JP2750775B2 - Compact zoom lens - Google Patents
Compact zoom lensInfo
- Publication number
- JP2750775B2 JP2750775B2 JP2115843A JP11584390A JP2750775B2 JP 2750775 B2 JP2750775 B2 JP 2750775B2 JP 2115843 A JP2115843 A JP 2115843A JP 11584390 A JP11584390 A JP 11584390A JP 2750775 B2 JP2750775 B2 JP 2750775B2
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- Japan
- Prior art keywords
- lens
- lens component
- positive
- zooming
- negative
- 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.)
- Expired - Lifetime
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Description
【発明の詳細な説明】 （産業上の利用分野） 本発明はズームレンズ、特にビデオカメラ等に好適な
コンパクトで明るく、高変倍比のズームレンズに関す
る。Description: BACKGROUND OF THE INVENTION The present invention relates to a zoom lens, particularly a compact, bright zoom lens having a high zoom ratio suitable for a video camera or the like.
（従来技術） 従来より、ビデオカメラ等に用いられる明るく、高変
倍比のズームレンズとして、特開昭62−24213号公報や
特開昭63−123009号公報に見られる様に、物体側から順
に正、負、正、正の各屈折力を有する４レンズ成分から
から構成され、変倍中第１レンズ成分と第３レンズ成分
とを固定のままとし、第２レンズ成分を一方向に移動さ
せて変倍を行ない、第４レンズ成分を前後に移動させる
ことによって変倍に伴う焦点位置の変動の補正を行うも
のが知られている。(Prior Art) Conventionally, as a bright and high zoom ratio zoom lens used for video cameras and the like, as seen in JP-A-62-24213 and JP-A-63-123009, Consists of four lens components having positive, negative, positive, and positive refractive powers in order. During zooming, the first lens component and the third lens component remain fixed, and the second lens component moves in one direction. There is known a zoom lens which performs zooming by moving the fourth lens component back and forth to correct a change in focal position caused by zooming.
（この発明が解決しようとする問題点） この方式のズームレンズは変倍に伴う像面位置の補正
のための第４レンズ成分の移動量が比較的大きく、レン
ズ系をコンパクトにしようとして全系を縮小してゆく
と、変倍に伴う収差の変動を十分に補正できなくなると
いう欠点があった。(Problems to be Solved by the Invention) In this type of zoom lens, the amount of movement of the fourth lens component for correcting the image plane position accompanying zooming is relatively large, and the entire system is designed to make the lens system compact. As a result, there is a disadvantage that fluctuations in aberration due to zooming cannot be sufficiently corrected.
本発明の目的は、ビデオカメラ等に好適で、変倍比６
倍程度、Ｆナンバー1.4〜2.0程度で、構成枚数が少な
く、全長、前玉径共にコンパクトでありながら上記の欠
点を含まないズームレンズを提供することにある。An object of the present invention is that it is suitable for a video camera or the like and has a variable power
It is an object of the present invention to provide a zoom lens which is approximately double, has an F number of about 1.4 to 2.0, has a small number of components, is compact in both the overall length and the diameter of the front lens, and does not include the above-mentioned disadvantages.
（問題を解決するための手段） 本発明のズームレンズは、基本的には、物体側から順
に、正の屈折力を有し、変倍時に固定のままである第１
レンズ成分、負の屈折力を有し、変倍の為に前後に移動
する第２レンズ成分、正の屈折力を有し変倍時に固定の
ままである第３レンズ成分、正の屈折力を有し、変倍に
伴う焦点位置の移動を補正する第４レンズ成分、変倍時
に固定のままである第５レンズ成分から構成され、第５
レンズ成分は、比較的弱い負の屈折力を有し、かつ非球
面を有することを特徴とする。(Means for Solving the Problem) The zoom lens according to the present invention basically has a first refractive power which, in order from the object side, has a positive refractive power and remains fixed during zooming.
A lens component, a second lens component having a negative refractive power and moving back and forth for zooming, a third lens component having a positive refractive power and remaining fixed during zooming, and a positive refractive power. A fourth lens component that corrects the movement of the focal position accompanying zooming, and a fifth lens component that remains fixed during zooming;
The lens component has a relatively weak negative refractive power and has an aspheric surface.
第２レンズ成分は広角側から望遠側に変倍するとき、
物体側から像側に移動する。When zooming from the wide-angle side to the telephoto side, the second lens component
Move from the object side to the image side.
第４レンズ成分に入射する光束はほぼアフォーカルに
なっていることがのぞましい。It is desirable that the light beam incident on the fourth lens component be substantially afocal.
本発明のズームレンズにおいて、フォーカシングは第
４レンズ成分によることが望ましいが、第１レンズ成分
あるいは第３レンズ成分によってもよい。In the zoom lens of the present invention, the focusing is desirably performed by the fourth lens component, but may be performed by the first lens component or the third lens component.
本発明のズームレンズは具体的には、第１レンズ成分
は少なくとも１枚の正レンズと少なくとも１枚の負レン
ズを含み、第２レンズ成分は少なくとも２枚の負レンズ
と少なくとも１枚の正レンズからなり、第３レンズ成分
は少なくとも１枚の正レンズからなり、第４レンズ成分
は少なくとも１枚の正レンズと少なくとも１枚の負レン
ズを含み、第５レンズ成分は少なくとも１枚の負レンズ
からなり、以下の条件を満足している。Specifically, in the zoom lens of the present invention, the first lens component includes at least one positive lens and at least one negative lens, and the second lens component includes at least two negative lenses and at least one positive lens. Wherein the third lens component comprises at least one positive lens, the fourth lens component comprises at least one positive lens and at least one negative lens, and the fifth lens component comprises at least one negative lens. And satisfies the following conditions.
0.25＜|f2|Fw/（fwZ）＜0.4 （１） 1.8＜f4/fw＜2.5 （２） 但し、fiは、第ｉレンズ成分の合成焦点距離、fwは全
系の広角端の焦点距離、Fwは広角端のＦナンバー、Ｚは
変倍比である。0.25 <| f 2 | F w / (f w Z) <0.4 (1) 1.8 <f 4 / f w <2.5 (2) where f i is the composite focal length of the i-th lens component and f w is the total focal length at the wide angle end of the system, F w represents the F number at the wide angle end, Z is the zoom ratio.
第４レンズ成分もしくは第５レンズ成分中に非球面を
導入することが望ましいが、そのうち少なくとも１面
は、その軸上曲率半径を曲率半径として持つ母球面に関
し母球面が凸の面に対しては、屈折面の中心から周辺に
向かって凸を向けた方向に変形量を有する非球面であ
り、母球面が凹の面に対しては、屈折率の中心から周辺
に向かって凹を向けた方向に変形量を有する非球面であ
って、物体側から順にｉ番目の非球面の有効半径位置で
の変型量をΔｉとしたとき、上記の方向を正の向きとし
て、 0.001＜FwΣΔi/fw＜0.02 （３）で あることが望ましい。但しΣは第４レンズ成分および第
５レンズ成分中のすべての非球面についての和である。It is desirable to introduce an aspheric surface into the fourth lens component or the fifth lens component. At least one of the surfaces has a convex spherical surface with respect to a convex spherical surface having a radius of curvature having an on-axis radius of curvature. , An aspheric surface having a deformation amount in a direction from the center of the refraction surface toward the periphery toward the periphery, and a direction in which the concave surface faces the periphery from the center of the refractive index to the surface where the base spherical surface is concave. a non-spherical surface having a deformation amount, when the variation amount of the effective radial position of the i-th aspherical surface from the object side to the delta i, the direction of the a positive direction, 0.001 <F w Sigma] [delta] i It is desirable that / f w <0.02 (3). Where Σ is the sum of all aspherical surfaces in the fourth and fifth lens components.
本発明のズームレンズは、更に具体的には、第１レン
ズ成分は、物体側から順に、負のメニスカスレンズと両
凸レンズからなる１組の正のダブレット、及び物体側に
凸を向けた正のメニスカスレンズとから構成され、第２
レンズ成分は、物体側から順に、像側に強い面を向けた
負レンズ、及び両凹レンズと正レンズからなる負のダブ
レットとから構成され、第３レンズ成分は、１枚の正レ
ンズもしくは、１枚の正レンズと負のメニスカスレンズ
からなる正のダブレットであり、第４レンズ成分は、少
なくとも、像側に強い面を向けた負レンズ、１枚の正レ
ンズを物体側から順に含み、第５レンズ成分は、比較的
弱い屈折力を有する負の単レンズからなり、以下の各条
件を満足することが望ましい。More specifically, in the zoom lens according to the present invention, the first lens component includes, in order from the object side, a set of a positive doublet including a negative meniscus lens and a biconvex lens, and a positive lens having a convex surface facing the object side. And a meniscus lens.
The lens component includes, in order from the object side, a negative lens having a strong surface facing the image side, and a negative doublet including a biconcave lens and a positive lens. The third lens component includes one positive lens or 1 lens. The fourth lens component includes at least a negative lens having a strong surface facing the image side and one positive lens in order from the object side. The fifth lens component includes a positive doublet including one positive lens and a negative meniscus lens. The lens component is composed of a negative single lens having relatively weak refractive power, and preferably satisfies the following conditions.
但し、 n2-:第２レンズ成分中の負レンズの屈折率の平均値 ν2-:第２レンズ成分中の負レンズのアッベ数の平均値 ν2+:第２レンズ成分中の正レンズのアッベ数 n3 :第３レンズ成分中の正レンズの屈折率 である。 Here, n 2- : average value of the refractive index of the negative lens in the second lens component ν 2- : average value of the Abbe number of the negative lens in the second lens component ν 2+ : positive lens in the second lens component Abbe number n 3 : is the refractive index of the positive lens in the third lens component.
第５レンズ成分は比較的弱い負の屈折力を有する上
に、他のレンズ成分と異なり、変倍に係わらず像面近傍
に置かれるため、温度、湿度等の環境変化による焦点位
置変動が少ないので、プラスチックレンズによって構成
することもできる。The fifth lens component has a relatively weak negative refracting power and, unlike other lens components, is located near the image plane regardless of zooming, so that the focal position fluctuation due to environmental changes such as temperature and humidity is small. Therefore, it can be constituted by a plastic lens.
（作用） 本発明のズームレンズの基本的な構成中、最も像側に
変倍時に固定のままの第５レンズ成分を置くことは、変
倍比６倍程度の高変倍ズームレンズをコンパクトに構成
する上できわめて効果的である。特に、第５レンズ成分
の屈折力を負とすることによって第４レンズ成分と第５
レンズ成分の合成系の望遠比を小さくできるので、第５
レンズ成分を置かない場合に比べてレンズ系の全長を短
くできる。また、ズーム系をコンパクトに構成しようと
すると、第２レンズ成分で発生する負の歪曲収差が広角
端で補正が困難となりがちであるが、負の屈折力の第５
レンズ成分を置くことによってこのような効果を一部打
ち消すことができるため、従来に比べてズーム系の全長
や前玉径を小さくできる。(Function) In the basic configuration of the zoom lens of the present invention, placing the fifth lens component which is fixed at the most image side at the time of zooming makes it possible to make a high zoom zoom lens having a zoom ratio of about 6 times compact. Very effective in constructing. In particular, by making the refractive power of the fifth lens component negative,
Since the telephoto ratio of the lens component combining system can be reduced,
The total length of the lens system can be shortened as compared with the case where no lens component is provided. Further, if it is attempted to make the zoom system compact, it tends to be difficult to correct negative distortion caused by the second lens component at the wide-angle end.
By arranging the lens component, such an effect can be partially canceled out, so that the total length of the zoom system and the diameter of the front lens can be reduced as compared with the related art.
第４レンズ成分に入射する光束をほぼアフォーカルに
することにより、変倍に伴う該成分の移動による収差変
化を少なくできる。また第４レンズ成分を物体側に繰り
出すことによってフォーカシングを行う場合、フォーカ
シングに伴う該成分の移動による収差変化を少なくでき
る。By making the light beam incident on the fourth lens component substantially afocal, aberration changes due to movement of the component due to zooming can be reduced. When focusing is performed by extending the fourth lens component toward the object side, a change in aberration due to movement of the component due to focusing can be reduced.
正の屈折力を有する第１レンズ成分及び第４レンズ成
分にそれぞれ少なくとも１枚の負レンズ、負の屈折力を
有する第２レンズ成分に少なくとも１枚の正レンズが含
まれているのは、変倍の全領域において軸上の色収差お
よび倍率の色収差の補正を十分に行う為である。正の屈
折力を有する第３レンズ成分には必ずしも負レンズが含
まれてはいないが、第４レンズ成分の色補正を過剰にバ
ランスさせることによって、これを省略しても全系の色
収差の補正をすることができる。The first lens component and the fourth lens component having a positive refractive power each include at least one negative lens, and the second lens component having a negative refractive power includes at least one positive lens. This is to sufficiently correct axial chromatic aberration and lateral chromatic aberration in the entire area of the magnification. Although the third lens component having a positive refractive power does not necessarily include a negative lens, the color correction of the fourth lens component is excessively balanced to correct the chromatic aberration of the entire system even if this is omitted. Can be.
第２レンズ成分に少なくとも２枚の負レンズが含まれ
ているのは、第２レンズ成分に屈折力を十分に持たせ、
変倍のための移動量を小さくし、前玉径をコンパクトに
するためである。The reason that the second lens component includes at least two negative lenses is that the second lens component has sufficient refractive power,
This is to reduce the moving amount for zooming and make the front lens diameter compact.
条件（１）は第２レンズ成分の焦点距離の適正値に関
し、上限を越えて焦点距離の絶対値が大きくなると収差
補正上は有利であるが、第１レンズ成分から第３レンズ
成分までの長さが増大し、コンパクトな系を得られな
い。下限を越えると前述の様な簡素な構成では、変倍に
伴う収差変動、特に歪曲収差、コマ収差の変動が補正不
可能となり、広角端での負の歪曲収差が過大となる。The condition (1) relates to an appropriate value of the focal length of the second lens component. If the absolute value of the focal length exceeds the upper limit and the absolute value of the focal length increases, it is advantageous for aberration correction, but the length from the first lens component to the third lens component is long. And a compact system cannot be obtained. If the lower limit is exceeded, with the simple configuration as described above, aberration fluctuations due to zooming, especially distortion and coma fluctuations, cannot be corrected, and negative distortion at the wide-angle end becomes excessive.
条件（２）は、第４レンズ成分の焦点距離に関し、下
限を越えると、第４レンズ成分の前方から撮像面までの
長さは短くなる傾向となり、全長の短縮化には有利であ
るが、第４レンズ成分全体の画角が大きくなり、画面隅
に入射する光束が第一レンズ成分を通過する高さが高く
なり、前玉系の増大につながる。上限を越え焦点距離が
長くなると、レンズ系の全長が長くなるだけでなく、所
定の口径を得るための絞りが大きくなる。Condition (2) relates to the focal length of the fourth lens component. If the lower limit of the fourth lens component is exceeded, the length from the front of the fourth lens component to the imaging surface tends to be short, which is advantageous for shortening the overall length. The angle of view of the entire fourth lens component increases, and the height at which the light beam entering the corner of the screen passes through the first lens component increases, leading to an increase in the front lens system. When the focal length exceeds the upper limit and the focal length increases, not only does the overall length of the lens system increase, but also the aperture for obtaining a predetermined aperture increases.
本発明のズームレンズの具体的な構成中、第１レンズ
成分が、物体側から順に、負のメニスカスレンズと両凸
レンズからなる１組の正のダブレット、及び物体側に凸
を向けた正のメニスカスレンズとから構成されているの
は、主として中間焦点距離から望遠端にわたる球面収差
およびコマ収差の変動を抑える為である。像側にある正
のメニスカスレンズは軸上光束に対してほぼアプラナチ
ックに構成されており、強い負の屈折力を有する第２レ
ンズ成分で発生する負の歪曲収差を補正する効果をも有
する。In a specific configuration of the zoom lens of the present invention, the first lens component includes, in order from the object side, a set of a positive doublet composed of a negative meniscus lens and a biconvex lens, and a positive meniscus convex toward the object side. The lens and the lens are mainly used to suppress fluctuations in spherical aberration and coma from the intermediate focal length to the telephoto end. The positive meniscus lens on the image side is substantially aplanatic with respect to the on-axis light beam, and has an effect of correcting negative distortion generated by the second lens component having strong negative refractive power.
第２レンズ成分は、物体側から順に、像側に強い面を
向けた負レンズ、及び両凹レンズと負レンズからなる負
のダブレットとから構成されているが、これによって主
点位置を物体側に寄せ厚肉化による全系の大型化を抑え
つつ、変倍に伴う収差変動、特に歪曲収差や非点収差の
変動を少なくできる。The second lens component is composed of, in order from the object side, a negative lens having a strong surface facing the image side, and a negative doublet composed of a biconcave lens and a negative lens. While suppressing an increase in the size of the entire system due to the increased thickness, it is possible to reduce aberration fluctuations caused by zooming, particularly fluctuations in distortion and astigmatism.
第３レンズ成分は、１枚の正レンズで構成されるが、
これを正レンズと負のメニスカスレンズからなる正のダ
ブレットとすることにより、変倍全域での軸上の色収差
の補正が容易になる。また口径比の大きい場合には、面
数が増えたことによる自由度を主として球面収差の補正
に充てることが可能となる。第３レンズ成分が１枚の正
レンズで構成される場合、このレンズの少なくとも１面
に非球面を用いることが球面収差の補正上有利である。The third lens component is composed of one positive lens,
By making this a positive doublet composed of a positive lens and a negative meniscus lens, it becomes easy to correct axial chromatic aberration over the entire zoom range. When the aperture ratio is large, the degree of freedom due to the increased number of surfaces can be mainly used for correcting spherical aberration. When the third lens component is composed of one positive lens, using an aspheric surface for at least one surface of this lens is advantageous in correcting spherical aberration.
第４レンズ成分は、少なくとも、像側に強い面を向け
た負レンズ、少なくとも１枚の正レンズを物体側から順
に含んでいるが、負レンズの像側の強い凹面は第２レン
ズ成分で発生する負の歪曲収差を補正する働きがある。The fourth lens component includes at least a negative lens having a strong surface facing the image side and at least one positive lens in order from the object side. The strong concave surface on the image side of the negative lens is generated by the second lens component. It has the function of correcting negative distortion.
第４レンズ成分もしくは第５レンズ成分中の非球面の
うち少なくとも１面を、その軸上曲率半径を曲率半径と
して持つ母球面に関し、母球面が凸の面に対しては屈折
面の中心から周辺に向かって凸を向けた方向に変型量を
有する非球面であり、母球面が凹の面に対しては、屈折
面の中心から周辺に向かって凹を向けた方向に変型量を
有する非球面とすることは、ズーム系をコンパクトに構
成しようとする際、強い負の屈折力を有する第２レンズ
成分において発生する負の歪曲収差を十分に補正するう
えで効果的である。At least one of the aspheric surfaces in the fourth lens component or the fifth lens component is related to a base sphere having an on-axis radius of curvature as a radius of curvature. Aspheric surface having a deformation amount in the direction of the convex toward the surface, and for a surface whose concave spherical surface is concave, the aspheric surface having a deformation amount in the direction of the concave surface from the center of the refraction surface toward the periphery. This is effective for sufficiently correcting the negative distortion generated in the second lens component having a strong negative refractive power when the zoom system is to be made compact.
条件（３）は第４レンズ成分および第５レンズ成分中
のすべての非球面についての各レンズ面の有効径におけ
る非球面変型量の和に関し、下限を超えると系全体をコ
ンパクトに構成しようとすると、広角端での負の歪曲収
差を補正することが困難となり、上限を超えると歪曲収
差の補正には有効であるが、変倍全域に渡って像面湾曲
がオーバーとなる。Condition (3) relates to the sum of the aspherical deformation amounts of the effective diameters of the respective lens surfaces for all the aspherical surfaces in the fourth lens component and the fifth lens component. However, it becomes difficult to correct negative distortion at the wide-angle end. If the upper limit is exceeded, it is effective in correcting distortion, but the curvature of field becomes excessive over the entire zoom range.
条件（４）は第２レンズ成分を構成する負レンズの屈
折率に関し、この条件をはずれると上述の構成の下では
広角端の負の歪曲収差が補正困難となる。Condition (4) relates to the refractive index of the negative lens constituting the second lens component. If this condition is not met, it becomes difficult to correct negative distortion at the wide-angle end under the above-described configuration.
条件（５）は第２レンズ成分を構成する負レンズと正
レンズのアッベ数の差に関し、条件をはずれると変倍時
の色収差の変動、特に倍率の色収差の変動が大きくな
り、広角端では像高の小さい方向に、望遠端では像高の
大きい方向に短波長の結像点がシフトしすぎる傾向とな
る。The condition (5) relates to the difference in Abbe number between the negative lens and the positive lens constituting the second lens component. If the condition is not satisfied, the fluctuation of chromatic aberration during zooming, particularly the fluctuation of chromatic aberration of magnification increases, The short-wavelength imaging point tends to shift too much in the direction of smaller height and in the direction of larger image height at the telephoto end.
条件（６）は第３レンズ成分を構成する正レンズの屈
折率に関し、条件をはずれると、変倍全域にわたって球
面収差の補正が困難となる。The condition (6) relates to the refractive index of the positive lens constituting the third lens component. If the condition is not satisfied, it becomes difficult to correct spherical aberration over the entire zoom range.
（実施例） 以下、本発明の実施例を挙げる。(Examples) Examples of the present invention will be described below.
実施例中にはプラスチックレンズが用いられているも
のがあり、これらのレンズには＊印が付してある。プラ
スチックレンズには一般に、環境温度の変化による屈折
率の変化があるが、本発明の実施例では、各プラスチッ
クレンズの屈折力を最適に組合せることによって、屈折
率の変化に伴う焦点位置の変動を抑えている。プラスチ
ックレンズ材料としては、PC（ポリカーボネート）およ
び、PMMA（ポリメチルメタクリレート）等が用いられ
る。これらの材料は温度に対して略線形に屈折力が変化
する。以下にデータを示す。In some embodiments, plastic lenses are used, and these lenses are marked with *. In general, plastic lenses have a change in refractive index due to a change in environmental temperature. However, in the embodiment of the present invention, a change in focal position due to a change in refractive index is achieved by optimally combining the refractive power of each plastic lens. Is suppressed. As a plastic lens material, PC (polycarbonate), PMMA (polymethyl methacrylate), or the like is used. These materials change their refractive power approximately linearly with temperature. The data is shown below.
PC PMMA 基準屈折率（20℃） 1.583 1.492 屈折率 （50℃） 1.5788 1.4884 実施例における非球面係数の定義は次の通りである。 PC PMMA Reference refractive index (20 ° C) 1.583 1.492 Refractive index (50 ° C) 1.5788 1.4884 The definition of the aspherical coefficient in the examples is as follows.
但し、 x:非球面の頂点を原点とし、光軸に沿って物体側から
像側に向かう座標 h:非球面の頂点を原点とし、光軸に垂直な座標 C:非球面の近軸曲率 を表す。 Where x is the vertex of the aspheric surface as the origin, coordinates from the object side to the image side along the optical axis h: coordinates of the vertex of the aspheric surface as the origin, and coordinates perpendicular to the optical axis C: paraxial curvature of the aspheric surface Represent.
なお、表中の各記号は、Ｒは各屈折率の曲率半径、Ｄ
は曲率面間隔、Ｎはレンズ材料の屈折率、νｄは同じく
アッベ数、ｆはレンズ全系の焦点距離、２ωは画角、Ｆ
はＦナンバー、fBはバックフォーカスを示す。In addition, each symbol in the table, R is the radius of curvature of each refractive index, D
Is the distance between the curvature planes, N is the refractive index of the lens material, v d is the Abbe number, f is the focal length of the entire lens system, 2ω is the angle of view, F
F-number, f B denotes the back focus.
（発明の効果） 本発明のズームレンズは、各実施例及びその収差図に
見るように、変倍比が６程度、Ｆナンバーが1.4〜2.0程
度と明るく高変倍比を有するにもかかわらず、コンパク
トで、諸収差がよく補正され、しかも変倍に伴う諸収差
の変動が極めて小さく、ビデオカメラ等に好適なものと
なっている。 (Effects of the Invention) As can be seen from the examples and the aberration diagrams thereof, the zoom lens according to the present invention has a bright and high zoom ratio with a zoom ratio of about 6 and an F-number of about 1.4 to 2.0. It is compact, well corrected for various aberrations, and has extremely small fluctuations in various aberrations due to zooming, making it suitable for video cameras and the like.
第１図は本発明のズームレンズの基本構成を示す光学配
置図、第２、３、４、５図はそれぞれ本発明のズームレ
ンズの第１、２、３、４実施例の断面図、第６、７、
８、９図はそれぞれ上記第１、２、３、４実施例の収差
曲線図である。FIG. 1 is an optical arrangement diagram showing a basic configuration of a zoom lens according to the present invention. FIGS. 2, 3, 4, and 5 are sectional views of first, second, third and fourth embodiments of the zoom lens according to the present invention, respectively. 6, 7,
8 and 9 are aberration curve diagrams of the first, second, third and fourth embodiments, respectively.
Claims (1)
に際しては移動しない第１レンズ成分、負の屈折力を有
し，変倍の為に前後に移動する第２レンズ成分、正の屈
折力を有し，変倍に際しては移動しない第３レンズ成
分、正の屈折力を有し，変倍に伴う焦点位置の移動を補
正する第４レンズ成分、比較的弱い負の屈折力を有し，
かつ非球面を有する，変倍時に際しては移動しない第５
レンズ成分を有し、以下の条件を満足することを特徴と
するズームレンズ。 0.25＜|f2|Fw/（fwZ）＜0.4 1.8＜f4/fw＜2.5 0.001＜FwΣΔi/fw＜0.02 ただし、 fi ：第ｉレンズ成分の合成焦点距離 fw ：全系の広角端の焦点距離 Fw ：広角端のＦナンバー Z ：変倍比 Δi :物体側から順にｉ番目の非球面の有効半径位置で
の軸上曲率半径を曲率半径としてもつ母球面からの変形
量で、母球面が凸の面に対しては、屈折面の中心から周
辺に向かって凸を向けた方向に変形量を有する場合を
正、母球面が凹の面に対しては、屈折面の中心から周辺
に向かって凹を向けた方向に変形量を有する場合を正と
する ΣΔi:第４レンズ成分および第５レンズ成分中の非球面
の変形量Δｉの総和1. A first lens component having a positive refractive power and not moving at the time of zooming, and a second lens component having a negative refractive power and moving back and forth for zooming in order from the object side. A third lens component having a positive refractive power and not moving at the time of zooming; a fourth lens component having a positive refractive power and correcting the movement of the focal position due to the zooming; relatively weak negative refraction; Have power,
5th which has an aspheric surface and does not move during zooming
A zoom lens having a lens component and satisfying the following conditions. 0.25 <| f 2 | F w / (f w Z) <0.4 1.8 <f 4 / f w <2.5 0.001 <F w ΣΔ i / f w <0.02 where f i is the composite focal length f of the i-th lens component w : focal length at the wide-angle end of the entire system F w : F-number at the wide-angle end Z: zoom ratio Δ i : has an on-axis radius of curvature at the effective radius position of the i-th aspheric surface in order from the object side as a radius of curvature. The amount of deformation from the base sphere, with respect to a convex surface of the base sphere, positive if the amount of deformation is in the direction of convex from the center of the refraction surface toward the periphery, positive, if the base sphere is concave Te is a ΣΔ a positive i if having a deformation amount in a direction toward the concave toward the periphery from the center of the refracting surface: the sum of the deformation amount of the aspherical surface of the fourth lens component and the fifth lens in component delta i
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2115843A JP2750775B2 (en) | 1990-05-07 | 1990-05-07 | Compact zoom lens |
| US07/689,559 US5202992A (en) | 1990-04-27 | 1991-04-23 | Zoom lens apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2115843A JP2750775B2 (en) | 1990-05-07 | 1990-05-07 | Compact zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0413109A JPH0413109A (en) | 1992-01-17 |
| JP2750775B2 true JP2750775B2 (en) | 1998-05-13 |
Family
ID=14672505
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2115843A Expired - Lifetime JP2750775B2 (en) | 1990-04-27 | 1990-05-07 | Compact zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2750775B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7327953B2 (en) | 2003-09-08 | 2008-02-05 | Sony Corporation | Zoom lens and imaging device |
| CN100578283C (en) * | 2006-12-06 | 2010-01-06 | 索尼株式会社 | Zoom lens and image pick-up apparatus |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05264902A (en) * | 1992-03-19 | 1993-10-15 | Konica Corp | Zoom lens |
| JPH09269452A (en) * | 1996-03-29 | 1997-10-14 | Canon Inc | Rear focus system zoom lens |
| JPH0968653A (en) * | 1995-08-30 | 1997-03-11 | Olympus Optical Co Ltd | Zoom lens |
| JP3593400B2 (en) * | 1995-12-12 | 2004-11-24 | 日本電産コパル株式会社 | Rear focus zoom lens |
| JP2007322804A (en) | 2006-06-01 | 2007-12-13 | Sony Corp | Zoom lens and imaging apparatus |
| CN110119023A (en) * | 2019-06-16 | 2019-08-13 | 福建福光股份有限公司 | 6000000 high-resolution zoom camera lenses |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS647013A (en) * | 1987-06-30 | 1989-01-11 | Ricoh Kk | Small-sized high variable power zoom lens |
| JP2526923B2 (en) * | 1987-09-09 | 1996-08-21 | 株式会社ニコン | Zoom lenses |
-
1990
- 1990-05-07 JP JP2115843A patent/JP2750775B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7327953B2 (en) | 2003-09-08 | 2008-02-05 | Sony Corporation | Zoom lens and imaging device |
| CN100578283C (en) * | 2006-12-06 | 2010-01-06 | 索尼株式会社 | Zoom lens and image pick-up apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0413109A (en) | 1992-01-17 |
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