JPH1184239A - Zoom lens - Google Patents
Zoom lensInfo
- Publication number
- JPH1184239A JPH1184239A JP23638497A JP23638497A JPH1184239A JP H1184239 A JPH1184239 A JP H1184239A JP 23638497 A JP23638497 A JP 23638497A JP 23638497 A JP23638497 A JP 23638497A JP H1184239 A JPH1184239 A JP H1184239A
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- JP
- Japan
- Prior art keywords
- lens
- lens group
- zoom
- refractive power
- group
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、家庭用のビデオカ
メラ等に好適なズームレンズに関する。特には、ズーム
比のさらなる高倍率化を達成することのできるズームレ
ンズに関する。The present invention relates to a zoom lens suitable for a home video camera and the like. In particular, the present invention relates to a zoom lens capable of achieving a higher zoom ratio.
【０００２】[0002]
【従来の技術】家庭用ビデオカメラのズームレンズを例
に採って説明する。この種のズームレンズにおいては、
撮像素子の小型化に伴って、次の２つの方向で商品開発
がなされてきている。１つは、ズーム比が同じでより小
型化を達成する方向であり、他の１つは実用的な大きさ
の中でより高倍率化する方向である。2. Description of the Related Art A zoom lens of a home video camera will be described as an example. In this type of zoom lens,
With the downsizing of the imaging device, product development has been performed in the following two directions. One is to achieve a smaller size with the same zoom ratio, and the other is to increase the magnification within a practical size.
【０００３】後者の高倍率なズームレンズを実現する技
術の一例として、特開平８−５９１３号がある。同号の
ズームレンズは、物体側より順に正、負、正、負、正の
屈折力配置の５つのレンズ群からなり、少なくとも第２
レンズ群と第４レンズ群を移動させることによりズーミ
ングとフォーカシングを行うことにより、前玉径（物体
側のレンズの径）を小型にして約２０倍のズーム比を得
るものである。前玉径を小さくできれば、望遠端で使用
するときに有効な光学式手振れ補正装置、たとえば可変
頂角プリズムなどをレンズの物体側に装着する際、手振
れ補正装置を小型にできて、民生用高倍率ズームの実用
性を高める上で好都合である。As one example of a technique for realizing the latter high-magnification zoom lens, there is JP-A-8-5913. The same zoom lens is composed of five lens units having positive, negative, positive, negative, and positive refractive power arrangement in order from the object side.
By performing zooming and focusing by moving the lens unit and the fourth lens unit, the diameter of the front lens (the diameter of the lens on the object side) is reduced, and a zoom ratio of about 20 times is obtained. If the diameter of the front lens can be reduced, an optical image stabilization device that is effective when used at the telephoto end, for example, when a variable apex prism or the like is mounted on the object side of the lens, the image stabilization device can be reduced in size, and the height for consumer use can be reduced. This is convenient for enhancing the practicality of the magnification zoom.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、撮像素
子のさらなる小型化を活かして、高倍率化をさらに進め
て、たとえば５０倍ズームレンズに上記特開平８−５９
１３号の技術をそのまま適用すると、次のような問題点
が生じていた。すなわち、ズーミングによる収差変動
や、望遠端での色収差及び球面収差などが補正できなか
った。そのため、従来技術では、レンズの実用的な大き
さを維持した上での高倍率化は２０倍くらいが限界であ
った。However, taking advantage of the further miniaturization of the image pickup device, the magnification is further increased and, for example, a 50-fold zoom lens is disclosed in Japanese Patent Laid-Open No. 8-59.
If the technology of No. 13 is applied as it is, the following problems occur. That is, aberration fluctuation due to zooming, chromatic aberration and spherical aberration at the telephoto end could not be corrected. For this reason, in the conventional technology, the limit of increasing the magnification while maintaining the practical size of the lens is about 20 times.
【０００５】本発明は、このような問題点に鑑みてなさ
れたもので、家庭用のビデオカメラ等に好適なズームレ
ンズであって、特には、ズーム比のさらなる高倍率化を
達成することのできるズームレンズを提供することを目
的とする。より具体的には、上記従来技術を画面対角線
長４．５mmで変倍比約２０倍に適用した場合と同様の大
きさで、画面対角線長３mmで約５０倍の変倍比を実現
し、撮像素子の小型化を高倍率化に活かすとともに諸収
差が良好に補正されたズームレンズを提供することを目
的とする。The present invention has been made in view of the above problems, and is directed to a zoom lens suitable for a home video camera and the like. In particular, the present invention is intended to achieve a higher zoom ratio. It is an object of the present invention to provide a zoom lens that can be used. More specifically, the same size as when the above-described conventional technique is applied to a screen diagonal length of 4.5 mm and a magnification ratio of about 20 times is realized, and a zoom ratio of about 50 times is realized with a screen diagonal length of 3 mm and It is an object of the present invention to provide a zoom lens in which the miniaturization of an image sensor is utilized for increasing the magnification and various aberrations are satisfactorily corrected.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するた
め、本発明のズームレンズは、 物体側より順に、正の
屈折力の第１レンズ群、負の屈折力の第２レンズ群、正
の屈折力の第３レンズ群、負の屈折力の第４レンズ群、
正の屈折力の第５レンズ群からなり、 少なくとも第２
レンズ群及び第４レンズ群を光軸方向に移動させること
により、変倍並びに変倍による像位置の変動補正及びフ
ォーカシングを行うズームレンズであって； 上記第１
レンズ群が、物体側より順に配列された凹レンズと凸レ
ンズの接合レンズ及び凸レンズを有し、 上記第２レン
ズ群が、物体側より順に配列された凹レンズ及び凹レン
ズと凸レンズの接合レンズを有し、 上記第３レンズ群
が、物体側より順に配列された凸レンズ及び凸レンズと
凹レンズの接合レンズを有し、 上記第４レンズ群が、
物体側より順に配列された凹レンズ及び凹レンズと凸レ
ンズの接合レンズを有し、 上記第５レンズ群が、物体
側より順に配列された凸レンズ及び凸レンズと凹レンズ
の接合レンズを有することを特徴とする。In order to solve the above problems, a zoom lens according to the present invention comprises, in order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a positive lens unit. A third lens group having a refractive power, a fourth lens group having a negative refractive power,
A fifth lens unit having a positive refractive power, and at least a second lens unit.
A zoom lens that performs zooming and corrects image position fluctuation and focusing by zooming by moving a lens group and a fourth lens group in the optical axis direction;
The lens group has a cemented lens of a concave lens and a convex lens and a convex lens arranged in order from the object side, and the second lens group has a cemented lens of a concave lens and a concave lens and a convex lens arranged in order from the object side, A third lens group including a convex lens arranged in order from the object side and a cemented lens of the convex lens and the concave lens;
It has a concave lens and a cemented lens of a concave lens and a convex lens arranged in order from the object side, and the fifth lens group has a convex lens and a cemented lens of a convex lens and a concave lens arranged in order from the object side.
【０００７】広角端から望遠端へズーミングするとき、
上記第２レンズ群が物体側から像側へ移動し、第２レン
ズ群の横倍率が高くなって全体の焦点距離を長くする働
きをする。このとき上記第４レンズ群が、広角端から第
２レンズ群の横倍率が−１になるまでは物体側から像側
へ移動して増倍の働きをし、第２レンズ群の横倍率が−
１から望遠端までは反転して像側から物体側へ移動して
減倍の働きをする。なお、第４レンズ群の移動方向が反
転する位置を変曲点と呼ぶこととする。When zooming from the wide-angle end to the telephoto end,
The second lens group moves from the object side to the image side, and the lateral magnification of the second lens group is increased to function to increase the overall focal length. At this time, the fourth lens unit moves from the object side to the image side to increase the magnification from the wide-angle end until the lateral magnification of the second lens unit becomes −1, and the lateral magnification of the second lens unit becomes large. −
From 1 to the telephoto end, the image is inverted and moved from the image side to the object side to perform the function of magnification reduction. The position where the moving direction of the fourth lens group is reversed is called an inflection point.
【０００８】入射瞳は、広角端では、第２レンズ群が絞
りから遠い位置にあるため、第１レンズ群寄りに位置
し、広角端の画角と入射瞳位置から前玉を通る主光線の
光線高が決まる。第２レンズ群が像側へ移動するにつれ
て入射瞳は第１レンズ群から遠ざかり、画角は徐々に狭
くなるので、その入射瞳位置と画角から決まる主光線の
前玉における光線高が変化する。広角端の画角が６０度
程度で変倍比が１０倍以上のズームレンズでは、通常、
広角端より少し画角が狭いズーム位置で主光線の前玉光
線高が最大になることが多い。しかし、上記５群構成の
ズームレンズでは、入射瞳位置の変化は第２レンズ群の
移動のみで決まるのに対して、画角変化は広角端から変
曲点までは第４レンズ群も変倍の役割を果たす。そのた
め、主光線の前玉光線高が最大になるときの画角をより
狭くできるので、主光線高で決まる前玉径を小さくでき
る効果がある。The entrance pupil is located near the first lens group at the wide-angle end because the second lens group is far from the stop, and the angle of view at the wide-angle end and the position of the principal ray passing through the front lens from the entrance pupil position. The ray height is determined. As the second lens group moves toward the image side, the entrance pupil moves away from the first lens group, and the angle of view gradually narrows. Therefore, the ray height at the front lens of the principal ray determined by the position of the entrance pupil and the angle of view changes. . In a zoom lens with a wide-angle end angle of view of about 60 degrees and a zoom ratio of 10 or more,
At the zoom position where the angle of view is slightly narrower than the wide-angle end, the front ray height of the principal ray often becomes maximum. However, in the zoom lens having the five-group configuration, the change in the entrance pupil position is determined only by the movement of the second lens group, whereas the change in the angle of view also changes the magnification of the fourth lens group from the wide-angle end to the inflection point. Plays a role. Therefore, the angle of view when the height of the front ray of the principal ray is maximized can be narrowed, and the diameter of the front ray determined by the height of the principal ray can be reduced.
【０００９】[0009]
【発明の実施の形態】本発明のズームレンズでは、高倍
率化により前玉径が大型化するのを抑える効果がさらに
顕著になるように、広角端から変曲点までの第４レンズ
群の倍率変化が大きくなる屈折力配置に設定することが
好ましい。具体的には、広角端における第４レンズ群の
横倍率をβ４Ｗとすると、３＜β４Ｗ＜８とすることが
好ましい。この値の下限を下回ると、第４レンズ群の移
動量が増加して小型化が達成しにくい。一方、上記値の
上限を越えると、第４レンズ群でフォーカシングする際
の倍率変化が大きくなって不自然になる。特に、オート
フォーカスのために第４レンズ群を光軸方向に微小振動
させてコントラストの変化を見る動作をさせたときに、
画角が周期的に変化するのが顕著に見えて問題となる。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the zoom lens according to the present invention, the fourth lens group from the wide-angle end to the inflection point is made so that the effect of suppressing an increase in the front lens diameter due to an increase in magnification becomes more remarkable. It is preferable to set the refractive power arrangement such that the change in magnification is large. Specifically, assuming that the lateral magnification of the fourth lens group at the wide angle end is β4W, it is preferable that 3 <β4W <8. If the value is below the lower limit of this value, the amount of movement of the fourth lens group increases, and it is difficult to achieve downsizing. On the other hand, when the value exceeds the upper limit of the above value, a change in magnification at the time of focusing with the fourth lens group becomes large, and the image becomes unnatural. In particular, when the fourth lens group is slightly vibrated in the optical axis direction for the purpose of autofocusing and the operation of observing a change in contrast is performed,
The fact that the angle of view periodically changes becomes noticeable and poses a problem.
【００１０】上述の従来例では、第４レンズ群が１枚乃
至２枚のレンズで構成されていた。しかし、本発明で
は、第４レンズ群の倍率変化をより大きくして、収差変
動、特にワイド側における球面収差が第３レンズ群と第
４レンズ群との間で打ち消しあっていることに起因する
球面収差の変動をあまり増大しないように抑えることを
重視した。そのために、第４レンズ群に、倍率変化によ
る収差変動の小さい第２レンズ群と同様の構成、すなわ
ち物体側より順に凹レンズ及び凹レンズと凸レンズの接
合レンズの３枚構成を適用することで、高倍率化と小型
化を両立させた。In the above-mentioned conventional example, the fourth lens group is composed of one or two lenses. However, in the present invention, the change in magnification of the fourth lens group is increased, and aberration fluctuation, particularly spherical aberration on the wide side, is canceled out between the third lens group and the fourth lens group. The emphasis was on suppressing the fluctuation of the spherical aberration so as not to increase too much. For this reason, by applying the same configuration as the second lens group in which aberration variation due to magnification change is small, that is, a three-lens configuration of a concave lens and a cemented lens of a concave lens and a convex lens in order from the object side, to the fourth lens group, a high magnification is obtained. And miniaturization.
【００１１】次に、望遠端の画角が狭くなることにより
顕著になる色収差を良好に補正することと小型化とを両
立させるための好ましい構成について説明する。望遠端
の２次スペクトルは、第１レンズ群の残存色収差が第２
レンズ群以降のレンズ系で拡大されることが支配的要因
である。この第１レンズ群の残存色収差を低減するに
は、第１レンズ群の凸レンズにアッベ数が８０以上のい
わゆる超低分散ガラスを用いることが効果的であること
を本発明者は見出した。それ以外の設計手段、たとえば
第１レンズ群の枚数を増やすなどして異常分散性のある
一般的なガラスで色消しを行うような手段も考えられる
が、小型化との両立が果たしにくい。Next, a description will be given of a preferred configuration for achieving both good correction of chromatic aberration, which becomes conspicuous as the angle of view at the telephoto end becomes narrow, and miniaturization. The secondary spectrum at the telephoto end shows that the residual chromatic aberration of the first lens group is
The dominant factor is that the magnification is increased by the lens system after the lens group. In order to reduce the residual chromatic aberration of the first lens group, the present inventors have found that it is effective to use so-called ultra-low dispersion glass having an Abbe number of 80 or more for the convex lens of the first lens group. Other design means, such as increasing the number of first lens groups to perform achromatization with general glass having anomalous dispersion, can be considered, but it is difficult to achieve compatibility with miniaturization.
【００１２】図１は、本発明の１実施例に係るズームレ
ンズの基本的な構成を示すレンズ断面図である。（Ａ）
は広角端状態、（Ｂ）はズーム比約３０倍（焦点距離が
広角端の３０倍）の状態、（Ｃ）は望遠端状態である。
前述のように、本実施例では、絞りＳは固定されており
第３レンズ群の直前に配置されている。像面ＩＭ（ＣＣ
Ｄ結像面）の前のＦは、フィルターに相当する平行平面
ガラスである。FIG. 1 is a sectional view showing a basic structure of a zoom lens according to an embodiment of the present invention. (A)
10B shows a state at the wide-angle end, FIG. 13B shows a state at a zoom ratio of about 30 (the focal length is 30 times the wide-angle end), and FIG.
As described above, in this embodiment, the stop S is fixed, and is disposed immediately before the third lens group. Image plane IM (CC
F before (D imaging plane) is a parallel plane glass corresponding to a filter.
【００１３】次に望遠端で補正不足になりがちな球面収
差の補正について説明する。図１における二点鎖線は、
軸上無限遠物点から出た光線の光路を示す。第１レンズ
群は補正不足の球面収差が残っており、第２レンズ群は
補正過剰の球面収差を発生させるものとする。図１
（Ａ）の広角端から望遠方向へズーミングすると、図１
（Ｂ）に示すように、軸上無限遠物点から出た光線が第
１レンズ群を通る光線高が高くなる。これによって、第
１レンズ群で発生する補正不足の球面収差が増大する。
また同時に、第２レンズ群を通る光線高も高くなること
から、第２レンズ群から発生する補正過剰の球面収差も
増大して、第１レンズ群と第２レンズ群が球面収差の変
化を打ち消すように働く。したがって、ズーム位置が図
１（Ｂ）までは、第１レンズ群と第２レンズ群との間の
球面収差の打ち消しの条件が保たれる。Next, correction of spherical aberration that tends to be insufficiently corrected at the telephoto end will be described. The two-dot chain line in FIG.
The optical path of the light beam emitted from the object point at infinity on the axis is shown. The first lens group has an undercorrected spherical aberration, and the second lens group has an overcorrected spherical aberration. FIG.
When zooming in the telephoto direction from the wide-angle end of FIG.
As shown in (B), the height of the light beam that has exited from the object point on the axis at infinity passes through the first lens group. As a result, undercorrected spherical aberration that occurs in the first lens group increases.
At the same time, the height of light rays passing through the second lens group is also increased, so that the overcorrected spherical aberration generated from the second lens group is also increased, and the first lens group and the second lens group cancel the change in spherical aberration. Work like that. Therefore, the condition for canceling the spherical aberration between the first lens group and the second lens group is maintained until the zoom position is up to FIG.
【００１４】しかしながら、さらに望遠側へズーミング
すると、上記光線は第１レンズ群の有効径で制限を受け
て第１レンズ群の光線高は一定のままである。しかし、
第２レンズ群を通る光線高はズーミングとともに低くな
って、第２レンズ群から発生する補正過剰の球面収差が
減少に転じるため、望遠端では球面収差が補正不足にな
る。そこで本実施例では、上記のような第１レンズ群と
第２レンズ群の打ち消しにのみ頼るのではなく、第１レ
ンズ群の球面収差の残存量を減少させるために、第１レ
ンズ群の少なくとも１面に非球面を導入し、有効径にお
いて近軸球面の深さより浅くなる非球面形状としてい
る。一方、第１レンズ群の枚数を増やして屈折力を分散
させることで、発生する球面収差を減少させる設計手段
もある。しかし、小型化と両立しにくくなるため、非球
面により球面収差の発生を抑えるのが効果的である。However, when zooming further to the telephoto side, the light rays are restricted by the effective diameter of the first lens group, so that the light height of the first lens group remains constant. But,
The height of the light ray passing through the second lens group decreases with zooming, and the overcorrected spherical aberration generated from the second lens group starts to decrease, so that the spherical aberration is insufficiently corrected at the telephoto end. Therefore, in this embodiment, in order to reduce the remaining amount of spherical aberration of the first lens unit, at least the first lens unit should be used, instead of relying only on the cancellation of the first lens unit and the second lens unit. An aspherical surface is introduced on one surface, and has an aspherical shape in which the effective diameter is shallower than the depth of the paraxial spherical surface. On the other hand, there is a design means for reducing the generated spherical aberration by increasing the number of first lens groups and dispersing the refractive power. However, since it is difficult to achieve compatibility with miniaturization, it is effective to suppress the occurrence of spherical aberration by using an aspherical surface.
【００１５】この第１レンズ群に非球面を導入する手段
として、ガラスモールド非球面、精研削非球面、プラス
チック非球面、複合非球面が考えられる。しかし、第１
レンズ群の外径が大きため、ガラスモールド非球面と精
研削非球面はコストが高いので、本発明の主なターゲッ
トである家庭用ビデオカメラにはあまり適当でない。一
方、プラスチック非球面は、温度変化、湿度変化などの
環境条件によって屈折力や収差が変化して、設計性能を
常に維持することができず、高倍率ズームにはあまり適
当とはいえない。しかし複合非球面、すなわちガラスレ
ンズの表面に樹脂の薄い非球面層を形成することで、安
いコストで目標性能を満足できる。As means for introducing an aspherical surface into the first lens group, a glass molded aspherical surface, a finely ground aspherical surface, a plastic aspherical surface, and a composite aspherical surface can be considered. But the first
Due to the large outer diameter of the lens group, the cost of the glass mold aspherical surface and the finely ground aspherical surface is high, so that they are not very suitable for the home video camera which is the main target of the present invention. On the other hand, a plastic aspherical surface changes its refractive power and aberration due to environmental conditions such as temperature change and humidity change, and cannot always maintain design performance, and is not very suitable for high-magnification zoom. However, by forming a thin aspherical layer of resin on the surface of a composite aspherical surface, that is, a glass lens, the target performance can be satisfied at low cost.
【００１６】次に広角端における球面収差とコマ収差の
補正について説明する。軸上無限遠物点から出た光線は
第３レンズ群で光線高が最大となるので、球面収差とコ
マ収差は第３レンズ群で発生する量が大きい。良好な収
差補正を得るには、収差の発生の支配的な構成要素に対
して、収差の発生しにくい構成要素として非球面を導入
して、有効径において近軸球面の深さより浅くなる非球
面形状にすることで球面収差とコマ収差の発生を小さく
抑えることができる。第３レンズ群から発生する球面収
差とコマ収差を球面のみの構成で抑えるには枚数の増加
が避けられず、小型化と両立しにくい。Next, correction of spherical aberration and coma at the wide-angle end will be described. Since the ray height of the ray coming from the object point on the axis at infinity is maximized in the third lens group, the amount of spherical aberration and coma generated in the third lens group is large. In order to obtain good aberration correction, an aspheric surface is introduced as a component that is unlikely to cause aberrations for a component that is dominant in the generation of aberrations, and the aspheric surface becomes shallower than the paraxial sphere in effective diameter. By forming the shape, the occurrence of spherical aberration and coma can be suppressed to a small value. In order to suppress spherical aberration and coma generated from the third lens group by using only a spherical surface, an increase in the number of lenses is inevitable, and it is difficult to achieve compatibility with miniaturization.
【００１７】次に、第５レンズ群の構成について説明す
る。高倍率化のために第４レンズ群の移動量が大きくな
るので、第５レンズ群は絞りＳから遠い位置に配置する
ことになる。そのため主光線が第５レンズ群を通る光線
高が高くなり射出瞳が像面の後方に位置するようにな
る。主光線は第５レンズ群で大きな偏角で屈折するの
で、第５レンズ群の正の屈折力の影響で像面湾曲がアン
ダーになりやすく、広角端の歪曲収差は樽型で大きくな
りやすい。この第５レンズ群で発生する収差を軽減する
ためには、正の屈折力を２つのレンズ群に分担させると
ともに、負の屈折力を持つ接合面を配置し、さらに少な
くとも１面を非球面とし、有効径において近軸球面の深
さより浅くなる非球面形状とすることで、少ない枚数で
良好な収差補正と小型化を両立させることができる。Next, the configuration of the fifth lens group will be described. Since the amount of movement of the fourth lens group is increased to increase the magnification, the fifth lens group is arranged at a position far from the stop S. Therefore, the height of the principal ray passing through the fifth lens group is increased, and the exit pupil is located behind the image plane. Since the principal ray is refracted by the fifth lens group with a large deflection angle, the curvature of field tends to be under due to the influence of the positive refractive power of the fifth lens group, and the distortion at the wide-angle end tends to be large in a barrel shape. In order to reduce the aberration generated in the fifth lens group, a positive refractive power is shared between the two lens groups, a cemented surface having a negative refractive power is arranged, and at least one surface is made aspherical. By making the aspherical surface of the effective diameter smaller than the depth of the paraxial spherical surface, it is possible to achieve both good aberration correction and miniaturization with a small number of sheets.
【００１８】[0018]
【実施例】次に本実施例の数値例を以下に示す。数値例
において各符号の意味は以下のとおりである。 ｆ：焦点距離（mm） Ｆ：Ｆナンバー ２ω：画角 ｒｉ：第ｉ番目の面の曲率半径（mm） ｄｉ：第ｉ番目の面間隔（mm） ｎｉ：第ｉ番目のレンズのｄ線の屈折率 νｉ：第ｉ番目のレンズのアッベ数 非球面の定義：非球面の深さをｘｉ、光軸からの高さを
Ｈとして、 ｘｉ＝Ｈ2 ／ｒｉ｛１＋（１−Ｈ2 ／ｒｉ2)1/2 ｝＋Σ
ＡｊＨｊ である。ただし、ｉａは第ｉ番目の面に付けた複合非球
面にかかわる数値を示す。Next, numerical examples of this embodiment will be shown below. The meaning of each code in the numerical example is as follows. f: focal length (mm) F: F number 2ω: angle of view ri: radius of curvature of the i-th surface (mm) di: i-th surface interval (mm) ni: d-line of the i-th lens refractive index .nu.i: i-th lens Abbe number aspherical definition: the depth of the aspherical xi, the height from the optical axis as H, xi = H 2 / ri {1+ (1-H 2 / ri 2 ) 1/2 1/2 +｝
AjH j . Here, ia indicates a numerical value related to the composite aspherical surface attached to the i-th surface.
【００１９】[0019]
【外１】 [Outside 1]
【００２０】[0020]
【外２】 [Outside 2]
【００２１】図２及び図３は、本発明の第１実施例及び
第２実施例の諸収差図を示す。図中の各図は、それぞれ
広角端状態、ズーム比３０倍の状態、望遠端状態での無
限遠合焦状態における諸収差図を表す。各収差図におい
て、球面収差図中の実線はｄ線についての球面収差、破
線はｇ線についての球面収差、一点鎖線はｃ線について
の球面収差である。非点収差図中の実線はサジタル像
面、破線はメリディオナル像面を示す。各収差図から、
本実施例は諸収差が良好に補正され、優れた結像性能を
有していることは明らかである。FIGS. 2 and 3 show various aberration diagrams of the first embodiment and the second embodiment of the present invention. Each figure in the figure shows various aberration diagrams in a wide-angle end state, a state of a zoom ratio of 30 times, and a focusing state at infinity at a telephoto end state. In each aberration diagram, the solid line in the spherical aberration diagram is the spherical aberration for the d line, the broken line is the spherical aberration for the g line, and the one-dot chain line is the spherical aberration for the c line. The solid line in the astigmatism diagram indicates the sagittal image plane, and the broken line indicates the meridional image plane. From each aberration diagram,
It is clear that this embodiment has excellent aberrations corrected for various aberrations and excellent imaging performance.
【００２２】[0022]
【発明の効果】以上に記載したところから明らかなよう
に、本発明のズームレンズは、物体側より凸、凹、凸、
凹、凸の屈折力配置のズームレンズにおいて、各レンズ
群に適切なレンズ構成を設定することにより、従来技術
では困難であったズーム比の高倍率化に適したレンズ構
成を提供することができる。さらに高倍率化で補正が困
難になる諸収差に対しては、第１レンズ群の２枚の凸レ
ンズのうち少なくとも１枚のアッベ数を８０以上とする
ことや、上記第１、第３若しくは第５レンズ群の少なく
とも１面を、有効径において近軸球面の深さより浅くな
る非球面形状とすることで十分に補正でき。As is apparent from the above description, the zoom lens according to the present invention has a convex, concave, convex,
In a zoom lens having concave and convex refractive power arrangements, by setting an appropriate lens configuration for each lens group, it is possible to provide a lens configuration suitable for increasing the zoom ratio, which has been difficult with the prior art. . For various aberrations that are more difficult to correct at higher magnifications, the Abbe number of at least one of the two convex lenses in the first lens group is set to 80 or more, or the first, third, or third lens is used. Sufficient correction can be made by making at least one surface of the five lens groups into an aspherical shape whose effective diameter is shallower than the depth of the paraxial spherical surface.
【図１】本発明の１実施例に係るズームレンズの基本的
な構成を示すレンズ断面図である。（Ａ）は広角端状
態、（Ｂ）はズーム比約３０倍の状態、（Ｃ）は望遠端
状態である。FIG. 1 is a lens cross-sectional view showing a basic configuration of a zoom lens according to one embodiment of the present invention. (A) is a wide-angle end state, (B) is a state where the zoom ratio is about 30 times, and (C) is a telephoto end state.
【図２】本発明の第１実施例のズームレンズの諸収差図
を示す。図中の各図はそれぞれ広角端状態、ズーム比３
０倍の状態、望遠端状態での無限遠合焦状態における諸
収差図を表す。FIG. 2 shows various aberration diagrams of the zoom lens according to the first embodiment of the present invention. Each figure in the figure is the wide-angle end state, and the zoom ratio is 3
FIG. 4 shows various aberration diagrams in a state of 0 × and a focusing state at infinity at a telephoto end state.
【図３】本発明の第２実施例のズームレンズの諸収差図
を示す。図中の各図はそれぞれ広角端状態、ズーム比３
０倍の状態、望遠端状態での無限遠合焦状態における諸
収差図を表す。FIG. 3 shows various aberration diagrams of the zoom lens according to a second embodiment of the present invention. Each figure in the figure is the wide-angle end state, and the zoom ratio is 3
FIG. 4 shows various aberration diagrams in a state of 0 × and a focusing state at infinity at a telephoto end state.
Ｉ：第１レンズ群、ＩＩ：第２レンズ群、III ：第３レ
ンズ群、IV：第４レンズ群、Ｖ：第５レンズ群、Ｓ：絞
り、Ｆ：フィルターに相当する平行平面ガラス、ＩＭ：
ＣＣＤ撮像素子I: first lens group, II: second lens group, III: third lens group, IV: fourth lens group, V: fifth lens group, S: stop, F: parallel plane glass corresponding to a filter, IM :
CCD image sensor
Claims (7)
ズ群、負の屈折力の第２レンズ群、正の屈折力の第３レ
ンズ群、負の屈折力の第４レンズ群、正の屈折力の第５
レンズ群からなり、 少なくとも第２レンズ群及び第４
レンズ群を光軸方向に移動させることにより、変倍並び
に変倍による像位置の変動補正及びフォーカシングを行
うズームレンズであって；上記第１レンズ群が、物体側
より順に配列された凹レンズと凸レンズの接合レンズ及
び凸レンズを有し、 上記第２レンズ群が、物体側より順に配列された凹レン
ズ及び凹レンズと凸レンズの接合レンズを有し、 上記第３レンズ群が、物体側より順に配列された凸レン
ズ及び凸レンズと凹レンズの接合レンズを有し、 上記第４レンズ群が、物体側より順に配列された凹レン
ズ及び凹レンズと凸レンズの接合レンズを有し、 上記第５レンズ群が、物体側より順に配列された凸レン
ズ及び凸レンズと凹レンズの接合レンズを有することを
特徴とするズームレンズ。A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, in order from the object side; Fifth of positive refractive power
And at least a second lens group and a fourth lens group.
What is claimed is: 1. A zoom lens that performs zooming and corrects image position fluctuation and focusing by zooming by moving a lens group in an optical axis direction; a concave lens and a convex lens in which the first lens group is arranged in order from the object side. The second lens group has a concave lens arranged in order from the object side and a cemented lens of the concave lens and the convex lens, and the third lens group has a convex lens arranged in order from the object side. And a cemented lens of a convex lens and a concave lens, wherein the fourth lens group has a concave lens and a cemented lens of a concave lens and a convex lens arranged in order from the object side, and the fifth lens group is arranged in order from the object side. A zoom lens comprising a convex lens and a cemented lens of a convex lens and a concave lens.
ち少なくとも１枚のアッベ数が８０以上であることを特
徴とする請求項１記載のズームレンズ。2. The zoom lens according to claim 1, wherein at least one of the two convex lenses in the first lens group has an Abbe number of 80 or more.
有効径において近軸球面の深さより浅くなる非球面形状
であることを特徴とする請求項１記載のズームレンズ。3. At least one surface of the first lens group,
2. The zoom lens according to claim 1, wherein the zoom lens has an aspherical shape whose effective diameter is smaller than the depth of the paraxial spherical surface.
有効径において近軸球面の深さより浅くなる非球面形状
であることを特徴とする請求項１記載のズームレンズ。4. The at least one surface of the third lens group,
2. The zoom lens according to claim 1, wherein the zoom lens has an aspherical shape whose effective diameter is smaller than the depth of the paraxial spherical surface.
有効径において近軸球面の深さより浅くなる非球面形状
であることを特徴とする請求項１記載のズームレンズ。5. At least one surface of the fifth lens group,
2. The zoom lens according to claim 1, wherein the zoom lens has an aspherical shape whose effective diameter is smaller than the depth of the paraxial spherical surface.
複合非球面であることを特徴とする請求項３、４又は５
記載のズームレンズ。6. The aspherical surface according to claim 3, wherein the aspherical surface is a composite aspherical surface formed of a thin layer of resin.
The zoom lens described.
４Ｗが ３＜β４Ｗ＜８ であることを特徴とする請求項１〜５いずれか１項記載
のズームレンズ。7. The lateral magnification β of the fourth lens group at the wide-angle end
The zoom lens according to any one of claims 1 to 5, wherein 4W satisfies 3 <β4W <8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23638497A JP3821330B2 (en) | 1997-09-02 | 1997-09-02 | Zoom lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23638497A JP3821330B2 (en) | 1997-09-02 | 1997-09-02 | Zoom lens |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005330692A Division JP2006099130A (en) | 2005-11-15 | 2005-11-15 | Zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1184239A true JPH1184239A (en) | 1999-03-26 |
| JP3821330B2 JP3821330B2 (en) | 2006-09-13 |
Family
ID=16999990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23638497A Expired - Fee Related JP3821330B2 (en) | 1997-09-02 | 1997-09-02 | Zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3821330B2 (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001033703A (en) * | 1999-07-16 | 2001-02-09 | Canon Inc | Rear focus type zoom lens |
| JP2001124992A (en) * | 1999-10-29 | 2001-05-11 | Canon Inc | Variable power optical system having vibration-proof function, and optical equipment equipped with the same |
| JP2006047348A (en) * | 2004-07-30 | 2006-02-16 | Canon Inc | Zoom lens and imaging device having the same |
| JP2008233164A (en) * | 2007-03-16 | 2008-10-02 | Olympus Imaging Corp | Imaging optical system, and electronic imaging device equipped therewith |
| US7446804B2 (en) | 2004-06-14 | 2008-11-04 | Sony Corporation | Camera system and zoom lens |
| WO2009125823A1 (en) * | 2008-04-07 | 2009-10-15 | Canon Kabushiki Kaisha | Zoom lens system and camera including the same |
| JP2010032700A (en) * | 2008-07-28 | 2010-02-12 | Nikon Corp | Zoom lens, optical device having the same and method for varying power |
| JP2010032702A (en) * | 2008-07-28 | 2010-02-12 | Nikon Corp | Zoom lens, optical device comprising the same, and power variation method |
| WO2010098407A1 (en) * | 2009-02-26 | 2010-09-02 | 株式会社タムロン | Zoom lens |
| JP2012098699A (en) * | 2010-10-07 | 2012-05-24 | Canon Inc | Zoom lens and imaging device with the same |
| US8736968B2 (en) | 2008-07-28 | 2014-05-27 | Nikon Corporation | Zoom lens, optical apparatus having same, and method of manufacturing zoom lens |
-
1997
- 1997-09-02 JP JP23638497A patent/JP3821330B2/en not_active Expired - Fee Related
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001033703A (en) * | 1999-07-16 | 2001-02-09 | Canon Inc | Rear focus type zoom lens |
| JP4510178B2 (en) * | 1999-07-16 | 2010-07-21 | キヤノン株式会社 | Zoom lens |
| JP2001124992A (en) * | 1999-10-29 | 2001-05-11 | Canon Inc | Variable power optical system having vibration-proof function, and optical equipment equipped with the same |
| US7446804B2 (en) | 2004-06-14 | 2008-11-04 | Sony Corporation | Camera system and zoom lens |
| KR101154474B1 (en) | 2004-06-14 | 2012-06-13 | 소니 주식회사 | Camera system and zoom lens |
| JP2006047348A (en) * | 2004-07-30 | 2006-02-16 | Canon Inc | Zoom lens and imaging device having the same |
| JP2008233164A (en) * | 2007-03-16 | 2008-10-02 | Olympus Imaging Corp | Imaging optical system, and electronic imaging device equipped therewith |
| CN102216825A (en) * | 2008-04-07 | 2011-10-12 | 佳能株式会社 | Zoom lens system and camera including the same |
| WO2009125823A1 (en) * | 2008-04-07 | 2009-10-15 | Canon Kabushiki Kaisha | Zoom lens system and camera including the same |
| US8130451B2 (en) | 2008-04-07 | 2012-03-06 | Canon Kabushiki Kaisha | Zoom lens system and camera including the same |
| JP2010032702A (en) * | 2008-07-28 | 2010-02-12 | Nikon Corp | Zoom lens, optical device comprising the same, and power variation method |
| JP2010032700A (en) * | 2008-07-28 | 2010-02-12 | Nikon Corp | Zoom lens, optical device having the same and method for varying power |
| US8736968B2 (en) | 2008-07-28 | 2014-05-27 | Nikon Corporation | Zoom lens, optical apparatus having same, and method of manufacturing zoom lens |
| CN102334059A (en) * | 2009-02-26 | 2012-01-25 | 株式会社腾龙 | Zoom lens |
| WO2010098407A1 (en) * | 2009-02-26 | 2010-09-02 | 株式会社タムロン | Zoom lens |
| US8614855B2 (en) | 2009-02-26 | 2013-12-24 | Tamron Co., Ltd. | Zoom lens |
| JP2012098699A (en) * | 2010-10-07 | 2012-05-24 | Canon Inc | Zoom lens and imaging device with the same |
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