JP3263835B2 - Super wide-angle zoom lens - Google Patents
Super wide-angle zoom lensInfo
- Publication number
- JP3263835B2 JP3263835B2 JP07641294A JP7641294A JP3263835B2 JP 3263835 B2 JP3263835 B2 JP 3263835B2 JP 07641294 A JP07641294 A JP 07641294A JP 7641294 A JP7641294 A JP 7641294A JP 3263835 B2 JP3263835 B2 JP 3263835B2
- Authority
- JP
- Japan
- Prior art keywords
- lens group
- lens
- refractive power
- focusing
- focal length
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Description
【0001】[0001]
【産業上の利用分野】本発明は、35ミリ一眼レフカメ
ラ用交換レンズで、広角端の画角が100°以上、ズー
ム比1.9倍程度の超広角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 an interchangeable lens for a 35 mm single-lens reflex camera, and relates to an ultra-wide-angle zoom lens having an angle of view at the wide-angle end of 100 DEG or more and a zoom ratio of about 1.9 times.
【0002】[0002]
【従来の技術】35ミリ一眼レフカメラ用広角レンズの
フォーカス方式は、第1レンズ群をそのまま繰り出すフ
ロントフォーカス方式が一般的であった。しかし、近年
のオートフォーカス化と更なる広角化に伴い、大きく重
い第1レンズ群をフォーカスに使う方法がAF一眼レフ
カメラのフォーカス動作に負担になってきたため、後ろ
のレンズ群でフォーカスを行ういわゆるインナーフォー
カス方式が台頭し始めている。2. Description of the Related Art As a focus system of a wide-angle lens for a 35 mm single-lens reflex camera, a front focus system in which a first lens group is extended as it is is generally used. However, with the recent adoption of autofocus and further widening of the angle, a method of using the large and heavy first lens group for focusing has become a burden on the focusing operation of the AF single-lens reflex camera. The inner focus method is beginning to emerge.
【0003】インナーフォーカスについては、第1レン
ズ群より後ろの第2レンズ群以降で行う方法が近年数多
く提案され実用化されているが、この方式は、有限距離
におけるズーミング時のピントずれを防ぐ為に補正カム
を必要とし機構が複雑になる問題をかかえていた。ま
た、特開平4−15612号公報では第1レンズ群の後
部でフォーカシングを行っており、繰り出し量がズーミ
ングによらないので複雑な機構を必要としないのだが、
フォーカシング部は負パワーなので前方に動き、そのた
め前部との間にスペースを確保する必要があり、画角が
大きくなるとレンズ径が大きくなるという問題があっ
た。As for inner focus, many methods have been proposed and put to practical use in the second and subsequent lens groups after the first lens group in recent years. However, this method is intended to prevent defocus during zooming at a finite distance. However, there is a problem that a compensating cam is required and the mechanism becomes complicated. In JP-A-4-15612, focusing is performed at the rear portion of the first lens group, and the amount of extension does not depend on zooming, so that a complicated mechanism is not required.
Since the focusing unit has a negative power, it moves forward, so it is necessary to secure a space between the focusing unit and the front unit, and there is a problem that the lens diameter increases as the angle of view increases.
【0004】[0004]
【発明が解決しようとする課題】撮影画角が100°を
超えズーム比1.9倍以上の超広角でありながらシステ
ムがコンパクトであり、簡単な機構に加えてフォーカシ
ング群を駆動するパワーが小さく、フォーカシングによ
る収差変動の少ない高性能インナーフォーカス方式のズ
ームレンズを提供することを目的としている。Although the angle of view is more than 100 ° and the super wide angle of the zoom ratio is 1.9 times or more, the system is compact, and in addition to the simple mechanism, the power for driving the focusing unit is small. It is an object of the present invention to provide a high performance inner focus type zoom lens with less aberration fluctuation due to focusing.
【0005】[0005]
【課題を解決するための手段】本発明の超広角ズームレ
ンズは、物体側より順に負の屈折力の第1レンズ群、正
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レンズ群とからなり、広角端から望遠
端までの変倍に際して第1レンズ群と変倍用の第2レン
ズ群の間隔を減少し、第2レンズ群と第3レンズ群の間
隔、第3レンズ群と第4レンズ群の間隔を増大させる。
該第1レンズ群は、少なくとも3枚以上の負レンズから
なる負の屈折力の第1Aレンズ群と光軸上を移動させて
焦点合わせを行う正の屈折力の第1Bレンズ群で構成さ
れ、かつ以下の条件を満足することにより課題を解決し
た。An ultra-wide-angle zoom lens according to the present invention comprises, in order from the object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a positive refractive power. group,
A fourth lens unit having a negative refractive power, which reduces the distance between the first lens unit and the second lens unit for zooming during zooming from the wide-angle end to the telephoto end; The distance between the groups and the distance between the third lens group and the fourth lens group are increased.
The first lens group includes a first A lens group having a negative refractive power including at least three negative lenses and a first B lens group having a positive refractive power that moves on the optical axis to perform focusing. The problem was solved by satisfying the following conditions.
【0006】(1) 2.5<│f1B/f1A│<3.3 (2) 1.3< f1B/fW <2.0 (3) 1.7< f2/fW <2.8 ただし、 f1A:第1Aレンズ群の焦点距離 f1B:第1Bレンズ群の焦点距離 f2:第2レンズ群の焦点距離 fW:全系において広角端の焦点距離 である。(1) 2.5 <│f 1B / f 1A │ <3.3 (2) 1.3 <f 1B / f W <2.0 (3) 1.7 <f 2 / f W < 2.8 where f 1A : focal length of the first A lens group f 1B : focal length of the first B lens group f 2 : focal length of the second lens group f W : focal length at the wide angle end in the whole system.
【0007】[0007]
【作用】条件式(1)は、第1レンズ群中の負の屈折力
の第1Aレンズ群と正の屈折力の第1Bレンズ群のパワ
ーの関係を規定するもので、条件式(1)の下限を越え
ると、フォーカスによる球面収差が大きくアンダーとな
り、近距離時の性能が劣化する。また、上限を越える
と、第1Bレンズ群の屈折力が弱くなりフォーカシング
の移動量が大きくなるうえ、負の歪曲収差や非点収差が
増大し補正が難しくなる。条件式(1)を外れると、第
1Aレンズ群と第1Bレンズ群の負と正の屈折力のバラ
ンスがくずれる結果、色収差等の収差が第1レンズ群内
で適切な補正ができず後群での補正に負担がかかる。The conditional expression (1) defines the relationship between the power of the first A lens unit having a negative refractive power and the power of the first B lens unit having a positive refractive power in the first lens unit. If the lower limit is exceeded, spherical aberration due to focusing will be largely under, and the performance at short distance will be degraded. If the upper limit is exceeded, the refractive power of the first B lens group becomes weak, the amount of movement of focusing increases, and negative distortion and astigmatism increase, making correction difficult. If the conditional expression (1) is not satisfied, the balance between the negative and positive refractive powers of the first and second lens units A and B is lost, so that aberrations such as chromatic aberration cannot be properly corrected in the first lens unit and the rear unit It takes a burden to make corrections.
【0008】条件式(2)は、システム全体のパワーと
第1Bレンズ群のパワーの関係を規定するもので、条件
式(2)の下限を越えると、第1Bレンズ群の屈折力が
強くなりフォーカシングの際、球面収差がアンダーにな
り好ましくない。また、条件式(2)の上限を越える
と、第1Bレンズ群の屈折力が弱くなり、フォーカスの
移動量が大きくなって、コンパクト化に不利なため望ま
しくない。Conditional expression (2) defines the relationship between the power of the entire system and the power of the first lens unit. If the lower limit of conditional expression (2) is exceeded, the refractive power of the first lens unit becomes strong. At the time of focusing, the spherical aberration is undesirably under. If the upper limit of conditional expression (2) is exceeded, the refractive power of the first B lens unit will be weak, and the amount of movement of the focus will be large.
【0009】条件式(3)は、第2レンズ群のパワーを
規定するもので、条件式(3)の下限を越えると、第2
レンズ群の正のパワーが強くなりすぎて第2レンズ群内
のレンズの個々の面で発生する非点収差、コマ収差等が
大きくなり好ましくない。また、上限を越えると第2レ
ンズ群のパワーが弱くなり各面で発生する収差は小さく
なるが、しかし、ズーミングの移動量が大きくなりコン
パクト化に不利なため望ましくない。Conditional expression (3) defines the power of the second lens unit. If the lower limit of conditional expression (3) is exceeded, the second condition is satisfied.
The positive power of the lens group becomes too strong, and astigmatism, coma, and the like generated on individual surfaces of the lenses in the second lens group become undesirably large. If the upper limit is exceeded, the power of the second lens unit is weakened, and the aberration generated on each surface is reduced. However, it is not desirable because the moving amount of zooming is large, which is disadvantageous for downsizing.
【0010】[0010]
【実施例】以下に、本発明の超広角ズームレンズの数値
実施例1、数値実施例2および数値実施例3を示す。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following are Numerical Embodiments 1, 2, and 3 of the ultra-wide-angle zoom lens of the present invention.
【0011】ここで、fは焦点距離、FnoはFナンバ
ー、rは物体側より順に第i番目のレンズ面の曲率半
径、dは物体側より順に第i番目のレンズ厚および空気
間隔、nは物体側より順に第i番目のレンズの屈折率、
νは物体側より順に第i番目のレンズのアッベ数であ
る。また数値実施例1において、Iはr1からr10ま
での負の屈折力の第1レンズ群、IIはr11からr16
までの正の屈折力の第2レンズ群、IIIはr17からr
19までの正の屈折力の第3レンズ群、IVはr20から
r27までの負の屈折力の第4レンズ群、Vはr1から
r8までの負の屈折力の第1Aレンズ群、VIはr9から
r10までの正の屈折力の第1Bレンズ群であり、数値
実施例2および数値実施例3において、Iはr1からr
10までの負の屈折力の第1レンズ群、IIはr11から
r15までの正の屈折力の第2レンズ群、IIIはr16
からr18までの正の屈折力の第3レンズ群、IVはr1
9からr26までの負の屈折力の第4レンズ群、Vはr
1からr8までの負の屈折力の第1Aレンズ群、VIはr
9からr10までの正の屈折力の第1Bレンズ群であ
る。Here, f is the focal length, Fno is the F number, r is the radius of curvature of the i-th lens surface in order from the object side, d is the i-th lens thickness and air space in order from the object side, and n is The refractive index of the i-th lens in order from the object side,
ν is the Abbe number of the i-th lens in order from the object side. In Numerical Example 1, I represents the first lens unit having a negative refractive power from r1 to r10, and II represents r11 to r16.
The second lens group having a positive refractive power up to, III is from r17 to r17
A third lens group having a positive refractive power up to 19, IV is a fourth lens group having a negative refractive power from r20 to r27, V is a first A lens group having a negative refractive power from r1 to r8, and VI is r9. A first B lens unit having a positive refractive power ranging from r1 to r10. In Numerical Embodiments 2 and 3, I is from r1 to r10.
A first lens group having a negative refractive power of up to 10, II is a second lens group having a positive refractive power of r11 to r15, and III is r16.
The third lens unit having a positive refractive power from to r18, and IV is r1
The fourth lens unit having a negative refractive power from 9 to r26, and V is r
The first A lens group having negative refractive power from 1 to r8, and VI is r
This is a first B lens unit having a positive refractive power of 9 to r10.
【0012】数値実施例1 f=18.69〜24.80〜33.26 Fno=3.66〜4.09〜4.59 i r d n ν ( 1) 30.1787 2.1753 1.81600 46.5 ( 2) 21.0094 6.2214 ( 3) 41.9811 1.8078 1.81600 46.5 ( 4) 22.2073 5.4849 ( 5) 151.1433 1.5467 1.83500 43.0 ( 6) 31.7466 4.9287 ( 7) − 68.1162 1.4419 1.83500 43.0 ( 8) 91.2595 1.0000 ( 9) 47.7431 8.0254 1.62004 36.3 (10) − 33.7422 31.6091 (11) 0.0 1.4000 (12) 57.0984 2.0816 1.51823 58.9 (13) − 93.8781 0.1680 (14) 19.2051 1.8781 1.48749 70.2 (15) 31.3897 2.0009 (16) 0.0 7.0576 (17) 24.7956 3.4865 1.51680 64.4 (18) − 25.1283 1.0000 1.80610 33.3 (19) −152.6527 0.6663 (20) − 60.2230 1.0000 1.80450 39.7 (21) 24.1981 1.0955 (22) −187.0719 2.4854 1.51680 64.4 (23) − 23.3701 0.1000 (24) −106.2266 1.8519 1.51680 64.4 (25) − 37.0951 0.1000 (26) − 82.2167 1.5808 1.51680 64.4 (27) − 44.2276 │f1B/f1A│=2.81 f1B/fW =1.77 f2/fW =2.14Numerical Example 1 f = 18.69 to 24.80 to 33.26 Fno = 3.66 to 4.09 to 4.59 irdn ν (1) 30.1787 2.1753 1.81600 46.5 (2) 21.0094 6.2214 (3) 41.9811 1.8078 1.81600 46.5 (4) 22.2073 5.4849 (5) 151.143 1.5467 1.883500 43. 0 (6) 31.7466 4.9287 (7) -68.1162 1.4419 1.83500 43.0 (8) 91.25595 1.0000 (9) 47.7431 8.0254 1.62004 36.3 (10)-33.7422 31.6091 (11) 0.0 1.4000 (12) 57.0984 2.0816 1.5823 58.9 (13)-93.8787 0.1680 (14) 19.2051 1.8787 1.4 8749 70.2 (15) 31.3897 2.0009 (16) 0.0 7.0576 (17) 24.7956 3.4865 1.5680 64.4 (18)-25.1283 1.0000 1.80610 33.3 (19) -152.6527 0.6666 (20) -60.2230 1.0000 1.80450 39.7 (21) 24.1981 1.0955 (22) -187.0719 2.4854 1. 51680 64.4 (23) -23.3701 0.1000 (24) -106.2266 1.8519 1.5680 64.4 (25) -37.0951 0.1000 (26) -82.2167 1.5808 1.51680 64.4 (27) - 44.2276 │f 1B / f 1A │ = 2.81 f 1B / f W = 1.77 f 2 / f W = 2.14
【0013】[0013]
【表1】 [Table 1]
【0014】数値実施例2 f=18.86〜24.99〜33.53 Fno=3.72〜4.16〜4.69 i r d n ν ( 1) 30.3165 2.1686 1.81600 46.5 ( 2) 20.5890 6.3227 ( 3) 41.5335 1.7870 1.81600 46.5 ( 4) 21.8544 5.4080 ( 5) 136.8326 1.5319 1.83500 43.0 ( 6) 31.8197 4.8916 ( 7) − 67.1935 1.4455 1.83500 43.0 ( 8) 100.8640 1.0000 ( 9) 46.0054 8.0648 1.62004 36.3 (10) − 34.2616 32.4076 (11) 50.8428 2.1579 1.51823 58.9 (12) − 94.8576 0.1000 (13) 18.4121 1.9649 1.48749 70.2 (14) 31.1045 2.2524 (15) 0.0 6.1152 (16) 26.2656 3.3840 1.51680 64.4 (17) − 25.8750 1.0000 1.80610 33.3 (18) −325.1597 0.2932 (19) − 57.6740 1.0000 1.80450 39.7 (20) 24.1142 1.0762 (21) −235.5853 2.3267 1.51680 64.4 (22) − 26.2558 0.1000 (23) − 82.0135 1.8090 1.51680 64.4 (24) − 34.9765 0.1000 (25) − 83.0941 2.0102 1.51680 64.4 (26) − 33.1938 │f1B/f1A│=2.80 f1B/fW =1.75 f2/fW =1.96Numerical Example 2 f = 18.86 to 24.99 to 33.53 Fno = 3.72 to 4.16 to 4.69 irdn ν (1) 30.3165 2.1686 1.81600 46.5 (2) 20.5890 6.3227 (3) 41.5335 1.7870 1.81600 46.5 (4) 21.8544 5.3080 (5) 136.8326 1.5319 1.83500 43. 0 (6) 31.8197 4.8916 (7)-67.1935 1.4455 1.83500 43.0 (8) 100.8640 1.0000 (9) 46.0054 8.0648 1.62004 36.3 (10) -34.2616 32.4076 (11) 50.8428 2.1579 1.5823 58.9 (12) -94.8576 0.1000 (13) 18.4121 1.9649 1.48749 70.2 (14 31.104.5 2.2524 (15) 0.0 6.1152 (16) 26.2656 3.3840 1.5680 64.4 (17)-25.8750 1.0000 1.80610 33.3 (18) -325.1597 0.2932 (19)-57.6740 1.0000 1.80450 39.7 (20) 24.1142 1.0762 (21) -235.5853 2.3267 1.5680 64.4 (22 )-26.2558 0.100 (23)-82.0135 1.8090 1.5680 64.4 (24)-34.9765 0.1000 (25)-83.0941 2.0102 1.5680 64.4 (26) - 33.1938 │f 1B / f 1A │ = 2.80 f 1B / f W = 1.75 f 2 / f W = 1.96
【0015】[0015]
【表2】 [Table 2]
【0016】数値実施例3 f=18.90〜25.14〜33.85 Fno=3.73〜4.17〜4.71 i r d n ν ( 1) 30.6881 2.1672 1.81600 46.5 ( 2) 20.5707 6.4079 ( 3) 42.9500 1.7808 1.81600 46.5 ( 4) 21.9951 5.3952 ( 5) 150.9339 1.5276 1.83500 43.0 ( 6) 32.5951 4.7630 ( 7) − 69.2686 1.4474 1.83500 43.0 ( 8) 106.8850 0.7897 ( 9) 45.5970 8.0695 1.62004 36.3 (10) − 34.4471 32.3114 (11) 56.7441 2.1326 1.51823 58.9 (12) − 83.6346 0.1000 (13) 18.3840 2.0230 1.48749 70.2 (14) 32.5460 2.2183 (15) 0.0 6.2997 (16) 28.1928 3.3465 1.51680 64.4 (17) − 24.7217 1.0000 1.80610 33.3 (18) −201.3004 0.2925 (19) − 52.1469 1.0000 1.80450 39.7 (20) 24.9391 1.1101 (21) −227.8951 2.3758 1.51680 64.4 (22) − 26.0955 0.1000 (23) − 77.5455 1.8261 1.51680 64.4 (24) − 34.1893 0.1000 (25) − 81.2645 2.0772 1.51680 64.4 (26) − 32.1277 │f1B/f1A│=2.79 f1B/fW =1.74 f2/fW =1.92Numerical Example 3 f = 18.90 to 25.14 to 33.85 Fno = 3.73 to 4.17 to 4.71 irdn ν (1) 30.6881 2.1672 1.81600 46.5 (2) 20.5707 6.4079 (3) 42.9500 1.7808 1.816600 46.5 (4) 21.9951 5.3952 (5) 150.339 1.5276 1.83500 43. 0 (6) 32.5951 4.7630 (7) -69.2686 1.4474 1.83500 43.0 (8) 106.8850 0.77897 (9) 45.5970 8.0696 1.62004 36.3 (10)-34.4471 32.3114 (11) 56.7441 2.1326 1.5823 58.9 (12)-83.6346 0.1000 (13) 18.3840 2.0230 1.48749 70.2 (14 32.5460 2.2183 (15) 0.0 6.2997 (16) 28.1928 3.3465 1.5680 64.4 (17)-24.7217 1.0000 1.80610 33.3 (18)- 201.3004 0.2925 (19) -52.1469 1.0000 1.80450 39.7 (20) 24.9391 1.1101 (21) -227.8951 2.3758 1.5680 64.4 (22) -26.0955 0.1000 (23)-77.5455 1.8261 1.5680 64.4 (24)-34.1893 0.1000 (25)-81.2645 2.0772 1.5680 64.4 ( 26) - 32.1277 │f 1B / f 1A │ = 2.79 f 1B / f W = 1.74 f 2 / f W = 1.92
【0017】[0017]
【表3】 [Table 3]
【0018】コンパクト化を実現するのに第1レンズ群
Iは、負の屈折力がきわめて強いので非点収差、歪曲収
差等の発生を小さくするために高屈折率のガラスを使用
すると共に負レンズをメニスカス状の3枚以上で構成す
ることが望ましい。フォーカシングは第1Aレンズ群V
のみでもよく、また、第1Aレンズ群Vと第1Bレンズ
群VIを一体でフォーカシング群として使ってもフォーカ
シングによる収差変動は小さく問題ない。そしてまた、
第1Bレンズ群VIによるによるフォーカシングは、重量
が小さく駆動に負担がかからないうえに、第1Bレンズ
群VIのパワーが強いので、フォーカシング移動量が少な
く正のパワーであるから像側に移動し、これがフローデ
ィング効果になって収差移動を小さくする。さらに、像
側への移動はズームスペースがそのまま使えてフォーカ
シングのためのスペースを余分に確保する必要がなく全
長をコンパクトに構成できる。First lens group for realizing compactness
Since I has a very strong negative refractive power, it is desirable to use a glass with a high refractive index to reduce the occurrence of astigmatism, distortion, and the like, and to configure the negative lens with three or more meniscus lenses. Focusing on the 1st A lens group V
In addition, even if the first A lens group V and the first B lens group VI are integrally used as a focusing group, the aberration variation due to focusing is small and there is no problem. and again,
Focusing by the first B lens group VI is light in weight and does not impose a burden on driving. In addition, since the power of the first B lens group VI is strong, the focusing movement amount is small and the power is positive. The movement of aberration is reduced due to the floating effect. Further, the movement to the image side can use the zoom space as it is, and it is not necessary to secure an extra space for focusing, and the entire length can be made compact.
【0019】[0019]
【発明の効果】以上説明したように、本発明によりフォ
ーカスの際の収差変動が少なく、物体距離無限遠から近
距離まで高性能を持ち、フォーカシング部を軽量化し合
焦が速く、オートフォーカスに適した超広角ズームレン
ズを提供することができる。As described above, according to the present invention, aberration fluctuation at the time of focusing is small, high performance is obtained from an infinite object distance to a short distance, the focusing unit is lightened, focusing is fast, and it is suitable for autofocusing. An ultra-wide-angle zoom lens can be provided.
【図1】実施例1のレンズ構成図である。FIG. 1 is a lens configuration diagram of a first embodiment.
【図2】実施例1の広角端無限遠時の収差図である。FIG. 2 is an aberration diagram for Example 1 at infinity at the wide-angle end.
【図3】実施例1の中間焦点距離時無限遠時の収差図で
ある。FIG. 3 is an aberration diagram of Example 1 at an intermediate focal length and at infinity.
【図4】実施例1の望遠端無限遠時の収差図である。FIG. 4 is an aberration diagram at a telephoto end at infinity according to the first embodiment.
【図5】実施例2のレンズ構成図である。FIG. 5 is a lens configuration diagram of a second embodiment.
【図6】実施例2の広角端無限遠時の収差図である。FIG. 6 is an aberration diagram at a wide-angle end at infinity according to a second embodiment.
【図7】実施例2の中間焦点距離時無限遠時の収差図で
ある。FIG. 7 is an aberration diagram for Example 2 at an intermediate focal length and at infinity.
【図8】実施例2の望遠端無限遠時の収差図である。FIG. 8 is an aberration diagram at a telephoto end at infinity according to a second embodiment.
【図9】実施例3のレンズ構成図である。FIG. 9 is a lens configuration diagram of a third embodiment.
【図10】実施例3の広角端無限遠時の収差図である。FIG. 10 is an aberration diagram for Example 3 at infinity at the wide-angle end.
【図11】実施例3の中間焦点距離時無限遠時の収差図
である。FIG. 11 is an aberration diagram for Example 3 at an intermediate focal length and at infinity.
【図12】実施例3の望遠端無限遠時の収差図である。FIG. 12 is an aberration diagram at a telephoto end at infinity according to a third embodiment.
I 負の屈折力の第1レンズ群 II 正の屈折力の第2レンズ群 III 正の屈折力の第3レンズ群 IV 負の屈折力の第4レンズ群 V 負の屈折力の第1Aレンズ群 VI 正の屈折力の第1Bレンズ群 I First lens group with negative refractive power II Second lens group with positive refractive power III Third lens group with positive refractive power IV Fourth lens group with negative refractive power V 1A lens group with negative refractive power VI 1B lens group with positive refractive power
───────────────────────────────────────────────────── フロントページの続き (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 Continued on the front page (58) Fields surveyed (Int. Cl. 7 , DB name) G02B 9/00-17/08 G02B 21/02-21/04 G02B 25/00-25/04
Claims (1)
群、正の屈折力の第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レンズ群とからなり、該第1レ
ンズ群は少なくとも3枚以上の負レンズからなる負の屈
折力の第1Aレンズ群と、光軸上を移動させて焦点合わ
せをおこなう正の屈折力の第1Bレンズ群で構成され、
かつ以下の条件を満足することを特徴とする超広角ズー
ムレンズ。 (1) 2.5<│f1B/f1A│<3.3 (2) 1.3< f1B/fW <2.0 (3) 1.7< f2/fW <2.8 ただし、 f1A:第1Aレンズ群の焦点距離 f1B:第1Bレンズ群の焦点距離 f2:第2レンズ群の焦点距離 fW:全系において広角端の焦点距離 である。1. A first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power are arranged in order from the object side. The first lens group is composed of a first A lens group having a negative refractive power composed of at least three or more negative lenses and a first B lens group having a positive refractive power that moves on the optical axis to perform focusing. And
And an ultra-wide-angle zoom lens satisfying the following conditions. (1) 2.5 <│f 1B / f 1A │ <3.3 (2) 1.3 <f 1B / f W <2.0 (3) 1.7 <f 2 / f W <2.8 Here, f 1A : focal length of the first A lens group f 1B : focal length of the first B lens group f 2 : focal length of the second lens group f w : focal length at the wide angle end in the whole system.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP07641294A JP3263835B2 (en) | 1994-03-24 | 1994-03-24 | Super wide-angle zoom lens |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP07641294A JP3263835B2 (en) | 1994-03-24 | 1994-03-24 | Super wide-angle zoom lens |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH07261082A JPH07261082A (en) | 1995-10-13 |
JP3263835B2 true JP3263835B2 (en) | 2002-03-11 |
Family
ID=13604523
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP07641294A Expired - Lifetime JP3263835B2 (en) | 1994-03-24 | 1994-03-24 | Super wide-angle zoom lens |
Country Status (1)
Country | Link |
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JP (1) | JP3263835B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7576921B2 (en) | 2007-04-06 | 2009-08-18 | Canon Kabushiki Kaisha | Zoom lens and image projection apparatus |
CN102472884A (en) * | 2009-12-25 | 2012-05-23 | 松下电器产业株式会社 | Image-capturing optical system, interchangeable lens device, and camera system |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3508273B2 (en) * | 1995-03-08 | 2004-03-22 | 株式会社ニコン | Zoom lens |
JP4481714B2 (en) * | 2004-04-27 | 2010-06-16 | Hoya株式会社 | Super wide-angle lens system |
JP4632724B2 (en) | 2004-09-07 | 2011-02-16 | オリンパス株式会社 | Zoom lens |
JP5340759B2 (en) * | 2009-02-02 | 2013-11-13 | パナソニック株式会社 | Zoom lens system, interchangeable lens device, and camera system |
JP5253604B2 (en) * | 2012-06-20 | 2013-07-31 | キヤノン株式会社 | Zoom lens and image projection apparatus |
CN117310998B (en) * | 2023-11-29 | 2024-04-05 | 江西联昊光电有限公司 | Optical system and near-eye display device |
-
1994
- 1994-03-24 JP JP07641294A patent/JP3263835B2/en not_active Expired - Lifetime
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7576921B2 (en) | 2007-04-06 | 2009-08-18 | Canon Kabushiki Kaisha | Zoom lens and image projection apparatus |
CN102472884A (en) * | 2009-12-25 | 2012-05-23 | 松下电器产业株式会社 | Image-capturing optical system, interchangeable lens device, and camera system |
CN102472884B (en) * | 2009-12-25 | 2014-03-19 | 松下电器产业株式会社 | Image-capturing optical system, interchangeable lens device, and camera system |
Also Published As
Publication number | Publication date |
---|---|
JPH07261082A (en) | 1995-10-13 |
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