JPH032709A - Switching type zoom lens - Google Patents

Switching type zoom lens

Info

Publication number
JPH032709A
JPH032709A JP1137152A JP13715289A JPH032709A JP H032709 A JPH032709 A JP H032709A JP 1137152 A JP1137152 A JP 1137152A JP 13715289 A JP13715289 A JP 13715289A JP H032709 A JPH032709 A JP H032709A
Authority
JP
Japan
Prior art keywords
lens group
focal length
lens
negative
positive
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.)
Pending
Application number
JP1137152A
Other languages
Japanese (ja)
Inventor
Hisayuki Masumoto
升本　久幸
Tetsuya Arimoto
哲也 有本
Mitsuko Date
伊達　光子
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 JP1137152A priority Critical patent/JPH032709A/en
Publication of JPH032709A publication Critical patent/JPH032709A/en
Pending 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
    • G02B15/02—Optical objectives with means for varying the magnification by changing, adding, or subtracting a part of the objective, e.g. convertible objective
    • G02B15/04—Optical objectives with means for varying the magnification by changing, adding, or subtracting a part of the objective, e.g. convertible objective by changing a part
    • 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
    • G02B15/142—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 two groups only
    • G02B15/1421—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 two groups only the first group being positive

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

Abstract

PURPOSE:To prevent considerable extension of the overall length and complica tion by performing switching of a first positive lens group or a second negative lens group to a third positive lens or a third negative lens group in the long focus end of a main lens system. CONSTITUTION:A focal length longer than the focal length in the long focus end of the main lens system is attained by switching of the first positive lens group or the second negative lens group to the third positive lens group or the third negative lens in the long focus end of the main lens system, and conditions of inequalities I to III are satisfied. In inequalities I to III, fC, fN, fT, fW, fL, TLI, and TLH are the focal length of the first positive lens group or the second negative lens group to be switched, the focal length of the third lens group to be switched, the longest focal length of the main lens system before switching, the shortest focal length of the main lens system before switching, the focal length of the lens system after switching, the distance from the front end of lenses in the long focus end of the main lens system to the image surface before switching, and the distance from the front end of lenses of the lens system to the image surface after switching respectively. Thus, considerable extension of the overall length and complication are prevented.

Description

【発明の詳細な説明】 童粟上皇肌里公団 本発明はズームレンズに関し、ズームレンズの長焦点端
において、特に一部のレンズ群を他のレンズ群に変換す
ることにより長焦点側における焦点距離よりさらに長焦
点側の焦点距離を達成する切換え式ズームレンズに関す
る。[Detailed Description of the Invention] The present invention relates to a zoom lens, and the present invention relates to a zoom lens, and particularly, the focal length at the long focal length end of the zoom lens is changed by converting some lens groups into other lens groups. The present invention relates to a switching zoom lens that achieves a longer focal length.

従来立及歪 従来より、ズームレンズの通常の変倍領域（変倍比が２
倍程度）を超えて更に変倍を行い変倍領域を拡大する方
法としては、レンズ中の一部のレンズをさらに移動させ
ることによる通常のズーミングの延長上で行う方法が一
般的によく知られている．この方法では簡単に焦点距離
を変化させることができるが、ズームレンズの全長が長
くなり、操作性も悪くなるという問題点がある。Conventional standing distortion Conventionally, the normal magnification range of zoom lenses (zoom ratio is 2)
A generally well-known method for expanding the magnification range by further changing the magnification beyond the normal zooming range is to extend normal zooming by moving some lenses in the lens further. ing. Although this method allows the focal length to be easily changed, there are problems in that the overall length of the zoom lens becomes longer and the operability becomes worse.

また、ズームレンズを構成するレンズ群のうち、一部の
レンズ群を焦点距離の異なる他のレンズ群と交換するこ
とによって、変倍領域を拡大する種々のタイプのズーム
レンズが従来より提案されている．しかし、このタイプ
のズームレンズの変倍比は２倍以下であり、それ以上の
高い変倍比を有するものは実現されていない。In addition, various types of zoom lenses have been proposed in the past that expand the variable power range by replacing some of the lens groups that make up the zoom lens with other lens groups that have different focal lengths. There is. However, the variable power ratio of this type of zoom lens is 2 times or less, and a zoom lens with a higher variable power ratio has not been realized.

が”しようとする課 本発明の目的は、長焦点側の焦点距離を効率良く拡大し
うる変倍比が３倍以上のズームレンズであって、長焦点
端より更に長焦点側へ焦点距離を拡大したときに全長の
大幅な増大化や複雑化が生じ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 to provide a zoom lens with a variable power ratio of 3 times or more that can efficiently expand the focal length on the long focal length side, and which extends the focal length further from the long focal length end to the long focal length side. It is an object of the present invention to provide a zoom lens that does not cause a significant increase in overall length or complication when doing so.

課　を　゛するための 上記目的を達成するために、本発明に係る切換え式ズー
ムレンズは、物体側から順に、第１正レンズ群及び第２
負レンズ群から成り少なくとも前記第１正レンズ群と前
記第２負レンズ群との間隔を変化させることによりズー
ミングを行う主レンズ系と、前記第１正レンズ群と変換
自在に設けられた第３正レンズ群又は前記第２負レンズ
群と変換自在に設けられた第３負レンズ群から成る第３
レンズ群と、から構成され、前記主レンズ系の長焦点端
において、前記第１正レンズ群の前記第３正レンズ群へ
の変換又は前記第２負レンズ群の前記第３負レンズ群へ
の変換を行うことによって主レンズ系の長焦点端におけ
る焦点距離よりさらに長焦点側の焦点距離を達成すると
共に下記の条件を満足する構成となっている。In order to achieve the above object, the switching zoom lens according to the present invention includes a first positive lens group and a second positive lens group in order from the object side.
a main lens system comprising a negative lens group and performing zooming by changing the distance between at least the first positive lens group and the second negative lens group; and a third lens system provided to be convertible with the first positive lens group. a third lens group consisting of a positive lens group or a third negative lens group that is convertible with the second negative lens group;
a lens group, at the long focal point end of the main lens system, converting the first positive lens group to the third positive lens group or converting the second negative lens group to the third negative lens group. By performing the conversion, a focal length further on the long focal point side than the focal length at the long focal end of the main lens system can be achieved, and the configuration satisfies the following conditions.

但し ｆｃ　：変換される第１正レンズ群又は第２負レンズ群
の焦点距離 ｆ２　：変換する第３レンズ群の焦点距離ｆＴ　：前記
変換前の主レンズ系の最長焦点距離 ｆｏ　：前記変換前の主レンズ系の最短焦点距離 ｒＬ　：前記変換後のレンズ系の焦点距離ｒｔ，＋：前
記変換前の主レンズ系の長焦点端におけるレンズ先端か
ら像面までの 距離 ＴＬＩ　：前記変換後のレンズ系のレンズ先端から像面
までの距離 である。However, fc : focal length of the first positive lens group or second negative lens group to be converted f2 : focal length of the third lens group to be converted fT : longest focal length of the main lens system before the conversion fo : focal length of the main lens system before the conversion Shortest focal length rL of the main lens system: Focal length rt of the lens system after the conversion, +: Distance from the lens tip to the image plane at the long focal point of the main lens system before the conversion TLI: Lens system after the conversion is the distance from the lens tip to the image plane.

従って、本発明の目的である長焦点側の焦点距離の拡大
（長焦点化）を図る方法としては、上記条件■．■，■
を満足する必要があり、具体的には以下の（イ）、（口
）による方法が挙げられる。Therefore, as a method for expanding the focal length on the long focal length side (long focal length), which is the objective of the present invention, the above condition (2) is used. ■，■
It is necessary to satisfy the following, and specifically, the following methods (a) and (g) are mentioned.

（イ）前記第１正レンズ群（Ｌｌ）を第３レンズ群（第
３正レンズ群）　（ＬＨ　）と変換する方法。(a) A method of converting the first positive lens group (Ll) into a third lens group (third positive lens group) (LH).

（口）前記第２負レンズ群（Ｌ，）を第３レンズ群（第
３負レンズ群）　（ＬＨ　）と変換する方法。(Example) A method of converting the second negative lens group (L,) into a third lens group (third negative lens group) (LH).

上記方法（イ）、（口）において、条件■について説明
する．尚、方法（イ）においては、第３レンズ群（ＬＨ
　）は第３正レンズ群であり、変換されるレンズ群の焦
点路＃（ｒｃ　）は第１正レンズ群（Ｌ、）の焦点距離
である．また、方法（口）においては、第３レンズ群（
ＬＨ）は第３負レンズ群であり、変換されるレンズ群の
焦点距離（ｆ、）は第２負レンズ群（ＬＭ）の焦点距離
である。In the above methods (a) and (g), condition (■) will be explained. In addition, in method (a), the third lens group (LH
) is the third positive lens group, and the focal path #(rc) of the lens group to be converted is the focal length of the first positive lens group (L, ). In addition, in the method (mouth), the third lens group (
LH) is the third negative lens group, and the focal length (f, ) of the lens group to be converted is the focal length of the second negative lens group (LM).

まず、（イ）の方法において、通常ズーム域の長焦点端
での後続の第２負レンズ群（Ｌ、）の横倍率をβとし、
変換される第１正レンズ群（Ｌ、）の焦点距離をｆ、と
し、長焦点端での主レンズ系の焦点距離をｆ７とすると
、 Ｉｔ””ｆ。β で示される関係式が得られる。First, in method (a), let β be the lateral magnification of the subsequent second negative lens group (L,) at the long focal end of the normal zoom range,
If the focal length of the first positive lens group (L,) to be converted is f, and the focal length of the main lens system at the long focal length end is f7, then It""f. The relational expression shown by β is obtained.

従って、この第１正レンズ群（Ｌｌ）の像点位置と第３
正レンズ群（ｔ、Ｎ）の像点位置とが一致するように、
第１正レンズ群（１，＋）を第３正レンズ群（ＬＨ）と
交換すると、以下の関係式で示される主レンズ系の新た
な焦点距離（ｒｔ　）が得られる。Therefore, the image point position of this first positive lens group (Ll) and the third
so that the image point position of the positive lens group (t, N) matches,
When the first positive lens group (1,+) is replaced with the third positive lens group (LH), a new focal length (rt) of the main lens system is obtained as expressed by the following relational expression.

ｆｔ＝ｆＮβ 本発明の目的は長焦点化であるから、ｆ、＜ｒＮであれ
ば条件■がこれに従う。ft=fNβ Since the purpose of the present invention is to make the focal point long, if f<rN, the condition (2) follows.

次に（ロ）の方法について説明すると、後続の第２負レ
ンズ群（Ｌ、）に対しての物点と像点の間隔をＤとし、
第２負レンズ群（Ｌｌ）の焦点距離をｆｃとし、第２負
レンズ群（Ｌｌ）の横倍率をβとしたとき、周知の如く で示される関係式が成立する。通常、第２負レンズ群（
Ｌｌ）の横倍率（β）は、β〉１で構成される。ズーム
レンズの全長が大型化するのを防ぎつつ、主レンズ系の
焦点距離を拡大させるためには、第２負レンズ群（Ｌ、
）を焦点距離がｆ、の第３負レンズ群（ＬＨ）におきか
えた場合、前記りがほぼ一定として、前記βを増大させ
る必要がある。つまり、変換する第３負レンズ群（ｔ、
＋＋）の横倍率をβ゛　とすると、 で示される関係式が成立するので、（１〈）β〈方法（
ロ）においてはｆＮ、ｆｃ＜Ｏであるので、１　　　１
　　となる。従って、−船釣に条〈 ｆ、　　　　　　ｆｃ 件■を満足せしめることが長焦点化につながることにな
る。Next, to explain method (b), let the distance between the object point and the image point for the subsequent second negative lens group (L,) be D,
When the focal length of the second negative lens group (Ll) is fc and the lateral magnification of the second negative lens group (Ll) is β, the well-known relational expression shown below holds true. Usually, the second negative lens group (
The lateral magnification (β) of Ll) is composed of β>1. In order to increase the focal length of the main lens system while preventing the overall length of the zoom lens from increasing, the second negative lens group (L,
) is replaced with the third negative lens group (LH) having a focal length of f, it is necessary to increase the above β while assuming that the above is approximately constant. In other words, the third negative lens group (t,
If the horizontal magnification of ++) is β゛, the relational expression shown is established, so (1〈)β〈method (
In (b), fN and fc<O, so 1 1
becomes. Therefore, satisfying the condition (f, fc) for boat fishing will lead to a longer focal length.

条件■は本発明のズームレンズにおける焦点距離頭載を
規定するものである。ｆＬ／ｒアが条件■の下限を越え
る場合は、長焦点端における焦点距離の拡大が不十分で
本発明の目的をはずれる。Condition (2) defines the focal length of the zoom lens of the present invention. If fL/ra exceeds the lower limit of condition (2), the focal length at the long focal length end will not be sufficiently expanded and the object of the present invention will be missed.

また、上限を越えて焦点距離をさらに拡大しようとする
と、交換すべき第３レンズ群（ＬＨ）の構成が複雑化す
るか又は複雑化を避けた場合収差劣化がもたらされる。Furthermore, if the focal length is further increased beyond the upper limit, the configuration of the third lens group (LH) to be replaced will become complicated, or if complication is avoided, aberrations will deteriorate.

条件■は長焦点化の結果、ズームレンズの全長を大きく
しないように規定するものである。条件■の下限を越え
る構成は、収差性能の劣化につながる。また、上限を越
える場合は収差補正上有利となるが、ズームレンズの全
長が長くなってしまう。Condition (2) stipulates that the total length of the zoom lens should not be increased as a result of increasing the focal length. A configuration that exceeds the lower limit of condition (2) leads to deterioration of aberration performance. Furthermore, if the upper limit is exceeded, it is advantageous in terms of aberration correction, but the total length of the zoom lens becomes longer.

なお、方法（イ）によれば、単なる長焦点端における長
焦点化のみならず、ズーム域全体としての長焦点化をも
達成することができる。例えば第１正レンズ群（Ｌ、）
の玉砕をねじ込み式などで構成すれば、第１正レンズ群
（Ｌｌ）の交換後のズーミングで延長ズームとすること
ができる。この際、交換用の新たなズームカム機構は必
要とされない。Note that according to method (a), it is possible to achieve not only a long focal length at the long focal length end but also a long focal length for the entire zoom range. For example, the first positive lens group (L,)
If the lens is configured as a screw-in type, extended zooming can be achieved by zooming after replacing the first positive lens group (Ll). At this time, a new zoom cam mechanism for replacement is not required.

また、（ロ）の方法は特に正レンズ先行型の高倍率ズー
ムレンズに応用した場合有効である。−般に正レンズ先
行型の高倍率ズームレンズは、長焦点端で、第１正レン
ズ群（Ｌ、）が前方へ繰り出され、第２レンズ群以降が
第１正レンズ群（Ｌｌ）と広い間隔をおいた第２負レン
ズ群（Ｌ、）として作用する所謂テレフォトタイプを構
成するわけであるが、その第２負レンズ群（Ｌｌ）の構
成は単独の長焦点レンズの後群としてはかなり複雑なも
のといえる０本発明は、その点に着目し、該第２負レン
ズ群（Ｌ、）を比較的簡単な構成の第３負レンズ群（Ｌ
Ｈ）に変換することで大幅な長焦点化を達成できること
を見出したものである。Furthermore, method (b) is particularly effective when applied to a high-power zoom lens with a positive lens first type. -Generally, in a positive lens-first high-power zoom lens, at the long focal length end, the first positive lens group (L,) is extended forward, and the second and subsequent lens groups are wide as the first positive lens group (Ll). It constitutes a so-called telephoto type that acts as a spaced second negative lens group (L,), but the configuration of the second negative lens group (Ll) is that it cannot be used as a rear group of a single long focal length lens. The present invention focuses on this point, which can be said to be quite complicated, and replaces the second negative lens group (L) with a relatively simple third negative lens group (L).
It was discovered that by converting to H), a significantly longer focal length can be achieved.

つまり、本実施例においては変換する第３レンズ群（Ｌ
、４）が、前記変換される第１正レンズ群（Ｌｌ）又は
第２負レンズ群（Ｌｍ）と同じレンズの構成枚数か又は
少ないレンズの構成枚数で構成されることにより、コス
トアップの軽減を図っている。In other words, in this embodiment, the third lens group (L
, 4) is configured with the same number of lenses as the first positive lens group (Ll) or second negative lens group (Lm) to be converted, or with a smaller number of lenses, thereby reducing cost increase. We are trying to

以上のように本発明によれば、コンパクトで操作性がよ
（、しかも諸収差が良好に補正され変倍比が３倍以上の
切換え式ズームレンズを実現することが出来る。As described above, according to the present invention, it is possible to realize a switching type zoom lens which is compact and has good operability (in addition, various aberrations are well corrected and the variable power ratio is 3 times or more).

裏」Ｌ糎 以下、本発明に係る切換え式ズームレンズの実施例を示
す。Embodiments of the switching zoom lens according to the present invention will be shown below.

但し、各実施例において、ｒ１〜ｒｔ４は曲率半径、ｄ
１〜ａＺ３は軸上面間隔を示し、Ｎ、〜Ｎ１３　＋　　
シ１〜シ１３はｄ線に対する屈折率、アツベ数を示す。However, in each example, r1 to rt4 are the radius of curvature, d
1 to aZ3 indicate the distance between the axial surfaces, N, to N13 +
C1 to C13 indicate the refractive index and Atsube number for the d-line.

また、ｆは焦点距離＋ＦＮＯはＦナンバーを示す。Further, f represents the focal length+FNO represents the F number.

また、実施例中における非球面は、その非球面上の任意
の点を（ｘ、ｙ、ｚ）としたとき、全て次式にて定義す
るものとする。Furthermore, all aspherical surfaces in the examples are defined by the following equations, where (x, y, z) is an arbitrary point on the aspherical surface.

非球面頂点からの距離（＝　、ｒＰ−「嘔−）Ｃ０：非
球面頂点における曲率 Ａｉ：ｉ次の非球面曲率 である。Distance from the aspherical apex (=, rP - "y") C0: Curvature at the aspherical apex Ai: i-th order aspherical curvature.

〈実施例１〉 （切換え前） ｆ　＝３９．３〜５８．５〜８６．６ Ｆ、。−３゜５〜５．３〜７．８ 但し、Ｘ：非球面の光軸に平行な方向における非球面頂
点からの変位 Φ：非球面の光軸に垂直な方向における１１Ｍ敗 ｒｓ”　　：　　Ａ４＝−０，１０２９７ｘｌＯ−３Ａ
、＝　−０，６４６２４ｘｌＯ−’ へ５＝−０，４８８１５ｘｌＯ−” Ａｌｅ　　＝　　０．６８３３６　　×ｌＱ−＋６Ｊｉ
１ｇ　＝−０，４６６９１ｘｌＯ−目（切換え後） ｆ　＝１２８．０ ＦＮＯ＝９．１ 薯１１旧乳敗 ｒｓ”　：　Ａａ　＝　　０．１２２１８　　Ｘ　１０
−　’Ａ、＝　−０，４４３５０Ｘｌ０−’ Ａ＊＝　　０．３１５０８　　Ｘｌ０−”Ａ、。−−０
，５７６７６ｘｌＯ−” Ａｌｔ　　−０，４０４８７ｘｔｏ−”〈実施例２〉 （切換え前） ｆ　−３６，０〜６０．０〜１０１．５ＦＮＯ−４，１
〜５．６〜５．８ 皿圭主怪　釉」Ｊ酊匪阻　皿訴崖　　ヱヱ丘敗（切換え
後） ｆ　＝１９５．０ Ｆ）ｌＧ＝９．３ 尚、上記実施例１は前記方法（イ）、すなわち、第１正
レンズ群（Ｌｌ）を第３正レンズ群（Ｌイ）と変換する
方法に相当し、実施例２は方法（ロ）、すなわち、第２
負レンズ群（Ｌ、）を第３負レンズ群（Ｌｓ　）と変換
する方法に相当する。<Example 1> (Before switching) f = 39.3 to 58.5 to 86.6 F. -3゜5~5.3~7.8 However, X: Displacement from the apex of the aspherical surface in the direction parallel to the optical axis of the aspherical surface Φ: 11M loss in the direction perpendicular to the optical axis of the aspherical surface rs": A4 =-0,10297xlO-3A
, = −0,64624xlO−' to 5=−0,48815xlO−” Ale = 0.68336 ×lQ−+6Ji
1g = -0,46691xlO-th (after switching) f = 128.0 FNO = 9.1 11 old milk loss rs”: Aa = 0.12218 x 10
- 'A, = -0,44350Xl0-' A*= 0.31508 Xl0-"A,.--0
,57676xlO-" Alt -0,40487xto-"<Example2> (Before switching) f -36,0~60.0~101.5FNO-4,1
~5.6~5.8 Sarakeishukai Glaze' J Inobuen Sarasukei Eieoka defeat (after switching) f = 195.0 F) lG = 9.3 In addition, the above-mentioned Example 1 is the above-mentioned method (a), that is, the method of converting the first positive lens group (Ll) into the third positive lens group (La), and the second embodiment corresponds to the method (b), that is, the second positive lens group.
This corresponds to a method of converting the negative lens group (L,) into the third negative lens group (Ls).

第１図は切換え前の実施例１のレンズ＃Ｉ成を示してお
り、第２図は切換え後の実施例１のレンズ構成を示して
いる。また、第３図は切換え前の実施例２のレンズ構成
を示しており、第４図は切換え後の実施例２のレンズ構
成を示している。また、第１図中、主レンズ系を構成す
る第１正レンズ群（Ｌｌ）及び第２負レンズ群（Ｌｌ）
について、最短焦点距離状Ｂ　（Ｗ）から最長焦点距離
状Ｍ　（Ｔ）へのズーミングによる移動を矢印（１）及
び（２）によって模式的に示している。第３図中、第１
正レンズ群（Ｌｌ）並びに第２負レンズ群（Ｌ、）を構
成するレンズ群（Ｌａ　）　（Ｌｍ　）及び（Ｌ、）に
ついて、最短焦点距離状態（−）から最長焦点距離状態
（Ｔ）へのズーミングによる移動を矢印（３）〜（６）
によって模式的に示している。FIG. 1 shows the lens configuration of Example 1 before switching, and FIG. 2 shows the lens configuration of Example 1 after switching. Further, FIG. 3 shows the lens configuration of Example 2 before switching, and FIG. 4 shows the lens configuration of Example 2 after switching. In addition, in FIG. 1, the first positive lens group (Ll) and the second negative lens group (Ll) that constitute the main lens system
, movement by zooming from the shortest focal length B (W) to the longest focal length M (T) is schematically shown by arrows (1) and (2). In Figure 3, 1st
For the lens groups (La) (Lm) and (L,) constituting the positive lens group (Ll) and the second negative lens group (L,), from the shortest focal length state (-) to the longest focal length state (T) Use arrows (3) to (6) to move by zooming.
This is schematically shown.

第５図及び第６図は実施例１及び２にそれぞれ対応する
収差図で、それぞれ＜Ｓ　＞は主レンズ系の最短焦点距
離状態、〈河〉は主レンズ系の中間焦点距離状態、〈Ｌ
〉は主レンズ系の最長焦点距離状態、〈超Ｌ〉は切換え
後の焦点距離状態での諸収差を表わす、また、実線（ｄ
）はｄ線に対する球面収差を表わし、点線（ＳＣ）は正
弦条件を表わす。5 and 6 are aberration diagrams corresponding to Examples 1 and 2, respectively, where <S> is the shortest focal length state of the main lens system, <Ri> is the intermediate focal length state of the main lens system, and <L
> represents the longest focal length state of the main lens system, and <ultra L> represents various aberrations at the focal length state after switching.
) represents the spherical aberration for the d-line, and the dotted line (SC) represents the sine condition.

更に点線（ＤＭ）と実線（Ｏ３）はメリジオナル面とサ
ジタル面での非点収差をそれぞれ表わしている。Further, the dotted line (DM) and the solid line (O3) represent astigmatism on the meridional plane and the sagittal plane, respectively.

２里坐四星 本発明によれば、主レンズ系の長焦点端における焦点距
離よりさらに長焦点側の焦点距離が達成されると共に、
このように主レンズ系の最長焦点距離よりさらに焦点距
離を延長しても全長の大幅な増大化や複雑化が生じるこ
とのない、変倍比が３倍以上の切換え式ズームレンズを
実現することができる。According to the present invention, a focal length further on the long focal point side than the focal length at the long focal end of the main lens system is achieved, and
To realize a switching type zoom lens with a variable power ratio of 3 times or more, which does not significantly increase the overall length or become complicated even when the focal length is extended beyond the longest focal length of the main lens system. I can do it.

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

第１図は切換え前の実施例１のレンズ構成図、第２図は
切換え後の実施例１のレンズ構成図であり、第３図は切
換え前の実施例２のレンズ構成図、第４図は切換え後の
実施例２のレンズ構成図である。第５図及び第６図は実
施例１及び実施例２にそれぞれ対応する収差図である。 （Ｌｌ）・・−第１正レンズ群。 （Ｌｌ）−・−第２負レンズ群。 （Ｌｓ　）−−・第３レンズ群。FIG. 1 is a lens configuration diagram of Example 1 before switching, FIG. 2 is a lens configuration diagram of Example 1 after switching, FIG. 3 is a lens configuration diagram of Example 2 before switching, and FIG. 2 is a lens configuration diagram of Example 2 after switching. FIG. 5 and 6 are aberration diagrams corresponding to Example 1 and Example 2, respectively. (Ll)...-first positive lens group. (Ll)--Second negative lens group. (Ls) ---Third lens group.

Claims (2)

【特許請求の範囲】[Claims] （１）物体側から順に、第１正レンズ群及び第２負レン
ズ群から成り少なくとも前記第１正レンズ群と前記第２
負レンズ群との間隔を変化させることによりズーミング
を行う主レンズ系と、前記第１正レンズ群と変換自在に
設けられた第３正レンズ群又は前記第２負レンズ群と変
換自在に設けられた第３負レンズ群から成る第３レンズ
群と、から構成され、前記主レンズ系の長焦点端におい
て、前記第１正レンズ群の前記第３正レンズ群への変換
又は前記第２負レンズ群の前記第３負レンズ群への変換
を行うことによって主レンズ系の長焦点端における焦点
距離よりさらに長焦点側の焦点距離を達成すると共に下
記の条件を満足することを特徴とする切換え式ズームレ
ンズ； １／ｆ＿Ｎ＜１／ｆ＿Ｃ １．２＜ｆ＿Ｌ／Ｆ＿Ｔ＜ｆ＿Ｔ／ｆ＿Ｗ ０．９＜ＴＬ＿Ｎ／ＴＬ＿Ｉ＜１．１ 但し ｆ＿Ｃ：変換される第１正レンズ群又は第２負レンズ群
の焦点距離 ｆ＿Ｎ：変換する第３レンズ群の焦点距離 ｆ＿Ｔ：前記変換前の主レンズ系の最長焦点距離 ｆ＿Ｗ：前記変換前の主レンズ系の最短焦点距離 ｆ＿Ｌ：前記変換後のレンズ系の焦点距離 ＴＬ＿Ｉ：前記変換前の主レンズ系の長焦点端における
レンズ先端から像面までの距離 ＴＬ＿Ｎ：前記変換後のレンズ系のレンズ先端から像面
までの距離 である。(1) Consisting of a first positive lens group and a second negative lens group in order from the object side, at least the first positive lens group and the second negative lens group.
a main lens system that performs zooming by changing the distance from the negative lens group; and a third positive lens group that is provided to be convertible to the first positive lens group, or a third positive lens group that is provided to be convertible to the second negative lens group. a third lens group consisting of a third negative lens group, and at the long focal point end of the main lens system, the first positive lens group is converted into the third positive lens group, or the second negative lens A switching type, characterized in that by converting the group into the third negative lens group, a focal length further on the long focal point side than the focal length at the long focal end of the main lens system is achieved, and the following conditions are satisfied: Zoom lens; 1/f_N<1/f_C 1.2<f_L/F_T<f_T/f_W 0.9<TL_N/TL_I<1.1 where f_C is the value of the first positive lens group or second negative lens group to be converted. Focal length f_N: Focal length of the third lens group to be converted f_T: Longest focal length of the main lens system before conversion f_W: Shortest focal length of the main lens system before conversion f_L: Focal length of the lens system after conversion TL_I: Distance from the lens tip to the image plane at the long focal point end of the main lens system before the conversion TL_N: Distance from the lens tip of the lens system to the image plane after the conversion. （２）前記変換する第３レンズ群は、前記変換される第
１正レンズ群又は第２負レンズ群と同じレンズの構成枚
数か又は少ないレンズの構成枚数で構成されていること
を特徴とする第１請求項に記載の切換え式ズームレンズ
。(2) The third lens group to be converted is composed of the same number of lenses as the first positive lens group or the second negative lens group to be converted, or a smaller number of lenses. A switchable zoom lens according to claim 1.
JP1137152A 1989-05-30 1989-05-30 Switching type zoom lens Pending JPH032709A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1137152A JPH032709A (en) 1989-05-30 1989-05-30 Switching type zoom lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1137152A JPH032709A (en) 1989-05-30 1989-05-30 Switching type zoom lens

Publications (1)

Publication Number Publication Date
JPH032709A true JPH032709A (en) 1991-01-09

Family

ID=15192038

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1137152A Pending JPH032709A (en) 1989-05-30 1989-05-30 Switching type zoom lens

Country Status (1)

Country Link
JP (1) JPH032709A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014041705A1 (en) 2012-09-12 2014-03-20 エム・テクニック株式会社 Method for manufacturing metal microparticles
JP2015179228A (en) * 2014-03-20 2015-10-08 株式会社オプトロジック Imaging lens
US9419326B2 (en) 2009-09-22 2016-08-16 Samsung Electro-Mechanics Co., Ltd. Antenna pattern frame, method and mold for manufacturing the same, method for manufacturing an electronic device case, and electronic device
CN114063252A (en) * 2021-11-26 2022-02-18 福建福光股份有限公司 Miniaturized large-power fog-penetrating optical system with sixty-five million pixels

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9419326B2 (en) 2009-09-22 2016-08-16 Samsung Electro-Mechanics Co., Ltd. Antenna pattern frame, method and mold for manufacturing the same, method for manufacturing an electronic device case, and electronic device
WO2014041705A1 (en) 2012-09-12 2014-03-20 エム・テクニック株式会社 Method for manufacturing metal microparticles
JP2015179228A (en) * 2014-03-20 2015-10-08 株式会社オプトロジック Imaging lens
CN114063252A (en) * 2021-11-26 2022-02-18 福建福光股份有限公司 Miniaturized large-power fog-penetrating optical system with sixty-five million pixels

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