JP3352263B2 - Zoom lens - Google Patents

Zoom lens

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Publication number
JP3352263B2
JP3352263B2 JP33593494A JP33593494A JP3352263B2 JP 3352263 B2 JP3352263 B2 JP 3352263B2 JP 33593494 A JP33593494 A JP 33593494A JP 33593494 A JP33593494 A JP 33593494A JP 3352263 B2 JP3352263 B2 JP 3352263B2
Authority
JP
Japan
Prior art keywords
lens
lens group
zoom
positive
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 - Fee Related
Application number
JP33593494A
Other languages
Japanese (ja)
Other versions
JPH08179213A (en
Inventor
宏志 遠藤
秀樹 小川
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP33593494A priority Critical patent/JP3352263B2/en
Publication of JPH08179213A publication Critical patent/JPH08179213A/en
Application granted granted Critical
Publication of JP3352263B2 publication Critical patent/JP3352263B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【産業上の利用分野】本発明はズームレンズに関し、特
に広角端での撮影画角が82度程度、Fナンバー2.8
〜3.6程度、変倍比3.3〜4.1程度の全変倍範囲
にわたり良好なる光学性能を有した写真用カメラやビデ
オカメラ、そして電子スチルカメラ等に好適な高変倍
比、広画角のズームレンズに関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens, and in particular, has a photographic field angle of about 82 degrees at the wide angle end and an F-number of 2.8.
A high zoom ratio suitable for a photographic camera, a video camera, an electronic still camera, etc., having good optical performance over the entire zoom range of about 3.3 to 4.1 and a zoom ratio of about 3.3 to 4.1; The present invention relates to a wide-angle zoom lens.

【0002】[0002]

【従来の技術】従来より写真用カメラやビデオカメラ等
の撮影系には高変倍比で広画角で、しかも全変倍範囲に
わたり高コントラストで高い光学性能を有したズームレ
ンズが要求されている。
2. Description of the Related Art Conventionally, a photographing system such as a photographic camera or a video camera has been required to have a zoom lens having a high zoom ratio, a wide angle of view, and a high contrast and high optical performance over the entire zoom range. I have.

【0003】例えば、特開昭57−2014号公報や特
開昭60−39613号公報等では物体側より順に正、
負、正、負、そして正の屈折力の5つのレンズ群を有
し、広角端での撮影画角が75度程度、変倍比が5程度
の広画角で高変倍比のズームレンズが提案されている。
又特開平5−119260号公報では前述と同様の屈折
力配置の5つのレンズ群を有し、広角端での撮影画角が
75度程度、変倍比が3.5〜7倍程度の広画角で高変
倍比のズームレンズが提案されている。又、特開平4−
70708号公報では、物体側より順に正、負、正、
正、そして負の屈折力の5つのレンズ群より成り、広角
端の撮影画角が70度程度、変倍比7程度のズームレン
ズが提案されている。
[0003] For example, in Japanese Patent Application Laid-Open Nos. 57-2014 and 60-39613, the positive,
A zoom lens with five lens groups of negative, positive, negative, and positive refractive power, a wide angle of view with a shooting angle of view of about 75 degrees at the wide angle end, and a zoom ratio of about 5 with a high zoom ratio. Has been proposed.
Japanese Patent Application Laid-Open No. 5-119260 has five lens groups having the same refractive power arrangement as described above, and has a wide angle of view of about 75 degrees at a wide-angle end and a zoom ratio of about 3.5 to 7 times. 2. Description of the Related Art A zoom lens having an angle of view and a high zoom ratio has been proposed. In addition, Japanese Unexamined Patent Publication No.
In Japanese Patent No. 70708, positive, negative, positive,
A zoom lens has been proposed which includes five lens groups having positive and negative refractive power, has a shooting angle of view of about 70 degrees at the wide-angle end, and has a zoom ratio of about 7.

【0004】[0004]

【発明が解決しようとする課題】一般に物体側より順に
正、負、正、負、そして正の屈折力の5つのレンズ群よ
り成る5群ズームレンズにおいて、広角端での撮影画角
が82度程度の広画角化及び変倍比3〜4程度の高変倍
化を図りつつ全変倍範囲にわたり高い光学性能を維持
し、所定の口径比を得るにはレンズ系を構成する各レン
ズ群の光学的諸定数を適切に設定することが重要となっ
てくる。
Generally, in a five-unit zoom lens composed of five lens units having positive, negative, positive, negative, and positive refractive powers in order from the object side, the photographic field angle at the wide angle end is 82 degrees. In order to maintain a high optical performance over the entire zoom range and achieve a predetermined aperture ratio while achieving a wide angle of view and a high zoom ratio of about 3 to 4, each lens group constituting a lens system It is important to appropriately set the optical constants of.

【0005】例えば前述の5群ズームレンズにおいて、
変倍に伴う各レンズ群の移動条件や各レンズ群の屈折力
そして変倍作用をする第2群の変倍比や倍率等を適切に
設定しないと諸収差の発生が増大し、全変倍範囲にわた
り良好なる画質の映像を得るのが難しくなってくる。
For example, in the above-described five-unit zoom lens,
Unless the conditions for moving each lens unit during zooming, the refractive power of each lens unit, and the zooming ratio and magnification of the second unit that performs zooming, are not set properly, the occurrence of various aberrations increases, and all zooming occurs. It becomes difficult to obtain images of good image quality over the range.

【0006】本発明は、5群ズームレンズにおいて、主
に変倍に伴う各レンズ群の移動条件や、各レンズ群の屈
折力、そして第2群の結像倍率等を適切に設定すること
により広角端の撮影画角が82度程度、変倍比3〜4程
度の全変倍範囲にわたり、しかも全画面にわたり高い光
学性能を有するズームレンズ及びそれを用いたカメラの
提供を目的とする。
According to the present invention, in a five-unit zoom lens, the moving conditions of each lens unit mainly due to zooming, the refractive power of each lens unit, and the imaging magnification of the second unit are appropriately set. It is an object of the present invention to provide a zoom lens having a high optical performance over the entire zoom range with a photographing angle of view at the wide angle end of about 82 degrees and a zoom ratio of about 3 to 4, and a camera using the same.

【0007】[0007]

【課題を解決するための手段】本発明のズームレンズ
は、物体側より順に、正の屈折力の第1レンズ群、負の
屈折力の第2レンズ群、正の屈折力の第3レンズ群、負
の屈折力の第4レンズ群、正の屈折力の第5レンズ群を
有し、広角端から望遠端への変倍に際して、該第1レン
ズ群と第2レンズ群の間隔が増加し、該第2レンズ群と
第3レンズ群の間隔が減少し、該第3レンズ群と第4レ
ンズ群の間隔が増大し、該第4レンズ群と第5レンズ群
の間隔が減少するように移動させるズームレンズであっ
て、該第2レンズ群の広角端における無限遠物体のとき
の結像倍率をβ2W、該第i群の焦点距離をfiとした
とき、 0.18<|β2W|<0.255 ‥‥‥(1) 0.7<f5/|f4|<1.2 ‥‥‥(2) なる条件を満足することを特徴としている。
A zoom lens according to the present invention comprises, in order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power. A fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power, and when zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases. The distance between the second lens group and the third lens group is reduced, the distance between the third lens group and the fourth lens group is increased, and the distance between the fourth lens group and the fifth lens group is reduced. 0.18 <| β2W | <where the imaging magnification at the wide-angle end of the second lens group at an infinity object is β2W and the focal length of the i-th group is fi. 0.255 ‥‥‥ (1) 0.7 <f5 / | f4 | <1.2 ‥‥‥ (2) It is a symptom.

【0008】[0008]

【実施例】図1〜図5は本発明の数値実施例1〜5の広
角端におけるレンズ断面図である。図6〜図10は本発
明の数値実施例1〜5の諸収差図である。収差図におい
て(A)は広角端、(B)は望遠端を示しいている。
1 to 5 are sectional views of a lens at a wide angle end according to Numerical Examples 1 to 5 of the present invention. 6 to 10 are graphs showing various aberrations of Numerical Examples 1 to 5 of the present invention. In the aberration diagrams, (A) shows the wide-angle end, and (B) shows the telephoto end.

【0009】図中、L1は正の屈折力の第1群、L2は
負の屈折力の第2群、L3は正の屈折力の第3群、L4
は負の屈折力の第4群、L5は正の屈折力の第5群、S
Pは絞りであり、第3群の前方に設けている。IPは像
面である。
In the figure, L1 is a first group having a positive refractive power, L2 is a second group having a negative refractive power, L3 is a third group having a positive refractive power, L4
Denotes a fourth unit having a negative refractive power, L5 denotes a fifth unit having a positive refractive power, and
P denotes an aperture, which is provided in front of the third lens group. IP is an image plane.

【0010】本実施例では広角端から望遠端への変倍に
際して、各レンズ群を矢印の如く物体側へ第1群と第2
群の間隔が増加し、第2群と第3群の間隔が減少し、第
3群と第4群の間隔が増大し、第4群と第5群の間隔が
減少するように移動させている。尚、絞りSPは第3群
と一体的に移動させている。
In this embodiment, upon zooming from the wide-angle end to the telephoto end, the first and second lens units are moved toward the object side as indicated by arrows.
The distance between the groups increases, the distance between the second and third groups decreases, the distance between the third and fourth groups increases, and the distance between the fourth and fifth groups decreases. I have. The stop SP is moved integrally with the third lens unit.

【0011】本実施例では、このように変倍の際に5つ
のレンズ群を移動させることにより複数のレンズ群に変
倍をバランス良く分担させ、効率良く変倍を行うと共
に、特に中間のズーム領域での収差補正を良好に行って
いる。
In this embodiment, by moving the five lens units during zooming in this way, the zooming is shared among a plurality of lens units in a well-balanced manner, so that the zooming can be performed efficiently, and especially, the intermediate zoom. The aberration correction in the region is performed well.

【0012】本実施例では前述の如く、5つのレンズ群
の屈折力と変倍に伴う各レンズ群の移動条件を設定する
と共に第2群の広角端の無限遠物体のときの結像倍率β
2Wや、第4群と第5群の焦点距離の比、f5/|f4
|を条件式(1),(2)を満足するようにしている。
In this embodiment, as described above, the refracting power of the five lens units and the conditions for moving each of the lens units upon zooming are set, and the imaging magnification β for the infinity object at the wide-angle end of the second unit.
2W or the ratio of the focal lengths of the fourth and fifth lens units, f5 / | f4
Is satisfied so as to satisfy the conditional expressions (1) and (2).

【0013】次に前述の条件式(1),(2)の技術的
意味について説明する。条件式(1)は広角端の物体無
限遠での第2群の結像倍率を規定するものであり、下限
値を超えることは第1群の焦点距離が長くなりすぎるこ
とを意味し、レンズ全長の短縮が困難となる。又上限値
を超えることは第1群の焦点距離が短くなりすぎること
を意味し、レンズ全長の短縮には有利であるが、収差補
正が困難となり、広角化に不利である。
Next, the technical meaning of the conditional expressions (1) and (2) will be described. Conditional expression (1) defines the imaging magnification of the second lens unit at infinity at the wide-angle end. Exceeding the lower limit means that the focal length of the first lens unit becomes too long. It is difficult to shorten the overall length. Exceeding the upper limit means that the focal length of the first lens unit becomes too short, which is advantageous for shortening the overall length of the lens, but makes aberration correction difficult and disadvantageous for widening the angle of view.

【0014】条件式(2)は第4群の焦点距離に対する
第5群の焦点距離の比を規定し、主に広角化を達成しつ
つ、所定のバックフォーカスを確保する為のものであ
る。下限値を超えて第5群の焦点距離が短くなると広角
化及びバックフォーカスの確保には有利であるが、この
レンズ群で発生する諸収差、特に非点収差が大きくなり
好ましくない。又下限値を超えて第5群の焦点距離が長
くなると、収差補正には有利だが、広角化、コンパクト
化が難しくなってくる。
Conditional expression (2) defines the ratio of the focal length of the fifth lens group to the focal length of the fourth lens group, and is intended mainly to achieve a wide angle and to secure a predetermined back focus. If the focal length of the fifth lens unit is shorter than the lower limit and the fifth lens unit is short, it is advantageous for widening the angle and securing the back focus. If the focal length of the fifth lens unit becomes longer than the lower limit, it is advantageous for aberration correction, but it becomes difficult to widen the angle and make it compact.

【0015】本発明では以上のようなレンズ構成により
広角端での撮影画角が82度と広画角で変倍比3〜4程
度、Fナンバー2.8〜3.6程度の全変倍範囲にわた
り良好なる光学性能を有したズームレンズを得ている。
In the present invention, with the above-described lens configuration, the photographic field angle at the wide-angle end is 82 degrees, and a wide field of view has a zoom ratio of about 3 to 4 and an F number of about 2.8 to 3.6. A zoom lens having good optical performance over a range is obtained.

【0016】また本発明においてはフォーカスを第2群
を移動させて行っており、これにより、第1群でフォー
カスを行った場合に比べて第1群のレンズ外径の増大を
防止しつつ、撮影可能な至近距離の短縮化を図ってい
る。又、第5群中にレンズ中心からレンズ周辺にいくに
従い正の屈折力が弱くなる形状の非球面を用いることに
より、主に球面収差、非点収差、そして像面弯曲をバラ
ンス良く補正している。特に広角側での高次の像面弯曲
を良好に補正している。
Further, in the present invention, focusing is performed by moving the second unit, thereby preventing an increase in the lens outer diameter of the first unit as compared with the case where focusing is performed by the first unit. The shortest possible shooting distance has been reduced. Also, by using an aspherical surface having a shape in which the positive refractive power becomes weaker from the center of the lens toward the periphery of the lens in the fifth lens unit, mainly spherical aberration, astigmatism, and curvature of field are corrected in a well-balanced manner. I have. In particular, high-order field curvature on the wide-angle side is favorably corrected.

【0017】本発明に係るズームレンズは以上の諸条件
を満足することにより達成されるが、更に広画角化及び
高変倍化を図る際の収差変動を良好に補正し、高い光学
性能を得るには次の諸条件のうちの少なくとも1つを満
足させるのが良い。
The zoom lens according to the present invention can be achieved by satisfying the above-mentioned conditions. However, it is possible to satisfactorily correct aberration fluctuations when widening the angle of view and increasing the zoom ratio, thereby achieving high optical performance. To achieve this, it is preferable to satisfy at least one of the following conditions.

【0018】(1−1)前記第1群は物体側に凸面を向
けたメニスカス状の負レンズと正レンズとを接合した貼
合わせレンズ、そして物体側に凸面を向けたメニスカス
状の正レンズを有し、前記第2群は物体側へ凸面を向け
たメニスカス状の負レンズ、両レンズ面が凹面の負レン
ズ、両レンズ面が凸面の正レンズ、そして物体側に凹面
を向けた負レンズを有していることである。これにより
第1群のレンズ外径を小さくし、コンパクト化を図り、
又広角端での広画角化を図りつつ、全変倍範囲にわたり
諸収差を良好に補正している。
(1-1) The first group includes a cemented lens formed by joining a negative meniscus lens having a convex surface facing the object side and a positive lens, and a positive meniscus lens having a convex surface facing the object side. The second group includes a meniscus negative lens having a convex surface facing the object side, a negative lens having both lens surfaces concave, a positive lens having both convex lens surfaces, and a negative lens having a concave surface facing the object side. Is to have. As a result, the outer diameter of the lens of the first group is reduced to achieve compactness,
In addition, various aberrations are satisfactorily corrected over the entire zoom range while widening the angle of view at the wide angle end.

【0019】(1−2)前記第3群は物体側に凸面を向
けたメニスカス状の負レンズと両レンズ面が凸面の正レ
ンズとを接合した貼合わせレンズ、そして両レンズ面が
凸面の正レンズを有していることである。これにより、
所定の変倍比を確保しつつ、変倍に伴う諸収差の発生を
少なくしている。特に全変倍範囲にわたり球面収差を良
好に補正している。
(1-2) The third group is a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens having both convex lens surfaces are joined, and both positive lens surfaces are convex. That is, it has a lens. This allows
While ensuring a predetermined zoom ratio, the occurrence of various aberrations due to zooming is reduced. In particular, spherical aberration is favorably corrected over the entire zoom range.

【0020】(1−3)前記第5群は両レンズ面が凸面
の2つの正レンズと物体側に凹面を向けた負レンズを有
していることである。これにより、変倍に伴う球面収差
等の諸収差の変動をバランス良く補正している。
(1-3) The fifth lens unit includes two positive lenses each having a convex surface on both lens surfaces and a negative lens having a concave surface facing the object side. As a result, variations in various aberrations such as spherical aberration due to zooming are corrected in a well-balanced manner.

【0021】[0021]

【0022】[0022]

【0023】(1−)前記第1群と第2群の広角端に
おける合成焦点距離をf12w、広角端における全系の
焦点距離をfwとしたとき 5.8<f1/|f2|<7 ‥‥‥() 1.4<f5/|f12w|<2.5 ‥‥‥() 0.8<f3/fw<1.1 ‥‥‥() 1.0<f5/|f4|<1.1 ‥‥‥() なる条件を満足することである。
( 1-4 ) When the combined focal length of the first lens unit and the second lens unit at the wide-angle end is f12w, and the focal length of the entire system at the wide-angle end is fw, 5.8 <f1 / | f2 | <7 ‥‥‥ ( 3 ) 1.4 <f5 / | f12w | <2.5 ‥‥‥ ( 4 ) 0.8 <f3 / fw <1.1 ‥‥‥ ( 5 ) 1.0 <f5 / | f4 | <1.1 ‥‥‥ ( 6 ).

【0024】条件式()は第2群の焦点距離に対する
第1群の焦点距離の比を規定し、主に望遠端における第
3群のレンズ外径を小さくし、又高変倍を達成するもの
であり、下限値を超えて第1群の正の屈折力が強くなる
とこの第1群で発生する望遠側の収差、特に球面収差が
大きくなり、これを他のレンズ群でバランス良く補正す
ることが難しくなる。又上限値を超えて第1群の正の屈
折力が弱くなるとコンパクト化が難しくなってくる。
Conditional expression ( 3 ) defines the ratio of the focal length of the first lens unit to the focal length of the second lens unit, and mainly reduces the lens outer diameter of the third lens unit at the telephoto end and achieves high zooming. When the positive refractive power of the first lens unit is increased beyond the lower limit, aberrations on the telephoto side, particularly spherical aberration, generated in the first lens unit are increased, and this is corrected by other lens units in a well-balanced manner. It becomes difficult to do. If the positive refractive power of the first lens unit is weakened beyond the upper limit, it becomes difficult to reduce the size of the first lens unit.

【0025】条件式()は広角端の物体無限遠での第
1群と第2群の合成焦点距離に対して第5群の焦点距離
の比を規定し、主に所定のバックフォーカスを確保しつ
つ、コンパクト及び高性能を達成する為のものであり、
下限値を超えて第5群の正の屈折力が強くなるとバック
フォーカスの確保には有利であるが、第5群で発生する
諸収差、特に像面弯曲が大きくなり、これを他のレンズ
群で良好に補正するのが困難となる。又上限値を超えて
第5群の正の屈折力が弱くなるとバックフォーカスの確
保及びコンパクト化が難しくなってくる。
Conditional expression ( 4 ) defines the ratio of the focal length of the fifth lens unit to the composite focal length of the first lens unit and the second lens unit at infinity at the wide-angle end. It is for achieving compactness and high performance while securing
If the positive refractive power of the fifth lens unit is increased beyond the lower limit value, it is advantageous for securing the back focus. However, various aberrations generated in the fifth lens unit, particularly the curvature of field, increase, and this is reduced to other lens units. And it is difficult to make a good correction. If the positive refractive power of the fifth lens unit is weakened beyond the upper limit, it becomes difficult to secure the back focus and to make the lens compact.

【0026】条件式()は広角端での全系の焦点距離
に対して第3群の焦点距離の比を規定するものであり、
下限値を超えて第3群の正の屈折力が強くなるとコンパ
クト化には有利であるが、第3群で発生する諸収差、特
に球面収差が大きくなり、これを他のレンズ群でバラン
ス良く補正することが困難になる。又上限値を超えて第
3群の正の屈折力が弱くなると多群化の効果が小さくな
り、レンズ全長、レンズ外径が増大してくる。
Conditional expression ( 5 ) defines the ratio of the focal length of the third lens unit to the focal length of the entire system at the wide-angle end.
If the positive refractive power of the third lens unit is increased beyond the lower limit value, it is advantageous for compactness. However, various aberrations, particularly spherical aberration, generated in the third lens unit become large, and this is well balanced by other lens units. It becomes difficult to correct. If the positive refractive power of the third lens unit is weakened beyond the upper limit, the effect of multi-grouping is reduced, and the overall length of the lens and the outer diameter of the lens are increased.

【0027】条件式()は前述した条件式(2)の数
値範囲を更に特定するものであり、これにより広角端の
撮影画角82度程度で変倍比4程度のズームレンズを容
易に得ている。
The conditional expression ( 6 ) further specifies the numerical range of the conditional expression (2), whereby a zoom lens having a photographic field angle of about 82 degrees at the wide-angle end and a zoom ratio of about 4 can be easily realized. It has gained.

【0028】(1−)前記第2群の望遠端の無限遠物
体のときの結像倍率をβ2Tとしたとき |β2T|<1 ‥‥‥() なる条件を満足することである。
( 1-5 ) When the imaging magnification of the second lens group at the telephoto end at infinity is β2T, the following condition is satisfied: | β2T | <1 ( 7 )

【0029】条件式()の条件を満足することで広角
端から望遠端へのズーミング時、第2群の結像倍率が等
倍をはさまない為に無限遠物体から至近物体へのフォー
カシングのとき第2群を常に同一方向へ繰り出すことに
なり第2群でのフォーカシングを可能としている。
When the zooming from the wide-angle end to the telephoto end is satisfied by satisfying the condition of the conditional expression ( 7 ), focusing from an object at infinity to a close object is performed because the imaging magnification of the second lens unit does not fall within the same magnification. In this case, the second lens unit is always moved in the same direction, thereby enabling focusing in the second lens unit.

【0030】次に本発明の数値実施例を示す。数値実施
例においてRiは物体側より順に第i番目のレンズ面の
曲率半径、Diは物体側より第i番目のレンズ厚及び空
気間隔、Niとνiは各々物体側より順に第i番目のレ
ンズのガラスの屈折率とアッベ数である。又前述の各条
件式と数値実施例における諸数値との関係を[表−1]
に示す。非球面形状は光軸方向にX軸、光軸と垂直方向
にH軸、光の進行方向を正としRを近軸曲率半径、A,
B,C,D,Eを各々非球面係数としたとき、
Next, numerical examples of the present invention will be described. In the numerical examples, Ri is the radius of curvature of the i-th lens surface in order from the object side, Di is the i-th lens thickness and air spacing from the object side, and Ni and νi are the i-th lens surfaces in order from the object side. The refractive index and Abbe number of glass. [Table 1] shows the relationship between the above-described conditional expressions and various numerical values in the numerical examples.
Shown in The aspherical shape has an X axis in the optical axis direction, an H axis in a direction perpendicular to the optical axis, a positive traveling direction of light, R is a paraxial radius of curvature, and A,
When B, C, D, and E are aspheric coefficients, respectively,

【0031】[0031]

【数1】 なる式で表わしている。尚、「e−0x」は「10-x」を
表わしている。
(Equation 1) It is represented by the following equation. Note that "e-0x" represents "10- x ".

【0032】[0032]

【外1】 [Outside 1]

【0033】[0033]

【外2】 [Outside 2]

【0034】[0034]

【外3】 [Outside 3]

【0035】[0035]

【外4】 [Outside 4]

【0036】[0036]

【外5】 [Outside 5]

【0037】[0037]

【表1】 [Table 1]

【0038】[0038]

【発明の効果】本発明によれば以上のように、5群ズー
ムレンズにおいて、主に変倍に伴う各レンズ群の移動条
件や、各レンズ群の屈折力、そして第2群の結像倍率等
を適切に設定することにより広角端の撮影画角が82度
程度、変倍比3〜4程度の全変倍範囲にわたり、しかも
全画面にわたり高い光学性能を有するズームレンズを達
成することができる。
As described above, according to the present invention, in the five-unit zoom lens, the moving condition of each lens unit mainly due to zooming, the refractive power of each lens unit, and the imaging magnification of the second unit By appropriately setting the zoom angle, etc., it is possible to achieve a zoom lens having a wide angle of view of about 82 degrees at the wide angle end, a wide zoom range of about 3 to 4 and a high optical performance over the entire screen. .

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

【図1】本発明の数値実施例1の広角端のレンズ断面図FIG. 1 is a sectional view of a lens at a wide angle end according to Numerical Embodiment 1 of the present invention.

【図2】本発明の数値実施例2の広角端のレンズ断面図FIG. 2 is a sectional view of a lens at a wide-angle end according to a second numerical embodiment of the present invention.

【図3】本発明の数値実施例3の広角端のレンズ断面図FIG. 3 is a sectional view of a lens at a wide-angle end according to a third numerical embodiment of the present invention;

【図4】本発明の数値実施例4の広角端のレンズ断面図FIG. 4 is a sectional view of a lens at a wide-angle end according to a fourth embodiment of the present invention.

【図5】本発明の数値実施例5の広角端のレンズ断面図FIG. 5 is a sectional view of a lens at a wide angle end according to Numerical Example 5 of the present invention.

【図6】本発明の数値実施例1の収差図FIG. 6 is an aberration diagram of a numerical example 1 of the present invention.

【図7】本発明の数値実施例2の収差図FIG. 7 is an aberration diagram of a numerical example 2 of the present invention.

【図8】本発明の数値実施例3の収差図FIG. 8 is an aberration diagram of a numerical example 3 of the present invention.

【図9】本発明の数値実施例4の収差図FIG. 9 is an aberration diagram of a numerical example 4 of the present invention.

【図10】本発明の数値実施例5の収差図FIG. 10 is an aberration diagram of a numerical example 5 of the present invention.

【符号の説明】[Explanation of symbols]

L1 第1群 L2 第2群 L3 第3群 L4 第4群 L5 第5群 SP 絞り F 像面 d d線 g g線 ΔS サジタル像面 ΔM メリディオナル像面 L1 First lens unit L2 Second lens unit L3 Third lens unit L4 Fourth lens unit L5 Fifth lens unit SP Aperture F Image plane d d-line g g-line ΔS Sagittal image plane ΔM Meridional image plane

───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平6−230285(JP,A) 特開 平5−119260(JP,A) 特開 平1−154014(JP,A) 特開 昭63−266415(JP,A) 特開 昭57−2014(JP,A) 特開 昭57−164710(JP,A) 特開 昭60−39613(JP,A) 特開 平8−94932(JP,A) (58)調査した分野(Int.Cl.7,DB名) G02B 9/00 - 17/08 G02B 21/02 - 21/04 G02B 25/00 - 25/04 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-230285 (JP, A) JP-A-5-119260 (JP, A) JP-A-1-154014 (JP, A) JP-A-63- 266415 (JP, A) JP-A-57-2014 (JP, A) JP-A-57-164710 (JP, A) JP-A-60-39613 (JP, A) JP-A-8-94932 (JP, A) (58) Field surveyed (Int.Cl. 7 , DB name) G02B 9/00-17/08 G02B 21/02-21/04 G02B 25/00-25/04

Claims (8)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 物体側より順に、正の屈折力の第1レン
ズ群、負の屈折力の第2レンズ群、正の屈折力の第3レ
ンズ群、負の屈折力の第4レンズ群、正の屈折力の第5
レンズ群を有し、広角端から望遠端への変倍に際して、
該第1レンズ群と第2レンズ群の間隔が増加し、該第2
レンズ群と第3レンズ群の間隔が減少し、該第3レンズ
群と第4レンズ群の間隔が増大し、該第4レンズ群と第
5レンズ群の間隔が減少するように移動させるズームレ
ンズであって、該第2レンズ群の広角端における無限遠
物体のときの結像倍率をβ2W、該第i群の焦点距離を
fiとしたとき、 0.18<|β2W|<0.255 0.7<f5/|f4|<1.2 なる条件を満足することを特徴とするズームレンズ。
A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, in order from the object side; Fifth of positive refractive power
With a lens group, when zooming from the wide-angle end to the telephoto end,
The distance between the first lens group and the second lens group increases,
A zoom lens that moves so that the distance between the lens group and the third lens group decreases, the distance between the third lens group and the fourth lens group increases, and the distance between the fourth lens group and the fifth lens group decreases. 0.18 <| β2W | <0.255 0 where β2W is the imaging magnification when the object at infinity is at the wide-angle end of the second lens unit, and fi is the focal length of the i-th unit. 0.7 <f5 / | f4 | <1.2.
【請求項2】 前記第1レンズ群と第2レンズ群の広角
端における合成焦点距離をf12w、広角端における全
系の焦点距離をfwとしたとき 5.8<f1/|f2|<7 1.4<f5/|f12w|<2.5 0.8<f3/fw<1.1 1.0<f5/|f4|<1.1 なる条件を満足することを特徴とする請求項1又は2の
ズームレンズ。
2. When the combined focal length of the first lens unit and the second lens unit at the wide-angle end is f12w, and the focal length of the entire system at the wide-angle end is fw, 5.8 <f1 / | f2 | <71. 4 <f5 / | f12w | <2.5 0.8 <f3 / fw <1.1 1.0 <f5 / | f4 | <1.1 2 zoom lens.
【請求項3】 前記第1レンズ群は物体側に凸面を向け
たメニスカス状の負レンズと正レンズとを接合した貼合
わせレンズ、そして物体側に凸面を向けたメニスカス状
の正レンズを有し、前記第2レンズ群は物体側へ凸面を
向けたメニスカス状の負レンズ、両レンズ面が凹面の負
レンズ、両レンズ面が凸面の正レンズ、そして物体側に
凹面を向けた負レンズを有していることを特徴とする請
求項1のズームレンズ。
3. The first lens group includes a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens are joined, and a positive meniscus lens having a convex surface facing the object side. The second lens group includes a meniscus negative lens having a convex surface facing the object side, a negative lens having both lens surfaces concave, a positive lens having both lens surfaces convex, and a negative lens having a concave surface facing the object side. The zoom lens according to claim 1, wherein
【請求項4】 前記第3レンズ群は物体側に凸面を向け
たメニスカス状の負レンズと両レンズ面が凸面の正レン
ズとを接合した貼合わせレンズ、そして両レンズ面が凸
面の正レンズを有していることを特徴とする請求項1の
ズームレンズ。
Wherein said third lens group cemented lens negative lens and both lens surfaces of the meniscus form convex toward the object side is joined to the positive lens convex, and a positive lens of both lens surfaces is convex The zoom lens according to claim 1, further comprising: a zoom lens.
【請求項5】 前記第5レンズ群は両レンズ面が凸面の
2つの正レンズと物体側に凹面を向けた負レンズを有し
ていることを特徴とする請求項1のズームレンズ。
5. The zoom lens according to claim 1, wherein said fifth lens group includes two positive lenses each having a convex surface on both lens surfaces and a negative lens having a concave surface facing the object side.
【請求項6】 前記第2レンズ群の望遠端の無限遠物体
のときの結像倍率をβ2Tとしたとき |β2T|<1 なる条件を満足することを特徴とする請求項1のズーム
レンズ。
6. When was .beta.2T imaging magnification when the infinite object at the telephoto end of the second lens group | .beta.2T | <zoom lens according to claim 1, characterized by satisfying one condition:.
【請求項7】 前記第2レンズ群を移動させてフォーカ
スを行っていることを特徴とする請求項1のズームレン
ズ。
7. The zoom lens according to claim 1, wherein the focusing is performed by moving said second lens group.
【請求項8】 請求項1乃至8いずれか1項のズームレ
ンズを有することを特徴とするカメラ。
8. A camera comprising the zoom lens according to claim 1.
JP33593494A 1994-12-21 1994-12-21 Zoom lens Expired - Fee Related JP3352263B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP33593494A JP3352263B2 (en) 1994-12-21 1994-12-21 Zoom lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP33593494A JP3352263B2 (en) 1994-12-21 1994-12-21 Zoom lens

Publications (2)

Publication Number Publication Date
JPH08179213A JPH08179213A (en) 1996-07-12
JP3352263B2 true JP3352263B2 (en) 2002-12-03

Family

ID=18293984

Family Applications (1)

Application Number Title Priority Date Filing Date
JP33593494A Expired - Fee Related JP3352263B2 (en) 1994-12-21 1994-12-21 Zoom lens

Country Status (1)

Country Link
JP (1) JP3352263B2 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002062478A (en) 2000-08-22 2002-02-28 Olympus Optical Co Ltd Zoom lens
JP4789349B2 (en) * 2001-06-11 2011-10-12 キヤノン株式会社 Zoom lens and optical apparatus having the same
JP4525039B2 (en) 2003-09-30 2010-08-18 株式会社ニコン Zoom lens
JP4876509B2 (en) * 2005-09-28 2012-02-15 株式会社ニコン Zoom lens
JP4799209B2 (en) * 2006-02-22 2011-10-26 パナソニック株式会社 Zoom lens system and camera system including the same
JP5344589B2 (en) * 2009-03-31 2013-11-20 キヤノン株式会社 Zoom lens and imaging apparatus having the same
JP6536020B2 (en) 2014-11-26 2019-07-03 リコーイメージング株式会社 Zoom lens system

Also Published As

Publication number Publication date
JPH08179213A (en) 1996-07-12

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