JPS6142246B2 - - Google Patents
Info
- Publication number
- JPS6142246B2 JPS6142246B2 JP53021385A JP2138578A JPS6142246B2 JP S6142246 B2 JPS6142246 B2 JP S6142246B2 JP 53021385 A JP53021385 A JP 53021385A JP 2138578 A JP2138578 A JP 2138578A JP S6142246 B2 JPS6142246 B2 JP S6142246B2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- positive
- group
- negative
- object side
- 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
Links
- 230000005499 meniscus Effects 0.000 claims description 9
- 239000002131 composite material Substances 0.000 claims description 4
- 239000000178 monomer Substances 0.000 claims 1
- 230000004075 alteration Effects 0.000 description 24
- 230000014509 gene expression Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 3
- 206010010071 Coma Diseases 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Description
本発明は、負の屈折力を有する前群と正の屈折
力を有する後群の２群より成り、前群と後群の間
の空気間隔を変化させることによつて、ズーミン
グを行うズームレンズ系に関する。
このタイプのズームレンズ系は、レトロフオー
カスの屈折力配置になり、広角ズームレンズ系を
構成するのに有利であるため、従来から、特公昭
40−8985、特開昭49−2548、特開昭51−82642、
特開昭51−83543等において、各種のタイプが提
案されている。
しかしながら、これらは変倍に伴なう諸収差の
変動を抑えるべく複雑なレンズ構成を要求するも
のであり、レンズ枚数も多い故、経済的に有利な
レンズ構成とは言い難い。
本発明は、これらの欠点を克服し、上記の如く
タイプのレンズ系に於いて、特に前群のレンズタ
イプを簡素化し、経済的に有利な構成にし、か
つ、レンズ系のコンパクト化を計るとともに収差
の残存量及び変倍に伴う収差の変動量を小さくす
ることを目的とするものである。
本発明の特徴は、全体として発散屈折力を有す
る前群と、全体として収斂屈折力を有する後群
の２群によつて構成され、前群と後群との
空気間隔を変化させることによつてズーミングを
行うズームレンズ系に於いて、前群は、物体側
より順に像側に曲率の強い凹面を有する負単レン
ズ−１、および物体側に凸面を向けた正メニス
カス単レンズ−２より成り、後群は、物体側
より順に２枚以上のレンズより成る正レンズ群
−１、像側に曲率の強い凹面を有する負レンズ
−２、及び少くとも１枚の正レンズより成る最後
部レンズ群−３を有するとともに、次の諸条件
を満足することにある。
(1) 0.75L＜｜I｜＜1.5L
(2) 0.03｜I｜＜d2＜0.3｜I｜
(3) 0.28｜I｜＜r3＜0.50｜I｜
但し、Lは最長焦点距離に設定した状態にお
ける全系の合成焦点距離；
Iは前群の合成焦点距離；
d2は前群中における負単レンズ−１と正メ
ニスカス単レンズ−２の間の空気間隔；
r3は前群中における正メニスカス単レンズ
−２の物体側の面の曲率半径。
本発明は上記のように、条件(1)を満足する前群
において、これを像側に曲率の強い凹面を有する
負単レンズ−１と物体側に凸面を向けた正メニ
スカス単レンズ−２の２枚の単レンズにより構
成し、かつ、これら２枚の単レンズの間の空気レ
ンズを条件(2)，(3)によつて規定される特定の形状
とすることにより簡素な構成の前群を実現した
ものである。
上記条件式(1)〜(3)は本発明の特徴である前群の
構成に関するものであり、以下これらについて詳
細に説明する。条件式(1)は前群の焦点距離を規
制するもので、ズーミング時のレンズ移動の型式
を実用的な範囲に抑え、レンズ系全体の大きさを
定めるものである。｜I｜が条件式(1)の上限を
越えて大きくなつていく時の傾向としては前群の
移動量が大きくなり、そのレンズ径を大きくする
ことが必要になり、かつ後群のレンズ枚数を増
さなければ、ペツツバール和の補正が困難にな
る。また、｜I｜が条件式(1)の下限を越えて小
さくなつていく時の傾向としては、前群のレンズ
径を小さくすることは可能であるが最長焦点距離
の状態での高次の球面収差の発生が大きくなり最
短焦点距離の状態での歪曲収差の負偏位も大きく
なる。
次に条件式(2)はズーミングによる球面収差、像
面彎曲、コマ収差、歪曲収差等の変動を少なく保
つとともに、レンズ全長を実用的な範囲に規定す
るものである。d2が条件式(2)の下限を越えて小さ
くなつていくときの傾向としては、最短焦点距離
の状態で負の歪曲収差の発生が大きくなるととも
に、中間焦点距離の状態での像面彎曲が大きくな
り、かつ、高次の球面収差のズーミングによる変
動が大きくなる。またｄIが条件式(2)の上限を越
えて大きくなつていく時の傾向としては前群の後
方主点距離が長くなり、前群と後群の間の薄肉間
隔を大きく取らねばならなくなる。すなわち、全
系が大きくなり、実用的な解は得難い。
条件式(3)は最長焦点距離の状態での高次の球面
収差の発生及び中間焦点距離の状態での像面の負
偏位、並びに最短焦点距離の状態での負の歪曲収
差の発生等を防ぐためのものである。r3が条件式
(3)の下限を越えて小さくなつていくときの傾向と
しては、最長焦点距離の状態で球面収差の負偏位
が大きくなり、３次の領域で補正したとしても高
次の球面収差が残存する。また、最短焦点距離の
状態での負の歪曲収差の発生が大きくなる。また
r3が条件式(3)の上限を越えて大きくなつていくと
きの傾向としては、最長焦点距離の状態で球面収
差の正偏位が大きくなり、かつ、中間焦点距離の
状態での像面の負偏位が大きくなる。
以下の第１〜第４表に本発明の実施例を示す。
各実施例から明らかなように本発明においては、
後群について種々の構成をとることが可能であ
る。
The present invention is a zoom lens that is composed of two groups, a front group having a negative refractive power and a rear group having a positive refractive power, and performs zooming by changing the air distance between the front group and the rear group. Regarding the system. This type of zoom lens system has a retrofocus refractive power arrangement, which is advantageous for constructing a wide-angle zoom lens system, so it has traditionally been
40-8985, JP-A-49-2548, JP-A-51-82642,
Various types have been proposed in Japanese Patent Application Laid-Open No. 51-83543. However, these require a complicated lens configuration in order to suppress fluctuations in various aberrations due to zooming, and since the number of lenses is large, it is hard to say that these are economically advantageous lens configurations. The present invention overcomes these drawbacks, simplifies the lens type of the front group in particular in the above-mentioned type of lens system, provides an economically advantageous configuration, and makes the lens system compact. The objective is to reduce the amount of residual aberrations and the amount of variation in aberrations due to zooming. A feature of the present invention is that it is composed of two groups, a front group that has a diverging refractive power as a whole, and a rear group that has a convergent refractive power as a whole, and that the air distance between the front group and the rear group is changed. In a zoom lens system that performs zooming, the front group consists of, in order from the object side, a negative single lens 1 having a concave surface with a strong curvature toward the image side, and a positive meniscus single lens 2 having a convex surface facing the object side. , the rear group includes, in order from the object side, a positive lens group-1 consisting of two or more lenses, a negative lens group-2 having a concave surface with a strong curvature on the image side, and a rearmost lens group consisting of at least one positive lens. -3 and also satisfy the following conditions. (1) 0.75 L < | I | <1.5 L (2) 0.03 | I | <d 2 <0.3 | I | (3) 0.28 | I | <r 3 <0.50 | I | However, L is the maximum focal length The composite focal length of the entire system in the set state; I is the composite focal length of the front group; d 2 is the air distance between negative single lens -1 and positive meniscus single lens -2 in the front group; r 3 is the air distance between the negative single lens -1 and positive meniscus single lens -2 in the front group; The radius of curvature of the object-side surface of the positive meniscus single lens-2 inside. As described above, the present invention consists of a negative single lens 1 having a concave surface with a strong curvature on the image side and a positive meniscus single lens 2 having a convex surface facing the object side in the front group satisfying condition (1). The front group is made up of two single lenses, and the air lens between these two single lenses has a specific shape defined by conditions (2) and (3), resulting in a simple structure. This has been realized. The above conditional expressions (1) to (3) relate to the configuration of the front group, which is a feature of the present invention, and will be explained in detail below. Conditional expression (1) regulates the focal length of the front group, limits the type of lens movement during zooming to a practical range, and determines the size of the entire lens system. As | I | increases beyond the upper limit of conditional expression (1), the tendency is for the amount of movement of the front group to increase, making it necessary to increase the lens diameter, and increasing the number of lenses in the rear group. If we do not increase this, it will be difficult to correct the Petzval sum. Furthermore, as | I | decreases beyond the lower limit of conditional expression (1), the tendency is that although it is possible to reduce the lens diameter of the front group, the higher-order The occurrence of spherical aberration increases, and the negative deviation of distortion aberration at the shortest focal length also increases. Next, conditional expression (2) is intended to keep fluctuations in spherical aberration, field curvature, coma aberration, distortion, etc. due to zooming to a minimum, and to define the total lens length within a practical range. As d 2 decreases beyond the lower limit of conditional expression (2), the tendency is for negative distortion to increase at the shortest focal length, and to reduce field curvature at intermediate focal lengths. becomes larger, and fluctuations in higher-order spherical aberration due to zooming become larger. Furthermore, as d I increases beyond the upper limit of conditional expression (2), the tendency is for the distance between the rear principal points of the front group to become longer, and it becomes necessary to increase the thin wall distance between the front and rear groups. . In other words, the entire system becomes large and it is difficult to obtain a practical solution. Condition (3) requires the occurrence of high-order spherical aberration at the longest focal length, negative deviation of the image plane at an intermediate focal length, and negative distortion at the shortest focal length, etc. This is to prevent r 3 is the conditional expression
(3) As the lower limit is exceeded, the tendency is for the negative deviation of spherical aberration to become large at the longest focal length, and even if it is corrected in the third-order region, higher-order spherical aberrations remain. do. In addition, negative distortion aberration increases in the state of the shortest focal length. Also
As r 3 increases beyond the upper limit of conditional expression (3), the tendency is that the positive deviation of spherical aberration becomes large at the longest focal length, and the image plane becomes larger at the intermediate focal length. The negative deviation of becomes large. Examples of the present invention are shown in Tables 1 to 4 below.
As is clear from each example, in the present invention,
Various configurations are possible for the rear group.
【表】
【table】
【表】
【table】
【表】
【table】
【表】
上記第１表における実施例１は、第１図に示す
ように前群が２枚、後群が４枚の単レンズよ
り構成されるもので、本発明の中では、最もコス
ト面で有利なレンズタイプである。後群の正レ
ンズ群−１には可能な限り低分散のガラスを使
用して、色収差のズーミングによる変動を抑え、
かつ、物体側に強い曲率を持たせることによつ
て、球面収差を補正している。このレンズタイプ
は開放ＦNOが3.5程度までのレンズ系で実用的で
ある。
第２表における実施例２では、第２図に示すよ
うに後群の正レンズ群−１に接合レンズを導
入することによつて、高次の軸上色収差の発生を
抑え、かつ、短焦点側でのコマ収差の発生及び色
収差の軸外フレアーの発生を防いでいる。従つ
て、色収差に対する要求が厳しい場合に適したタ
イプである。この色収差に対する要求を満たす別
の方式としては、負レンズ−２を接合レンズに
することも考えられる。
第３表における実施例３は、第３図に示すよう
に後群の−１に３枚の正単レンズを導入した
ものであり、球面収差の補正がより容易になる。
したがつて、実施例１のタイプに比べＦNOの明る
いレンズに適している。但し、この場合、前群
での球面収差の発生を抑えるべくｄIをある程度
大きな値にする必要がある。
第４表における実施例４は第４図に示すように
後群の−３を２枚の正レンズによつて構成す
るものであり、球面収差及び軸外フレアーを少な
くするのに適している。したがつて、実施例３の
第５図乃至第８図にそれぞれ上記実施例１乃至４
の収差曲線図を示す。【table】
Embodiment 1 in Table 1 above is composed of a single lens with two lenses in the front group and four lenses in the rear group, as shown in FIG. It is a lens type. The rear positive lens group -1 uses glass with as low dispersion as possible to suppress fluctuations in chromatic aberration due to zooming.
In addition, by providing a strong curvature on the object side, spherical aberration is corrected. This lens type is practical for lenses with an aperture f/ NO of up to about 3.5. In Example 2 in Table 2, by introducing a cemented lens into the positive lens group -1 of the rear group, as shown in FIG. This prevents the occurrence of coma aberration and off-axis flare due to chromatic aberration. Therefore, this type is suitable for cases where there are strict requirements regarding chromatic aberration. Another method that satisfies this requirement for chromatic aberration is to use a cemented lens as the negative lens-2. In Example 3 in Table 3, as shown in FIG. 3, three positive single lenses are introduced in -1 of the rear group, making it easier to correct spherical aberration.
Therefore, it is suitable for a lens with a brighter F NO than the type of Example 1. However, in this case, it is necessary to set d I to a somewhat large value in order to suppress the occurrence of spherical aberration in the front group. Embodiment 4 in Table 4 has the rear group -3 composed of two positive lenses as shown in FIG. 4, and is suitable for reducing spherical aberration and off-axis flare. Therefore, FIGS. 5 to 8 of Example 3 correspond to the above-mentioned Examples 1 to 4, respectively.
shows an aberration curve diagram.
第１図乃至第４図は、それぞれ、実施例１乃至
４のレンズ構成図であり、第５図乃至第８図は、
それぞれ、実施例１乃至４の収差曲線図である。
……前群、−１……負単レンズ、−２…
…正メニスカス単レンズ、……後群。
FIGS. 1 to 4 are lens configuration diagrams of Examples 1 to 4, respectively, and FIGS. 5 to 8 are
3A and 3B are aberration curve diagrams of Examples 1 to 4, respectively. ...Front group, -1...Negative single lens, -2...
...Positive meniscus single lens, ...rear group.
Claims (1)
体として収斂屈折力を有する後群の２群によつ
て構成され、前群と後群との空気間隔を変化
させることによつてズーミングを行うズームレン
ズ系に於いて、前群は、物体側より順に像側に
曲率の強い凹面を有する負単レンズ−１、およ
び物体側に凸面を向けた正メニスカス単レンズ
−２より成り、後群は、物体側より順に２枚以
上のレンズより成る正レンズ群−１、像側に曲
率の強い凹面を有する負レンズ−２、及び少く
とも１枚の正レンズより成る最後部レンズ群−
３を有するとともに、次の諸条件に満足すること
を特徴とするズームレンズ系： (1) 0.75L＜｜I｜＜1.5L (2) 0.03｜I｜＜d2＜0.3｜I｜ (3) 0.28｜I｜＜r3＜0.50｜I｜ 但し、Lは最長焦点距離に設定した状態にお
ける全系の合成焦点距離； Iは前群の合成焦点距離； d2は前群中における負単レンズ−１と正メ
ニスカス単レンズ−２の間の空気間隔； r3は前群中における正メニスカス単レンズ
−２の物体側の面の曲率半径。 ２ 後群において、−１は物体側に強い曲率
を持つ２枚の正単レンズより成り、−２は負単
レンズより成り、−３は正単レンズより成るこ
とを特徴とする特許請求の範囲第１項記載のズー
ムレンズ系。 ３ 後群において、−１は物体側に強い曲率
を持つ正単レンズと接合レンズより成り、−２
は負単レンズより成り、−３は正単レンズより
成ることを特徴とする特許請求の範囲第１項記載
のズームレンズ系。 ４ 後群において、−１は物体側に強い曲率
を持つ３枚の正単レンズより成り、−２は負単
レンズより成り、−３は正単レンズより成るこ
とを特徴とする特許請求の範囲第１項記載のズー
ムレンズ系。 ５ 後群において、−１は物体側に強い曲率
を持つ２枚の正単レンズより成り、−２は負単
レンズより成り、−３は２枚の正単レンズより
成ることを特徴とする特許請求の範囲第１項記載
のズームレンズ系。[Claims] 1. Consisting of two groups: a front group having a diverging refractive power as a whole and a rear group having a convergent refractive power as a whole, and by changing the air distance between the front group and the rear group. Therefore, in a zoom lens system that performs zooming, the front group consists of a negative single lens 1 having a concave surface with a strong curvature facing the image side in order from the object side, and a positive meniscus single lens 2 having a convex surface facing the object side. The rear group includes, in order from the object side, a positive lens group-1 consisting of two or more lenses, a negative lens group-2 having a concave surface with a strong curvature on the image side, and a rearmost lens consisting of at least one positive lens. group-
3 and satisfying the following conditions: (1) 0.75 L < | I | < 1.5 L (2) 0.03 | I | < d 2 < 0.3 | I | (3 ) 0.28｜ I ｜＜r 3 ＜0.50｜ I ｜ However, L is the composite focal length of the entire system with the longest focal length set; I is the composite focal length of the front group; d 2 is the negative monomer in the front group. Air distance between lens-1 and positive meniscus single lens-2; r3 is the radius of curvature of the object-side surface of positive meniscus single lens-2 in the front group. 2. In the rear group, -1 consists of two positive single lenses with strong curvature on the object side, -2 consists of a negative single lens, and -3 consists of a positive single lens. The zoom lens system according to item 1. 3 In the rear group, -1 consists of a positive single lens with strong curvature on the object side and a cemented lens, and -2
2. The zoom lens system according to claim 1, wherein -3 is composed of a single negative lens, and -3 is composed of a single positive lens. 4. Claims characterized in that in the rear group, -1 consists of three positive single lenses with strong curvature on the object side, -2 consists of a negative single lens, and -3 consists of a positive single lens. The zoom lens system according to item 1. 5. A patent characterized in that, in the rear group, -1 consists of two positive single lenses with strong curvature on the object side, -2 consists of a negative single lens, and -3 consists of two positive single lenses. A zoom lens system according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2138578A JPS54114236A (en) | 1978-02-24 | 1978-02-24 | Zoom lens system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2138578A JPS54114236A (en) | 1978-02-24 | 1978-02-24 | Zoom lens system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54114236A JPS54114236A (en) | 1979-09-06 |
| JPS6142246B2 true JPS6142246B2 (en) | 1986-09-19 |
Family
ID=12053608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2138578A Granted JPS54114236A (en) | 1978-02-24 | 1978-02-24 | Zoom lens system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54114236A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55163511A (en) * | 1979-06-08 | 1980-12-19 | Nippon Kogaku Kk <Nikon> | 2-group constitution zoom lens |
| JPS5767908A (en) * | 1980-10-14 | 1982-04-24 | Canon Inc | Wide-angle zoom lens |
| JPS5964811A (en) * | 1982-10-05 | 1984-04-12 | Minolta Camera Co Ltd | Two-component zoom lens system |
| JPS6268112U (en) * | 1986-09-04 | 1987-04-28 | ||
| JP2643215B2 (en) * | 1988-01-18 | 1997-08-20 | ミノルタ株式会社 | Zoom lens |
| US4993814A (en) * | 1988-01-18 | 1991-02-19 | Minolta Camera Kabushiki Kaisha | Zoom lens system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492548A (en) * | 1972-04-18 | 1974-01-10 | ||
| JPS5182642A (en) * | 1974-12-28 | 1976-07-20 | Nippon Kogaku Kk | Kokakuzuumurenzukei |
| JPS5183542A (en) * | 1975-01-18 | 1976-07-22 | Katsu Kogei Jugen | FURENNERURENZUNOSEIZOHOHO |
| JPS5360246A (en) * | 1976-11-11 | 1978-05-30 | Fuji Photo Optical Co Ltd | Zoom lens |
-
1978
- 1978-02-24 JP JP2138578A patent/JPS54114236A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492548A (en) * | 1972-04-18 | 1974-01-10 | ||
| JPS5182642A (en) * | 1974-12-28 | 1976-07-20 | Nippon Kogaku Kk | Kokakuzuumurenzukei |
| JPS5183542A (en) * | 1975-01-18 | 1976-07-22 | Katsu Kogei Jugen | FURENNERURENZUNOSEIZOHOHO |
| JPS5360246A (en) * | 1976-11-11 | 1978-05-30 | Fuji Photo Optical Co Ltd | Zoom lens |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54114236A (en) | 1979-09-06 |
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