JPS61133916A - Telephone zoom lens - Google Patents

Telephone zoom lens

Info

Publication number
JPS61133916A
JPS61133916A JP59255910A JP25591084A JPS61133916A JP S61133916 A JPS61133916 A JP S61133916A JP 59255910 A JP59255910 A JP 59255910A JP 25591084 A JP25591084 A JP 25591084A JP S61133916 A JPS61133916 A JP S61133916A
Authority
JP
Japan
Prior art keywords
lens
lens group
refractive power
group
positive refractive
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.)
Granted
Application number
JP59255910A
Other languages
Japanese (ja)
Other versions
JPH0629908B2 (en
Inventor
Yoshinobu Kudo
工藤　▲吉▼信
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Minolta Co Ltd
Original Assignee
Minolta Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Minolta Co Ltd filed Critical Minolta Co Ltd
Priority to JP59255910A priority Critical patent/JPH0629908B2/en
Publication of JPS61133916A publication Critical patent/JPS61133916A/en
Publication of JPH0629908B2 publication Critical patent/JPH0629908B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/144—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only
    • G02B15/1441—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive
    • G02B15/144113—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive arranged +-++

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

PURPOSE:To obtain a titled lens which is compact, whose zoom ratio is a high variable power of 3.5-4, and also which can correct an aberration satisfactorily by combining the lenses of four groups for satisfying condition of a specified expression. CONSTITUTION:This zoom lens consists of the first lens group I having a positive refractive power, the second lens group II having a negative refractive power, and the fourth lens group IV having a positive refractive power, in order from an object side. In this state, at the time of focusing, the first lens group I is moved on the optical axis, and at the time of zooming, the first lens group I, the second lens group II and the third lens group III are moved on the optical axis, and also the fourth lens group IV is constituted of a front group IVa constituted of one piece or two pieces of single lenses having a positive refractive power and having a positive refractive power as a whole, and a rear group IVb consisting of a constitution of three pieces of a single lens having a positive refractive power, a single lens having a negative refractive power, and a single lens having a positive refractive power, in order from the object side, and having a negative refractive power as a whole, and also constituted so as to satisfy a condition of an expression.

Description

【発明の詳細な説明】 本発明は、構成が簡単かつコン／ｆりｌ・で高変倍率を
有する望遠ズームレンズに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telephoto zoom lens that is simple in construction, has a high zoom ratio, and has a high zoom ratio.

物体側から順に、正の屈折力を有する第１レンズ群、負
の屈折力を有する第２レンズ群、正の屈折力を有する第
３レンズ群及び正の屈折力を有する第４レンズ群からな
り、フォーカシングに際し第１レンズ群か光軸上を移動
せしめられ、ズーミングに際し第２，３レンズ群か移動
せしめられる望遠ズームレンズは特開昭５８−２０２４
２０号公報において知られている。しかしながら、この
ようなレンズにおいては、ズーム比をより太き（する為
には第１レンズ群を前方に大きく移動させる必要かある
ので、レンズ全長か大きくなり、かつ、構成枚数も多く
なる。Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power. , a telephoto zoom lens in which the first lens group is moved on the optical axis during focusing and the second and third lens groups are moved during zooming is disclosed in Japanese Patent Application Laid-Open No. 58-2024.
It is known from Publication No. 20. However, in such a lens, in order to increase the zoom ratio, it is necessary to move the first lens group forward by a large distance, so the total length of the lens becomes large and the number of lenses in the lens structure increases.

そこで、ズーム比を太き（しつつレンズ全長をコンパク
トにし構成を簡単にする為の第１の方法は、最も像側に
配される第４レンズ群を望遠比の小さい望遠タイプで構
成することである。すなわち、第４レンス群を前・後群
の２群に分割し、前群を正、後群を負とすることである
。しかし、望遠比を小さくする為には、この前・後群と
もそれぞれ強い屈折力を必要とするので収差補正か非常
に困難になる。そこで、従来は、通常、前・後群ともそ
れぞれ正レンズと負レンズとの組合せからなる２〜３枚
から構成されている。第２の方法は、ズーミングに際し
移動せしめられる第２レンズ群の負の合成屈折力を強く
して移動量を減少せしめることであるけれども、そうす
ると、他のレンズ群をも強い屈折力にせねばならず、収
差補正上の困難さが増してくる。第３の方法は、各レン
ズ群のともにコンパクトで構成の簡単な望遠ズームレン
ズを良好な収差補正のらとに提供することを目的とする
。Therefore, the first way to increase the zoom ratio (while also making the overall length of the lens compact and simplifying the configuration) is to configure the fourth lens group, which is located closest to the image side, as a telephoto type with a small telephoto ratio. In other words, the fourth lens group is divided into two groups, the front and rear groups, and the front group is positive and the rear group is negative.However, in order to reduce the telephoto ratio, it is necessary to Since each of the rear groups requires strong refractive power, it is extremely difficult to correct aberrations.Therefore, conventionally, each of the front and rear groups was composed of two or three elements each consisting of a combination of a positive lens and a negative lens. The second method is to strengthen the negative composite refractive power of the second lens group that is moved during zooming and reduce the amount of movement. The purpose of the third method is to provide a telephoto zoom lens in which each lens group is compact and simple in construction, with good aberration correction. shall be.

上記目的達成の為に、本発明に係る望遠ズームレンズは
、物体側より順に、正の屈折力を有する第１レンズ群（
Ｉ）と、負の屈折力を有する第２レンズ群（ＩＯと、正
の屈折力を有する第３レンズ群（２）と、正の屈折力を
有する第４レンズ群に）とからなり、フォーカシングに
際し第１レンズ群（Ｉ）か光軸上を移動せしめられると
ともに、ズーミングに際し第１レンズ群（Ｉ）、第２レ
ンズ群（ＩＩ）及び第３レンズ群＠）が光軸上を移動せ
しめられ、更に、第４レンズ群■は、正の屈折力を有す
る単レンズ１枚もしくは２枚からなり全体として正の屈
折力を有する前群ＣｒＶａ）と、物体側から順に正の屈
折力を有する単レンズ、負の屈折力を有する単レンズ、
及び正の屈折力を有する単レンズの３枚構成からなり全
体として負の屈折力を有する後群（ＩＶｂ　’）とから
なり、かつ以下の条件を満足することを特徴とするもの
である。In order to achieve the above object, the telephoto zoom lens according to the present invention has a first lens group having positive refractive power (
I) and a second lens group (IO, a third lens group (2) having a positive refractive power, and a fourth lens group having a positive refractive power) having a negative refractive power, and focusing During zooming, the first lens group (I) is moved on the optical axis, and during zooming, the first lens group (I), the second lens group (II), and the third lens group @) are moved on the optical axis. Furthermore, the fourth lens group (2) is composed of one or two single lenses having positive refractive power, and a front group CrVa) having positive refractive power as a whole, and a single lens group having positive refractive power in order from the object side. lens, single lens with negative refractive power,
and a rear group (IVb') having a negative refractive power as a whole, and is characterized by satisfying the following conditions.

（１ン　０．０５　＜　Δｘ／ｆｉ（１，０（２）　　
０．４＜［ａ／Ｅ４＜１．３但し、ここで、Δｘはズー
ミングの際の第１レンズ！　（１）の移動量、［１は第
１２２１群（Ｉ）の焦点距離、ｆａは第４レンズ群の前
群（ＩＶａ　）の焦点距離、ｆ４は第４レンズ群（５）
の焦点距離である。(1n 0.05 < Δx/fi(1,0(2)
0.4<[a/E4<1.3 However, here, Δx is the first lens during zooming! (1) amount of movement, [1 is the focal length of the 1221st group (I), fa is the focal length of the front group (IVa) of the 4th lens group, f4 is the focal length of the 4th lens group (5)
is the focal length of

以下各条件について説明する。まず、本発明にの小さい
望遠タイプで構成する。すなわち１．第４レンズ群■を
正の屈折力を有する前群（ＩＶａ）と負の屈折力を有す
る後群（ＩＶｂ）によって構成する。Each condition will be explained below. First, it consists of a small telephoto type according to the present invention. That is, 1. The fourth lens group (2) is composed of a front group (IVa) having a positive refractive power and a rear group (IVb) having a negative refractive power.

更に構成を簡単かつコンパクトにするとともに第４レン
ズ群■の望遠比を小さくする為に、第４レンズ群の前群
（ＩＶａ　）を正レンズのみ１枚もしくは２枚で構成す
る。従来のレンズではこの前群は正レンズと負レンズと
の組合せで構成されているものかほとんどであったのに
対し、本発明では正レンズのみからなるので収差補正は
困難になりがちである。そこで、第４レンズ群の後群（
ＩＶｂ　）を、正、負、正の３枚の単レンズで構成して
良好な収差補正を維持する。Furthermore, in order to simplify and compact the structure and to reduce the telephoto ratio of the fourth lens group (2), the front group (IVa) of the fourth lens group is composed of only one or two positive lenses. In most conventional lenses, this front group is made up of a combination of a positive lens and a negative lens, whereas in the present invention, it is made up of only a positive lens, so it tends to be difficult to correct aberrations. Therefore, the rear group of the fourth lens group (
IVb) is composed of three positive, negative, and positive single lenses to maintain good aberration correction.

条件（１）は、上記構成をこおいて、３．５〜４のズー
ム比を達成する為のズーミング時の第１２２１群（Ｉ）
の移動量を、その焦点距離に基づいて規定するものであ
る。条件（１）の下限を越えると所望のズーム比を得る
ことが困難となり、一方、条件（１）の上限を越えると
、第１２２１群（Ｉ）の移動量か大きくなりすぎてコン
パクト性か維持できない。Condition (1) is the 1221st group (I) during zooming to achieve a zoom ratio of 3.5 to 4, taking into account the above configuration.
The amount of movement of the lens is defined based on its focal length. If the lower limit of condition (1) is exceeded, it will be difficult to obtain the desired zoom ratio, while if the upper limit of condition (1) is exceeded, the amount of movement of the 1221st group (I) will become too large, making it difficult to maintain compactness. Can not.

条件（２）は、第４レンズ群の前群（ＩＶａ　）の屈折
力を規定するものである。条件（２）の下限を越えると
、前群（ｌＶａ　）の屈折力は強（なり、レンズ系はコ
ンパクトになるが、収差のバランスか（ずれ、諸収差の
良好な補正か困難になってくる。また条件（２）の上限
を越えると前群（ＩＶａ　）の屈折力か翁まり、収差補
正は有利になるものの、レンズ系自体か大型化してしま
う。Condition (2) defines the refractive power of the front group (IVa) of the fourth lens group. If the lower limit of condition (2) is exceeded, the refractive power of the front group (lVa) becomes strong (and the lens system becomes compact), but it becomes difficult to balance aberrations (misalignment and properly correct various aberrations). Moreover, if the upper limit of condition (2) is exceeded, the refractive power of the front group (IVa) decreases, and although aberration correction becomes advantageous, the lens system itself becomes larger.

上記条件（１）　（２）の上に、更に収差補正の為、コ
ンパクト性の為及び高変倍率化の為に好ましい条件を以
下に示す。In addition to the above conditions (1) and (2), preferred conditions for aberration correction, compactness, and high magnification are shown below.

（３）　　０．１５　＜　ｌ　ｆａ　／　ｔｂ　ｌ　＜
　０．７（４）　　０．７　＜　ｆ１／　ｆ４＜　１．
４（５）　　０．１５＜ｄｅ／ｆ４＜０．４但し、ここ
で、Ｅｂは第４レンズ群の後群（ＩＶｂ）の焦点距離、
ｄｅは第４レンズ群の前群（ＩＶａ　）と後群（ＩＶｂ
）との軸上空気間隔である。(3) 0.15 < l fa / tb l <
0.7 (4) 0.7 < f1/ f4 < 1.
4(5) 0.15<de/f4<0.4 However, here, Eb is the focal length of the rear group (IVb) of the fourth lens group,
de is the front group (IVa) and rear group (IVb) of the fourth lens group.
) is the on-axis air spacing.

本発明では、高変倍率を良好な収差補正のもとに実現す
るので、第４レンズ群の前群（ＩＶａ　”）と後群（Ｉ
Ｖｂ）との屈折力のバランスを保つことか必要である。In the present invention, since a high magnification is achieved with good aberration correction, the front group (IVa'') and rear group (IVa'') of the fourth lens group
It is necessary to maintain a balance of refractive power with Vb).

このバランスを規定するのか条件（３）であり、条件（
３）の下限を越えるとレンズ系のコンパクト性には有利
であるか、諸収差の良好な補正が困難１こなる。一方、
条件（３）の上限を越えると、レンズ系か大型化してし
まい、本発明の趣旨に反する。Condition (3) and condition (
If the lower limit of 3) is exceeded, it may be advantageous for the compactness of the lens system, or it may become difficult to properly correct various aberrations. on the other hand,
If the upper limit of condition (3) is exceeded, the lens system will become larger, which is contrary to the purpose of the present invention.

条件（５）は第４レンズ群の前群（］Ｖａ　）と後群（
ＩＶｂ）との軸上空気間隔を規定するものであり、条件
（３）と相俟って、高変倍率スームをコン１＜クトに実
現するために必要な条件である。条件（５）の上限を越
えると、レンズ系は大型化するのみならず、球面収差、
コマ収差の良好な補正か困難になってくる。一方、条件
（５）の下限を越えると、レンズ系はコンパクトにはな
るが、球面収差、非点収差の良好な補正か困難になる。Condition (5) is the front group ( ] Va ) and rear group ( ) of the fourth lens group.
IVb), and together with condition (3), this is a necessary condition to achieve a high zoom ratio compactly. If the upper limit of condition (5) is exceeded, the lens system will not only become larger, but will also suffer from spherical aberration,
It becomes difficult to properly correct coma aberration. On the other hand, if the lower limit of condition (5) is exceeded, the lens system becomes compact, but it becomes difficult to properly correct spherical aberration and astigmatism.

さらに、本発明においてコンパ・クト性の為ｉζは、従
来から行なわれているように、第２レンズ群（ＩＩ）の
移動量を小さくするという方法をとる。このためには、
第２レンズ群（ＩＩ）の負の屈折力を強くするのである
か、それに伴ない、第１．第３．第４レンズ群（Ｉ）（
２）■とも、強い屈折力が必要となる。しかし、良好な
収差補正を得るためには、各群に与えられる屈折力のバ
ランスか重要となる。これを規定するのが条件（４）で
あり、第１２２１群（【）を第と ４レンズｎｍｌで焦点距離の比によって、各群の屈折力
のバランスを規定している。条件（４）の下限を越える
と、変倍系のパワーが強くなりすぎて高次の球面収差、
コマ収差、色収差の補正がスーム全域にわたって困難に
なり、また、上限を越えると収差補正上は有利になるも
のの、レンズ全系のコンパクト性が失なわれ、本発明の
趣旨に反することになる。Furthermore, in order to achieve compactness in the present invention, iζ is determined by reducing the amount of movement of the second lens group (II), as has been conventionally done. For this purpose,
Is it because the negative refractive power of the second lens group (II) is strengthened? Third. 4th lens group (I) (
2) Both require strong refractive power. However, in order to obtain good aberration correction, it is important to balance the refractive power given to each group. Condition (4) defines this, and the balance of refractive power of each group is defined by the ratio of the focal lengths of the 1221st group ([) and the 4th lens nml. If the lower limit of condition (4) is exceeded, the power of the variable power system becomes too strong, resulting in higher-order spherical aberrations,
It becomes difficult to correct comatic aberration and chromatic aberration over the entire zoom range, and if the upper limit is exceeded, although it is advantageous in terms of aberration correction, the compactness of the entire lens system is lost, which goes against the purpose of the present invention.

なお本発明においては、上述の条件に加えさらに以下の
条件を満足するのが望ましい。すなわち、第４レンズ群
の前群（ＩＶａ　）を正の屈折力を有する１枚の単レン
ズで構成し、かつ、そのレンズのｄ線に対する屈折率を
Ｎａとするとき、 （６）　　１．４９　＜　Ｎａ　＜　１．８を満足する
ことか望ましい。もしくは第４レンズ群の前群（ｌＶａ
）を各々正の屈折力を有する２枚の単レンズで構成し、
かつ、そのレンズのｄ線に対する屈折率をそれぞれＮａ
ｘ、　Ｎａｚとするとき、を満足することか望ましい。In the present invention, it is desirable that the following conditions be satisfied in addition to the above-mentioned conditions. That is, when the front group (IVa) of the fourth lens group is composed of one single lens having positive refractive power, and the refractive index of the lens for the d-line is Na, (6) 1.49 It is desirable that <Na < 1.8 be satisfied. Or the front group of the fourth lens group (lVa
) is composed of two single lenses each having positive refractive power,
And the refractive index of the lens for the d-line is Na
When x and Naz, it is desirable to satisfy the following.

条件（６）及び（７）は、各々第４レンズ群の前群（Ｉ
Ｖａ　）か１枚の単レンズで構成される場合と２枚の単
レンズで構成される場合の使用する硝子の屈折率の範囲
を規定するものである。すなわち、レンズ系をコンパク
トにしようとするペッツバール和か小さくなりすぎて、
像面性の悪化をまねく。これを良好に保つため（とは、
第４レンズ群の前群（ＩＶａ　）の正レンズを比較的低
い屈折率の硝種で構成することが必要である３条件（６
）及び（７）の範囲内で構成することによって、球面収
差と像面湾曲の補正が良好になされ、これを越えるとズ
ーム全域にわたる良好な収差補正が困難になる。Conditions (6) and (7) are satisfied for the front group (I) of the fourth lens group, respectively.
Va ) defines the range of the refractive index of the glass to be used when it is constructed from one single lens and when it is constructed from two single lenses. In other words, the Petzval sum that attempts to make the lens system compact becomes too small.
This leads to deterioration of image quality. In order to keep this in good condition (
Three conditions (6
) and (7), spherical aberration and curvature of field can be well corrected; if this is exceeded, it becomes difficult to correct aberrations well over the entire zoom range.

更に、ズーミングに際し、第４レンズｎ（５）をも移動
させると、高変倍率を得るのに有利であり、特に、第４
レンズｎ（Ｉ）と一体的に移動させると、鏡胴の構成を
簡単にすることができる。Furthermore, when zooming, if the fourth lens n(5) is also moved, it is advantageous to obtain a high zoom ratio.
If it is moved integrally with lens n(I), the structure of the lens barrel can be simplified.

以上のように、本発明では主レンズ系となる第４レンズ
群（５）を正の単レンズ１枚乃至２枚の前群上、負、正
の３枚の後群の、４枚乃至５枚のレンズで構成すること
により、ズーム全域に亘って良好な収差性能を有するコ
ンパクトなズームレンズ系を実現したものである。As described above, in the present invention, the fourth lens group (5), which is the main lens system, is composed of four to five positive single lenses, the front group consisting of one to two positive single lenses, and the rear group consisting of three negative and positive single lenses. By constructing the lens with a single lens, a compact zoom lens system with good aberration performance over the entire zoom range is realized.

次に、本発明に基つ（実施例を示す。ｒｉ（ｉ＝１、２
．３・・・）は物体側から順に数えたレンズ面の曲率半
径、ｄｉは物体側から順に数えた軸上面間隔、Ｎｉは物
体側から順に数えたレンズのｄ線に対する屈折率、νｉ
はそのアツベ数である。Next, based on the present invention (Example will be shown. ri (i=1, 2
．． 3...) is the radius of curvature of the lens surface counted from the object side, di is the axial surface spacing counted from the object side, Ni is the refractive index of the lens for the d-line counted from the object side, νi
is its Atsube number.

実施例Ｉ Ｅ＝２９３．０〜１５０．０〜７６．５　　ＦＮＯ＝　
４．５〜５．８曲率半径　　軸上面間隔　　　屈折率（
Ｎｄ）　　分散（νｄ）Δｘ／ｆｔ＝０，２７　　　　
　　　ｆａ／ｆ４＝０．７６１　ｆａ／ｆｂｌ＝Ｑ、５
，５．　　　　　　ｆｔ／ｆ４＝０．９０ｄ　ｅ／　ｆ
　４　＝０．２８ 実施例２　　　ｆ＝２９３．０〜１５００〜７６．５　
　Ｆ醜＝４．５〜５．８曲率半径　軸上面間隔　　　屈
曲率（Ｎｄ）　　分散（νｄ）Δｘ／ｆｔ＝Ｑ、２７　
　　　　　　ｆａ／ｆ４＝Ｑ、７９１ｆａ／ｆｂｌ＝ｏ
、４９　　　　　　Ｅ１／Ｅ４＝ｌＯＢａｅ／Ｅ４＝０
．３３ Δ”／　ｔ　１＝０．２２　　　　　　　　ｆａ／ｆ　
４＝０，８６１　ｆａ／ｆｂ　ｌ＝０．３９　　　　　
　ｆ　ｔ／１４＝１．０４ｄ　ｅ／　Ｅ　４　＝０．３
１ 実施例４　　　Ｅ＝２９３．０〜１５００〜７６．５　
　ＦＮ［Ｌ＝４．５〜５．８曲率半径　　軸上面間隔　
　　　屈折率（Ｎｄ）　　分散（νｄ）Δｘ／ｆ　ｉ　
＝０，２８　　　　　　　　ｔ　ａ／ｆ　４＝０．８２
１　ｆａ／’ｆｂ　ｌ＝Ｑ、４６　　　　Ｅ　ｔ／　ｔ
４＝ｔ、ｔｓ（１ｅ／ｆ４＝Ｑ、３４Example I E=293.0-150.0-76.5 FNO=
4.5 to 5.8 Radius of curvature Axial surface spacing Refractive index (
Nd) Dispersion (νd)Δx/ft=0,27
fa/f4=0.761 fa/fbl=Q, 5
,5. ft/f4=0.90d e/f
4 =0.28 Example 2 f=293.0-1500-76.5
F ugliness = 4.5 to 5.8 Radius of curvature Upper surface spacing Curvature (Nd) Dispersion (νd) Δx/ft = Q, 27
fa/f4=Q, 791fa/fbl=o
, 49 E1/E4=lOBae/E4=0
．． 33 Δ”/t 1=0.22 fa/f
4=0,861 fa/fb l=0.39
f t/14=1.04d e/E 4 =0.3
1 Example 4 E=293.0-1500-76.5
FN [L = 4.5 to 5.8 radius of curvature, spacing between top surfaces of shafts
Refractive index (Nd) Dispersion (νd) Δx/f i
=0,28 t a/f 4=0.82
1 fa/'fb l=Q, 46 E t/t
4=t, ts(1e/f4=Q, 34

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

第１．３．５．７図はそれぞれ本発明の実施例１゜２、
３．４の最長焦点距離状態の断面及び最短焦点距離状態
への移動を示す模・成因であり、第２，４゜６．８図は
それぞれ順に上記実施例の収差図である。 ■・・・第１レンズ群 ■・・・第２レンズ群 ■・・・第３レンズ群 ＩＶ−・・第４レンズ群 ■３・・・第４レンズ群の前群 ＩＶｂ・・・第４レンズ群の後群 出願人　　　ミノルタカメラ株式会社 〜Ｎ’？’）驕−呻 蚤Ｉ帖膣滅焔 手続補正書 昭和６０年０４月１８日Figures 1.3.5.7 show embodiments 1 and 2 of the present invention, respectively.
3.4 is a model showing the cross section of the longest focal length state and the movement to the shortest focal length state, and Figures 2 and 4.6.8 are aberration diagrams of the above embodiment, respectively. ■...First lens group ■...Second lens group ■...Third lens group IV-...Fourth lens group ■3...Front group IVb of the fourth lens group...Fourth Applicant for the rear group of lenses: Minolta Camera Co., Ltd. ~N'? ') Arrogance - Moaning I Chapter Amendments to Procedures for Vaginal Burning April 18, 1985

Claims (1)

【特許請求の範囲】 １、物体側より順に、正の屈折力を有する第１レンズ群
と、負の屈折力を有する第２レンズ群と、正の屈折力を
有する第３レンズ群と、正の屈折力を有する第４レンズ
群とからなり、フォーカシングに際し第１レンズ群が光
軸上を移動せしめられるとともに、ズーミングに際し第
１レンズ群、第２レンズ群及び第３レンズ群が光軸上を
移動せしめられ、更に第４レンズ群は、正の屈折力を有
する単レンズ１枚もしくは２枚からなり、全体として正
の屈折力を有する前群と、物体側から順に、正の屈折力
を有する単レンズ、負の屈折力を有する単レンズ、及び
正の屈折力を有する単レンズの３枚構成からなり全体と
して負の屈折力を有する後群とからなり、かつ以下の条
件を満足することを特徴とする望遠ズームレンズ； ０．０５＜Δｘ／ｆ＿１＜１．０ ０．４＜ｆａ／ｆ＿４＜１．３ 但し、ここで Δｘ；ズーミングの際の第１レンズ群の移動量ｆ＿１；
第１レンズ群の焦点距離 ｆａ；第４レンズ群の前群の焦点距離 ｆ＿４；第４レンズ群の焦点距離 である。 ２、更に以下の条件を条件を満足することを特徴とする
特許請求の範囲第１項記載の望遠ズームレンズ； ０．１５＜｜ｆａ／ｆｂ｜＜０．７ ０．７＜ｆ＿１／ｆ＿４＜１．４ ０．１５＜ｄｅ／ｆ＿４＜０．４ 但し、ここで、 ｆｂ；第４レンズ群の後群の焦点距離 ｄｅ；第４レンズ群の前群と後群との軸上空気間隔であ
る。 ３、第４レンズ群の前群は正の屈折力を有する単レンズ
１枚からなり、以下の条件を満足することを特徴とする
特許請求の範囲第２項記載の望遠ズームレンズ； １．４９＜Ｎａ＜１．８ 但し、ここで、 Ｎａ；第４レンズ群の前群を構成する単レンズのｄ線に
対する屈折率 である。 ４、第４レンズ群の前群は、それぞれ正の屈折力を有す
る２枚の単レンズからなり、かつ以下の条件を満足する
ことを特徴とする特許請求の範囲第２項記載の望遠ズー
ムレンズ； １．４７＜（Ｎａ＿１＋Ｎａ＿２）／２＜１．８２但し
、ここで、 Ｎａ＿１、Ｎａ＿２；それぞれ、第４レンズ群の前群を
構成する２枚の単レンズのｄ線に対す る屈折率 である。 ５、第４レンズ群は、ズーミングに際し、光軸上を移動
せしめられることを特徴とする特許請求の範囲第１項記
載の望遠ズームレンズ。 ６、第４レンズ群は、ズーミングに際し、第１レンズ群
と一体的に光軸上を移動せしめられることを特徴とする
特許請求の範囲第５項記載の望遠ズームレンズ。[Claims] 1. In order from the object side, 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, and a positive refractive power. The first lens group is moved along the optical axis during focusing, and the first lens group, second lens group, and third lens group are moved along the optical axis during zooming. The fourth lens group is made up of one or two single lenses each having a positive refractive power, including a front group having a positive refractive power as a whole and a front group having a positive refractive power in order from the object side. It consists of a single lens, a single lens with negative refractive power, and a single lens with positive refractive power, and a rear group that has negative refractive power as a whole, and satisfies the following conditions. Characteristic telephoto zoom lens; 0.05<Δx/f_1<1.0 0.4<fa/f_4<1.3 where Δx; movement amount f_1 of the first lens group during zooming;
Focal length fa of the first lens group; Focal length f_4 of the front group of the fourth lens group; Focal length of the fourth lens group. 2. A telephoto zoom lens according to claim 1, further satisfying the following conditions: 0.15<|fa/fb|<0.7 0.7<f_1/f_4< 1.4 0.15<de/f_4<0.4 However, where, fb: Focal length of the rear group of the fourth lens group de; Axial air distance between the front and rear groups of the fourth lens group be. 3. The telephoto zoom lens according to claim 2, wherein the front group of the fourth lens group consists of one single lens having positive refractive power, and satisfies the following conditions: 1.49 <Na<1.8 However, Na: is the refractive index for the d-line of the single lens constituting the front group of the fourth lens group. 4. The telephoto zoom lens according to claim 2, wherein the front group of the fourth lens group is composed of two single lenses each having a positive refractive power, and satisfies the following conditions. ; 1.47<(Na_1+Na_2)/2<1.82, where: Na_1, Na_2; Each is the refractive index for the d-line of the two single lenses constituting the front group of the fourth lens group. 5. The telephoto zoom lens according to claim 1, wherein the fourth lens group is moved on the optical axis during zooming. 6. The telephoto zoom lens according to claim 5, wherein the fourth lens group is moved along the optical axis integrally with the first lens group during zooming.
JP59255910A 1984-12-03 1984-12-03 Telephoto zoom lens Expired - Lifetime JPH0629908B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59255910A JPH0629908B2 (en) 1984-12-03 1984-12-03 Telephoto zoom lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59255910A JPH0629908B2 (en) 1984-12-03 1984-12-03 Telephoto zoom lens

Publications (2)

Publication Number Publication Date
JPS61133916A true JPS61133916A (en) 1986-06-21
JPH0629908B2 JPH0629908B2 (en) 1994-04-20

Family

ID=17285267

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59255910A Expired - Lifetime JPH0629908B2 (en) 1984-12-03 1984-12-03 Telephoto zoom lens

Country Status (1)

Country Link
JP (1) JPH0629908B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6468709A (en) * 1987-09-09 1989-03-14 Nikon Corp Zoom lens
DE3832107A1 (en) * 1987-09-21 1989-04-06 Asahi Optical Co Ltd TELE-ZOOM LENS SYSTEM
JP2013140404A (en) * 2013-04-18 2013-07-18 Canon Inc Zoom lens and optical apparatus
US8681431B2 (en) 2010-03-31 2014-03-25 Canon Kabushiki Kaisha Zoom lens and optical apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59116509A (en) * 1982-12-24 1984-07-05 Shimadzu Corp Load cell scale

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59116509A (en) * 1982-12-24 1984-07-05 Shimadzu Corp Load cell scale

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6468709A (en) * 1987-09-09 1989-03-14 Nikon Corp Zoom lens
DE3832107A1 (en) * 1987-09-21 1989-04-06 Asahi Optical Co Ltd TELE-ZOOM LENS SYSTEM
US4836663A (en) * 1987-09-21 1989-06-06 Asahi Kogaku Kogyo Kabushiki Kaisha Telephoto zoom lens system
US8681431B2 (en) 2010-03-31 2014-03-25 Canon Kabushiki Kaisha Zoom lens and optical apparatus
JP2013140404A (en) * 2013-04-18 2013-07-18 Canon Inc Zoom lens and optical apparatus

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Publication number Publication date
JPH0629908B2 (en) 1994-04-20

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