JPH0763991A - Two-group zoom lens - Google Patents
Two-group zoom lensInfo
- Publication number
- JPH0763991A JPH0763991A JP6132239A JP13223994A JPH0763991A JP H0763991 A JPH0763991 A JP H0763991A JP 6132239 A JP6132239 A JP 6132239A JP 13223994 A JP13223994 A JP 13223994A JP H0763991 A JPH0763991 A JP H0763991A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- group
- positive power
- power
- zoom
- 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
Links
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Abstract
Description
【０００１】[0001]
【技術分野】本発明は、ＳＬＲカメラ等に用いる、２倍
程度の変倍比を持つ標準域の２群ズームレンズに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standard-group two-group zoom lens having a zoom ratio of about 2 times, which is used for an SLR camera or the like.
【０００２】[0002]
【従来技術およびその問題点】２倍程度の変倍比をもつ
標準域のズームレンズであって、負、正の２群で構成さ
れる２群ズームレンズは、従来、特開昭59-142515 号、
特開平1-185607号、特開平1-239516号、特開平4-114115
号等で、数多く開示されている。2. Description of the Related Art A zoom lens in a standard range having a zoom ratio of about 2 times, which is a two-group zoom lens composed of two groups, a negative group and a positive group, is conventionally disclosed in Japanese Patent Laid-Open No. 59-142515. issue,
JP-A-1-185607, JP-A1-239516, JP-A-4-114115
And many others.
【０００３】[0003]
【発明の目的】本発明は、これらの従来提案されている
２群ズームレンズより、さらに廉価でコンパクト化が可
能な２群ズームレンズを得ることを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-group zoom lens which is more inexpensive and more compact than these conventionally proposed two-group zoom lenses.
【０００４】[0004]
【発明の概要】本発明は、物体側から順に、負のパワー
の第Ｉレンズ群と正のパワーの第IIレンズ群とで構成さ
れ、この第Ｉ、第IIレンズ群を相対的に動かして変倍を
行なう２群ズームレンズにおいて、第IIレンズ群を、正
のパワーの第II−１レンズと、正のパワーの第II−２レ
ンズと、負のパワーの第II−３レンズと、正のパワーの
第II−４レンズとで構成して、この第II−２レンズと第
II−３レンズを接合レンズとし、かつ、次の条件式を満
足するようにしたことを特徴としている。SUMMARY OF THE INVENTION The present invention comprises, in order from the object side, a negative power I lens group and a positive power II lens group, which are moved relative to each other. In a two-group zoom lens that performs zooming, the second lens group includes a positive power II-1 lens, a positive power II-2 lens, a negative power II-3 lens, and a positive power II-2 lens. This II-2 lens and the II-II lens
It is characterized in that the II-3 lens is a cemented lens and the following conditional expression is satisfied.
【０００５】（ａ）０．１＜nN−nP＜０．４ （ｂ）−１．３＜rC／f2＜−０．５ （ｃ）０．６＜d1-2／fw＜１．２ 但し、 nP；第II−２レンズの屈折率、 nN；第II−３レンズの屈折率、 rC；第II−２レンズと第II−３レンズの接合面の曲率半
径、 f2；第IIレンズ群の焦点距離、 d1-2；第Ｉレンズ群と第IIレンズ群の間隔、 fw；全系の広角側の焦点距離、 である。(A) 0.1 <nN-nP <0.4 (b) -1.3 <r C / f 2 <-0.5 (c) 0.6 <d 1-2 / f w < 1.2 where nP is the refractive index of the II-2 lens, nN is the refractive index of the II-3 lens, r C is the radius of curvature of the cemented surface between the II-2 lens and the II-3 lens, f 2 The focal length of the II lens group, d 1-2 ; the distance between the I lens group and the II lens group, f w ; the focal length of the entire system on the wide-angle side.
【０００６】第Ｉレンズ群は、例えば、負のパワーの第
I −１レンズと、負のパワーの第I−２レンズと、正の
パワーの第I −３レンズとで構成することが望ましい。The I-th lens group includes, for example, a negative-power first lens group.
It is preferable that the lens is composed of an I-1 lens, a negative power I-2 lens, and a positive power I-3 lens.
【０００７】また、本発明は、別の態様によると、物体
側から順に、負のパワーの第Ｉレンズ群と正のパワーの
第IIレンズ群とで構成され、この第Ｉ、第IIレンズ群を
相対的に動かして変倍を行なう２群ズームレンズにおい
て、第Ｉレンズ群を、物体側に凸の負メニスカス形状の
第I −１レンズと、像面側に凸の負メニスカス形状の第
I −２レンズと、物体側に凸の正メニスカス形状の第I
−３レンズとで構成し、かつ、次の条件式を満足するよ
うにしたことを特徴としている。 （ｄ）０＜f1／r2-2＜１．２ 但し、 f1；第Ｉレンズ群の焦点距離、 r2-2；第I −２レンズの第２面の曲率半径、 である。According to another aspect of the present invention, in order from the object side, it is composed of a negative power I lens group and a positive power II lens group. The I and II lens groups In a two-group zoom lens that performs zooming by moving relative to, the I-th lens group includes a negative meniscus I-1 lens having a convex surface on the object side and a negative meniscus convex lens having a convex surface on the image side.
I -2 lens and a positive meniscus shape I convex on the object side
-3 lens, and the following conditional expression is satisfied. (D) 0 <f 1 / r 2-2 <1.2, where f 1 is the focal length of the I-th lens group, r 2-2 is the radius of curvature of the second surface of the I-th 2nd lens.
【０００８】[0008]
【発明の実施例】以下本発明の２群ズームレンズの実施
例を説明する。本発明の２群ズームレンズは、第Ｉレン
ズ群が第I −１ないし第I −３レンズの３枚のレンズか
らなり、第IIレンズ群が第II−１ないし第II−４レンズ
の４枚のレンズからなるものである。そして、第II−２
レンズと第II−３レンズは、接合（貼合せ）レンズとな
っている。Embodiments of the two-group zoom lens according to the present invention will be described below. In the two-group zoom lens of the present invention, the I-th lens group is composed of three lenses I-1 to I-3, and the II-lens group is composed of four lenses II-1 to II-4. It consists of a lens. And II-2
The lens and the II-3 lens are cemented (bonded) lenses.
【０００９】条件式（ａ） ０．１＜nN−nP＜０．４（nP；第II−２レンズの屈折
率、nN；第II−３レンズの屈折率）及び、 同（ｂ） −１．３＜rC／f2＜−０．５（rC；第II−２レンズと第
II−３レンズの接合面の曲率半径、f2；第IIレンズ群の
焦点距離）は、いずれも、この接合レンズに関する条件
である。Conditional expression (a) 0.1 <nN-nP <0.4 (nP; refractive index of lens II-2, nN; refractive index of lens II-3) and (b) -1 .3 <r C / f 2 < -0.5 (r C; and the II-2 lens No.
The radius of curvature of the cemented surface of the II-3 lens, f 2 ; the focal length of the second lens group II) are all conditions relating to this cemented lens.
【００１０】本発明の２群ズームレンズでは、この接合
レンズを構成する第II−２レンズと第II−３レンズをそ
れぞれ正のパワーと負のパワーの組み合わせとしてお
り、特にこれらのパワーを強くすることによって、レン
ズの小型化と良好な収差補正を図っている。この第II−
２レンズと第II−３レンズの接合は、さらに、製造誤差
による影響を少なくし、安定した生産性を確保して、コ
ストダウン効果を狙ったものである。In the two-group zoom lens of the present invention, the second lens II-2 and the third lens II-3, which form this cemented lens, have a combination of positive power and negative power, respectively, and these powers are particularly strengthened. As a result, the lens is downsized and the aberration is favorably corrected. This II-
The cementing of the 2nd lens and the II-3rd lens is intended to further reduce the influence of manufacturing error, ensure stable productivity, and reduce the cost.
【００１１】条件式（ａ）は、第II−２レンズと第II−
３レンズの屈折率差の条件であり、この条件を外れて屈
折率差の小さいレンズ材料を使うと、接合面で十分な球
面収差の補正ができず、さらにコマ収差が悪化する。逆
に、この屈折率差が条件を外れて大きいと、結果的に正
の第II−２レンズの屈折率nPが小さくなり、ペッツバー
ル和が大きくなって、像面湾曲、非点隔差の補正が困難
になる。理論上は、負の第II−３レンズの屈折率nNの屈
折率を上げることによりペッツバール和を小さくするこ
とができるが、屈折率の高いレンズ材料は、一般に高価
でありコスト的に望ましくない。Conditional expression (a) is defined by the II-th lens and the II-
This is a condition for the difference in refractive index between the three lenses, and if a lens material having a small difference in refractive index is used outside this condition, spherical aberration cannot be sufficiently corrected at the cemented surface, and coma becomes worse. On the other hand, if this difference in refractive index is large outside the conditions, as a result, the refractive index nP of the positive II-2 lens becomes small, the Petzval sum becomes large, and the field curvature and astigmatic difference are corrected. It will be difficult. In theory, the Petzval sum can be reduced by increasing the refractive index of the negative refractive index nN of the lens No. II-3, but a lens material having a high refractive index is generally expensive and not desirable in terms of cost.
【００１２】本発明においては、第II−１レンズとし
て、屈折率の比較的高いレンズ材料を用いることが好ま
しい。第II−１レンズに収差補正を分担させ、第II−２
レンズとして、屈折率の比較的低い材料を用いることが
できるからである。In the present invention, it is preferable to use a lens material having a relatively high refractive index as the II-1 lens. The second II-1 lens shares the aberration correction with the second II-2 lens.
This is because a material having a relatively low refractive index can be used as the lens.
【００１３】次に条件（ｂ）は、第II−２レンズと第II
−３レンズの接合面の曲率半径を規定しており、球面収
差補正を良好に行なうための条件である。本発明の２群
ズームレンズは、条件（ａ）で確保した屈折率差を利用
し、接合面を発散面とし球面収差を補正しているため、
接合面の曲率をこの条件式の下限を越えて緩くすること
は望ましくない。逆に、上限値を越えて曲率を強くする
と、高次収差発生の要因となる。Next, the condition (b) is the second lens II and the second lens II.
This is a condition for satisfactorily correcting spherical aberration, which defines the radius of curvature of the cemented surface of the −3 lens. Since the two-group zoom lens of the present invention utilizes the refractive index difference secured under the condition (a) and uses the cemented surface as a diverging surface to correct spherical aberration,
It is not desirable to loosen the curvature of the joint surface beyond the lower limit of this conditional expression. On the contrary, if the curvature exceeds the upper limit and the curvature is increased, it becomes a factor of occurrence of high-order aberrations.
【００１４】条件式（ｃ） ０．６＜d1-2／fw＜１．２（d1-2；第Ｉレンズ群と第II
レンズ群の間隔、fw；全系の広角側の焦点距離）は、ズ
ーミングの移動範囲を規定する条件である。Conditional expression (c) 0.6 <d 1-2 / fw <1.2 (d 1-2 ; the 1st lens group and the 2nd lens group)
The distance between lens groups, f w ; the focal length on the wide-angle side of the entire system) is a condition that defines the moving range of zooming.
【００１５】第Ｉレンズ群と第IIレンズ群との間隔をよ
り広く取れば、広角化は可能であるが、この条件式の上
限を越えて群間隔を広くとると、周辺減光が発生しやす
くなり、好ましくない。逆に下限値を下回ると、所望の
変倍比がとれない。If the distance between the I-th lens group and the II-th lens group is made wider, a wider angle can be achieved. However, if the distance between the first lens group and the second lens group is wider than the upper limit of this conditional expression, peripheral dimming occurs. It becomes easy and not preferable. On the other hand, if the value is below the lower limit, the desired zoom ratio cannot be obtained.
【００１６】条件（ｄ） ０＜f1／r2-2＜１．２（f1；第Ｉレンズ群の焦点距離、
r2-2；第I −２レンズの第２面の曲率半径）は、第I レ
ンズ群の第I −２レンズの形状に関するものである。Condition (d) 0 <f 1 / r 2-2 <1.2 (f 1 ; focal length of the I-th lens group,
r 2-2 ; radius of curvature of the second surface of the I-th 2nd lens) relates to the shape of the I-th 2nd lens of the I-th lens group.
【００１７】広角レンズや広角を含むズームレンズの広
角時において、コンパクト化を図るため、前群の負レン
ズのパワーを上げると、歪曲収差が増えるという性質が
ある。これを補正するために、物体側に近いレンズに弱
い正レンズを付加する手法が広く知られている。例えば
特開平4-114115号公報、同2-167515号公報、 同4-261511
号公報等には、この手法を用いたレンズ系が開示されて
いる。これに対し、本発明は、負のパワーを持つ第I −
２レンズの像側の面を凸とすることにより、正レンズを
付加したのと同様の歪曲収差補正効果を得ることを特徴
の一つとしている。これにより、正レンズ１枚を付加す
ることなく、コンパクトな構成でありながら、歪曲収差
の少ないズームレンズを提供することができる。When a wide-angle lens or a zoom lens including a wide-angle lens is wide-angled, distortion is increased by increasing the power of the negative lens in the front group in order to make the lens compact. To correct this, a method of adding a weak positive lens to a lens close to the object side is widely known. For example, JP-A-4-114115, JP-A-2-167515, and JP-A-4-261511
A lens system using this method is disclosed in, for example, Japanese Patent Publication. On the other hand, the present invention is the first I − having negative power.
One of the features is that the image-side surfaces of the two lenses are made convex so that the same distortion aberration correction effect as when a positive lens is added can be obtained. With this, it is possible to provide a zoom lens having a compact structure and less distortion, without adding one positive lens.
【００１８】この条件式（ｄ）の下限値を越えて第I −
２レンズの像側の面を弱い凸面とすると、歪曲収差を十
分補正できなくなってしまう。逆に上限値を越えて第I
−２レンズの像側の面の凸形状を強くすると、第I −２
レンズの負のパワーが弱くなり、レンズ全系として広角
化が困難になる。理論的には、第I −２レンズの物体側
の面をより強い凹面にして第I −２レンズの負のパワー
を確保することも考えられるが、内方コマ収差の発生要
因となり、好ましくない。If the lower limit of conditional expression (d) is exceeded,
If the image-side surface of the two lenses is a weak convex surface, the distortion cannot be sufficiently corrected. Conversely, if the upper limit is exceeded,
-2 If the convex shape of the image side surface of the lens is increased,
The negative power of the lens becomes weak, and it becomes difficult to widen the angle as the entire lens system. Theoretically, it is conceivable to secure the negative power of the I-2 lens by making the object-side surface of the I-2 lens a stronger concave surface, but this is not preferable because it causes inward coma. .
【００１９】［実施例１］図１は、本発明の２群ズーム
レンズの実施例１の広角端におけるレンズ構成図であ
る。絞Ｓの前の第Ｉレンズ群は、第I −１ないし第I −
３レンズ（I −１、I −２、I −３レンズ）からなり、
絞Ｓの後の第IIレンズ群は、第II−１ないし第II−４レ
ンズ（II−１、II−２、II−３、II−４レンズ）からな
っている。第I レンズ群のすべてのレンズは、メニスカ
ス形状をなし、第II−２レンズと第II−３レンズは接合
レンズである。[Embodiment 1] FIG. 1 is a lens configuration diagram at the wide-angle end of Embodiment 1 of a two-group zoom lens according to the present invention. The I-th lens group in front of the diaphragm S includes I-1 to I-
It consists of 3 lenses (I-1, I-2, I-3 lens),
The II lens group after the diaphragm S is composed of II-1 to II-4 lenses (II-1, II-2, II-3, II-4 lenses). All the lenses of the I-th lens group have a meniscus shape, and the II-II lens and the II-III lens are cemented lenses.
【００２０】このレンズ系の具体的数値データを表１に
示し、短焦点距離端、中間焦点距離、及び長焦点距離端
における諸収差をそれぞれ図２、図３、及び図４に示
す。諸収差図中、ＳＡは球面収差、ＳＣは正弦条件、ｄ
線、ｇ線、Ｃ線は、それぞれの波長における、球面収差
によって示される色収差と倍率色収差、Ｓはサジタル、
Ｍはメリディオナルを示している。表中、ｒはレンズ各
面の曲率半径、ｄはレンズ厚もしくはレンズ間隔、Ｎは
屈折率、νはアッベ数を示す。Specific numerical data of this lens system are shown in Table 1, and various aberrations at the short focal length end, the intermediate focal length end, and the long focal length end are shown in FIGS. 2, 3, and 4, respectively. In various aberration diagrams, SA is spherical aberration, SC is sine condition, d
Line, g line, and C line are chromatic aberration and chromatic aberration of magnification indicated by spherical aberration at respective wavelengths, S is sagittal,
M indicates meridional. In the table, r is the radius of curvature of each surface of the lens, d is the lens thickness or lens spacing, N is the refractive index, and ν is the Abbe number.
【００２１】[0021]
【表１】 FNO ＝ 1:4.2〜4.9 〜5.9 f ＝ 36.03〜50.00 〜68.00 ω ＝ 32.1 ゜〜23.3゜〜17.4゜ FB ＝41.41 〜50.42 〜 62.04 f1＝-54.610 f2＝35.238 fw＝36.03 面 No. ｒ ｄ Ｎ ν １ 38.966 2.00 1.77250 49.6 ２ 17.670 7.08 ３ -47.206 1.60 1.68250 44.7 ４ -61.564 0.50 ５ 21.018 2.54 1.80518 25.4 ６ 24.929 28.52-13.60-3.41（可変） 絞 1.21 ７ 33.325 3.17 1.75500 52.3 ８ -66.840 0.10 ９ 14.913 4.59 1.50378 66.8 １０ -44.114 3.68 1.83400 37.2 １１ 13.983 4.36 １２ -40.374 2.31 1.58267 46.4 １３ -21.741 [Table 1] F NO = 1: 4.2 to 4.9 to 5.9 f = 36.03 to 50.00 to 68.00 ω = 32.1 ° to 23.3 ° to 17.4 ° F B = 41.41 to 50.42 to 62.04 f 1 = -54.610 f 2 = 35.238 f w = 36.03 surface No. rd N ν 1 38.966 2.00 1.77250 49.6 2 17.670 7.08 3 -47.206 1.60 1.68250 44.7 4 -61.564 0.50 5 21.018 2.54 1.80518 25.4 6 24.929 28.52-13.60-3.41 (variable) aperture 1.21 7 33.325 3.17 1.17 -66.840 0.10 9 14.913 4.59 1.50378 66.8 10 -44.114 3.68 1.83400 37.2 11 13.983 4.36 12 -40.374 2.31 1.58267 46.4 13 -21.741
【００２２】［実施例２］図５は、本発明の２群ズーム
レンズの実施例２の広角端におけるレンズ構成図であ
る。このレンズ系の具体的数値データを表２に示し、短
焦点距離端、中間焦点距離、及び長焦点距離端における
諸収差をそれぞれ図６、図７、及び図８に示す。[Embodiment 2] FIG. 5 is a lens configuration diagram of Embodiment 2 of the two-group zoom lens according to the present invention at the wide-angle end. Table 2 shows specific numerical data of this lens system, and FIGS. 6, 7, and 8 show various aberrations at the short focal length end, the intermediate focal length end, and the long focal length end, respectively.
【００２３】[0023]
【表２】 FNO ＝ 1:4.2〜4.9 〜5.9 f ＝ 36.03〜50.00 〜68.00 ω ＝ 32.2 ゜〜23.4゜〜17.4゜ FB ＝42.34 〜51.32 〜 62.89 f1＝-54.828 f2＝35.259 fw＝36.03 面 No. ｒ ｄ Ｎ ν １ 36.069 2.00 1.79500 45.3 ２ 17.554 6.46 ３ -71.175 1.60 1.80400 46.6 ４ -137.630 0.50 ５ 22.681 2.63 1.80518 25.4 ６ 29.260 28.63-13.65-3.41（可変） 絞 1.21 ７ 42.968 1.21 1.71299 53.9 ８ -101.850 0.10 ９ 19.444 8.42 1.69680 56.5 １０ -22.971 1.50 1.83400 37.2 １１ 15.854 3.66 １２ -51.274 2.35 1.64328 47.9 １３ -23.543[Table 2] F NO = 1: 4.2 to 4.9 to 5.9 f = 36.03 to 50.00 to 68.00 ω = 32.2 ° to 23.4 ° to 17.4 ° F B = 42.34 to 51.32 to 62.89 f 1 = -54.828 f 2 = 35.259 f w ＝ 36.03 surface No. rd ν ν 1 36.069 2.00 1.79500 45.3 2 17.554 6.46 3 -71.175 1.60 1.80400 46.6 4 -137.630 0.50 5 22.681 2.63 1.80518 25.4 6 29.260 28.63-13.65-3.41 (variable) aperture 1.21 7 42.968 3.918 1.71299 -101.850 0.10 9 19.444 8.42 1.69680 56.5 10 -22.971 1.50 1.83400 37.2 11 15.854 3.66 12 -51.274 2.35 1.64328 47.9 13 -23.543
【００２４】［実施例３］図９は、本発明の２群ズーム
レンズの実施例３の広角端におけるレンズ構成図であ
る。このレンズ系の具体的数値データを表３に示し、短
焦点距離端、中間焦点距離、及び長焦点距離端における
諸収差をそれぞれ図１０、図１１、及び図１２に示す。[Embodiment 3] FIG. 9 is a lens configuration diagram at the wide-angle end of Embodiment 3 of the two-group zoom lens according to the present invention. Table 3 shows specific numerical data of this lens system, and FIGS. 10, 11, and 12 show various aberrations at the short focal length end, the intermediate focal length end, and the long focal length end, respectively.
【００２５】[0025]
【表３】 FNO ＝ 1:3.9〜4.6 〜5.9 f ＝ 35.96〜50.00 〜75.00 ω ＝ 32.1 ゜〜23.4゜〜15.9゜ FB ＝42.60 〜52.50 〜 70.13 f1＝-49.063 f2＝34.598 fw＝35.96 面 No. ｒ ｄ Ｎ ν １ 39.540 1.65 1.77250 49.6 ２ 16.866 6.51 ３ -103.932 1.60 1.80610 40.9 ４ -518.960 0.10 ５ 22.598 2.77 1.80518 25.4 ６ 31.345 27.99-14.73-3.42（可変） 絞 1.20 ７ 47.904 3.21 1.69680 55.5 ８ -47.904 0.10 ９ 15.447 4.81 1.51633 64.1 １０ -43.109 5.61 1.83400 37.2 １１ 15.150 3.68 １２ -67.864 2.44 1.58267 46.4 １３ -25.449[Table 3] F NO = 1: 3.9 to 4.6 to 5.9 f = 35.96 to 50.00 to 75.00 ω = 32.1 ° to 23.4 ° to 15.9 ° F B = 42.60 to 52.50 to 70.13 f 1 = -49.063 f 2 = 34.598 f w ＝ 35.96 surface No. rd N ν 1 39.540 1.65 1.77250 49.6 2 16.866 6.51 3 -103.932 1.60 1.80610 40.9 4 -518.960 0.10 5 22.598 2.77 1.80518 25.4 6 31.345 27.99-14.73-3.42 (variable) aperture 1.20 7 47.904 3.21 1.69 1.68 -47.904 0.10 9 15.447 4.81 1.51633 64.1 10 -43.109 5.61 1.83400 37.2 11 15.150 3.68 12 -67.864 2.44 1.58267 46.4 13 -25.449
【００２６】次に、実施例１ないし３の各条件式に対応
する値を表４に示す。Table 4 shows the values corresponding to the conditional expressions of Examples 1 to 3.
【表４】 条件式(a) 条件式(b) 条件式(c) 条件式(d) 実施例１ ０．３３０２２ −１．２５２ ０．８２５ ０．８９０ 実施例２ ０．１３７２０ −０．６５１ ０．８２８ ０．４００ 実施例３ ０．３１７６７ −１．２４６ ０．８１７ ０．０９５ Table 4 Conditional Expression (a) Conditional Expression (b) Conditional Expression (c) Conditional Expression (d) Example 1 0.33022-1.252 0.825 0.890 Example 2 0.13720 -0.651 0.828 0.400 Example 3 0.31767-1.246 0.817 0.095
【００２７】表４から明らかなように、実施例１ないし
３の数値は、いずれも条件式（ａ）、（ｂ）、（ｃ）を
満足している。また、各収差図に示すように、本発明の
２群ズームレンズは、広角から望遠に至る全焦点距離域
において諸収差がよく補正されている。As is clear from Table 4, the numerical values of Examples 1 to 3 all satisfy the conditional expressions (a), (b) and (c). Further, as shown in each aberration diagram, in the two-group zoom lens of the present invention, various aberrations are well corrected in the entire focal length range from wide angle to telephoto.
【００２８】[0028]
【発明の効果】本発明の２群ズームレンズによれば、広
角から望遠を２倍程度の標準系ズームレンズを、コンパ
クトに、かつ安価に提供できる。通常はコンパクト化す
ると、特に第IIレンズ群の負レンズのパワーが大きくな
りやすく、製造誤差による性能劣化が発生しやすいが、
本発明では、パワーの大きい第II−２レンズと第II−３
レンズを接合したために、製造誤差による影響が少な
く、安定した生産性を確保でき、コストダウンを図るこ
とができる。According to the two-group zoom lens of the present invention, it is possible to provide a standard zoom lens having a wide-angle to telephoto ratio of about 2 times in a compact and inexpensive manner. Normally, if it is made compact, the power of the negative lens in the second lens group tends to increase, and performance deterioration due to manufacturing errors tends to occur.
In the present invention, the II-2 lens and the II-3 lens having high power are used.
Since the lenses are joined, the influence of manufacturing error is small, stable productivity can be secured, and cost can be reduced.
【００２９】また、第Ｉレンズ群を３枚構成にしてコン
パクト化すると、広角側での歪曲収差がマイナスの大き
な値となりやすいが、請求項３によれば、特に第I −２
レンズを像面側に凸の負メニスカス形状としたことによ
り、全系をコンパクトに保ちながら、歪曲収差の発生を
抑えることができた。If the I-th lens group is made up of three lenses and is made compact, the distortion on the wide-angle side tends to have a large negative value.
By making the lens a negative meniscus shape with a convex surface on the image side, it was possible to suppress the occurrence of distortion while keeping the entire system compact.
【図１】本発明による２群ズームレンズの第１の実施例
を示す、広角端におけるレンズ構成図である。FIG. 1 is a lens configuration diagram at a wide-angle end showing a first embodiment of a two-group zoom lens according to the present invention.
【図２】図１の実施例の広角端における諸収差図であ
る。FIG. 2 is a diagram of various types of aberration at the wide-angle end of the example of FIG.
【図３】図１の実施例の中間焦点距離における諸収差図
である。FIG. 3 is a diagram of various types of aberration at the intermediate focal length of the example of FIG.
【図４】図１の実施例の望遠端における諸収差図であ
る。FIG. 4 is a diagram of various types of aberration at the telephoto end of the embodiment of FIG.
【図５】本発明による２群ズームレンズの第２の実施例
を示す、広角端におけるレンズ構成図である。FIG. 5 is a lens configuration diagram at a wide-angle end showing a second embodiment of the two-group zoom lens according to the present invention.
【図６】図５の実施例の広角端における諸収差図であ
る。FIG. 6 is a diagram of various types of aberration at the wide-angle end of the embodiment of FIG.
【図７】図５の実施例の中間焦点距離における諸収差図
である。FIG. 7 is a diagram of various types of aberration at the intermediate focal length of the example of FIG.
【図８】図５の実施例の望遠端における諸収差図であ
る。8 is a diagram of various types of aberration at the telephoto end of the embodiment of FIG.
【図９】本発明による２群ズームレンズの第３の実施例
を示す、広角端におけるレンズ構成図である。FIG. 9 is a lens configuration diagram at a wide-angle end, showing a third embodiment of the second group zoom lens according to the present invention.
【図１０】図９の実施例の広角端における諸収差図であ
る。FIG. 10 is a diagram of various types of aberration at the wide-angle end of the example of FIG.
【図１１】図９の実施例の中間焦点距離における諸収差
図である。FIG. 11 is a diagram of various types of aberration at the intermediate focal length of the example of FIG.
【図１２】図９の実施例の望遠端における諸収差図であ
る。FIG. 12 is a diagram of various types of aberration at the telephoto end of the example of FIG.
Claims (3)
ズ群と正のパワーの第IIレンズ群とで構成され、この第
Ｉ、第IIレンズ群を相対的に動かして変倍を行なう２群
ズームレンズにおいて、 第IIレンズ群は、正のパワーの第II−１レンズと、正の
パワーの第II−２レンズと、負のパワーの第II−３レン
ズと、正のパワーの第II−４レンズとで構成されてい
て、第II−２レンズと第II−３レンズは接合され、 かつ、次の条件式を満足することを特徴とする２群ズー
ムレンズ。 （ａ）０．１＜nN−nP＜０．４ （ｂ）−１．３＜rC／f2＜−０．５ （ｃ）０．６＜d1-2／fw＜１．２ 但し、 nP；第II−２レンズの屈折率、 nN；第II−３レンズの屈折率、 rC；第II−２レンズと第II−３レンズの接合面の曲率半
径、 f2；第IIレンズ群の焦点距離、 d1-2；第Ｉレンズ群と第IIレンズ群の間隔、 fw；全系の広角側の焦点距離。1. A zoom lens system comprising, in order from the object side, a negative power I lens group and a positive power II lens group, and moving the I and II lens groups relative to each other. In the two-group zoom lens, the second lens group includes a positive power II-1 lens, a positive power II-2 lens, a negative power II-3 lens, and a positive power second lens. A two-group zoom lens comprising a II-4 lens, wherein the II-2 lens and the II-3 lens are cemented together and the following conditional expression is satisfied. (A) 0.1 <nN-nP <0.4 (b) -1.3 <r C / f 2 <-0.5 (c) 0.6 <d 1-2 / fw <1.2 Where nP is the refractive index of the second lens II-2, nN is the refractive index of the second lens II-3, r C is the radius of curvature of the cemented surface between the second lens II-2 and the second lens II-3, f 2 is the second lens II. Focal length of lens group, d 1-2 ; Distance between I-th lens group and II-lens group, f w ; Wide-angle focal length of the whole system.
のパワーの第I −１レンズと、負のパワーの第II−２レ
ンズと、正のパワーの第I −３レンズとで構成されてい
る２群ズームレンズ。2. The I-th lens group according to claim 1, comprising an I-1 lens having a negative power, a II-2 lens having a negative power, and an I-3 lens having a positive power. 2 group zoom lens that is used.
ズ群と正のパワーの第Ｉレンズ群とで構成され、この第
Ｉ、第IIレンズ群を相対的に動かして変倍を行なう２群
ズームレンズにおいて、 第Ｉレンズ群は、物体側に凸の負メニスカス形状の第I
−１レンズと、像面側に凸の負メニスカス形状の第I −
２レンズと、物体側に凸の正メニスカス形状の第I −３
レンズとで構成され、 かつ、次の条件式を満足することを特徴とする２群ズー
ムレンズ。 （ｄ）０＜f1／r2-2＜１．２ 但し、 f1；第Ｉレンズ群の焦点距離、 r2-2；第I −２レンズの第２面の曲率半径。3. The zoom lens system is composed of, in order from the object side, an I-th lens unit having a negative power and an I-th lens unit having a positive power, and these I and II lens units are moved relatively to each other. In the 2-group zoom lens, the I-th lens group is a negative meniscus-shaped I-th lens element convex on the object side.
-1 lens and the negative meniscus I-th lens convex on the image side
Two lenses and a positive meniscus I-3 convex on the object side
A two-group zoom lens that is composed of a lens and that satisfies the following conditional expression. (D) 0 <f 1 / r 2-2 <1.2 where f 1 is the focal length of the I-th lens group, r 2-2 is the radius of curvature of the second surface of the I-th 2nd lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6132239A JPH0763991A (en) | 1993-06-14 | 1994-06-14 | Two-group zoom lens |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14196193 | 1993-06-14 | ||
| JP5-141961 | 1993-06-14 | ||
| JP6132239A JPH0763991A (en) | 1993-06-14 | 1994-06-14 | Two-group zoom lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0763991A true JPH0763991A (en) | 1995-03-10 |
Family
ID=26466863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6132239A Pending JPH0763991A (en) | 1993-06-14 | 1994-06-14 | Two-group zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0763991A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012008347A (en) * | 2010-06-24 | 2012-01-12 | Ricoh Co Ltd | Imaging lens, imaging device, and information device |
| JP2013178391A (en) * | 2012-02-28 | 2013-09-09 | Nikon Corp | Optical system, optical device, and method for manufacturing optical system |
| JP2013250534A (en) * | 2012-06-04 | 2013-12-12 | Ricoh Co Ltd | Image forming lens, camera, and portable information terminal device |
| US8780463B2 (en) | 2010-06-24 | 2014-07-15 | Ricoh Company, Ltd. | Image-forming lens, and imaging apparatus and information device using the image-forming lens |
| WO2017160092A3 (en) * | 2016-03-18 | 2018-09-07 | 주식회사 에이스솔루텍 | Optical photographing lens system |
| US10268026B2 (en) | 2012-02-28 | 2019-04-23 | Nikon Corporation | Optical system, optical apparatus and method for manufacturing the optical system |
| JP2019132967A (en) * | 2018-01-31 | 2019-08-08 | 株式会社タムロン | Image capturing lens and image capturing device |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012008347A (en) * | 2010-06-24 | 2012-01-12 | Ricoh Co Ltd | Imaging lens, imaging device, and information device |
| US8780463B2 (en) | 2010-06-24 | 2014-07-15 | Ricoh Company, Ltd. | Image-forming lens, and imaging apparatus and information device using the image-forming lens |
| US9207430B2 (en) | 2010-06-24 | 2015-12-08 | Ricoh Company, Ltd. | Image-forming lens, and imaging apparatus and information device using the image-forming lens |
| US9952408B2 (en) | 2010-06-24 | 2018-04-24 | Ricoh Company, Ltd. | Image-forming lens, and imaging apparatus and information device using the image-forming lens |
| US10746963B2 (en) | 2010-06-24 | 2020-08-18 | Ricoh Company, Ltd. | Image-forming lens, and imaging apparatus and information device using the image-forming lens |
| JP2013178391A (en) * | 2012-02-28 | 2013-09-09 | Nikon Corp | Optical system, optical device, and method for manufacturing optical system |
| US10268026B2 (en) | 2012-02-28 | 2019-04-23 | Nikon Corporation | Optical system, optical apparatus and method for manufacturing the optical system |
| JP2013250534A (en) * | 2012-06-04 | 2013-12-12 | Ricoh Co Ltd | Image forming lens, camera, and portable information terminal device |
| WO2017160092A3 (en) * | 2016-03-18 | 2018-09-07 | 주식회사 에이스솔루텍 | Optical photographing lens system |
| JP2019132967A (en) * | 2018-01-31 | 2019-08-08 | 株式会社タムロン | Image capturing lens and image capturing device |
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