JPH10186227A - Telephotographic lens - Google Patents
Telephotographic lensInfo
- Publication number
- JPH10186227A JPH10186227A JP23133697A JP23133697A JPH10186227A JP H10186227 A JPH10186227 A JP H10186227A JP 23133697 A JP23133697 A JP 23133697A JP 23133697 A JP23133697 A JP 23133697A JP H10186227 A JPH10186227 A JP H10186227A
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- JP
- Japan
- Prior art keywords
- lens
- positive
- telephoto
- diffractive
- 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.)
- Pending
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、３５ｍｍカメラやビデ
オカメラ等に好適な良好に色収差が補正された望遠レン
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 telephoto lens which is suitable for a 35 mm camera, a video camera and the like, and has excellent chromatic aberration.
【０００２】[0002]
【従来の技術】望遠レンズでは、レンズの性能はおもに
色収差によって制限され、レンズ製造に用いることので
きる素材の特性から、可視域全域にわたる補正のために
は異常分散性を持つ高価な硝材を用いる必要があった。
その場合にも十分に色収差補正を行う場合には負レンズ
にアッベ数の小さい硝材を選択することができないた
め、正負のレンズそれぞれに強いパワーを持たせ色収差
を打ち消し合わせざるをえず、２次スペクトルの補正度
合いはレンズの重さとのバランスで決定されるものであ
った。2. Description of the Related Art In a telephoto lens, the performance of the lens is mainly limited by chromatic aberration, and an expensive glass material having anomalous dispersion is used for correction over the entire visible range due to characteristics of a material that can be used for manufacturing the lens. Needed.
Even in this case, if the chromatic aberration is sufficiently corrected, it is not possible to select a glass material having a small Abbe number for the negative lens, so the positive and negative lenses must have strong power to cancel the chromatic aberration. The degree of spectrum correction was determined by the balance with the weight of the lens.
【０００３】[0003]
【発明の目的】本発明は、回折レンズの色収差補正効果
を利用して、高価な異常分散性硝材を用いることなく、
少ないレンズ枚数で良好に色収差補正をされた小型、軽
量な望遠レンズを作ることを目的としている。SUMMARY OF THE INVENTION The present invention utilizes the chromatic aberration correction effect of a diffractive lens without using an expensive anomalous dispersion glass material.
An object of the present invention is to produce a small and lightweight telephoto lens with good chromatic aberration correction using a small number of lenses.
【０００４】[0004]
【課題を解決するための手段】本発明にかかる望遠レン
ズは、物体側から順に、正の第１レンズと負の第２レン
ズからなる前群と、正レンズと負レンズの２枚のレンズ
からなる後群で構成し、前記前群中にブレーズ化された
正の回折レンズ作用を持つ輪帯状構造を有する回折屈折
ハイブリッド面を配置し、さらに、前記第１レンズのア
ッベ数νd をν1 、部分分散比θgFをθ1 、前記第２レ
ンズのアッベ数νd をν2 、部分分散比θgFをθ2 とし
たとき ν2 ／ν1 ＜ 0.55 (1) 0.040 ＜ θ2 −θ1 (2) なる条件を満足する。『ブレーズ化』とは、回折レンズ
（回折格子）の回折効率を上げるために回折面形状を最
適化することを意味し、『回折屈折ハイブリッド面』と
は、回折作用と屈折作用を合わせ持つ面をいう。The telephoto lens according to the present invention comprises, in order from the object side, a front group consisting of a positive first lens and a negative second lens, and two lenses of a positive lens and a negative lens. A rear group, and a blazed diffractive refraction hybrid surface having a ring-shaped structure having a positive diffractive lens function is disposed in the front group. Further, the Abbe number νd of the first lens is set to ν1, When the dispersion ratio θgF is θ1, the Abbe number νd of the second lens is ν2, and the partial dispersion ratio θgF is θ2, the following condition is satisfied: ν2 / ν1 <0.55 (1) 0.040 <θ2-θ1 (2). “Blaze” means optimizing the shape of the diffraction surface to increase the diffraction efficiency of the diffraction lens (diffraction grating). “Diffraction / refraction hybrid surface” means a surface that has both diffraction and refraction. Say.
【０００５】さらに好ましくは、前記第１レンズの屈折
率ｎd をｎ1 、前記第２レンズの屈折率ｎd をｎ2 、前
記前群中の回折レンズ成分のｄ線における焦点距離をｆ
D 、全系の焦点距離をｆとして 0.180 ＜ ｎ2 −ｎ1 (3) 0.018 ＜ ｆ／ｆD ＜ 0.040 (4) を満足するものである。More preferably, the refractive index nd of the first lens is n1, the refractive index nd of the second lens is n2, and the focal length of the diffractive lens component in the front group at d-line is f.
D, satisfying 0.180 <n2-n1 (3) 0.018 <f / fD <0.040 (4) where f is the focal length of the entire system.
【０００６】さらに、明るいレンズとするためには、前
記前群中に少なくとも光軸近傍では周辺部に向かって正
のパワーが弱くなる非球面を持つことが好ましく、安価
に作製するためには、前記正の第１レンズが、前記前群
中の非球面と回折屈折ハイブリッド面の両者を持つこと
が好ましい。Further, in order to obtain a bright lens, it is preferable that the front group has an aspheric surface whose positive power decreases toward the peripheral portion at least near the optical axis. It is preferable that the positive first lens has both the aspherical surface and the diffractive refractive surface in the front group.
【０００７】前記後群は、前側から順に前群側に強い凹
面を有する負の第３レンズと正の第４レンズで構成さ
れ、第３レンズのシェーピングファクターＳＦ３を、第
３レンズの前側面の曲率半径をｒ5 、後側面の曲率半径
をｒ6 としてＳＦ３＝（ｒ5 ＋ｒ6 ）／（ｒ6 −ｒ5 ）
とするとき 0.70 ＜ ＳＦ３ (5) なる条件を満足することが好ましい。また、前群中の第
２レンズの形状として好ましい形態の一つが、前記第２
レンズが第１レンズ側に凸のメニスカスレンズであり、
第２レンズのシェーピングファクターＳＦ２を、第２レ
ンズの前側面の曲率半径をｒ3 、後側面の曲率半径をｒ
4 とするとき、ＳＦ２＝（ｒ4 ＋ｒ3 ）／（ｒ4 −ｒ3
） として ＳＦ２＜ −3.4 (6) なる条件を満足するものである。The rear group is composed of a negative third lens and a positive fourth lens having a strong concave surface on the front group side in order from the front side. The shaping factor SF3 of the third lens is determined by the front side surface of the third lens. SF3 = (r5 + r6) / (r6-r5) where the radius of curvature is r5 and the radius of curvature of the rear surface is r6.
It is preferable to satisfy the following condition: 0.70 <SF3 (5) One of the preferred forms of the second lens in the front group is the second lens.
The lens is a meniscus lens convex to the first lens side,
The shaping factor SF2 of the second lens is defined as follows: the radius of curvature of the front surface of the second lens is r3, and the radius of curvature of the rear surface is r.
4, SF2 = (r4 + r3) / (r4-r3)
) Satisfies the following condition: SF2 <−3.4 (6).
【０００８】[0008]
【作用】望遠レンズの軸上色収差はマージナル光線の入
射高さの２乗で寄与するため、前群中で十分な色収差補
正を行う必要がある。そのために、本発明にかかる望遠
レンズは、前群中の面に回折レンズ作用を持たせ２次ス
ペクトルの補正をおこなっている。ここで、前群を正レ
ンズと負レンズと回折レンズの３レンズの３レンズであ
ると考え、簡単化のためにレンズがそれぞれ薄肉レンズ
であり密着しているとすると、従来より、いわゆる３色
色補正のための条件として、薄肉の３レンズが密着して
配置する場合、３つのレンズのパワーをφ1 、φ2 、φ
3 、アッベ数をν1、ν2 、ν3 、部分分散比をθ1 、
θ2 、θ3 とするとき φ1 ／ν1 ＋φ2 ／ν2 ＋φ3 ／ν3 ＝０ (7) φ1 θ1 ／ν1 ＋φ2 θ2 ／ν2 ＋φ3 θ3 ／ν3 ＝０ (8) の２式が同時に満足されればよいことが知られている。
この(7)(8)の式から、 ( θ2 −θ1)φ2 ／ν2 ＝−( θ3 −θ1)φ3 ／ν3 (9) なる関係が導かれる。The axial chromatic aberration of the telephoto lens contributes by the square of the incident height of the marginal ray, so it is necessary to perform sufficient chromatic aberration correction in the front group. For this purpose, the telephoto lens according to the present invention has a surface in the front group having a diffractive lens function to correct the secondary spectrum. Here, assuming that the front group is composed of three lenses of a positive lens, a negative lens, and a diffractive lens, and assuming that the lenses are thin lenses and are in close contact for simplicity, a so-called three-color color is conventionally used. As a condition for the correction, when three thin lenses are arranged in close contact, the power of the three lenses is φ1, φ2, φ
3, Abbe number is ν1, ν2, ν3, partial dispersion ratio is θ1,
When θ2 and θ3 are set, φ1 / ν1 + φ2 / ν2 + φ3 / ν3 = 0 (7) It is known that the two expressions of φ1θ1 / ν1 + φ2θ2 / ν2 + φ3θ3 / ν3 = 0 (8) should be simultaneously satisfied. Have been.
From the equations (7) and (8), a relationship of (θ2−θ1) φ2 / ν2 = − (θ3−θ1) φ3 / ν3 (9) is derived.
【０００９】薄肉レンズが密着している場合、色収差補
正についてレンズの並び順は影響を与えないので、ここ
では第１番めのレンズを正レンズ、第２番めのレンズを
負レンズ、第３番目のレンズを回折レンズであるとして
考えると、(9) 式より第１レンズで発生する色収差( φ
1 ／ν1)を負レンズと回折レンズで補正するとき、その
補正の割合を、部分分散比の差とするときに３色色補正
が達成される事がわかる。When the thin lenses are in close contact with each other, the order of the lenses does not affect the correction of chromatic aberration. Therefore, here, the first lens is a positive lens, the second lens is a negative lens, and the third lens is a negative lens. Assuming that the second lens is a diffractive lens, from equation (9), the chromatic aberration (φ
When 1 / ν1) is corrected by the negative lens and the diffractive lens, it can be seen that three-color correction is achieved when the correction ratio is set to the difference in the partial dispersion ratio.
【００１０】一方、３レンズの合成パワーφは単に φ1 ＋φ2 ＋φ3 ＝φ の関係であり、負レンズのパワーφ2 が負の大きな値に
なると正レンズのパワーの増加が必要となる。それぞれ
のパワーを小さくしてトータルのパワーを確保すること
が、収差の発生の減少と、レンズの質量の減少のために
好ましい。正レンズのパワーφ1 に対する負レンズのパ
ワーφ2 の比を小さくしてレンズ全体の軽量、小型化、
および収差発生を少なくするための条件が以下の(1)(2)
式である。 ν2 ／ν1 ＜ 0.55 (1) 0.040 ＜ θ2 −θ1 (2) 各レンズが、同じ部分分散比であったとすれば、負レン
ズと正レンズのパワーの比はアッベ数の比になるため条
件式(1) が定まる。On the other hand, the combined power φ of the three lenses is simply a relation of φ1 + φ2 + φ3 = φ. If the power φ2 of the negative lens becomes a large negative value, the power of the positive lens needs to be increased. It is preferable to reduce the respective powers to secure the total power in order to reduce the occurrence of aberration and the mass of the lens. By reducing the ratio of the negative lens power φ2 to the positive lens power φ1, the overall lens is lighter and smaller,
And the conditions for reducing the occurrence of aberration are as follows (1) and (2)
It is an expression. ν2 / ν1 <0.55 (1) 0.040 <θ2−θ1 (2) Assuming that each lens has the same partial dispersion ratio, the ratio of the power of the negative lens to the power of the positive lens becomes the ratio of the Abbe number. 1) is determined.
【００１１】(9) 式より( θ3 −θ1)／( θ2 −θ1)を
小さくすると負レンズのパワーφ2を小さくすることが
できる。回折レンズの場合屈折力は波長に比例するた
め、θ3 は0.2956で一定である。屈折レンズでは光学ガ
ラスの部分分散比θgFは0.530から0.631 の間に分布し
ており、一般に低分散硝材の方が高分散硝材よりθgFが
小さい。条件式(2) を満足するように、負レンズに部分
分散θ2 が大きい材料を用い、正レンズにθ1 の小さい
ものを用い、色収差補正の回折レンズ寄与分を大きく、
負レンズの寄与分を小さくする。From equation (9), when (θ3−θ1) / (θ2−θ1) is reduced, the power φ2 of the negative lens can be reduced. In the case of a diffractive lens, since the refractive power is proportional to the wavelength, θ3 is constant at 0.2956. In a refractive lens, the partial dispersion ratio θgF of the optical glass is distributed between 0.530 and 0.631, and the low dispersion glass material generally has smaller θgF than the high dispersion glass material. In order to satisfy the conditional expression (2), a material having a large partial dispersion θ2 is used for the negative lens, a material having a small θ1 is used for the positive lens, and the contribution of the diffractive lens for chromatic aberration correction is increased.
Reduce the contribution of the negative lens.
【００１２】望遠レンズの望遠比を小さくした場合に像
面湾曲がオーバーにならないための条件が以下の(3) 式
である。 0.180 ＜ ｎ2 −ｎ1 (3) 本発明にかかる望遠レンズは、前述のように各レンズの
パワーを弱くしていることと、レンズ枚数が少ないこと
のため全長を短くしても像面湾曲がオーバーになりにく
いが、(3) 式を満足することでさらにレンズ全長の短縮
化を行っても像面湾曲が発生しにくい。The condition for preventing the field curvature from being excessive when the telephoto ratio of the telephoto lens is reduced is given by the following equation (3). 0.180 <n2-n1 (3) As described above, the telephoto lens according to the present invention has a reduced field curvature even when the overall length is shortened because the power of each lens is weak and the number of lenses is small. However, by satisfying the expression (3), even if the overall length of the lens is further reduced, the curvature of field hardly occurs.
【００１３】回折レンズの実際の形状には、透過、不透
過による振幅型、位相値として２値を取るバイナリー型
等もあるが写真など画像を利用する用途の場合像のコン
トラストが重要であり、また使用光源の波長幅が広いた
め、フレネルレンズ状にブレーズ化された輪帯状構造の
ものでなければならない。条件式(4) は回折レンズのパ
ワーを規定する式である。 0.018 ＜ｆ／ｆD ＜ 0.040 (4) 前述の(7)(8)式は、ｃｇＦのスペクトルで完全に３色の
色補正をする条件であるが、実際のレンズ設計では補正
後に残る他の波長の色収差や球面収差の色収差変化のバ
ランスで回折レンズのパワーは決定される。下限より回
折レンズのパワーが弱い場合は短波長側の軸上色収差が
オーバーに残ってしまい、上限を超えて回折レンズのパ
ワーが強い場合は長波長側で軸上色収差がアンダーにな
り、どちらも残留色収差が目立ってしまうため条件式
(4) を満足することが好ましい。The actual shape of the diffractive lens includes an amplitude type due to transmission and non-transmission, and a binary type which takes a binary value as a phase value. In the case of using an image such as a photograph, the contrast of the image is important. Further, since the used light source has a wide wavelength width, the light source must have a ring-shaped structure blazed into a Fresnel lens shape. Conditional expression (4) defines the power of the diffractive lens. 0.018 <f / fD <0.040 (4) The above-mentioned equations (7) and (8) are conditions for completely correcting three colors in the cgF spectrum, but other wavelengths remaining after the correction in the actual lens design. The power of the diffractive lens is determined by the balance of the chromatic aberration and the chromatic aberration change of the spherical aberration. If the power of the diffractive lens is weaker than the lower limit, the axial chromatic aberration on the short wavelength side will remain in excess, and if the power of the diffractive lens exceeds the upper limit, the axial chromatic aberration on the long wavelength side will be under. Conditional expression because residual chromatic aberration is noticeable
It is preferable to satisfy (4).
【００１４】前述のように、負レンズのパワーを弱くす
るための硝材選択を行うと、第２レンズが球面収差を補
正する能力が低下してしまうデメリットがある。とくに
本発明にかかるレンズタイプでは前群中の正レンズが１
枚であるため正レンズで発生する球面収差が大きく、球
面のみの設計では球面収差による性能の低下のためレン
ズの明るさはＦ値が５程度までが限界である。このため
前群中に少なくとも光軸近傍では周辺部に向かって正の
パワーが弱くなる非球面を持たせ、球面収差を補正する
ことが好ましい。非球面を１面持つことでＦ値が４より
明るいレンズとすることができる。As described above, if glass material is selected to weaken the power of the negative lens, there is a disadvantage that the ability of the second lens to correct spherical aberration is reduced. In particular, in the lens type according to the present invention, the number of positive lenses in the front group is one.
Since the number of lenses is large, the spherical aberration generated by the positive lens is large. In the case of the design using only a spherical surface, the brightness of the lens is limited to an F value of about 5 due to a decrease in performance due to the spherical aberration. For this reason, it is preferable to provide an aspheric surface in which the positive power becomes weaker toward the periphery at least in the vicinity of the optical axis in the front unit to correct spherical aberration. By having one aspherical surface, a lens having an F value higher than 4 can be obtained.
【００１５】回折レンズはガラスモールドや貼り合わせ
型非球面のようにガラスレンズに樹脂の薄膜を設けるこ
とで作ることも可能であるが、本発明の目的とする安価
なレンズとするためには、材料費が安価であるととも
に、成形性が良く、成形型のコストも安くなる樹脂モー
ルドとすることが好ましい。さらに、樹脂モールドレン
ズは重量が軽くなると言うメリットも併せ持っている。
このときに、レンズの製造上は非球面と回折屈折ハイブ
リッド面を一つのレンズ上に設け、モールド等の手法で
１工程で製造できるようにすることが好ましい。特に低
分散低屈折率の樹脂レンズで正の第１レンズを作りその
表面に非球面、回折屈折ハイブリッド面を設けること
が、効果的である。Although a diffractive lens can be made by providing a resin thin film on a glass lens, such as a glass mold or a laminated aspherical surface, in order to obtain an inexpensive lens as the object of the present invention, It is preferable to use a resin mold that has low material cost, good moldability, and low cost of the mold. Further, the resin mold lens has an advantage that the weight is reduced.
At this time, in manufacturing the lens, it is preferable that the aspherical surface and the diffractive refraction hybrid surface are provided on one lens so that the lens can be manufactured in one step by a method such as molding. In particular, it is effective to form a positive first lens with a resin lens having a low dispersion and a low refractive index and to provide an aspherical surface and a diffractive refraction hybrid surface on its surface.
【００１６】前記後群は、前側から順に前群側に強い凹
面を有する負の第３レンズと正の第４レンズで構成し、
第３レンズのシェーピングファクターＳＦ３を、第３レ
ンズの前側面の曲率半径をｒ5 、後側面の曲率半径をｒ
6 として、ＳＦ３＝（ｒ5 ＋ｒ6 ）／（ｒ6 −ｒ5 ）
とするとき、 0.70 ＜ ＳＦ３ (5) なる条件を満足することにより、パワー配置がアンバラ
ンスな望遠レンズでありながら正の歪曲収差を小さく抑
えることができる。The rear unit includes a negative third lens and a positive fourth lens having a strong concave surface on the front group side in order from the front side.
The shaping factor SF3 of the third lens is defined as follows: the radius of curvature of the front surface of the third lens is r5, and the radius of curvature of the rear surface is r.
SF3 = (r5 + r6) / (r6-r5)
By satisfying the condition of 0.70 <SF3 (5), it is possible to suppress the positive distortion to be small even though the telephoto lens has an unbalanced power arrangement.
【００１７】前記第２レンズの形状には、前後面ともに
緩い面になる場合と、第１レンズ側に凸面を向けたメニ
スカスレンズ形状になる場合の２タイプが存在する。前
者の場合、第２レンズが高分散硝材であり入射側面で球
面収差補正効果があるので、球面収差の高次成分が波長
によって変化してしまい、軸上色収差の補正がなされた
ときに球面収差の形状をそろえることができない。それ
に対し、第２レンズのシェーピングファクターＳＦ２
を、第２レンズの前側面の曲率半径をｒ3 、後側面の曲
率半径をｒ4 とするとき、ＳＦ２＝（ｒ4 ＋ｒ3 ）／
（ｒ4 −ｒ3 ） として、 ＳＦ２＜ −3.4 (6) なる条件を満足するような後者のタイプの場合、第２レ
ンズの球面収差補正効果が非常に小さいため球面収差の
波長変化がほとんどない収差補正が可能になる。このレ
ンズタイプでは、球面のみでの構成では球面収差が補正
不足になるので、前群中の非球面は必須のものである。There are two types of the shape of the second lens: a case where the front and rear surfaces are both loose, and a case where the second lens has a meniscus lens shape with the convex surface facing the first lens. In the former case, since the second lens is made of a high-dispersion glass material and has a spherical aberration correction effect on the incident side surface, the higher order component of the spherical aberration changes depending on the wavelength, and when the axial chromatic aberration is corrected, the spherical aberration is corrected. Cannot be made uniform. In contrast, the shaping factor SF2 of the second lens
If the radius of curvature of the front surface of the second lens is r3 and the radius of curvature of the rear surface is r4, SF2 = (r4 + r3) /
In the case of the latter type which satisfies the condition of SF2 <−3.4 (6) as (r4−r3), the spherical aberration correction effect of the second lens is very small, so that there is almost no change in the wavelength of the spherical aberration. Becomes possible. In this lens type, the spherical aberration is insufficiently corrected if only the spherical surface is used. Therefore, the aspherical surface in the front group is indispensable.
【００１８】[0018]
【発明の実施例】以下に本発明の数値実施例を示す。以
下の実施例１ないし９はいずれも、物体側より順に、物
体側に凸の第１レンズ１１と、物体側に凸面を向けた負
メニスカスレンズの第２レンズ１２、物体側に凹面を向
けた負メニスカスレンズの第３レンズ２１、及び両凸の
正の第４レンズ２２から構成されている。第１レンズ１
１と第２レンズ１２が前群１０、第３レンズ２１と第４
レンズ２２が後群２０を構成する。実施例９を除き、第
１レンズ１１の物体側面が回転対称非球面であり、実施
例５と６を除き、第１レンズ１１の像側面に回折レンズ
構造を持っている。実施例５と６は、第２レンズ１２の
物体側面に、回折レンズ構造を持っている。実施例の中
でｒは面の曲率半径、ｄは面間隔、ｎd はｄ線における
屈折率、νd はアッベ数、θgFは部分分散比を示す。ｆ
は焦点距離、FNO はＦナンバー、２ωは画角である。面
番号の後ろに * を付した面が回折屈折ハイブリッド面
である。非球面は、光軸に垂直な方向の高さをh 、高さ
h における光軸方向の変位量をΔＸ(h) 、光軸近傍の曲
率半径をr 、円錐係数をK 、ｎ次の非球面係数をAnとし
て以下の数式で表される。 ΔＸ(h) ＝(h2/r)/(1+(1-(1+K)h2/r2)1/2)+A2h2 +A4h4
+ ・・・ また、回折レンズは回折レンズが持つべき光路長の付加
量を光軸からの高さｈの関数( 光路差関数) ψ(h) とし
て表す。ｎ次の光路差関数係数をPn、波長をλとして光
路差関数は以下の数式で表される。 ψ(h) ＝（P2h2＋P4h4＋・・・）λ １次回折光の評価をする場合に波長λは任意の波長とす
ることができる。この表現形式ではｈ2 の項の係数が負
の時に近軸的に正のパワーを持ち、ｈ4の項の係数が正
の時に周辺に向かって負のパワーが増加する。なお表示
していない非球面係数、光路差関数の係数は０である。Embodiments of the present invention will be described below with reference to numerical embodiments. In each of the following Examples 1 to 9, in order from the object side, a first lens 11 convex to the object side, a second lens 12 of a negative meniscus lens having a convex surface facing the object side, and a concave surface facing the object side. It comprises a third lens 21 of a negative meniscus lens and a biconvex positive fourth lens 22. First lens 1
The first and second lenses 12 are in the front group 10, the third lens 21 and the fourth
The lens 22 forms the rear group 20. Except for the ninth embodiment, the object side surface of the first lens 11 is a rotationally symmetric aspheric surface. Except for the fifth and sixth embodiments, the first lens 11 has a diffractive lens structure on the image side surface. Embodiments 5 and 6 have a diffractive lens structure on the object side surface of the second lens 12. In the examples, r is the radius of curvature of the surface, d is the surface interval, nd is the refractive index at the d-line, νd is the Abbe number, and θgF is the partial dispersion ratio. f
Is the focal length, F NO is the F number, and 2ω is the angle of view. The surface marked with * after the surface number is the diffractive refraction hybrid surface. For aspheric surfaces, the height in the direction perpendicular to the optical axis is h, the height
The displacement amount in the optical axis direction at h is represented by ΔX (h), the radius of curvature near the optical axis is r, the conic coefficient is K, and the nth order aspherical coefficient is An. ΔX (h) = (h 2 / r) / (1+ (1- (1 + K) h 2 / r 2 ) 1/2 ) + A2h 2 + A4h 4
+ The diffractive lens expresses the additional amount of the optical path length that the diffractive lens should have as a function of the height h from the optical axis (optical path difference function) ψ (h). The optical path difference function is represented by the following equation, where the n-th order optical path difference function coefficient is Pn and the wavelength is λ. ψ (h) = (P2h 2 + P4h 4 +...) λ When evaluating the first-order diffracted light, the wavelength λ can be any wavelength. This representation has a paraxial manner positive power when the coefficient of the term of h 2 is negative, the coefficient of the term of h 4 is the negative power towards the periphery at the time of positive increases. The aspherical coefficients and optical path difference function coefficients not shown are 0.
【００１９】［実施例１］図１は本発明の第１実施例に
かかる望遠レンズのレンズ構成を示す図、表１は数値デ
ータである。FIG. 1 is a diagram showing a lens configuration of a telephoto lens according to a first embodiment of the present invention, and Table 1 shows numerical data.
【表１】 ｆ＝300.00 ＦNo＝4.0 画角２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 58.835 15.000 1.51633 64.1 0.5352 2* 285.500 1.000 3 89.463 7.500 1.80518 25.4 0.6153 4 62.478 100.000 5 -46.123 3.000 1.53172 48.9 0.5595 6 -198.349 4.200 7 291.571 5.000 1.67270 32.1 0.5922 8 -184.267 114.248 非球面係数 1 面 K=-0.3349、 A4= 0.000×10-8 A6=-3.000×10-13、 A8=-4.000×10-16 光路差関数ψ(h) の係数 2 面 P2=-0.079741、 P4= 2.3541 ×10-6、 P6=-2.3476×10-10 [Table 1] f = 300.00 FNo = 4.0 Angle of view 2ω = 8.2 ° Surface rd nd νd θgF 1 58.835 15.000 1.51633 64.1 0.5352 2 * 285.500 1.000 3 89.463 7.500 1.80518 25.4 0.6153 4 62.478 100.000 5 -46.123 3.000 1.53172 48.9 0.5595 6- 198.349 4.200 7 291.571 5.000 1.67270 32.1 0.5922 8 -184.267 114.248 Aspherical surface coefficient 1 surface K = -0.3349, A4 = 0.000 × 10 -8 A6 = -3.000 × 10 -13 , A8 = -4.000 × 10 -16 Optical path difference function ψ Coefficient of (h) 2 sides P2 = -0.079741, P4 = 2.3541 × 10 -6 , P6 = -2.3476 × 10 -10
【００２０】図２は実施例１の諸収差図である。球面収
差図において、ＳＡは球面収差を示しＳＣは正弦条件を
示す。また実線、各点線はそれぞれのスペクトル線の波
長に対する球面収差の色収差を示す。倍率色収差図にお
いて各点線はｄ線に対するそれぞれのスペクトル線の波
長の倍率色収差を示す。非点収差図において、実線Ｓが
サジタル像、波線Ｍがメリディオナル像の像面を示して
いる。歪曲収差図は主波長の歪曲収差を示している。FIG. 2 is a diagram showing various aberrations of the first embodiment. In the spherical aberration diagram, SA indicates spherical aberration, and SC indicates a sine condition. Solid lines and dotted lines show chromatic aberration of spherical aberration with respect to the wavelength of each spectral line. In the lateral chromatic aberration diagram, each dotted line indicates lateral chromatic aberration of the wavelength of each spectral line with respect to the d-line. In the astigmatism diagram, the solid line S indicates the sagittal image, and the wavy line M indicates the image plane of the meridional image. The distortion diagram shows distortion at the main wavelength.
【００２１】回折レンズのパワーφD は −２×Ｐ２×
λ で求められ、実施例１の場合、波長0.00058756mm
（ｄ線）では −２×−0.079741×0.00058756 ＝ 0.000093705／mm 焦点距離ｆD は1 ／φD より 10672. mmである。The power φD of the diffractive lens is −2 × P2 ×
λ. In the case of the first embodiment, the wavelength is 0.00058756 mm.
In (d line), -2 * -0.079741 * 0.00058756 = 0.000093705 / mm The focal length fD is 10672.mm from 1 / [phi] D.
【００２２】実施例のデータから実際のレンズの微視的
形状を決定するには光路差関数ψ(h) から、輪帯の境に
なる点の高さｈと、光路長の波長の整数倍の成分を消去
したフレネルレンズ状の光路差関数ψ’を求める。輪帯
の切り替え点の高さh は、位相差関数ψ(h) をλで割っ
たものの小数点以下部分が等しい値になる点、つまりＭ
ＯＤ（ψ(h),１）＝Ｃ となる点である。ただし、ＭＯ
Ｄ（Ｘ、Ｙ） はＸをＹで割った剰余を与える関数とす
る。定数項Ｃは輪帯の境界位置の位相を設定する定数で
あり、０から１の任意の値をとる。図３に、Ｃを0.5 と
した場合の回折レンズの微視的形状の模式図を示す。輪
帯の境では破線で示す巨視的形状に対し実線で示す微視
的形状は±0.5 λの位相差を持っている。定数項Ｃを持
つ場合、微視的形状用の光路差関数ψ’は以下に示す形
になり ψ'(h)＝（ＭＯＤ（ψ(h) −Ｃ, １）＋Ｃ）λ この光路長差を満足するよう巨視的形状と微細形状の光
軸方向の差Ｓを決定し、レンズ加工用データをつくるこ
とで回折屈折ハイブリッド面を製造することができる。In order to determine the actual microscopic shape of the lens from the data of the embodiment, the height h of the boundary between the annular zones and the integral multiple of the wavelength of the optical path length are obtained from the optical path difference function ψ (h). Is determined to obtain a Fresnel lens-shaped optical path difference function ψ ′ in which the above component is eliminated. The height h of the switching point of the annular zone is a point at which a value obtained by dividing the phase difference function ψ (h) by λ has an equal value after the decimal point, that is, M
OD (ψ (h), 1) = C. However, MO
D (X, Y) is a function that gives a remainder obtained by dividing X by Y. The constant term C is a constant for setting the phase at the boundary position of the annular zone, and takes an arbitrary value from 0 to 1. FIG. 3 shows a schematic diagram of the microscopic shape of the diffraction lens when C is set to 0.5. At the boundary of the ring zone, the microscopic shape shown by the solid line has a phase difference of ± 0.5 λ with the macroscopic shape shown by the broken line. In the case of having a constant term C, the optical path difference function ψ ′ for a microscopic shape becomes as follows: ψ ′ (h) = (MOD (ψ (h) −C, 1) + C) λ This optical path difference By determining the difference S between the macroscopic shape and the fine shape in the optical axis direction so as to satisfy the above condition and creating data for lens processing, a diffractive refraction hybrid surface can be manufactured.
【００２３】［実施例２］図４は本発明の第２実施例に
かかる望遠レンズのレンズ構成を示す図、表２は数値デ
ータ、図５は諸収差図である。Embodiment 2 FIG. 4 is a diagram showing a lens configuration of a telephoto lens according to a second embodiment of the present invention, Table 2 is numerical data, and FIG. 5 is a diagram showing various aberrations.
【表２】 ｆ＝300.00 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 90.687 15.000 1.48749 70.2 0.5297 2* -577.131 7.000 3 -475.930 6.000 1.80518 25.4 0.6153 4 3686.742 146.100 5 -36.794 2.500 1.62041 60.3 0.5425 6 -88.395 4.200 7 -58.155 4.000 1.62004 36.3 0.5829 8 -40.243 63.755 非球面係数 1 面 A4=-5.120×10-8、 A6=-5.500 ×10-11、 A8=-4.000×10-16 光路差関数ψ(h) の係数 2 面 P2=-0.072822、 P4= 5.4454 ×10-6、 P6=-8.3552×10-12 Table 2 f = 300.00 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 90.687 15.000 1.48749 70.2 0.5297 2 * -577.131 7.000 3 -475.930 6.000 1.80518 25.4 0.6153 4 3686.742 146.100 5 -36.794 2.500 1.62041 60.3 0.5425 6 -88.395 4.200 7 -58.155 4.000 1.62004 36.3 0.5829 8 -40.243 63.755 Aspherical surface 1 A4 = -5.120 × 10 -8 , A6 = -5.500 × 10 -11 , A8 = -4.000 × 10 -16 Optical path difference function ψ ( h) Coefficient of 2 planes P2 = -0.072822, P4 = 5.4454 × 10 -6 , P6 = -8.3552 × 10 -12
【００２４】［実施例３］図６は本発明の第３実施例に
かかる望遠レンズのレンズ構成を示す図、表３は数値デ
ータ、図７は諸収差図である。Embodiment 3 FIG. 6 is a diagram showing a lens configuration of a telephoto lens according to a third embodiment of the present invention, Table 3 is numerical data, and FIG. 7 is a diagram showing various aberrations.
【表３】 ｆ＝300.00 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 90.824 15.000 1.48749 70.2 0.5297 2* -518.334 7.000 3 -442.322 6.000 1.80518 25.4 0.2956 4 4941.808 146.100 5 -52.195 2.500 1.62041 60.3 0.5425 6 2438.317 4.200 7 149.035 4.000 1.62004 36.3 0.5829 8 -213.801 61.014 非球面係数 1 面 A4=-5.230×10-8、 A6=-5.500 ×10-12 光路差関数ψ(h) の係数 2 面 P2=-0.071685、 P4= 6.2333 ×10-6、 P6=-1.1876 ×10-11 TABLE 3 f = 300.00 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 90.824 15.000 1.48749 70.2 0.5297 2 * -518.334 7.000 3 -442.322 6.000 1.80518 25.4 0.2956 4 4941.808 146.100 5 -52.195 2.500 1.62041 60.3 0.5425 6 2438.317 4.200 7 149.035 4.000 1.62004 36.3 0.5829 8 -213.801 61.014 Aspherical surface 1 plane A4 = -5.230 × 10 -8 , A6 = -5.500 × 10 -12 Coefficient of optical path difference function ψ (h) 2 plane P2 = -0.071685, P4 = 6.2333 × 10 -6 , P6 = -1.1876 × 10 -11
【００２５】［実施例４］図８は本発明の第４実施例に
かかる望遠レンズのレンズ構成を示す図、表４は数値デ
ータ、図９は諸収差図である。Embodiment 4 FIG. 8 is a diagram showing a lens configuration of a telephoto lens according to a fourth embodiment of the present invention, Table 4 is numerical data, and FIG. 9 is a diagram of various aberrations.
【表４】 ｆ＝300.00 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 84.943 15.000 1.49176 57.4 0.5607 2* -403.642 7.000 3 -372.072 6.000 1.80518 25.4 0.6153 4 767.168 144.700 5 -48.518 2.500 1.51633 64.1 0.5352 6 -119.326 3.300 7 65.005 4.000 1.67270 32.1 0.5922 8 93.730 75.918 非球面係数 1 面 A4=-5.110×10-8、 A6=-5.200 ×10-12、 A8=-9.500×10-16 光路差関数ψ(h) の係数 2 面 P2=-0.059066、 P4= 7.8094 ×10-6、 P6=-2.4609×10-11 Table 4 f = 300.00 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 84.943 15.000 1.49176 57.4 0.5607 2 * -403.642 7.000 3 -372.072 6.000 1.80518 25.4 0.6153 4 767.168 144.700 5 -48.518 2.500 1.51633 64.1 0.5352 6 -119.326 3.300 7 65.005 4.000 1.67270 32.1 0.5922 8 93.730 75.918 Aspherical surface 1 surface A4 = -5.110 × 10 -8 , A6 = -5.200 × 10 -12 , A8 = -9.500 × 10 -16 Optical path difference function ψ (h) P2 = -0.059066, P4 = 7.8094 × 10 -6 , P6 = -2.4609 × 10 -11
【００２６】実施例４はアクリル系の樹脂を第１レンズ
に用いた例である。望遠レンズでは、前群の正レンズは
低分散、低屈折率の素材が好ましいため、ガラス材料を
用いた他の実施例と比較し収差補正上のデメリットはほ
とんど存在しない。樹脂レンズを第１レンズとして使う
場合、樹脂レンズ上の回折屈折ハイブリッド面には、ハ
ードコートを行うことが困難なためユーザーにより拭か
れる可能性のある第１面は通常の屈折面にしてハードコ
ートを行い、第２面側を回折屈折ハイブリッド面とする
事が望ましい。Embodiment 4 is an example in which an acrylic resin is used for the first lens. In the telephoto lens, since the positive lens in the front group is preferably made of a material having a low dispersion and a low refractive index, there is almost no demerit in aberration correction as compared with other embodiments using a glass material. When a resin lens is used as the first lens, it is difficult to apply a hard coat on the diffractive refraction hybrid surface on the resin lens. It is desirable that the second surface side be a diffractive refraction hybrid surface.
【００２７】［実施例５］図１０は本発明の第５実施例
にかかる望遠レンズのレンズ構成を示す図、表５は数値
データ、図１１は諸収差図である。[Embodiment 5] FIG. 10 is a diagram showing a lens configuration of a telephoto lens according to a fifth embodiment of the present invention, Table 5 is numerical data, and FIG. 11 is a diagram of various aberrations.
【表５】 ｆ＝300.00 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 84.811 15.000 1.49176 57.4 0.5607 2 -413.169 7.000 3* -376.268 6.000 1.80518 25.4 0.6153 4 758.507 144.700 5 -48.518 2.500 1.51633 64.1 0.5352 6 -119.326 3.300 7 65.005 4.000 1.67270 32.1 0.5922 8 94.150 76.289 非球面係数 1 面 A4=-5.100×10-8、 A6=-5.200 ×10-12、 A8=-9.500×10-16 光路差関数ψ(h) の係数 3 面 P2=-0.065349、 P4= 9.2147×10-6、 P6=-3.3471 ×10-11 TABLE 5 f = 300.00 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 84.811 15.000 1.49176 57.4 0.5607 2 -413.169 7.000 3 * -376.268 6.000 1.80518 25.4 0.6153 4 758.507 144.700 5 -48.518 2.500 1.51633 64.1 0.5352 6 -119.326 3.300 7 65.005 4.000 1.67270 32.1 0.5922 8 94.150 76.289 Aspherical surface 1 surface A4 = -5.100 × 10 -8 , A6 = -5.200 × 10 -12 , A8 = -9.500 × 10 -16 Optical path difference function ψ (h) P3 = -0.065349, P4 = 9.2147 × 10 -6 , P6 = -3.3471 × 10 -11
【００２８】実施例５は実施例４とほぼ同じ近軸配置で
回折屈折ハイブリッド面を第２レンズに設けた例であ
る。実施例４の収差図と比較してほとんど違いは存在し
ない。回折屈折ハイブリッド面は前群中のどの面に置い
てもほぼ同等な性能を得ることができるため、製造の容
易性で位置を決定することができる。The fifth embodiment is an example in which a diffractive refraction hybrid surface is provided on the second lens in substantially the same paraxial arrangement as in the fourth embodiment. There is almost no difference compared with the aberration diagram of the fourth embodiment. Since the diffractive refraction hybrid surface can obtain almost the same performance regardless of where it is placed in the front group, the position can be determined with ease of manufacture.
【００２９】［実施例６］図１２は本発明の第６実施例
にかかる望遠レンズのレンズ構成を示す図、表６は数値
データ、図１３は諸収差図である。Embodiment 6 FIG. 12 is a diagram showing a lens configuration of a telephoto lens according to a sixth embodiment of the present invention, Table 6 is numerical data, and FIG. 13 is a diagram of various aberrations.
【表６】 ｆ＝300.00 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 91.457 15.000 1.51633 64.1 0.5352 2 -686.243 7.390 3* ∞ 6.000 1.84666 23.8 0.6211 4 396.069 145.350 5 -36.994 3.000 1.58313 59.4 0.5432 6 344.762 6.300 7 ∞ 5.000 1.54814 45.8 0.5654 8 -44.912 60.304 非球面係数 1 面 A4=-7.230 ×10-8、 A6=-7.300 ×10-12、 A8=-1.000×10-15 光路差関数ψ(h) の係数 3 面 P2=-0.084281、 P4= 2.8000×10-6 [Table 6] f = 300.00 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 91.457 15.000 1.51633 64.1 0.5352 2 -686.243 7.390 3 * ∞ 6.000 1.84666 23.8 0.6211 4 396.069 145.350 5 -36.994 3.000 1.58313 59.4 0.5432 6 344.762 6.300 7 ∞ 5.000 1.54814 45.8 0.5654 8 -44.912 60.304 Aspherical surface 1 surface A4 = -7.230 × 10 -8 , A6 = -7.300 × 10 -12 , A8 = -1.000 × 10 -15 Optical path difference function ψ (h) Coefficient 3 side P2 = -0.084281, P4 = 2.8000 × 10 -6
【００３０】［実施例７］図１４は本発明の第７実施例
にかかる望遠レンズのレンズ構成を示す図、表７は数値
データ、図１５は諸収差図である。[Embodiment 7] FIG. 14 is a diagram showing a lens configuration of a telephoto lens according to a seventh embodiment of the present invention, Table 7 is numerical data, and FIG. 15 is a diagram of various aberrations.
【表７】 ｆ＝300.13 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 48.650 20.000 1.49176 57.4 0.5607 2* 202.222 1.000 3 58.372 7.500 1.80518 25.4 0.6153 4 38.696 139.790 5 -59.565 3.000 1.62041 60.3 0.5425 6 -541.819 1.000 7 68.820 6.000 1.60342 38.0 0.5795 8 465.499 非球面係数 1 面 K=-0.3240 光路差関数ψ(h) の係数 2 面 P2=-0.0661453、 P4=-4.7911×10-6、 P6= 1.2202×10-9 TABLE 7 f = 300.13 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 48.650 20.000 1.49176 57.4 0.5607 2 * 202.222 1.000 3 58.372 7.500 1.80518 25.4 0.6153 4 38.696 139.790 5 -59.565 3.000 1.62041 60.3 0.5425 6 -541.819 1.000 7 68.820 6.000 1.60342 38.0 0.5795 8 465.499 Aspherical surface 1 surface K = -0.3240 Coefficient of optical path difference function ψ (h) 2 surface P2 = -0.0661453, P4 = -4.7911 × 10 -6 , P6 = 1.2202 × 10 -9
【００３１】［実施例８］図１６は本発明の第８実施例
にかかる望遠レンズのレンズ構成を示す図、表８は数値
データ、図１７は諸収差図である。[Embodiment 8] FIG. 16 is a diagram showing a lens configuration of a telephoto lens according to an eighth embodiment of the present invention, Table 8 is numerical data, and FIG. 17 is a diagram of various aberrations.
【表８】 ｆ＝399.84 FNO ＝4.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 64.578 15.000 1.51633 64.1 0.5352 2* 238.447 1.000 3 81.231 7.500 1.78472 25.7 0.6128 4 57.433 90.000 5 385.709 6.000 1.59551 39.2 0.5771 6 -263.233 30.000 7 -81.964 4.000 1.51633 64.1 0.5352 8 -516.585 111.871 非球面係数 1 面 K=-0.3142 光路差関数ψ(h) の係数 2 面 P2=-0.0736243、 P4= 3.5745×10-6、 P6=-2.5354×10-10 Table 8 f = 399.84 F NO = 4.0 2ω = 8.2 ° face r d nd νd θgF 1 64.578 15.000 1.51633 64.1 0.5352 2 * 238.447 1.000 3 81.231 7.500 1.78472 25.7 0.6128 4 57.433 90.000 5 385.709 6.000 1.59551 39.2 0.5771 6 -263.233 30.000 7 -81.964 4.000 1.51633 64.1 0.5352 8 -516.585 111.871 Aspheric surface 1 surface K = -0.3142 Coefficient of optical path difference function ψ (h) 2 surface P2 = -0.0736243, P4 = 3.5745 × 10 -6 , P6 = -2.5354 × 10 -Ten
【００３２】実施例８は、第３レンズを正レンズ、第４
レンズを負レンズとした例である。他の実施例と比較す
ると後群径が大きく、全長が長くなっているが、結像性
能は十分なレベルに達している。In the eighth embodiment, the third lens is a positive lens and the fourth lens is a fourth lens.
This is an example in which the lens is a negative lens. The diameter of the rear group is larger and the overall length is longer than in the other examples, but the imaging performance has reached a sufficient level.
【００３３】［実施例９］図１８は本発明の第９実施例
にかかる望遠レンズのレンズ構成を示す図、表９は数値
データ、図１９は諸収差図である。Ninth Embodiment FIG. 18 is a diagram showing a lens configuration of a telephoto lens according to a ninth embodiment of the present invention, Table 9 is numerical data, and FIG. 19 is a diagram showing various aberrations.
【表９】 ｆ＝300.00 FNO ＝5.0 ２ω＝8.2 ° 面 ｒ ｄ ｎd νd θgF 1 73.925 11.000 1.51633 64.1 0.5352 2* -1229.234 8.000 3 -322.381 5.000 1.72825 28.5 0.6042 4 1015.211 100.000 5 -45.609 3.000 1.52630 51.1 0.5568 6 -147.421 7.000 7 -7412.876 5.000 1.71736 29.5 0.5975 8 -164.514 111.099 光路差関数ψ(h) の係数 2 面 P2=-0.093998 、 P4= 1.5980 ×10-5 [Table 9] f = 300.00 F NO = 5.0 2ω = 8.2 ° Surface rd nd νd θgF 1 73.925 11.000 1.51633 64.1 0.5352 2 * -1229.234 8.000 3 -322.381 5.000 1.72825 28.5 0.6042 4 1015.211 100.000 5 -45.609 3.000 1.52630 51.1 0.5568 6 -147.421 7.000 7 -7412.876 5.000 1.71736 29.5 0.5975 8 -164.514 111.099 Coefficient of optical path difference function ψ (h) 2 planes P2 = -0.093998, P4 = 1.5980 × 10 -5
【００３４】実施例９は前群中に非球面を用いない場合
の例である。球面収差の膨らみが大きくＦ5.0 としてい
る。Embodiment 9 is an example in which no aspherical surface is used in the front unit. The bulge of the spherical aberration is large and F5.0 is set.
【００３５】表１０に各実施例の条件式に対応する値を
示す。 条件式 (1) ν2 ／ν1 ＜ 0.55 条件式 (2) 0.040 ＜ θ2 −θ1 条件式 (3) 0.180 ＜ ｎ2 −ｎ1 条件式 (4) 0.018 ＜ ｆ／ｆD ＜ 0.040 条件式 (5) 0.70 ＜ SF3 条件式 (6) SF2 ＜ −3.4Table 10 shows values corresponding to the conditional expressions of each embodiment. Conditional expression (1) ν2 / ν1 <0.55 Conditional expression (2) 0.040 <θ2 − θ1 Conditional expression (3) 0.180 <n2 − n1 Conditional expression (4) 0.018 <f / fD <0.040 Conditional expression (5) 0.70 <SF3 Conditional expression (6) SF2 <−3.4
【表１０】 [Table 10]
【００３６】[0036]
【発明の効果】以上述べたように、本発明によれば、４
群４枚構成という少ない構成枚数であるにもかかわら
ず、軸上色収差、倍率色収差、球面収差、コマ収差、像
面湾曲、非点隔差、歪曲収差を十分に補正でき、安価な
望遠レンズを提供することが可能である。さらに、第１
レンズを樹脂製レンズとすれば、レンズの軽量化、生産
性の向上に効果が大きい。As described above, according to the present invention, 4
Provides an inexpensive telephoto lens that can sufficiently correct axial chromatic aberration, chromatic aberration of magnification, spherical aberration, coma aberration, field curvature, astigmatism, and distortion despite having a small number of components of four groups. It is possible to Furthermore, the first
If the lens is a resin lens, it is very effective in reducing the weight of the lens and improving the productivity.
【図１】本発明の望遠レンズの実施例１のレンズ構成図
である。FIG. 1 is a lens configuration diagram of a telephoto lens according to a first embodiment of the present invention.
【図２】実施例１の諸収差図である。FIG. 2 is a diagram illustrating various aberrations of the first embodiment.
【図３】回折レンズの微細形状決定の説明図である。FIG. 3 is an explanatory diagram for determining a fine shape of a diffraction lens.
【図４】本発明の望遠レンズの実施例２のレンズ構成図
である。FIG. 4 is a lens configuration diagram of a telephoto lens according to a second embodiment of the present invention.
【図５】実施例２の諸収差図である。FIG. 5 is a diagram illustrating various aberrations of the second embodiment.
【図６】本発明の望遠レンズの実施例３のレンズ構成図
である。FIG. 6 is a lens configuration diagram of a telephoto lens according to a third embodiment of the present invention.
【図７】実施例３の諸収差図である。FIG. 7 is a diagram illustrating various aberrations of the third embodiment.
【図８】本発明の望遠レンズの実施例４のレンズ構成図
である。FIG. 8 is a lens configuration diagram of a telephoto lens according to a fourth embodiment of the present invention.
【図９】実施例４の諸収差図である。FIG. 9 is a diagram illustrating various aberrations of the fourth embodiment.
【図１０】本発明の望遠レンズの実施例５のレンズ構成
図である。FIG. 10 is a lens configuration diagram of a telephoto lens according to a fifth embodiment of the present invention.
【図１１】実施例５の諸収差図である。FIG. 11 is a diagram illustrating various aberrations of the fifth embodiment.
【図１２】本発明の望遠レンズの実施例６のレンズ構成
図である。FIG. 12 is a lens configuration diagram of a telephoto lens according to a sixth embodiment of the present invention.
【図１３】実施例６の諸収差図である。FIG. 13 is a diagram illustrating various aberrations of the sixth embodiment.
【図１４】本発明の望遠レンズの実施例７のレンズ構成
図である。FIG. 14 is a lens configuration diagram of a telephoto lens according to a seventh embodiment of the present invention.
【図１５】実施例７の諸収差図である。FIG. 15 is a diagram illustrating various aberrations of the seventh embodiment.
【図１６】本発明の望遠レンズの実施例８のレンズ構成
図である。FIG. 16 is a lens configuration diagram of a telephoto lens according to an eighth embodiment of the present invention.
【図１７】実施例８の諸収差図である。FIG. 17 is a diagram illustrating various aberrations of the eighth embodiment.
【図１８】本発明の望遠レンズの実施例９のレンズ構成
図である。FIG. 18 is a lens configuration diagram of a telephoto lens according to a ninth embodiment of the present invention.
【図１９】実施例９の諸収差図である。FIG. 19 is a diagram illustrating various aberrations of the ninth embodiment.
Claims (6)
第２レンズからなる前群と、正レンズと負レンズの２枚
のレンズからなる後群とからなり、 前記前群中にブレーズ化された正の回折レンズ作用を持
つ輪帯状構造を有する回折屈折ハイブリッド面を持ち、 さらに、前記第１レンズのアッベ数νd をν1 、部分分
散比θgFをθ1 、前記第２レンズのアッベ数νd をν2
、部分分散比θgFをθ2 としたとき ν2 ／ν1 ＜ 0.55 0.040 ＜ θ2 −θ1 なる条件を満足することを特徴とする望遠レンズ。1. In order from an object side, the front group includes a front group including a first positive lens and a second negative lens, and a rear group including two lenses including a positive lens and a negative lens. It has a blazed diffractive refraction hybrid surface having a ring-like structure having a positive diffractive lens action. Further, the Abbe number νd of the first lens is ν1, the partial dispersion ratio θgF is θ1, and the Abbe number of the second lens is νd to ν2
A telephoto lens which satisfies a condition of ν2 / ν1 <0.55 0.040 <θ2−θ1 when a partial dispersion ratio θgF is θ2.
記第２レンズの屈折率ｎd をｎ2 、前記前群中の回折レ
ンズ成分のｄ線における焦点距離をｆD 、全系の焦点距
離をｆとするとき 0.180 ＜ ｎ2 −ｎ1 0.018 ＜ ｆ／ｆD ＜ 0.040 なる条件を満足することを特徴とする請求項１に記載の
望遠レンズ。2. The refractive index nd of the first lens is n1, the refractive index nd of the second lens is n2, the focal length at the d-line of the diffractive lens component in the front group is fD, and the focal length of the entire system is fD. The telephoto lens according to claim 1, wherein when f is satisfied, the following condition is satisfied: 0.180 <n2-n1 0.018 <f / fD <0.040.
辺部に向かって正のパワーが弱くなる非球面を持つこと
を特徴とする請求項１、または２に記載の望遠レンズ。3. The telephoto lens according to claim 1, wherein the front lens unit has an aspheric surface whose positive power decreases toward the periphery at least near the optical axis.
球面と回折屈折ハイブリッド面の両者を持つことを特徴
とする請求項１、２または３に記載の望遠レンズ。4. The telephoto lens according to claim 1, wherein the first positive lens has both an aspheric surface and a diffractive refractive surface in the front group.
強い凹面を有する負の第３レンズと、正の第４レンズで
構成され、第３レンズのシェーピングファクターＳＦ３
を第３レンズの前側面の曲率半径をｒ5 、後側面の曲率
半径をｒ6 として、 ＳＦ３＝（ｒ5 ＋ｒ6 ）／（ｒ6 −ｒ5 ）とするとき 0.70 ＜ＳＦ３ なる条件を満足することを特徴とする請求項１、２、３
または４に記載の望遠レンズ。5. The rear group is composed of, in order from the object side, a negative third lens having a strong concave surface on the front group side and a positive fourth lens, and a shaping factor SF3 of the third lens.
Where SF5 = (r5 + r6) / (r6-r5), where r5 is the radius of curvature of the front surface of the third lens and r6 is the radius of curvature of the rear surface of the third lens, the condition 0.70 <SF3 is satisfied. Claims 1, 2, and 3
Or the telephoto lens according to 4.
メニスカスレンズであり、該第２レンズのシェーピング
ファクターＳＦ２を、第２レンズの前側面の曲率半径を
ｒ3 、後側面の曲率半径をｒ4 として、ＳＦ２＝（ｒ4
＋ｒ3 ）／（ｒ4 −ｒ3 ） とするとき、 ＳＦ２＜ −3.4 なる条件を満足することを特徴とする請求項３、４また
は５に記載の望遠レンズ。6. The second lens is a meniscus lens convex to the first lens side, and the shaping factor SF2 of the second lens is determined by setting a radius of curvature of a front surface of the second lens to r3 and a radius of curvature of a rear surface of the second lens. As r4, SF2 = (r4
6. The telephoto lens according to claim 3, wherein, when + r3) / (r4 -r3), a condition of SF2 <-3.4 is satisfied.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23133697A JPH10186227A (en) | 1996-10-24 | 1997-08-27 | Telephotographic lens |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28209696 | 1996-10-24 | ||
| JP8-282096 | 1996-10-24 | ||
| JP23133697A JPH10186227A (en) | 1996-10-24 | 1997-08-27 | Telephotographic lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10186227A true JPH10186227A (en) | 1998-07-14 |
Family
ID=26529812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23133697A Pending JPH10186227A (en) | 1996-10-24 | 1997-08-27 | Telephotographic lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10186227A (en) |
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|---|---|---|---|---|
| JP2000258685A (en) * | 1999-03-10 | 2000-09-22 | Canon Inc | Photographing optical system |
| KR100405660B1 (en) * | 2001-10-10 | 2003-11-14 | 엘지전자 주식회사 | Diffractive optical system of telepoto type |
| JP2005215387A (en) * | 2004-01-30 | 2005-08-11 | Canon Inc | Optical system |
| JP2008176185A (en) * | 2007-01-22 | 2008-07-31 | Kyocera Corp | Imaging lens |
| JP2009286677A (en) * | 2008-05-30 | 2009-12-10 | Ohara Inc | Optical glass, preform and optical element |
| JP2012145789A (en) * | 2011-01-13 | 2012-08-02 | Nikon Corp | Optical system, optical equipment, and arrangement method of diffraction optical element |
| CN104898353A (en) * | 2014-03-07 | 2015-09-09 | 苹果公司 | Folded telephoto camera lens system |
| CN105607233A (en) * | 2016-03-23 | 2016-05-25 | 浙江舜宇光学有限公司 | Telephoto lens |
| WO2018037532A1 (en) * | 2016-08-25 | 2018-03-01 | 三菱電機株式会社 | Lens barrel |
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1997
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000258685A (en) * | 1999-03-10 | 2000-09-22 | Canon Inc | Photographing optical system |
| KR100405660B1 (en) * | 2001-10-10 | 2003-11-14 | 엘지전자 주식회사 | Diffractive optical system of telepoto type |
| JP2005215387A (en) * | 2004-01-30 | 2005-08-11 | Canon Inc | Optical system |
| JP4579553B2 (en) * | 2004-01-30 | 2010-11-10 | キヤノン株式会社 | Optical system and optical apparatus having the same |
| JP2008176185A (en) * | 2007-01-22 | 2008-07-31 | Kyocera Corp | Imaging lens |
| JP2009286677A (en) * | 2008-05-30 | 2009-12-10 | Ohara Inc | Optical glass, preform and optical element |
| JP2012145789A (en) * | 2011-01-13 | 2012-08-02 | Nikon Corp | Optical system, optical equipment, and arrangement method of diffraction optical element |
| US8988792B2 (en) | 2011-01-13 | 2015-03-24 | Nikon Corporation | Optical system, optical apparatus and method for arranging diffractive optical element |
| US9316810B2 (en) | 2014-03-07 | 2016-04-19 | Apple Inc. | Folded telephoto camera lens system |
| WO2015134173A1 (en) * | 2014-03-07 | 2015-09-11 | Apple Inc. | Folded telephoto camera lens systems |
| CN104898353A (en) * | 2014-03-07 | 2015-09-09 | 苹果公司 | Folded telephoto camera lens system |
| US10429614B2 (en) | 2014-03-07 | 2019-10-01 | Apple Inc. | Folded telephoto camera lens system |
| US11112582B2 (en) | 2014-03-07 | 2021-09-07 | Apple Inc. | Folded telephoto camera lens system |
| EP3916459A1 (en) * | 2014-03-07 | 2021-12-01 | Apple Inc. | Folded telephoto camera lens systems |
| US11782240B2 (en) | 2014-03-07 | 2023-10-10 | Apple Inc. | Folded telephoto camera lens system |
| CN105607233A (en) * | 2016-03-23 | 2016-05-25 | 浙江舜宇光学有限公司 | Telephoto lens |
| US10151903B2 (en) | 2016-03-23 | 2018-12-11 | Zhejiang Sunny Optics Co., Ltd. | Telephoto lens |
| WO2018037532A1 (en) * | 2016-08-25 | 2018-03-01 | 三菱電機株式会社 | Lens barrel |
| JPWO2018037532A1 (en) * | 2016-08-25 | 2018-08-30 | 三菱電機株式会社 | Lens barrel |
| CN108802976A (en) * | 2017-05-03 | 2018-11-13 | 信泰光学(深圳)有限公司 | Imaging lens |
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