JP2829981B2 - Telephoto lens for short-distance shooting - Google Patents

Telephoto lens for short-distance shooting

Info

Publication number
JP2829981B2
JP2829981B2 JP63233261A JP23326188A JP2829981B2 JP 2829981 B2 JP2829981 B2 JP 2829981B2 JP 63233261 A JP63233261 A JP 63233261A JP 23326188 A JP23326188 A JP 23326188A JP 2829981 B2 JP2829981 B2 JP 2829981B2
Authority
JP
Japan
Prior art keywords
lens
group
positive
negative
focusing
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 - Fee Related
Application number
JP63233261A
Other languages
Japanese (ja)
Other versions
JPH0281014A (en
Inventor
亘 辰野
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.)
Nikon Corp
Original Assignee
Nikon Corp
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 Nikon Corp filed Critical Nikon Corp
Priority to JP63233261A priority Critical patent/JP2829981B2/en
Publication of JPH0281014A publication Critical patent/JPH0281014A/en
Application granted granted Critical
Publication of JP2829981B2 publication Critical patent/JP2829981B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/02—Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length

Landscapes

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

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は無限遠から等倍までの近距離撮影が可能で、
しかも、200mm程度の焦点距離を有しながら近距離撮影
による全長変化の少ないレンズに関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention enables close-up photography from infinity to 1: 1.
In addition, the present invention relates to a lens having a focal length of about 200 mm and a small change in the overall length due to short-range shooting.

〔従来の技術〕[Conventional technology]

従来、等倍付近までの撮影を行うためには、ベローズ
等の接写用具を用いて、繰り出し量を増加させる方式が
公知である。ところが、この方式においては、操作が煩
雑であったり携帯に不便であったりする上に、繰り出し
量が著しく大きく、性能的にも不十分である。2. Description of the Related Art Conventionally, a method of increasing the feeding amount by using a close-up tool such as a bellows in order to perform photographing up to about the same magnification is known. However, in this method, the operation is complicated and it is inconvenient to carry, and the amount of dispensing is extremely large, and the performance is insufficient.

そこで、近距離での結像性能の劣化を防ぐため、フロ
ーティング方式を採用したマクロレンズが例えば、特公
昭62−42252号公報、特開昭55−140810号公報、特開昭6
1−132916号公報等において提案されている。Therefore, in order to prevent the deterioration of the imaging performance at a short distance, a macro lens adopting a floating method is disclosed in, for example, JP-B-62-42252, JP-A-55-140810, and JP-A-55-140810.
This is proposed in, for example, JP-A-1-132916.

〔発明が解決しようとする課題〕[Problems to be solved by the invention]

ところが、本発明と同一出願人による特公昭62−4225
2号公報においては、第１レンズ群が固定されていて全
長変化がなく重心の移動も極めて少ないという利点はあ
るが、焦点距離が162mmとやや短く、合焦の際での非点
収差の変動が大きいなどの問題点を有している。また、
無限遠から等倍までの撮影を実現しているものの、1/2
倍近辺（中間距離領域）での収差が甚大に発生している
という問題がある。However, Japanese Patent Publication No. 62-4225 by the same applicant as the present invention.
Japanese Patent Publication No. 2 has an advantage that the first lens group is fixed, the total length does not change, and the center of gravity moves very little. However, the focal length is slightly shorter at 162 mm, and the fluctuation of astigmatism during focusing is small. Is large. Also,
Although shooting from infinity to 1: 1 has been achieved,
There is a problem that aberration near double magnification (intermediate distance region) is extremely generated.

また、特開昭55−140810号公報においては、焦点距離
は200mm程度の焦点距離を有しているが、合焦による全
長の変化が大きく、しかも球面収差の変動が大きいとい
う問題を有している。Further, in Japanese Patent Application Laid-Open No. 55-140810, the focal length has a focal length of about 200 mm, but there is a problem that a change in the total length due to focusing is large and a fluctuation in spherical aberration is large. I have.

また、特開昭61−132916公報においては、焦点距離も
200mm程度で無限遠の時での全長も短く、収差変動も比
較的少ないが、無限遠から近距離への合焦による全長変
化が大きく、しかも構成枚数の多い第１レンズ群を繰り
出す方式の為に、重心の移動も大きいという問題点を有
している。Further, in JP-A-61-132916, the focal length is also
The total length at about 200mm at infinity is short, and the aberration variation is relatively small, but the total length change due to focusing from infinity to short distance is large, and the first lens group with a large number of components is extended. In addition, there is a problem that the shift of the center of gravity is large.

そこで、本発明はこの様な従来の課題に鑑みてなされ
たもので、合焦によるレンズ全長の変化量を30mm程度以
下としながらレンズ重心移動を極めて小さく抑え、また
昆虫等の生物撮影に有利な長いワーキングディスタンス
を確保して操作性の向上を図り、しかも、無限遠から等
倍にわたり優れた結像性能を有する焦点距離が200mm程
度の高性能な近距離撮影可能な望遠レンズを提供するこ
とを目的とする。Accordingly, the present invention has been made in view of such conventional problems, and it is possible to minimize the movement of the center of gravity of the lens while keeping the change in the overall length of the lens due to focusing to about 30 mm or less, and it is advantageous for photographing organisms such as insects. The objective is to provide a long-distance telephoto lens that secures a long working distance, improves operability, and has excellent imaging performance from infinity to 1x, and a high-performance close-up shooting with a focal length of about 200 mm. And

〔課題を解決する為の手段〕[Means for solving the problem]

本発明は上記の目的を達成するために、物体側から順
に、正の屈折力を持つ前群GFと正の屈折力を持つ後群GR
とを含み全体として正の屈折力を持つ第１レンズ群G
1と、負の屈折力を持つ第２レンズ群G2と、正の屈折力
を持つ第３レンズ群G3とを有し、 無限遠距離から近距離への合焦の際に、前記前群GFと
前記第２レンズ群G2との群間隔が拡大するように、前記
第２レンズ群G2を像面方向に移動させて該両群間隔を変
化させると共に、中間距離領域における合焦性能が良好
となるように隣接する２つの群により形成される少なく
とも１つの空気間隔を非線形に変化させ、 前記前群GFと前記後群GRとにより形成される空気間隔
が非線形に変化するように、前記前群GFと前記後群GRと
の内の少なくとも一方を非線形に移動させ、 前記前群GFは少なくとも１枚以上の正レンズと負レン
ズとを有し、前記後群GRは正レンズと負レンズとの接合
より成る接合レンズを有し、前記第２レンズ群G2は少な
くとも２枚以上の負レンズと１枚以上の正レンズとを有
し、前記第３レンズ群G3は正レンズと負レンズとの接合
レンズを有し、 前記前群GFの合焦による移動量をΔGFとし、前記第２
レンズ群G2の合焦による移動量をΔG2とし、前記前群GF
の焦点距離をfGFとし、前記後群GRの焦点距離をfGRと
し、前記前群GF中の負レンズの焦点距離をfAとし、前記
第３レンズ群G3中の接合レンズの接合面の曲率半径をrb
とし、全系の焦点距離をｆとし、前記第３レンズ群G3の
接合レンズ中の負レンズの屈折率をnaとし、前記第３レ
ンズ群G3の接合レンズ中の正レンズの屈折率をnbとした
とき、以下の条件式を満足することが望ましい。In order to achieve the above object, the present invention provides, in order from the object side, a front group G F having a positive refractive power and a rear group G R having a positive refractive power.
And the first lens group G having a positive refractive power as a whole
1, a second lens group G 2 having a negative refractive power, and a third lens group G 3 having a positive refractive power, when the infinite distance focusing to a close, the front as the group distance between the group G F and the second lens group G 2 is enlarged, with changing the both said group interval the second lens group G 2 is moved in the image plane direction, if in the intermediate distance area at least one air gap is changed to a non-linear, the change in the air gap is nonlinear, which is formed by the a front group G F and the rear group G R of focusing performance is formed by two adjacent groups so that good as to, at least one of the a front group G F and the rear group G R is moved to the non-linear, the front group G F has at least one positive lens and a negative lens, the rear group G R has a cemented lens consisting of the junction between the positive lens and the negative lens, the second lens group G 2 includes at least two or more Negative lens and having a one or more positive lenses, said third lens group G 3 includes a cemented lens of a positive lens and a negative lens, a moving amount of focusing of the front group G F delta GF of And the second
The movement amount of the focusing lens group G 2 and delta G2, the front group G F
Of the focal length and f GF, the focal length of the rear group G R and f GR, the focal length of the negative lens in the front group G F and f A, the cemented lens of the third in the lens group G 3 Let the radius of curvature of the joining surface be r b
And then, the focal length of the entire system is f, the refractive index of the refractive index of the third negative lens in the cemented lens of the lens group G 3 and n a, positive lens in the cemented lens of the third lens group G 3 the when the n b, it is preferable to satisfy the following condition.

−0.7＜ΔGF/ΔG2≦０ １＜fGR/fGF＜３ −３＜fA/fGF＜−1.4 −５＜rb/〔ｆ（nb−na）〕 〔作 用〕 前述の如く本発明と同一出願人による特公昭62−4225
2号公報等で提案した正負正タイプの３群望遠レンズに
おいては、無限遠付近と等倍付近での諸収差を比較的良
好に補正できるものの、撮影倍率が1/2倍近辺（中間距
離領域）での収差が大きく発生して結像性能が著しく低
下する。 -0.7 <Δ GF / Δ G2 ≦ 0 1 <f GR / f GF <3 -3 <f A / f GF <-1.4 -5 <r b / [f (n b -n a)] [for work] As described above, Japanese Patent Publication No. 62-4225 by the same applicant as the present invention.
In the positive / negative / positive type three-group telephoto lens proposed in Japanese Patent Publication No. 2 etc., although various aberrations near infinity and near the same magnification can be corrected relatively favorably, the photographing magnification is about 1/2 times (intermediate distance area). The aberration in (1) is large, and the imaging performance is significantly reduced.

この中間距離領域での収差の発生による性能劣化を抑
えるためには、無限遠距離から近距離への合焦の際に、
隣接する２つの群により形成される少なくとも１つの空
気間隔を非線型に変化させて収差補正上の自由度を向上
させることが必要である。In order to suppress the performance degradation due to the occurrence of aberration in this intermediate distance area, when focusing from infinity to close distance,
It is necessary to nonlinearly change at least one air gap formed by two adjacent groups to improve the degree of freedom in aberration correction.

そこで、本発明においては、第１レンズ群G1を前群GF
と後群GRとに２分割して、前群GFと第２レンズ群G2との
群間隔が拡大するようにこの両群間隔を変化させると共
に、前群GFと後群GRとにより形成される空気間隔が非線
型に変化するように、前群GFと後群GRとの内の少なくと
も一方を非線型に移動させている。Therefore, in the present invention, the first lens group G1 is replaced with the front group G F
And divided into a rear group G R when the front group G F and with the group distance between the second lens group G 2 alters the two groups apart to expand, front group G F and the rear group G R air gap to be formed so as to change to a non-linear, it is moved at least one of a front group G F and the rear group G R in the non-linear by the.

すると、合焦による第２レンズ群G2に入射する光線の
入射高を適切な高さに調節でき、結果的に第２レンズ群
G2の発散効果の度合を最適な状態に調節することが可能
である。このため、中間距離領域における第２レンズ群
G2の発散効果の効き過ぎによる収差の悪化を極めて良好
に抑えることができる。Then, to adjust the incident height of light rays incident on the second lens group G 2 by focusing on the appropriate height, resulting in the second lens group
It is possible to adjust the degree of divergence effect of G 2 to the optimum state. For this reason, the second lens group in the intermediate distance region
It is possible to suppress the deterioration of the aberration due to excessive braking effectiveness of the divergent effects of G 2 very well.

また、本発明においては、合焦による全長変化を小さ
くしながら良好な収差補正を行い、レンズ系のコンパク
ト化を図るためには、以下の条件を満足するように構成
されることが望ましい。Further, in the present invention, in order to perform favorable aberration correction while minimizing the total length change due to focusing and to achieve a compact lens system, it is desirable that the following conditions be satisfied.

（１）−0.7＜ΔGF/ΔG2≦０ （２） １＜fGR/fGF＜３ （３）−３＜fA/fGF＜−1.4 但し、 ΔGF:前群GFの合焦による移動量。 (1) -0.7 <Δ GF / Δ G2 ≦ 0 (2) 1 <f GR / f GF <3 (3) -3 <f A / f GF <-1.4 However, delta GF: move amount of focusing of the front group G F.

ΔG2:第２レンズ群GRの合焦による移動量。Delta G2: movement amount of the focus of the second lens group G R.

fGF :前群GFの焦点距離。f GF: focal length of the front group G F.

fGR :後群GRの焦点距離。f GR: focal length of the rear group G R.

fA ：前群中の負レンズの焦点距離。f A: focal length of the negative lens in the front group.

rb ：第３レンズ群中の接合面の曲率半径。r b: radius of curvature of the cemented surface in the third lens group.

f ：全系の焦点距離。f: focal length of the whole system.

na ：第３レンズ群の接合レンズ中の負レンズの屈折
率。n a: negative lens refractive index of in the cemented lens of the third lens group.

nb ：第３レンズ群の接合レンズ中の正レンズの屈折
率。n b : refractive index of the positive lens in the cemented lens of the third lens group.

尚、条件（１）において合焦時にレンズ群が物体側へ
移動する移動方向を負、像側に移動する移動方向を正と
する。In the condition (1), the moving direction in which the lens group moves to the object side during focusing is defined as negative, and the moving direction in which the lens group moves toward the image side is defined as positive.

以下において、本発明の各条件式について詳述する。 Hereinafter, each conditional expression of the present invention will be described in detail.

条件式（１）は前群GFと第２レンズ群G2とにおける無
限遠から等倍までの最適な移動量の比率を規定するもの
である。ところが、条件（１）の上限を越えると、全長
変化が大きくなる上に、等倍付近での撮影において第２
レンズ群G2に入射する光線が低くなりすぎるため球面収
差の補正が困難となるので好ましくない。逆にこの条件
の下限を越えると、前群GFと第２群G2との移動量が共に
増加するために好ましくない。Condition (1) defines the ratio of the optimum amount of movement from infinity like fold in the front group G F and the second lens group G 2 Prefecture. However, when the value exceeds the upper limit of the condition (1), the change in the total length becomes large, and the second time in the photographing at about the same magnification.
Correction of spherical aberration for rays entering the lens group G 2 becomes too low unpreferably difficult. On the contrary, below the lower limit of this condition it is not preferable because the amount of movement of a front group G F and the second group G 2 is increased together.

条件式（２）は前群GFと後群GRとの適切なの焦点距離
の比率を規定するものである。ところが、条件（２）の
上限を越えると、前群GFの屈折力が強くなるために、前
群GFで光線が曲がる角度がきつくなり球面収差やコマ収
差の補正が困難となる。逆にこの条件の下限を越える
と、収差補正には有利ではあるが全長が大きくなり好ま
しくない。Condition (2) defines the ratio of the appropriate focal length of the front group G F and the rear group G R. However, above the upper limit of condition (2), the refractive power of the front group G F becomes strong, it becomes difficult to correct spherical aberration and coma aberration becomes tighter angle a light ray bends in front group G F. Conversely, when the value goes below the lower limit of this condition, it is advantageous for aberration correction but undesirably increases the overall length.

条件式（３）は前群GFの中の負レンズと前群GFとの適
切なの焦点距離の比率を規定するものである。ところ
が、条件（３）の上限を越えると、球面収差が過剰補正
となり収差補正上好ましくない。逆にこの条件の下限を
越えると、球面収差の補正不足となるばかりか色収差の
補正も困難となる。尚、この負レンズを前群中の最も物
側に配置することがより好ましい。Condition (3) defines the negative lens and the appropriate ratio of the focal length of the front group G F in the front group G F. However, when the value exceeds the upper limit of the condition (3), the spherical aberration is excessively corrected, which is not preferable for aberration correction. Conversely, if the lower limit of this condition is exceeded, correction of spherical aberration will be insufficient and correction of chromatic aberration will also be difficult. It is more preferable to dispose the negative lens closest to the object in the front group.

条件式（４）は第３レンズ群G3中の接合レンズの接合
面における最適な面屈折力を規定するものである。とこ
ろが、条件（４）の上限を越えると、接合面の面屈折力
が強くなり過ぎるため球面収差が補正過剰となる。特に
補正の余裕のない近側での球面収差の補正が困難とな
る。また斜光線の入射角も大きくなり、コマ収差、非点
収差への変動も大きくなる。逆にこの条件の下限を越え
ると、接合面の面屈折力が弱くなり過ぎるため、斜光線
に悪影響を及ぼし、特に非点収差とコマ収差を十分補正
するのが困難となる。Condition (4) defines an optimal surface power in the cemented surface of the cemented lens in the third lens group G 3. However, when the value exceeds the upper limit of the condition (4), the surface refractive power of the cemented surface becomes too strong, and the spherical aberration is overcorrected. In particular, it becomes difficult to correct spherical aberration on the near side where there is no room for correction. In addition, the angle of incidence of oblique rays increases, and the fluctuation to coma and astigmatism also increases. Conversely, if the lower limit of this condition is exceeded, the surface refracting power of the cemented surface will be too weak, which will adversely affect oblique rays, making it difficult to sufficiently correct astigmatism and coma in particular.

〔実施例〕〔Example〕

以下に本発明による実施例について説明する。 Hereinafter, examples according to the present invention will be described.

各実施例はいずれもＦナンバー4.0程度の焦点距離200
mmである。第１〜第３実施例はいずれも、正の屈折力を
持つ前群GFと正の屈折力を持つ後群GRとから成る第１レ
ンズ群G1と、負の屈折力を持つ第２レンズ群G2と、正の
屈折力を持つ第３レンズ群G3より成り、第１図に示した
第１実施例と同様なレンズ構成を有している。Each example has a focal length of 200 with an F-number of about 4.0
mm. Both the first to third embodiments, the first lens group G 1 consisting of a rear group G R having a front group G F and positive refractive power having a positive refractive power, a having a negative refractive power a second lens group G 2, consists of the third lens group G 3 having a positive refractive power, and has the same lens configuration as the first embodiment shown in Figure 1.

そして、各実施例における具体的な構成は、物体側か
ら順に、像側に強い曲率の面を向けた負メニスカスレン
ズL1と、この負メニスカスレンズL1に接合された正レン
ズL2と、物体側に凸面を向けた正メニスカスレンズL3と
から成る前群GFと、物体側に凸面を向けた負メニスカス
レンズL4と、この負メニスカスレンズL4に接合された物
体側に強い曲率の面を向けた正レンズL5とから成る後群
GRと、像側に強い曲率の面を向けた正レンズL6と、この
正レンズL6に接合された負レンズL7と、両凹レンズL8と
から成る第２レンズ群G2と、負レンズL9と、この負レン
ズL9に接合された正レンズL10とから成る第３レンズ群G
3より成っている。And, the specific configuration in each embodiment, in order from the object side, a negative meniscus lens L 1 having its surface with a stronger curvature on the image side, a positive lens L 2 that is bonded to the negative meniscus lens L 1, a front group G F consisting of a positive meniscus lens L 3 Metropolitan having a convex surface facing the object, a negative meniscus lens L 4 with a convex surface facing the object side, a stronger curvature directed onto the object side, which are joined to the negative meniscus lens L 4 rear group consisting toward the surface positive lens L 5 Metropolitan
G R , a positive lens L 6 having a surface with a strong curvature directed to the image side, a negative lens L 7 joined to the positive lens L 6 , and a second lens group G 2 including a biconcave lens L 8 , a negative lens L 9, a third lens group G consisting of the positive lens L 10 Metropolitan joined to the negative lens L 9
Consists of three .

本発明の第１、第２実施例おける無限遠から等倍への
合焦は、第１、第２図に示す如く、前群GFと第２レンズ
群G2との群間隔が拡大するように前群GFが物体側へ、第
２レンズ群G2が像側へ移動しながら、前群GFと後群GRと
の空気間隔が非線型に変化するように後群GRが像側に凸
を描いて非線型に移動する。The first of the present invention, focusing from infinity to a magnification of definitive second embodiment, first, as shown in Figure 2, so that the group spacing between the front group G F and the second lens group G 2 is expanded in the front group G F is the object side, while the second lens group G 2 is moved toward the image side, the rear group G R as air gap varies nonlinearly with the front group G F and the rear group G R The lens moves non-linearly with a convex on the image side.

また、第３実施例においては内焦式を採用したもので
あり、第３実施例における無限遠から等倍への合焦は、
第３図に示す如く、前群GFと第２レンズ群G2との群間隔
が拡大するように第２レンズ群G2が像側へ移動しなが
ら、前群GFと後群GRとの空気間隔が非線型に変化するよ
うに後群GRが像側に凸を描いて非線型に移動する。In the third embodiment, an in-focus system is adopted. In the third embodiment, focusing from infinity to 1: 1 is performed as follows.
Third, as shown in FIG, front group G F and while the second lens group G 2 to the group interval is enlarged between the second lens group G 2 is moved toward the image side, the front group G F and the rear group G R rear group G R as air gap varies nonlinearly with the move to a non-linear drawing a convex to the image side.

以下の表１〜３にてそれぞれ第１〜第３実施例の諸元
の値を掲げる。表中、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、屈
折率ｎ及びアッベ数νはｄ線（λ＝587.6nm）に対する
値であり、２ωは画角、βは撮影倍率、Doは物体から第
１レンズ面の頂点までの距離である。The following Tables 1 to 3 list the values of the specifications of the first to third embodiments, respectively. In the table, the numbers at the left end represent the order from the object side, r is the radius of curvature of the lens surface, d is the distance between the lens surfaces, the refractive index n and the Abbe number ν are the values for the d line (λ = 587.6 nm), 2ω is the angle of view, β is the photographing magnification, and Do is the distance from the object to the vertex of the first lens surface.

表４にて、本発明の各実施例における条件対応値を掲
げる。 Table 4 shows the condition corresponding values in each embodiment of the present invention.

上記の表１〜表３に示す諸元の値から、第１、第２実
施例における合焦による全長の変化量は、それぞれ27.1
17mm、15.001mmであり、また、第３実施例においては内
焦式であるために全長は変化せず一定である。したがっ
て、無限遠から等倍にわたる合焦による全長の変化量及
びレンズの重心移動が極めて小さく操作性の向上が図ら
れていることが分かる。 From the values of the specifications shown in Tables 1 to 3, the change amount of the total length due to focusing in the first and second embodiments is 27.1, respectively.
The length is 17 mm and 15.001 mm. In the third embodiment, the total length is constant without change because of the inner focus type. Therefore, it can be seen that the amount of change in the overall length and the movement of the center of gravity of the lens due to focusing from infinity to equal magnification are extremely small, and operability is improved.

本発明の第１〜第３実施例における諸収差図はそれぞ
れ順に第４図〜第６図にて示しており、各実施例におけ
る諸収差図において（Ａ）は無限遠距離撮影状態におけ
る諸収差図、（Ｂ）は中間距離撮影状態（β＝−0.5
倍）における諸収差図、（Ｃ）は最至近距離撮影状態
（β＝−1.0倍）における諸収差図を示している。Various aberration diagrams in the first to third embodiments of the present invention are shown in order in FIGS. 4 to 6, respectively. In the various aberration diagrams in each embodiment, (A) shows various aberrations in an infinite distance shooting state. FIG. 7B shows the intermediate-distance shooting state (β = −0.5
(C) shows various aberration diagrams in the closest distance shooting state (β = −1.0 ×).

各収差図の比較から、従来から問題となっていた中間
距離撮影状態の収差が良好に補正されており、無限遠距
離から近距離（等倍）にわたり極めて優れた結像性能を
有していることが分かる。From the comparison of the aberration diagrams, the aberration in the intermediate-distance shooting state, which has conventionally been a problem, has been well corrected, and has extremely excellent imaging performance from infinity to short distance (1 ×). You can see that.

尚、本発明においては、無限遠距離から近距離への合
焦の際に、前群のみを非線型に移動させて、前群と後群
との空気間隔を非線型に変化させることも可能である。In the present invention, when focusing from an infinity distance to a short distance, only the front group can be moved nonlinearly, and the air gap between the front group and the rear group can be changed nonlinearly. It is.

〔発明の効果〕〔The invention's effect〕

本発明によれば、近距離撮影によるレンズ系の全長変
化を抑えながらレンズ系の重心移動を極めて小さくし、
また比較的長いワークディスタンスを確保して操作性の
向上を図り、しかも無限遠距離から近距離（等倍）にわ
たり極めて優れた結像性能を有する望遠レンズを達成す
ることができる。According to the present invention, the movement of the center of gravity of the lens system is extremely reduced while suppressing the change in the overall length of the lens system due to short-range shooting,
In addition, it is possible to secure a relatively long work distance to improve operability, and to achieve a telephoto lens having extremely excellent imaging performance from an infinite distance to a short distance (actual magnification).

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

第１図〜第３図はそれぞれ順に本発明の第１〜第３実施
例におけるレンズ構成図、第４図（Ａ）〜第６図（Ａ）
はそれぞれ順に本発明の第１〜第３実施例の無限遠距離
撮影状態における諸収差図、第４図（Ｂ）〜第６図
（Ｂ）はそれぞれ順に本発明の第１〜第３実施例の中間
距離撮影状態（β＝−0.5倍）における諸収差図、第４
図（Ｃ）〜第６図（Ｃ）はそれぞれ順に本発明の第１〜
第３実施例の最至近距離撮影状態（β＝−1.0倍）にお
ける諸収差図を示している。 〔主要部分の説明〕 GF……前群（G1……第１レンズ群） GR……後群（G1……第１レンズ群） G2……第２レンズ群 G3……第３レンズ群FIGS. 1 to 3 are lens configuration diagrams according to first to third embodiments of the present invention, respectively, and FIGS. 4 (A) to 6 (A).
Fig. 4 shows various aberration diagrams of the first to third embodiments of the present invention in an infinite distance shooting state, and Figs. 4 (B) to 6 (B) respectively show the first to third embodiments of the present invention. Of various aberrations at the time of shooting at an intermediate distance (β = −0.5 ×), FIG.
FIGS. 6 (C) to 6 (C) show the first to first embodiments of the present invention, respectively.
FIG. 10 shows various aberration diagrams of the third example in the closest distance shooting state (β = −1.0 ×). [Explanation of Main Parts] G F ... Front Group (G 1 ... First Lens Group) G R ... Rear Group (G 1 ... First Lens Group) G 2 ... Second Lens Group G 3. Third lens group

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】物体側から順に、正の屈折力を持つ前群GF
と正の屈折力を持つ後群GRとを含み全体として正の屈折
力を持つ第１レンズ群G1と、負の屈折力を持つ第２レン
ズ群G2と、正の屈折力を持つ第３レンズ群G3とを有し、 無限遠距離から近距離への合焦の際に、前記前群GFと前
記第２レンズ群G2との群間隔が拡大するように、前記第
２レンズ群G2を像面方向に移動させて該両群間隔を変化
させると共に、中間距離領域における合焦性能が良好と
なるように隣接する２つの群により形成される少なくと
も１つの空気間隔を非線形に変化させ、 前記前群GFと前記後群GRとにより形成される空気間隔が
非線形に変化するように、前記前群GFと前記後群GRとの
内の少なくとも一方を非線形に移動させ、 前記前群GFは少なくとも１枚以上の正レンズと負レンズ
とを有し、前記後群GRは正レンズと負レンズとの接合よ
り成る接合レンズを有し、前記第２レンズ群G2は少なく
とも２枚以上の負レンズと１枚以上の正レンズとを有
し、前記第３レンズ群G3は正レンズと負レンズとの接合
レンズを有し、 前記前群GFの合焦による移動量をΔGFとし、前記第２レ
ンズ群G2の合焦による移動量をΔG2とし、前記前群GFの
焦点距離をfGFとし、前記後群GRの焦点距離をfGRとし、
前記前群GF中の負レンズの焦点距離をfAとし、前記第３
レンズ群G3中の接合レンズの接合面の曲率半径をrbと
し、全系の焦点距離をｆとし、前記第３レンズ群G3の接
合レンズ中の負レンズの屈折率をnaとし、前記第３レン
ズ群G3の接合レンズ中の正レンズの屈折率をnbとしたと
き、以下の条件式を満足することを特徴とする近距離撮
影可能な望遠レンズ。 −0.7＜ΔGF/ΔG2≦０ １＜fGR/fGF＜３ −３＜fA/fGF＜−1.4 −５＜rb/〔ｆ（nb−na）〕1. A front group G F having a positive refractive power in order from the object side.
And a rear lens group G R having a positive refractive power, a first lens group G 1 having a positive refractive power as a whole, a second lens group G 2 having a negative refractive power, and a positive lens power. and a third lens group G 3, when the infinite distance focusing to a close, as the group distance between the front group G F and the second lens group G 2 is enlarged, the first the second lens group G 2 is moved in the image plane direction with changing the both said group interval, at least one air gap formed by the two groups focusing performance in the intermediate distance area are adjacent so as to better is changed to a non-linear, so that the air gap formed by the a front group G F and the rear group G R is changed nonlinearly, nonlinear at least one of the a front group G F and the rear group G R is moved, the front group G F has at least one positive lens and a negative lens, the rear group G R is a positive lens and a negative lens Has a cemented lens consisting of the junction of the second lens group G 2 has at least 2 or more negative lenses and one positive lens, said third lens group G 3 positive lens and a negative lens And the amount of movement of the front group G F by focusing is Δ GF , the amount of movement of the second lens group G 2 by focusing is Δ G2, and the focal length of the front group G F It was a f GF, the focal length of the rear group G R and f GR,
The focal length of the negative lens in the front group G F and f A, the third
The radius of curvature of the cemented surface of the cemented lens in the lens group G 3 and r b, the focal length of the entire system is f, the negative lens refractive index of in the cemented lens of the third lens group G 3 and n a, the third when the refractive index of the positive lens in the cemented lens of the lens group G 3 was used as n b, near field imaging allows telephoto lens satisfies the following conditional expression. −0.7 <Δ GF / Δ G2 ≦ 0 1 <f GR / f GF <3 −3 <f A / f GF <−1.4 −5 <r b / [f (n b −n a )]
JP63233261A 1988-09-17 1988-09-17 Telephoto lens for short-distance shooting Expired - Fee Related JP2829981B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63233261A JP2829981B2 (en) 1988-09-17 1988-09-17 Telephoto lens for short-distance shooting

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63233261A JP2829981B2 (en) 1988-09-17 1988-09-17 Telephoto lens for short-distance shooting

Publications (2)

Publication Number Publication Date
JPH0281014A JPH0281014A (en) 1990-03-22
JP2829981B2 true JP2829981B2 (en) 1998-12-02

Family

ID=16952309

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63233261A Expired - Fee Related JP2829981B2 (en) 1988-09-17 1988-09-17 Telephoto lens for short-distance shooting

Country Status (1)

Country Link
JP (1) JP2829981B2 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05323191A (en) * 1992-05-18 1993-12-07 Nikon Corp Telephoto lens for close-up photography
JPH085907A (en) * 1994-06-23 1996-01-12 Nikon Corp Telephoto lens optics
JP5157401B2 (en) * 2007-12-03 2013-03-06 株式会社ニコン Imaging lens, imaging apparatus and focusing method therefor
JP6251511B2 (en) * 2013-08-09 2017-12-20 株式会社タムロン Optical system and optical system focusing method

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5567717A (en) * 1978-11-17 1980-05-22 Canon Inc Focusing method which prevents change in angle of view
JPS58209707A (en) * 1982-05-31 1983-12-06 Asahi Optical Co Ltd Extremely compact telephoto lens
JPS6190157A (en) * 1984-10-09 1986-05-08 Konishiroku Photo Ind Co Ltd Photosensitive body processor

Also Published As

Publication number Publication date
JPH0281014A (en) 1990-03-22

Similar Documents

Publication Publication Date Title
JP3261716B2 (en) Reverse telephoto large aperture wide angle lens
JP2679130B2 (en) Lens capable of close-up photography
JPH083580B2 (en) Compact high-magnification zoom lens
JP2558138B2 (en) Zoom lens
JP3397440B2 (en) Zoom lens
JPH08201695A (en) Rear focus type zoom lens
JP3288746B2 (en) telescope lens
JP4550970B2 (en) Floating photography lens
JPH0642017B2 (en) Compact zoom lens
JP3412908B2 (en) Zoom lens
US5663834A (en) Eyepiece zoom lens system
JPH0319526B2 (en)
US5402268A (en) Telephoto lens system allowing short-distance photographing operation
JPH06308388A (en) Rear focus type zoom lens
JP3723643B2 (en) High zoom ratio zoom lens system
JP4203284B2 (en) Telephoto zoom lens
JP4380158B2 (en) Zoom lens
JPH0833512B2 (en) Gauss type rear focus lens
JP2829981B2 (en) Telephoto lens for short-distance shooting
JP2712370B2 (en) Telephoto lens for short-distance shooting
JP3590845B2 (en) Image position correction optical system
JP2503510B2 (en) Telephoto zoom lens
JP4360086B2 (en) Zoom lens
JPH06138385A (en) Telephoto lens
JP3041987B2 (en) Inner focus telephoto lens

Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees