral 3 denotes a cemented lens in which a biconcave negative lens L3n and a biconvex positive lens L3p are cemented in order from the object side.

【００５１】一方、負屈折力の第２レンズ群Ｇ2 は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。On the other hand, the second lens unit G2 having a negative refractive power has, in order from the object side, a fifth meniscus lens component L5 having a positive refractive power and a concave surface facing the object side, and a negative refractive power. The sixth lens component L6 has a meniscus shape with a concave surface facing the object side, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００５２】以下の表７に、本発明の実施例７の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。Table 7 below lists values of specifications and numerical values corresponding to conditions of Example 7 of the present invention. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００５３】[0053]

【表７】 実施例７の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝４．０〜７．７ ２ω＝
７６．３〜４４．９゜ （第２面非球面係数） ｋ＝0.2990×10 Ｃ4 ＝0.5275×10^-4 Ｃ6 ＝0.61
19×10^-6 Ｃ8 ＝0.2883×10^-8 Ｃ10＝0.9026×10^-10 （第１１面非球面係数） ｋ＝-0.9183 Ｃ4 ＝0.3001×10^-4 Ｃ6＝0.311
8×10^-6 Ｃ8 ＝-0.1809 ×10^-8 Ｃ10＝0.2062×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3883 40.1899 54.8767 d10 12.1985 6.3465 2.5791 B.f 6.4615 20.2858 37.4898 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝1.02 （２）ｆ1 ／ｆL4＝0.726 （３）Ｄ／ｆ1 ＝0.770 （４）ｆ1 ／ｆL3＝-0.337 （５）ｆ1 ／ｆL1＝-0.586 （６）ＤL3／ｆW ＝0.173 （７）Ｎ3n−Ｎ3p＝0.24000 （８）ν3p−ν3n＝26.8 〔実施例８〕実施例８の各レンズ群の具体的なレンズ構
成を図８に示す。Table 7 Specifications of Example 7 f = 28.4 to 54.9 F = 4.0 to 7.7 2ω =
76.3-44.9 ° (Second surface aspherical surface coefficient) k = 0.2990 x 10 C4 = 0.5275 x 10 ^-4 C6 = 0.61
19 x 10 ^-6 C8 = 0.2883 x 10 ^-8 C10 = 0.9026 x 10 ^-10 (11th surface aspherical coefficient) k = -0.9183 C4 = 0.3001 x 10 ^-4 C6 = 0.311
8 × 10 ⁻⁶ C8 = −0.1809 × 10 ⁻⁸ C10 = 0.2062 × 10 ^{−10 The} following shows the change in the interval during zooming. f 28.3883 40.1899 54.8767 d10 12.1985 6.3465 2.5791 Bf 6.4615 20.2858 37.4898 The values corresponding to the conditions are shown below. (1) f1 / fL2 = 1.02 (2) f1 / fL4 = 0.726 (3) D / f1 = 0.770 (4) f1 / fL3 = -0.337 (5) f1 / fL1 = -0.586 (6) DL3 / fw = 0.173 (7) N3n−N3p = 0.24000 (8) ν3p−ν3n = 26.8 [Embodiment 8] FIG. 8 shows a specific lens configuration of each lens group of Embodiment 8.

【００５４】図８に示される如く、正屈折力の第１レン
ズ群Ｇ1 は、物体側から順に、負屈折力を有し物体側に
凸面を向けたメニスカス形状の第１レンズ成分Ｌ1 と、
正屈折力を有し両凸形状の第２レンズ成分Ｌ2 と、負屈
折力を有し物体側に凹面を向けたメニスカス形状の第３
レンズ成分Ｌ3 と、正屈折力を有し物体側に凹面を向け
たメニスカス形状の第４レンズ成分Ｌ4 とからなり、第
１レンズ成分乃至第４レンズ成分の間は空気間隔であ
る。そして、前記第４レンズ成分Ｌ4 の物体側面は非球
面であり、前記第３レンズ成分Ｌ3は、物体側より順
に、両凹負レンズＬ3nと、両凸正レンズＬ3pとの接合レ
ンズである。一方、負屈折力の第２レンズ群Ｇ2 は、物
体側から順に、正屈折力を有し物体側に凹面を向けたメ
ニスカス形状の第５レンズ成分Ｌ5 と、負屈折力を有し
物体側に凹面を向けたメニスカス形状の第６レンズ成分
Ｌ6 とからなり、第５レンズ成分Ｌ5 の物体側面は非球
面である。また、絞りＳは第１レンズ群Ｇ1 と第２レン
ズ群Ｇ2 の間に位置し、ズーミングに際しては第１レン
ズ群Ｇ1 と一体で移動する。As shown in FIG. 8, the first lens unit G1 having positive refracting power has, in order from the object side, a first meniscus lens component L1 having negative refracting power and having a convex surface directed toward the object side.
A biconvex second lens component L2 having a positive refractive power and a meniscus third lens component L2 having a negative refractive power and having a concave surface facing the object side.
It is composed of a lens component L3 and a meniscus fourth lens component L4 having a positive refracting power and a concave surface facing the object side, and there is an air gap between the first lens component to the fourth lens component. The object side surface of the fourth lens component L4 is an aspherical surface, and the third lens component L3 is a cemented lens of, in order from the object side, a biconcave negative lens L3n and a biconvex positive lens L3p. On the other hand, the second lens unit G2 having negative refractive power has, in order from the object side, a fifth meniscus lens component L5 having positive refractive power and having a concave surface facing the object side, and a negative lens having negative refractive power toward the object side. It is composed of a meniscus sixth lens component L6 having a concave surface, and the object side surface of the fifth lens component L5 is aspheric. Further, the diaphragm S is located between the first lens group G1 and the second lens group G2, and moves together with the first lens group G1 during zooming.

【００５５】以下の表８に、本発明の実施例８の諸元の
値及び条件対応数値を掲げる。実施例の諸元表中のｆは
焦点距離、ＦはＦナンバー、 2ωは画角を表す。そし
て、左端の数字は物体側からの順序を表し、ｒはレンズ
面の曲率半径、ｄはレンズ面間隔、ｎ及びνはｄ線（波
長λ=587.6nm）に対する屈折率及びアッベ数の値であ
る。また、左端の数字に* 印を付した面は非球面であ
り、非球面形状は、光軸から垂直方向の高さｈにおけ
る、非球面の頂点の接平面からの光軸方向に沿った距離
をＸ（ｈ）とし、近軸曲率半径をｒ、円錐定数をｋ、ｎ
次の非球面係数をＣnとするとき、 Ｘ（ｈ）＝（ｈ² ／ｒ）／〔１＋（１−ｋｈ² ／ｒ² ）
^1/2 〕＋Ｃ4 ｈ⁴ ＋Ｃ6 ｈ⁶ ＋Ｃ8 ｈ⁸ ＋Ｃ10ｈ¹⁰ で表現する。Table 8 below shows values of specifications and numerical values corresponding to conditions of the eighth embodiment of the present invention. In the specification table of the embodiment, f is the focal length, F is the F number, and 2ω is the angle of view. The leftmost number represents the order from the object side, r is the radius of curvature of the lens surface, d is the lens surface spacing, and n and ν are the values of the refractive index and Abbe number for the d line (wavelength λ = 587.6 nm). is there. The surface marked with * at the left end is an aspherical surface, and the aspherical shape is the distance along the optical axis from the tangent plane of the vertex of the aspherical surface at the height h in the vertical direction from the optical axis. Is X (h), the paraxial radius of curvature is r, the conic constant is k, n
When the next non-spherical coefficient Cn, X (h) = ( h 2 / r) / ^{[1+ (1-kh 2 / r} 2)
^1/2] + C4 is expressed by ^{h 4 + C6 h 6 + C8} h 8 + C10h 10.

【００５６】[0056]

【表８】 実施例８の諸元値 ｆ＝２８．４〜５４．９ Ｆ＝３．９〜７．６ ２ω＝
７３．４〜４２．９゜ （第８面非球面係数） ｋ＝0.1000×10 Ｃ4 ＝-0.5080 ×10^-4 Ｃ6 ＝-0.1
729 ×10^-6 Ｃ8 ＝0 Ｃ10＝0 （第１１面非球面係数） ｋ＝0.1000×10 Ｃ4 ＝0.3664×10^-4 Ｃ6 ＝0.
3448×10^-6 Ｃ8 ＝-0.1171 ×10^-8 Ｃ10＝0.1821×10^-10 変倍における間隔の変化を以下に示す。 ｆ 28.3882 40.1894 54.8754 d10 12.2037 6.3517 2.5843 B.f 7.0143 20.8384 38.0417 条件対応数値を以下に示す。 （１）ｆ1 ／ｆL2＝1.55 （２）ｆ1 ／ｆL4＝0.974 （３）Ｄ／ｆ1 ＝0.651 （４）ｆ1 ／ｆL3＝-0.893 （５）ｆ1 ／ｆL1＝-0.968 （６）ＤL3／ｆW ＝0.212 （７）Ｎ3n−Ｎ3p＝0.28930 （８）ν3p−ν3n＝20.7 図９、図１２、図１５、図１８、図２１、図２４、図２
７、図３０は、それぞれ実施例１〜実施例８の広角端で
の諸収差図であり、図１０、図１３、図１６、図１９、
図２２、図２５、図２８、図３１は、それぞれ実施例１
〜実施例８の中間焦点距離状態での諸収差図であり、図
１１、図１４、図１７、図２０、図２３、図２６、図２
９、図３２は、それぞれ実施例１〜実施例８の望遠端で
の諸収差図である。各収差図において、Ｈは入射光線
高、Ｙは像高、ｄはｄ線（λ=587.6nm）及びｇはｇ線
（λ=435.8nm）を示し、非点収差図において点線はメリ
ジオナル像面を、実線はサジタル像面を示している。Table 8 Specifications of Example 8 f = 28.4 to 54.9 F = 3.9 to 7.6 2ω =
73.4-42.9 ° (Eighth surface aspherical surface coefficient) k = 0.1000 × 10 C4 = -0.5080 × ^10-4 C6 = -0.1
729 x 10 ^-6 C8 = 0 C10 = 0 (11th surface aspherical surface coefficient) k = 0.1000 x 10 C4 = 0.3664 x 10 ^-4 C6 = 0.
3448 × 10 ^-6 C8 = -0.1171 × 10 ^-8 C10 = 0.1821 × 10 ^{-10 The} following shows the change in the interval during zooming. f 28.3882 40.1894 54.8754 d10 12.2037 6.3517 2.5843 Bf 7.0143 20.8384 38.0417 The numerical values corresponding to the conditions are shown below. (1) f1 / fL2 = 1.55 (2) f1 / fL4 = 0.974 (3) D / f1 = 0.651 (4) f1 / fL3 = -0.893 (5) f1 / fL1 = -0.968 (6) DL3 / fW = 0.212 (7) N3n−N3p = 0.28930 (8) ν3p−ν3n = 20.7 FIG. 9, FIG. 12, FIG. 15, FIG. 18, FIG. 21, FIG. 24, FIG.
7 and 30 are graphs showing various aberrations at the wide-angle end of Examples 1 to 8, respectively, and FIGS. 10, 13, 16, and 19.
22, FIG. 25, FIG. 28, and FIG.
21 is a diagram of various types of aberration in the intermediate focal length state of Example 8, and FIGS. 11, 14, 17, 20, 20, 23, and 26.
9 and 32 are graphs showing various aberrations of Examples 1 to 8 at the telephoto end. In each aberration diagram, H is the incident ray height, Y is the image height, d is the d line (λ = 587.6 nm) and g is the g line (λ = 435.8 nm). In the astigmatism diagram, the dotted line is the meridional image plane. The solid line shows the sagittal image plane.

【００５７】各収差図から、各実施例は諸収差が良好に
補正され、優れた結像性能を有していることが明らかで
ある。From each aberration diagram, it is apparent that each embodiment has various aberrations well corrected and has excellent image forming performance.

【００５８】[0058]

【発明の効果】このように本発明によれば、広角端での
画角が７０°以上であり、広角端でのレンズ全長が広角
端の焦点距離の１．８倍以下の小型な形状であり、構成
枚数が７枚程度と少なく低コスト化に有利で、かつ結像
性能の優れた広角ズームレンズを提供することができ
る。As described above, according to the present invention, the angle of view at the wide-angle end is 70 ° or more, and the total lens length at the wide-angle end is 1.8 times or less than the focal length at the wide-angle end. Therefore, it is possible to provide a wide-angle zoom lens having a small number of constituent elements of about 7, which is advantageous for cost reduction and has excellent imaging performance.

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

【図１】本発明による実施例１のレンズ構成図。FIG. 1 is a lens configuration diagram of a first embodiment according to the present invention.

【図２】本発明による実施例２のレンズ構成図。FIG. 2 is a lens configuration diagram of a second embodiment according to the present invention.

【図３】本発明による実施例３のレンズ構成図。FIG. 3 is a lens configuration diagram of a third embodiment according to the present invention.

【図４】本発明による実施例４のレンズ構成図。FIG. 4 is a lens configuration diagram of a fourth embodiment according to the present invention.

【図５】本発明による実施例５のレンズ構成図。FIG. 5 is a lens configuration diagram of a fifth embodiment according to the present invention.

【図６】本発明による実施例６のレンズ構成図。FIG. 6 is a lens configuration diagram of a sixth embodiment according to the present invention.

【図７】本発明による実施例７のレンズ構成図。FIG. 7 is a lens configuration diagram of a seventh embodiment according to the present invention.

【図８】本発明による実施例８のレンズ構成図。FIG. 8 is a lens configuration diagram of Example 8 according to the present invention.

【図９】本発明による実施例１の広角端での諸収差図。FIG. 9 is a diagram of various types of aberration at the wide-angle end of Example 1 according to the present invention.

【図１０】本発明による実施例１の中間焦点距離状態で
の諸収差図。FIG. 10 is a diagram of various types of aberration in an intermediate focal length state of Example 1 according to the present invention.

【図１１】本発明による実施例１の望遠端での諸収差
図。FIG. 11 is a diagram of various types of aberration at the telephoto end according to the first exemplary embodiment of the present invention.

【図１２】本発明による実施例２の広角端での諸収差
図。FIG. 12 is a diagram of various types of aberration at the wide-angle end according to Example 2 of the present invention.

【図１３】本発明による実施例２の中間焦点距離状態で
の諸収差図。FIG. 13 is a diagram of various types of aberration in the intermediate focal length state of Example 2 according to the present invention.

【図１４】本発明による実施例２の望遠端での諸収差
図。FIG. 14 is a diagram of various types of aberration at the telephoto end of Embodiment 2 according to the present invention.

【図１５】本発明による実施例３の広角端での諸収差
図。FIG. 15 is a diagram of various types of aberration at the wide-angle end according to Example 3 of the present invention.

【図１６】本発明による実施例３の中間焦点距離状態で
の諸収差図。FIG. 16 is a diagram of various types of aberration in the intermediate focal length state of Example 3 according to the present invention.

【図１７】本発明による実施例３の望遠端での諸収差
図。FIG. 17 is a diagram of various types of aberration at the telephoto end of Embodiment 3 according to the present invention.

【図１８】本発明による実施例４の広角端での諸収差
図。FIG. 18 is a diagram of various types of aberration at the wide-angle end of Example 4 according to the present invention.

【図１９】本発明による実施例４の中間焦点距離状態で
の諸収差図。FIG. 19 is a diagram of various types of aberration in the intermediate focal length state of Example 4 according to the present invention.

【図２０】本発明による実施例４の望遠端での諸収差
図。FIG. 20 is a diagram of various types of aberration at the telephoto end of Embodiment 4 according to the present invention.

【図２１】本発明による実施例５の広角端での諸収差
図。FIG. 21 is a diagram of various types of aberration at the wide-angle end of Example 5 according to the present invention.

【図２２】本発明による実施例５の中間焦点距離状態で
の諸収差図。FIG. 22 is a diagram of various types of aberration in the intermediate focal length state of Example 5 according to the present invention.

【図２３】本発明による実施例５の望遠端での諸収差
図。FIG. 23 is a diagram of various types of aberration at the telephoto end of Embodiment 5 according to the present invention.

【図２４】本発明による実施例６の広角端での諸収差
図。FIG. 24 is a diagram of various types of aberration at the wide-angle end of Example 6 according to the present invention.

【図２５】本発明による実施例６の中間焦点距離状態で
の諸収差図。FIG. 25 is a diagram of various types of aberration in the intermediate focal length state of Example 6 according to the present invention.

【図２６】本発明による実施例６の望遠端での諸収差
図。FIG. 26 is a diagram of various types of aberration at the telephoto end of Embodiment 6 according to the present invention.

【図２７】本発明による実施例７の広角端での諸収差
図。FIG. 27 is a diagram of various types of aberration at the wide-angle end of Example 7 according to the present invention.

【図２８】本発明による実施例７の中間焦点距離状態で
の諸収差図。FIG. 28 is a diagram of various types of aberration in the intermediate focal length state of Example 7 according to the present invention.

【図２９】本発明による実施例７の望遠端での諸収差
図。FIG. 29 is a diagram of various types of aberration at the telephoto end of Embodiment 7 according to the present invention.

【図３０】本発明による実施例８の広角端での諸収差
図。FIG. 30 is a diagram of various types of aberration at the wide-angle end of Example 8 according to the present invention.

【図３１】本発明による実施例８の中間焦点距離状態で
の諸収差図。FIG. 31 is a diagram of various types of aberration in the intermediate focal length state of Example 8 according to the present invention.

【図３２】本発明による実施例８の望遠端での諸収差
図。FIG. 32 is a diagram of various types of aberration at the telephoto end of Example 8 according to the present invention.

【主要部分の符合の説明】[Explanation of the sign of the main part]

Ｇ1 ・・・ 第１レンズ群 Ｇ2 ・・・ 第２レンズ群 Ｓ ・・・ 絞り G1 ・ ・ ・ First lens group G2 ・ ・ ・ Second lens group S ・ ・ ・ Aperture

Claims (16)

【特許請求の範囲】[Claims] 【請求項１】物体側より順に、正の屈折力を持つ第１レ
ンズ群と、負の屈折力を持つ第２レンズ群を有し、前記
第１レンズ群と前記第２レンズ群との空気間隔を縮小さ
せることにより広角端から望遠端への変倍を行なうズー
ムレンズにおいて、前記第１レンズ群は、物体側から順
に、負屈折力の第１レンズ成分と正屈折力の第２レンズ
成分と正屈折力または負屈折力の第３レンズ成分と正屈
折力の第４レンズ成分を有し、前記第１レンズ群の焦点
距離をｆ1 、前記第２レンズ成分の焦点距離をｆL2、前
記第４レンズ成分の焦点距離をｆL4、前記第１レンズ群
の最も物体側のレンズ面から最も像側のレンズ面までの
軸上距離をＤとするとき、以下の条件を満足することを
特徴とする広角ズームレンズ。 ０ ＜ ｆ1／ｆL2 ＜ ２．５ ０．５ ＜ ｆ1 ／ｆL4 ＜ ２．０ Ｄ／ｆ1 ＜ ０．８４1. An air system comprising: a first lens group having a positive refractive power and a second lens group having a negative refractive power in order from the object side, wherein the first lens group and the second lens group are air. In a zoom lens that performs zooming from a wide-angle end to a telephoto end by reducing an interval, the first lens unit includes, in order from the object side, a first lens component having negative refractive power and a second lens component having positive refractive power. And a third lens component having positive refractive power or negative refractive power and a fourth lens component having positive refractive power, the focal length of the first lens unit is f1, the focal length of the second lens component is fL2, and the second lens component is fL2. When the focal length of the four lens components is fL4 and the axial distance from the most object side lens surface to the most image side lens surface of the first lens group is D, the following conditions are satisfied. Wide-angle zoom lens. 0 <f1 / fL2 <2.5 0.5 <f1 / fL4 <2.0 D / f1 <0.84 【請求項２】前記第３レンズ成分の焦点距離をｆL3とす
るとき、以下の条件式を満足することを特徴とする請求
項１記載の広角ズームレンズ。 −１．５ ＜ ｆ1 ／ｆL3 ＜ １．０2. The wide-angle zoom lens according to claim 1, wherein the following conditional expression is satisfied when the focal length of the third lens component is fL3. -1.5 <f1 / fL3 <1.0 【請求項３】前記第１レンズ成分の焦点距離をｆL1とす
るとき、以下の条件式を満足することを特徴とする請求
項１記載の広角ズームレンズ。 −２．０ ＜ ｆ1 ／ｆL1 ＜ −０．４3. The wide-angle zoom lens according to claim 1, wherein the following conditional expression is satisfied when the focal length of the first lens component is fL1. -2.0 <f1 / fL1 <-0.4 【請求項４】広角ズームレンズの広角端の焦点距離をｆ
W、前記第３レンズ成分の軸上レンズ厚をＤL3とすると
き、以下の条件式を満足することを特徴とする請求項１
記載の広角ズームレンズ。 ０．０８５ ＜ ＤL3／ｆW ＜ ０．４００4. The focal length at the wide-angle end of the wide-angle zoom lens is f
The following conditional expression is satisfied when W and the axial lens thickness of the third lens component is DL3.
Wide-angle zoom lens described. 0.085 <DL3 / fw <0.400 【請求項５】前記第３レンズ成分は負レンズと正レンズ
との接合レンズであることを特徴とする請求項１記載の
広角ズームレンズ。5. The wide-angle zoom lens according to claim 1, wherein the third lens component is a cemented lens of a negative lens and a positive lens. 【請求項６】前記第３レンズ成分を構成する負レンズと
正レンズの屈折率をそれぞれＮ3nとＮ3pとするとき、以
下の条件式を満足することを特徴とする請求項５記載の
広角ズームレンズ。 Ｎ3n−Ｎ3p ＞ ０．２6. The wide-angle zoom lens according to claim 5, wherein the following conditional expressions are satisfied when the refractive indices of the negative lens and the positive lens constituting the third lens component are N3n and N3p, respectively. . N3n-N3p> 0.2 【請求項７】前記第３レンズ成分を構成する負レンズと
正レンズのアッベ数をそれぞれν3nとν3pとするとき、
以下の条件式を満足することを特徴とする請求項５記載
の広角ズームレンズ。 ν3p−ν3n ＞ ４7. When the Abbe numbers of the negative lens and the positive lens constituting the third lens component are ν3n and ν3p, respectively,
The wide-angle zoom lens according to claim 5, wherein the following conditional expression is satisfied. ν3p-ν3n> 4 【請求項８】前記第２レンズ成分の物体側面が非球面で
あることを特徴とする請求項１記載の広角ズームレン
ズ。8. The wide-angle zoom lens according to claim 1, wherein an object side surface of the second lens component is an aspherical surface. 【請求項９】前記第２レンズ成分は物体側に凸面を向け
たメニスカス形状であることを特徴とする請求項８記載
の広角ズームレンズ。9. The wide-angle zoom lens according to claim 8, wherein the second lens component has a meniscus shape with a convex surface facing the object side. 【請求項１０】前記第１レンズ成分の像側面が非球面で
あることを特徴とする請求項１記載の広角ズームレン
ズ。10. The wide-angle zoom lens according to claim 1, wherein an image side surface of the first lens component is an aspherical surface. 【請求項１１】前記第１レンズ成分の物体側面が非球面
であることを特徴とする請求項１記載の広角ズームレン
ズ。11. The wide-angle zoom lens according to claim 1, wherein an object side surface of the first lens component is an aspherical surface. 【請求項１２】前記第４レンズ成分の物体側面が非球面
であることを特徴とする請求項１記載の広角ズームレン
ズ。12. The wide-angle zoom lens according to claim 1, wherein an object side surface of the fourth lens component is an aspherical surface. 【請求項１３】前記第４レンズ成分は物体側に凹面を向
けたメニスカス形状であることを特徴とする請求項１２
記載の広角ズームレンズ。13. The fourth lens component has a meniscus shape with a concave surface facing the object side.
Wide-angle zoom lens described. 【請求項１４】物体側より順に、正の屈折力を持つ第１
レンズ群と、負の屈折力を持つ第２レンズ群を有し、前
記第１レンズ群と前記第２レンズ群との空気間隔を縮小
させることにより広角端から望遠端への変倍を行なう広
角ズームレンズにおいて、前記第１レンズ群は、物体側
から順に、負屈折力の第１レンズ成分と正屈折力の第２
レンズ成分と正屈折力または負屈折力の第３レンズ成分
と正屈折力の第４レンズ成分を有し、前記第３レンズ成
分は負レンズと正レンズとの接合レンズであることを特
徴とする広角ズームレンズ。14. A first lens element having a positive refractive power in order from the object side.
A wide-angle lens having a lens group and a second lens group having a negative refractive power, and zooming from the wide-angle end to the telephoto end by reducing an air gap between the first lens group and the second lens group. In the zoom lens, the first lens group includes, in order from the object side, a first lens component having a negative refractive power and a second lens component having a positive refractive power.
It has a lens component and a third lens component of positive refractive power or negative refractive power and a fourth lens component of positive refractive power, and the third lens component is a cemented lens of a negative lens and a positive lens. Wide-angle zoom lens. 【請求項１５】前記第３レンズ成分を構成する負レンズ
と正レンズの屈折率をそれぞれＮ3nとＮ3pとするとき、
以下の条件式を満足することを特徴とする請求項１４記
載の広角ズームレンズ。 Ｎ3n−Ｎ3p ＞ ０．２15. The refractive index of the negative lens and the positive lens constituting the third lens component are N3n and N3p, respectively,
The wide-angle zoom lens according to claim 14, wherein the following conditional expression is satisfied. N3n-N3p> 0.2 【請求項１６】前記第３レンズ成分を構成する負レンズ
と正レンズのアッベ数をそれぞれν3nとν3pとすると
き、以下の条件式を満足することを特徴とする請求項１
４記載の広角ズームレンズ。 ν3p−ν3n ＞ ４16. The following conditional expression is satisfied when the Abbe numbers of the negative lens and the positive lens constituting the third lens component are ν3n and ν3p, respectively.
Wide-angle zoom lens described in 4. ν3p-ν3n> 4