JP2002072081A - Photographing optical system and optical equipment using the same - Google Patents
Photographing optical system and optical equipment using the sameInfo
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- JP2002072081A JP2002072081A JP2000263972A JP2000263972A JP2002072081A JP 2002072081 A JP2002072081 A JP 2002072081A JP 2000263972 A JP2000263972 A JP 2000263972A JP 2000263972 A JP2000263972 A JP 2000263972A JP 2002072081 A JP2002072081 A JP 2002072081A
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- lens
- lens group
- refractive power
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、撮影光学系及びそ
れを用いた光学機器に関し、特に手ブレや振動等による
画像ブレを補正する防振機能を有した銀塩写真カメラ、
ビデオカメラ、電子スチルカメラ、デジタルカメラ等の
光学機器に好適なものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing optical system and an optical apparatus using the same, and more particularly, to a silver halide photographic camera having an image stabilizing function for correcting image blur due to camera shake or vibration,
It is suitable for optical devices such as video cameras, electronic still cameras, and digital cameras.
【０００２】[0002]
【従来の技術】従来より長焦点距離の撮影光学系に好適
なレンズタイプとして、物体側から順に正の屈折力を有
する前方レンズ群と、負の屈折力を有する後方レンズ群
を有する撮影光学系、所謂望遠レンズが知られている。2. Description of the Related Art Conventionally, as a lens type suitable for a photographing optical system having a long focal length, a photographing optical system having a front lens group having a positive refractive power and a rear lens group having a negative refractive power in order from the object side. A so-called telephoto lens is known.
【０００３】一般的に望遠レンズでは、焦点距離を伸ば
すほど、また、レンズ全長の短縮を図り光学系のコンパ
クトにするほど軸上色収差及び倍率色収差が拡大し像性
能が悪化する傾向にある。その為、近軸軸上光線と瞳近
軸光線の光軸からの通過位置が比較的に高くなる前方レ
ンズ群に、蛍石等の異常部分分散を持った低分散の正レ
ンズと高分散の負レンズを用いて色収差の発生を低減し
た望遠レンズが種々提案されている。Generally, in a telephoto lens, the axial chromatic aberration and the chromatic aberration of magnification tend to increase as the focal length increases, and as the optical system becomes more compact by reducing the overall length of the lens, the image performance tends to deteriorate. Therefore, the front lens group where the passing position of the paraxial on-axis ray and the pupil paraxial ray from the optical axis is relatively high, the low-dispersion positive lens with anomalous partial dispersion such as fluorite and the high-dispersion Various telephoto lenses using a negative lens to reduce the occurrence of chromatic aberration have been proposed.
【０００４】光学系の色収差を補正する方法として、分
散の異なる２つの材質の硝材（レンズ）を組み合わせる
方法に対して、レンズ面やあるいは光学系の1部に回折
作用を有する回折格子を設けた回折光学素子を用いて、
色収差を減じる方法がＳＰＩＥVol．1354 Internationa
l Lens Design Conference（１９９０）等の文献や特開
平４−２１３４２１号公報、持開平６−３２４２６２号
公報、そしてＵＳＰ５０４４７０６号等により開示され
ている。As a method of correcting chromatic aberration of an optical system, a diffraction grating having a diffractive action is provided on a lens surface or a part of an optical system, as compared with a method of combining two glass materials (lenses) having different dispersions. Using a diffractive optical element,
A method of reducing chromatic aberration is described in SPIE Vol. 1354 Internationa
l Disclosed in documents such as the Lens Design Conference (1990), JP-A-4-213421, JP-A-6-324262, and US Pat. No. 5,044,706.
【０００５】これは、光学系中の屈折面と回折面とで
は、ある基準波長の光線に対する色収差の出方が逆方向
に発現するという物理現象を利用したものである。[0005] This utilizes a physical phenomenon in which chromatic aberration appears with respect to a light beam having a certain reference wavelength in the opposite direction between the refraction surface and the diffraction surface in the optical system.
【０００６】さらに、このような回折光学素子は、その
周期的構造の周期を変化させることで非球面レンズ的な
効果をも持たせることができ収差の低減に大きな効果が
ある。 又、多くの撮影レンズ（光学系）におけるフォ
ーカスは撮影レンズ全体を移動させたり、若しくは撮影
レンズの一郎を移動させたりして行っている。このうち
撮影レンズが長焦点距離を有する望遠レンズの場合は撮
影レンズが大型となり、又、高重量となるため、撮影レ
ンズ全体を移動させてフォーカスを行うのが機構的に困
難である。Further, such a diffractive optical element can have an effect like an aspheric lens by changing the period of the periodic structure, and has a great effect in reducing aberrations. Focusing in many photographing lenses (optical systems) is performed by moving the entire photographing lens or moving the photographing lens. When the photographing lens is a telephoto lens having a long focal length, the photographing lens becomes large and heavy, and it is mechanically difficult to move the entire photographing lens to perform focusing.
【０００７】このため、望遠レンズでは一部のレンズ群
を移動させてフォーカスを行っているものが多い。この
うち撮影レンズの前方レンズ群以外の比較的小型でしか
も軽量のレンズ系中の中央部分の一部のレンズ群を移動
させてフォーカスを行ったインナーフォーカス式を用い
ているものが種々と提案されている。For this reason, many telephoto lenses focus by moving some lens groups. Of these, various types that use an inner focus type in which focusing is performed by moving a part of the central lens group in a relatively small and lightweight lens system other than the front lens group of the photographing lens have been proposed. ing.
【０００８】例えば、特開昭５５−１４７６０６号公報
では焦点距離３００ｍｍ、Ｆナンバー２．８のインナー
フォーカス式の望遠レンズを、特開昭５９−６５８２０
号公報や特開昭５９−６５８２１号公報では焦点距離１
３５ｍｍ、Ｆナンバー２．８程度のインナーフォーカス
式の望遠レンズを提案している。For example, Japanese Patent Application Laid-Open No. Sho 55-147606 discloses an inner focus telephoto lens having a focal length of 300 mm and an F number of 2.8.
And Japanese Patent Application Laid-Open No. 59-65821, the focal length is 1
An inner-focus telephoto lens of about 35 mm and an F number of about 2.8 has been proposed.
【０００９】これらで提案されているインナーフォーカ
ス式の望遠レンズでは何れも物体側より順に正の屈折力
の第１群、負の屈折力の第２群、そして正の屈折力の第
３群の３つのレンズ群を有し、第２群を光軸上移動させ
てフォーカスを行っている。In any of the telephoto lenses of the inner focus type proposed here, the first lens unit having a positive refractive power, the second lens unit having a negative refractive power, and the third lens unit having a positive refractive power are arranged in order from the object side. It has three lens groups, and focuses by moving the second group on the optical axis.
【００１０】一方、近年では、光学系に加わった振動に
より発生する像面の変動（像ブレ）を打ち消すように光
学系の一部を移動させることで像ブレを補正する光学系
の発明が盛んにされており、前記のような長焦点距離の
望遠レンズでも手持ち撮影時の手ブレによる撮影画像の
プレが軽減されるようなものも開発されている。On the other hand, in recent years, an invention of an optical system for correcting an image blur by moving a part of the optical system so as to cancel a fluctuation (image blur) of an image plane generated by vibration applied to the optical system has been actively pursued. Even with the telephoto lens having a long focal length as described above, a telephoto lens having a reduced image quality due to camera shake during hand-held imaging has been developed.
【００１１】例えば、光学系中の一部のレンズ群を光軸
と直交する方向に移動させて撮影画像のブレを補正する
ものが、特開昭５０−８０１４７号公報や、特開昭５６
−２２３８１９号公報や、特開平７−２７０７２４号公
報、そして特開平８−２０１６９１号公報等で提案され
ている。For example, Japanese Patent Application Laid-Open No. 50-80147 and Japanese Patent Application Laid-Open No. 56-80147 disclose a method of correcting a blur of a photographed image by moving a part of lens groups in an optical system in a direction orthogonal to an optical axis.
Japanese Patent Application Laid-Open Nos. 223819/1996, 7-270724 / 1996 and 201691/1996.
【００１２】本出願人は特開２０００−８９１０１号公
報でインナーフォーカス式を採用し、防振機能を有した
望遠型の光学系を提案している。The present applicant has proposed a telephoto optical system adopting an inner focus system and having a vibration proof function in Japanese Patent Application Laid-Open No. 2000-89101.
【００１３】同公報では物体側より順に正の屈折力の第
１群、負の屈折力の第２群、正の屈折力の第３群を有
し、該第２群を光軸上移動させてフォーカスを行うイン
ナーフォーカス式の光学系において、第３群を物体側よ
り順に正の屈折力の第３ａ群、負の屈折力の第３ｂ群、
そして正の屈折力の第３ｃ群の３つのレンズ群より構成
し、該第３ｂ群を光軸と垂直方向に移動させて、像ブレ
を補正している。In this publication, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power are sequentially arranged from the object side, and the second lens unit is moved on the optical axis. In the inner focus type optical system that performs focusing by focusing, the third lens unit is a third lens unit having a positive refractive power, a third lens unit having a negative refractive power in order from the object side,
The third lens unit is composed of three lens units of a third lens unit having a positive refractive power, and the third lens unit is moved in a direction perpendicular to the optical axis to correct image blur.
【００１４】[0014]
【発明が解決しようとする課題】一般に、望遠レンズで
あっても光学系のコンパクト化に限界がある。例えば３
５ｍｍフィルムフォーマットで焦点距離３００ｍｍ以上
になるような所謂、超望遠レンズではレンズ全長が長く
なり、又レンズ本体も重たくなってくる。この為超望遠
レンズにおいては手持ちでの撮影が困難となり取り扱い
上非常に不便になってくる。In general, there is a limit to downsizing an optical system even with a telephoto lens. For example, 3
In a so-called super telephoto lens in which the focal length becomes 300 mm or more in a 5 mm film format, the overall length of the lens becomes longer and the lens body becomes heavier. For this reason, it is difficult for the super-telephoto lens to perform hand-held photographing, and the handling becomes very inconvenient.
【００１５】特に望遠レンズを使用する際には、望遠レ
ンズの振動（手ブレ）を抑制することが困難となる。望
遠レンズが振動によって傾くと、撮影画像はその傾き角
と望遠レンズの焦点距離に応じた変位を発生する。その
ためこのような撮影の際には、望遠レンズが振動によっ
て傾いた際にも撮影画像の変位、所謂撮影画像のブレが
発生しないようにする必要がある。In particular, when using a telephoto lens, it becomes difficult to suppress vibration (camera shake) of the telephoto lens. When the telephoto lens is tilted due to vibration, the captured image generates a displacement according to the tilt angle and the focal length of the telephoto lens. Therefore, in such shooting, it is necessary to prevent displacement of the shot image, that is, blurring of the shot image, even when the telephoto lens is tilted by vibration.
【００１６】又、望遠レンズでは焦点距離が長くなるほ
ど、色収差の発生が多くなり、これを良好に補正するのが
難しくなってくる。In a telephoto lens, as the focal length becomes longer, the occurrence of chromatic aberration increases, and it becomes difficult to satisfactorily correct this.
【００１７】本発明は、色収差を始めとする諸収差が良
好に補正されていながら望遠比０．７程度と非常にコン
パクトであり、さらに光学系に振動が加わった時の撮影
画像のブレを良好に補正できる防振機能をも有すること
で、広範囲の撮影領域に対応できる撮影光学系及びそれ
を用いた光学機器の提供を目的とする。The present invention is very compact with a telephoto ratio of about 0.7 while various aberrations including chromatic aberration are well corrected, and furthermore has a good image blurring when vibration is applied to the optical system. Another object of the present invention is to provide a photographing optical system capable of coping with a wide range of photographing areas and an optical apparatus using the same by also having an image stabilizing function capable of correcting the image quality.
【００１８】[0018]
【課題を解決するための手段】請求項１の発明の撮影光
学系は物体側より順に、正の屈折力を有する第１レンズ
群、負の屈折力を有する第２レンズ群、正の屈折力を有
する第３レンズ群を有し、無限遠物体から近距離物体へ
のフォーカシングに際し、前記第２レンズ群を光軸上像
側へ移動させる撮影光学系において、前記第１レンズ群
は、正の屈折力を有し、光軸に対して回転対称な回折光
学面を有し、前記第３レンズ群は負の屈折力を有する第
３Ｎレンズ群を有し、該第３Ｎレンズ群を光軸に対し略
垂直方向に移動することにより画像ブレの補正を行うこ
とを特徴としている。According to the first aspect of the present invention, a photographing optical system includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. In a taking optical system that moves the second lens group toward the image side on the optical axis at the time of focusing from an object at infinity to an object at a short distance, the first lens group has The third lens group has a 3N lens group having a negative refractive power, and has a refractive optical power and a diffraction optical surface that is rotationally symmetric with respect to the optical axis. On the other hand, the image blur is corrected by moving in a substantially vertical direction.
【００１９】請求項２の発明は請求項１の発明において
前記第３Ｎレンズ群は、正レンズ１枚と負レンズ１枚か
らなる接合レンズを有し、ν３ｐ、ν３ｎを前記接合レ
ンズの正レンズと負レンズの材質のアッベ数、Ｎ３ｐ、
Ｎ３ｎを前記接合レンズの正レンズと負レンズの材質の
屈折率としたとき ν３ｎ − ν３ｐ ＞ １５ Ｎ３ｎ、Ｎ３ｐ ＞ １．７ の条件式を満足することを特徴としている。According to a second aspect of the present invention, in the first aspect of the invention, the third N lens group has a cemented lens composed of one positive lens and one negative lens, and ν3p and ν3n are defined as the positive lens of the cemented lens. Abbe number of the material of the negative lens, N3p,
When N3n is the refractive index of the material of the positive lens and the negative lens of the cemented lens, the following conditional expression is satisfied: ν3n−ν3p> 15N3n, N3p> 1.7.
【００２０】請求項３の発明は請求項１又は２の発明に
おいて前記第３Ｎレンズ群は正レンズ1枚と負レンズ1枚
からなる接合レンズを有し、ｆ１、ｆ３Ｎ、ｆ３Ｃを順
に前記第１レンズ群、第３Ｎレンズ群、接合レンズの焦
点距離、ｆＴＬを全系の焦点距離としたとき ０．２５ ＜ ｆ１/ｆＴＬ ＜ ０．５５ −０．２５ ＜ ｆ３Ｎ/ｆＴＬ ＜ −０．０３ −０．４０ ＜ ｆ３Ｃ/ｆＴＬ ＜ −０．１０ の条件式を満足することを特徴としている。According to a third aspect of the present invention, in the first or second aspect, the third N lens group has a cemented lens composed of one positive lens and one negative lens, and f1, f3N, and f3C are sequentially assigned to the first lens. When the focal length of the lens group, the third N lens group, and the focal length of the cemented lens and fTL are the focal length of the entire system, 0.25 <f1 / fTL <0.55-0.25 <f3N / fTL <-0.03-0 .40 <f3C / fTL <−0.10.
【００２１】請求項４の発明は請求項１、２又は３の発
明において前記第３レンズ群は、前記第３Ｎレンズ群の
物体側に正の屈折力を有する第３１レンズ群、前記第３
Ｎレンズ群の像面側に正の屈折力を有する第３３レンズ
群を有していることを特徴としている。According to a fourth aspect of the present invention, in the first, second or third aspect, the third lens group is a 31st lens group having a positive refractive power on the object side of the 3N lens group.
It is characterized by having a 33rd lens group having a positive refractive power on the image plane side of the N lens group.
【００２２】請求項５の発明は請求項１、２、３又は４
の発明においてΦＤを前記回折光学面の設計波長で、か
つ設計回折次数の回折光に対する屈折力、ΦＴＬを全系
の屈折力としたとき ０．００５ ＜ ΦＤ/ΦＴＬ ＜ ０．１ の条件式を満足することを特徴としている。The invention of claim 5 is the invention of claim 1, 2, 3, or 4.
Where ΦD is the design wavelength of the diffractive optical surface and the refractive power for the diffracted light of the design diffraction order, and ΦTL is the refractive power of the entire system, the conditional expression of 0.005 <ΦD / ΦTL <0.1 is satisfied. It is characterized by satisfaction.
【００２３】請求項６の発明の光学機器は請求項１から
５のいずれか１項の撮影光学系を有していることを特徴
としている。According to a sixth aspect of the present invention, there is provided an optical apparatus including the photographing optical system according to any one of the first to fifth aspects.
【００２４】[0024]
【発明の実施の形態】図１、図３、図５、図７は本発明の
後述する撮影光学系の数値実施例１〜４のレンズ断面図
である。図２、図４、図６、図８は本発明の撮影光学系の
数値実施例１〜４の収差図である。収差図において
（Ａ）は基準状態、（Ｂ）は防振時の収差を示してい
る。図中Ｌ１は正の屈折力の第１群（第１レンズ群）、
Ｌ２は負の屈折力の２群（第２レンズ群）、Ｌ３は正の
屈折力の第３群（第３レンズ群）である。FIG. 1, FIG. 3, FIG. 5, and FIG. 7 are lens cross-sectional views of Numerical Examples 1 to 4 of a photographic optical system to be described later of the present invention. FIGS. 2, 4, 6, and 8 are aberration diagrams of Numerical Embodiments 1 to 4 of the imaging optical system according to the present invention. In the aberration diagrams, (A) shows the reference state, and (B) shows the aberration during image stabilization. In the figure, L1 is a first group (first lens group) having a positive refractive power,
L2 is a second group having a negative refractive power (second lens group), and L3 is a third group having a positive refractive power (third lens group).
【００２５】第３群Ｌ３は正の屈折力の第３１群（第３
１レンズ群）Ｌ３１、負の屈折力の第３Ｎ群（第３Ｎレ
ンズ群）Ｌ３Ｎ、そして正の屈折力の第３３群（第３３
レンズ群）Ｌ３の３つのレンズ群を有している。ＳＰは
開口絞り、ＩＰは像面、であり、フィルム、ＣＣＤ等の
撮像手段が設けられている。Ｄは正の屈折力を有する回
転対称な回折光学面であり、第１群Ｌ１中のレンズ面に
設けている。The third lens unit L3 is a first lens unit having a positive refractive power.
One lens unit) L31, a third lens unit (3N lens unit) L3N having negative refractive power, and a third lens unit (33rd lens unit) having positive refractive power.
(Lens group) L3. SP is an aperture stop, IP is an image plane, and an image pickup means such as a film or a CCD is provided. D is a rotationally symmetric diffractive optical surface having a positive refractive power, and is provided on the lens surface in the first unit L1.
【００２６】本実施形態では、第２群Ｌ２を矢印の如く
像面側へ移動させることにより無限遠物体から至近物体
へのフォーカスを行っている。In this embodiment, the second lens unit L2 is moved from the object at infinity to the closest object by moving the second unit L2 toward the image plane as shown by the arrow.
【００２７】撮影光学系が手ブレ（振動）を起こした時
の象ブレを補正する時には第３群Ｌ３中の第３Ｎ群Ｌ３
Ｎを光軸と垂直な方向に移動させている。When correcting elephant blurring caused by camera shake (vibration) of the photographing optical system, the third N group L3 in the third group L3 is used.
N is moved in a direction perpendicular to the optical axis.
【００２８】本実施形態では比較的径の小さくなってい
る第２群Ｌ２をフォーカシングレンズ群とすることで、
焦点調整機構の負荷の軽減が行えると同時に小型化も可
能となり、比較的コンパクトな望遠型の撮影光学系を構
成している。In this embodiment, the second lens unit L2 having a relatively small diameter is used as a focusing lens unit.
The load on the focus adjustment mechanism can be reduced, and at the same time, the size can be reduced, so that a relatively compact telephoto imaging optical system is configured.
【００２９】また、本発明による撮影光学系では、近軸
軸上光線と瞳近軸光線の光軸からの通過位置が一番高く
なる第１群Ｌ１内に回折光学面を配置することで軸上色
収差および倍率色収差を良好に補正可能な構成としてい
る。これにより、通常の屈折光学素子のみを用いた光学
系に比べ、全長（レンズ系全長）を短縮した際の軸上色
収差および倍率色収差の補正がしやすく、よりコンパク
トな光学系の構成を可能としている。In the photographing optical system according to the present invention, the diffractive optical surface is arranged in the first lens unit L1 in which the passing positions of the paraxial ray and the pupil paraxial ray from the optical axis become highest. The configuration is such that upper chromatic aberration and lateral chromatic aberration can be satisfactorily corrected. This makes it easier to correct axial chromatic aberration and chromatic aberration of magnification when the overall length (lens system length) is shortened as compared with an optical system using only ordinary refractive optical elements, thereby enabling a more compact optical system configuration. I have.
【００３０】そして、該第３群中に負の屈折力の第３Ｎ
群Ｌ３Ｎを設け、該第３Ｎ群を光軸に対し略垂直に移動
させることで、光学系に振動が加わった時の撮影画像の
ブレを補正するようにしている。このような構成とする
ことで、ブレ補正を行うレンズ群の径を小さくすること
ができ、補正レンズの駆動機構の負荷の軽減が行えると
同時にレンズ全体の小型化を可能とし、よりコンパクト
な望遠型の撮影光学系の構成を可能としている。Then, the third lens unit having a negative refractive power of 3N
A group L3N is provided, and the third N group is moved substantially perpendicularly to the optical axis, so that blurring of a captured image when vibration is applied to the optical system is corrected. With this configuration, it is possible to reduce the diameter of the lens group that performs blur correction, reduce the load on the drive mechanism of the correction lens, and at the same time, reduce the size of the lens as a whole. It is possible to configure a type of photographing optical system.
【００３１】以上のような構成とすることで、本発明の
撮影光学系は、特に色収差が良好に補正され且つ撮影光
学系に振動が加わった時の撮影画像のブレも良好に補正
できる防振機能をも有していながら、全体としてコンパ
クトな撮影光学系を構成することを可能としている。With the above-described configuration, the photographic optical system of the present invention can effectively correct chromatic aberration, and can also satisfactorily correct blurring of a photographic image when vibration is applied to the photographic optical system. While having functions, it is possible to construct a compact photographing optical system as a whole.
【００３２】次に本実施形態において第１レンズ群に設
けた回折光学面（回折面）について説明する。Next, the diffractive optical surface (diffractive surface) provided in the first lens group in this embodiment will be described.
【００３３】なお、本発明の実施形態では、正の屈折力
の回折面を１面設けた場合を示したが、更に回折面を追
加しても良く、これによれば、更に良好な光学性能が得
られる。追加する回折面は、正の屈折力であっても負の
屈折力であってもよく、特に負の屈折力の回折面を追加
する場合は、光学系の像面寄りで瞳近軸光線の入射高が
比較的高く、かつ、近軸軸上光線の入射高が比較的低く
なる位置に配置するのが良い。これにより、倍率色収差
を更に良好に補正することができる。また、各回折面は
平面或いは球面レンズに配置してあるが、非球面をベー
スとしてもよく、両面に施してもよい。更に、接合レン
ズの接合面に施しても良く、ベースの材質は光を透過す
るものであれば、特にガラスでなくても良い。In the embodiment of the present invention, the case where one diffractive surface having a positive refractive power is provided is shown. However, a further diffractive surface may be added. Is obtained. The diffractive surface to be added may have either a positive refractive power or a negative refractive power. In particular, when a diffractive surface having a negative refractive power is added, a paraxial pupil ray near the image plane of the optical system is generated. It is preferable to arrange the position where the incidence height is relatively high and the incidence height of the paraxial on-axis ray is relatively low. Thereby, chromatic aberration of magnification can be corrected more favorably. Further, although each diffraction surface is arranged on a flat or spherical lens, it may be based on an aspheric surface or may be provided on both surfaces. Furthermore, it may be applied to the cemented surface of the cemented lens, and the material of the base is not particularly limited to glass as long as it allows light to pass through.
【００３４】特に、第１レンズ群内の回折面について
は、軸上物点及び軸外物点からの光線が出来るだけ回折
面へ垂直に入射するよう、平面または物体側へ凸面を向
けたレンズ面あるいは物体へ緩い凹面を向けたレンズ面
に設けるのがよく、これにより、回折効率の低下を緩和
することが出来る。望ましくは、レンズ面の法線に対
し、±１５°未満で光線が入射するようなレンズ面に回
折面を設定するのが良い。In particular, regarding the diffractive surface in the first lens group, a lens whose convex surface is directed to a plane or an object side so that rays from an on-axis object point and an off-axis object point enter the diffractive surface as perpendicularly as possible. It is preferable to provide a lens surface with a gentle concave surface facing a surface or an object, so that a decrease in diffraction efficiency can be mitigated. Desirably, the diffractive surface should be set on the lens surface such that light rays are incident at less than ± 15 ° with respect to the normal to the lens surface.
【００３５】回折光学面の回折格子形状は、実際には図
９に示すようなキノフォーム形状の形態で実現される。The diffraction grating shape of the diffractive optical surface is actually realized in the form of a kinoform as shown in FIG.
【００３６】図９において１は回折面を設けるベースと
なる基材、２は回折格子を形成する光学材料（樹脂
部）、３は回折格子（回折面）である。In FIG. 9, reference numeral 1 denotes a base material on which a diffraction surface is provided, 2 denotes an optical material (resin portion) for forming a diffraction grating, and 3 denotes a diffraction grating (diffraction surface).
【００３７】図１０は図９に示す回折光学素子の１次回
折効率の波長依存性を示している。実際の回折素子の構
成は前述した基材１の表面に塗布した樹脂部２に、波長
５３０ｎｍで１次回折効率が１００％となるような格子
厚ｄの回折格子３を成形している。FIG. 10 shows the wavelength dependence of the first-order diffraction efficiency of the diffractive optical element shown in FIG. In the actual configuration of the diffraction element, a diffraction grating 3 having a grating thickness d such that the primary diffraction efficiency becomes 100% at a wavelength of 530 nm is formed on the resin portion 2 applied to the surface of the base material 1 described above.
【００３８】図１０で明らかなように設計次数での回折
効率は最適化した波長５３０ｎｍから離れるに従って低
下する。その低下した分、設計次数近接の次数０次、２
次回折光が増大することになり、これがフレアとなって
光学系の解像度の低下につながる。As is apparent from FIG. 10, the diffraction efficiency at the design order decreases as the distance from the optimized wavelength of 530 nm increases. Due to the decrease, the order 0 order near the design order, 2
The next-order diffracted light increases, which becomes a flare and leads to a decrease in the resolution of the optical system.
【００３９】そこで本発明では、図１１に示すような異
なる材質の回折格子を積層状に配置した形態の回折格子
形状を実施例の一つとして採用している。このような構
成にすることにより、より広い波長域で高い1次の回折
効率を得る構成とすることができる。図１２はこの構成
での回折光学素子の１次回折効率の波長依存性を示して
いる。Therefore, in the present invention, a diffraction grating shape in which diffraction gratings of different materials are arranged in a stacked manner as shown in FIG. 11 is employed as one of the embodiments. With such a configuration, it is possible to obtain a high first-order diffraction efficiency in a wider wavelength range. FIG. 12 shows the wavelength dependence of the first-order diffraction efficiency of the diffractive optical element having this configuration.
【００４０】この図から分かるように積層構造の回折格
子にすることで、設計次数の回折効率は使用波長のほぼ
全域で９５％以上の高い回折効率を有している。これに
より本発明の撮影光学系は高い解像度が得られ光学性能
は更に改善される。As can be seen from this figure, the diffraction efficiency of the design order has a high diffraction efficiency of 95% or more over almost the whole range of the used wavelength by using the diffraction grating having the laminated structure. Thereby, the imaging optical system of the present invention can obtain a high resolution, and the optical performance is further improved.
【００４１】なお、ここでの回折光学素子としては、材
質を樹脂に限定するものでなく、基材１によっては第１
の回折格子４を直接に基材１に形成してもよい。The material of the diffractive optical element here is not limited to resin, but depending on the substrate 1, the first
May be directly formed on the substrate 1.
【００４２】また更に、図１３のように積層構造を３層
以上の構成にすると、より良好な光学性能を得ることが
できる。Further, when the laminated structure has three or more layers as shown in FIG. 13, better optical performance can be obtained.
【００４３】このような構成とすることにより、空気層
に触れる部分の回折格子の格子厚を薄くすることが可能
となる。それにより回折格子のエッジの壁部分で発生す
る散乱光によるフレアが低減され、また回折格子に入射
する光の入射角の増大に伴う回折効率低下の軽減も可能
となり、光学性能は更に改善される。With such a configuration, it is possible to reduce the grating thickness of the portion of the diffraction grating that touches the air layer. As a result, flare due to scattered light generated at the wall portion of the edge of the diffraction grating is reduced, and a decrease in diffraction efficiency due to an increase in the incident angle of light incident on the diffraction grating can be reduced, thereby further improving optical performance. .
【００４４】図１４は、この構成での回折光学素子の１
次回折効率の波長依存性を示している。FIG. 14 shows one example of the diffractive optical element having this configuration.
The wavelength dependence of the second-order diffraction efficiency is shown.
【００４５】また、回折格子を図示のような積層構造に
することにより、格子面を外気に触れにくい構成とする
ことができ、ごみの付着、汚れなどによる画質を劣化さ
せる不要な散乱光の発生を低減することができる。Further, by making the diffraction grating a laminated structure as shown in the figure, the grating surface can be made hard to contact with the outside air, and unnecessary scattering light which deteriorates the image quality due to adhesion of dirt or dirt can be generated. Can be reduced.
【００４６】もちろん、本実施例のように回折光学面を
レンズの接合面に配置することは、このような観点から
も有効である。Of course, the arrangement of the diffractive optical surface on the joint surface of the lens as in this embodiment is effective from such a viewpoint.
【００４７】本発明の目的とする撮影光学系は以上の如
く構成することにより達成されるが、さらに、光学性質
を良好にするには次の諸条件のうち少なくとも１つを満
足させるのが良い。The photographing optical system aimed at by the present invention can be achieved by the above-mentioned configuration. To further improve the optical properties, it is preferable to satisfy at least one of the following conditions. .
【００４８】（ア−１）前記第３Ｎレンズ群は、正レン
ズ１枚と負レンズ１枚からなる接合レンズを有し、ν３
ｐ、ν３ｎを前記接合レンズの正レンズと負レンズの材
質のアッベ数、Ｎ３ｐ、Ｎ３ｎを前記接合レンズの正レ
ンズと負レンズの材質の屈折率としたとき ν３ｎ − ν３ｐ ＞ １５ （１） Ｎ３ｎ、Ｎ３ｐ ＞ １．７ （２） の条件式を満足することである。(A-1) The third N lens group has a cemented lens composed of one positive lens and one negative lens.
When p and ν3n are Abbe numbers of the materials of the positive lens and the negative lens of the cemented lens, and N3p and N3n are the refractive indexes of the materials of the positive lens and the negative lens of the cemented lens, ν3n−ν3p> 15 (1) N3n, N3p> 1.7 (2)
【００４９】（１）式は、ブレ補正用のレンズ群の色収
差補正に関わる条件式である。前記第３Ｎレンズ群を光
軸に対して略垂直方向に偏心させてブレ補正を行う本発
明の撮影光学系においては、ブレ補正時に前記第３Ｎレ
ンズ群で発生する偏心色収差を該第３Ｎレンズ群内であ
る程度補正しておくことが望ましい。そのためには前記
第３Ｎレンズ群は正レンズ１枚と負レンズ１枚より成る
接合レンズを有し、そのアッベ数の差が（１）式を満足
することが望ましい。Expression (1) is a conditional expression relating to chromatic aberration correction of the lens group for blur correction. In the photographing optical system of the present invention for performing blur correction by decentering the third N lens group in a direction substantially perpendicular to the optical axis, the eccentric chromatic aberration generated in the third N lens group at the time of blur correction is reduced by the third N lens group. It is desirable to make some corrections within the range. For this purpose, it is desirable that the 3N lens group has a cemented lens composed of one positive lens and one negative lens, and the difference in Abbe number satisfies the expression (1).
【００５０】（２）式は、ブレ補正用のレンズ群の偏心
収差補正に関わる条件式であり、（２）式の下限を超え
て第３Ｎレンズ群内の接合レンズの正レンズと負レンズ
の材質の屈折率が小さいと、偏心時のコマ収差や非点収
差等の補正が困難となり、また第３Ｎレンズ群全体の負
の屈折力が大きくできなくなるためブレ補正のために光
軸に対して略垂直方向に移動させる移動量が大きくなっ
て駆動機構の負荷が増大し、大型化を招き望ましくな
い。Expression (2) is a conditional expression relating to the correction of the eccentric aberration of the lens unit for blur correction, and exceeds the lower limit of expression (2) and exceeds the lower limit of expression (2). If the refractive index of the material is small, it becomes difficult to correct coma and astigmatism during decentering, and the negative refractive power of the entire 3N lens group cannot be increased. The amount of movement in the substantially vertical direction is increased, and the load on the drive mechanism is increased.
【００５１】（１）、（２）の条件は、本発明の撮影光
学系が回折光学面を適切に配置して成ることから、より
効果的に働くものである。The conditions (1) and (2) work more effectively because the photographic optical system of the present invention has an appropriately arranged diffractive optical surface.
【００５２】色収差補正に関する（１）式の条件だけで
いえば、前記正レンズは一般的に高屈折率である高分散
ガラス、前記負レンズは一般的に低屈折率である低分散
ガラスというように、（２）式の条件を外れて負レンズ
側の材質の屈折率を下げてまでもアッベ数の差を大きく
することがより有効である。しかし、全系での色収差を
良好に補正できる第１群内に効果的に回折光学面を配置
することで、第３Ｎレンズ群内だけでの色収差補正の負
荷を軽減し、その負荷が軽減した分を正レンズと負レン
ズの両方の材質の屈折率を上げて偏心時の緒収差の補正
を行うことと偏心移動距離の縮小化に振り分けている。In terms of only the condition of equation (1) relating to chromatic aberration correction, the positive lens is generally a high dispersion glass having a high refractive index, and the negative lens is generally a low dispersion glass having a low refractive index. In addition, it is more effective to increase the difference in Abbe number even if the refractive index of the material on the negative lens side is lowered by deviating from the condition of the expression (2). However, by effectively arranging the diffractive optical surface in the first group capable of satisfactorily correcting chromatic aberration in the entire system, the load of chromatic aberration correction only in the third N lens group was reduced, and the load was reduced. It is divided into correcting the aberration at the time of decentering by increasing the refractive index of the material of both the positive lens and the negative lens, and reducing the eccentric moving distance.
【００５３】尚、更に好ましくは条件式（１）、（２）
の数値を下記の如く設定するのが良い。It is more preferable that conditional expressions (1) and (2) be satisfied.
Should be set as follows.
【００５４】ν３ｎ − ν３ｐ ＞ ２０ Ｎ３ｎ、Ｎ３ｐ ＞ １．７３ （ア−２）前記第３Ｎレンズ群は正レンズ1枚と負レン
ズ1枚からなる接合レンズを有し、ｆ１、ｆ３Ｎ、ｆ３Ｃ
を順に前記第１レンズ群、第３Ｎレンズ群、接合レンズ
の焦点距離、ｆＴＬを全系の焦点距離としたとき ０．２５ ＜ ｆ１/ｆＴＬ ＜ ０．５５ （３） −０．２５ ＜ ｆ３Ｎ/ｆＴＬ ＜ −０．０３ （４） −０．４０ ＜ ｆ３Ｃ/ｆＴＬ ＜ −０．１０ （５） の条件式を満足することである。Ν3n−ν3p> 20 N3n, N3p> 1.73 (A-2) The third N lens group has a cemented lens composed of one positive lens and one negative lens, and f1, f3N, f3C
Is the focal length of the first lens group, the 3N lens group, the cemented lens, and fTL is the focal length of the entire system in order. 0.25 <f1 / fTL <0.55 (3) −0.25 <f3N / fTL <−0.03 (4) −0.40 <f3C / fTL <−0.10 (5)
【００５５】（３）式は第１レンズ群の屈折力を規定し
コンパクト化と収差補正のバランスを取るための条件式
である。条件式（３）の上限を超えて第１レンズ群の正
の屈折力が弱くなると光学系全体のコンパクト化が難し
くなり、また下限を超えて正の屈折力が強くなるとコン
パクト化に伴い増大する球面収差が補正困難となり望ま
しくない。Expression (3) is a conditional expression for defining the refractive power of the first lens unit and balancing the compactness and the aberration correction. If the positive refractive power of the first lens unit is weakened beyond the upper limit of the conditional expression (3), it becomes difficult to make the entire optical system compact, and if the positive refractive power becomes strong beyond the lower limit, the size increases with the downsizing. It is difficult to correct spherical aberration, which is not desirable.
【００５６】（４）式はブレ補正用のレンズ群の偏心移
動量と収差補正のバランス取るための条件式である。条
件式（４）の上限を超えて第３Ｎレンズ群の負の屈折力
が強まると、非偏心時の第３レンズ群内での緒収差の補
正が困難となり望ましくない。逆に下限を超えて負の屈
折力が弱まるとブレ補正のために光軸に対して略垂直方
向に偏心させる偏心移動量が大きくなり望ましくない。Expression (4) is a conditional expression for balancing the amount of eccentric movement of the lens unit for blur correction and aberration correction. When the negative refractive power of the third N lens group is increased beyond the upper limit of the conditional expression (4), it becomes difficult to correct aberrations in the third lens group when the lens is not decentered. Conversely, if the negative refractive power is weakened below the lower limit, the amount of eccentric movement for eccentricity in a direction substantially perpendicular to the optical axis for blur correction is undesirably large.
【００５７】（５）式はブレ補正用のレンズ群内の接合
レンズの屈折力を規定し、諸収差を良好に補正するため
の条件式である。条件式（５）の上限を超えて接合レン
ズの負の屈折力が強まるとブレ補正用のレンズ群内での
色収差のバランスが崩れ望ましくない。Expression (5) is a conditional expression for defining the refractive power of the cemented lens in the lens unit for blur correction and favorably correcting various aberrations. If the negative refractive power of the cemented lens exceeds the upper limit of the conditional expression (5), the balance of chromatic aberration in the lens group for blur correction is undesirably lost.
【００５８】逆に下限を超えて負の屈折力が弱まると偏
心時のコマ収差や非点収差などの収差補正が困難となる
と同時に、第３Ｎレンズ群全体の負の屈折力も強くする
ことが難しくなり望ましくない。Conversely, when the negative refractive power is weakened below the lower limit, it becomes difficult to correct aberrations such as coma and astigmatism upon decentering, and it is also difficult to increase the negative refractive power of the entire third N lens group. It is not desirable.
【００５９】また、更なる光学性能向上のためには、前
記条件式の数値範囲は以下のようにすることが好まし
い。 ０．３ ＜ ｆ１/ｆＴＬ ＜ ０．４５ −０．１５ ＜ ｆ３Ｎ/ｆＴＬ ＜ −０．０８ −０．３５ ＜ ｆ３Ｃ/ｆＴＬ ＜ −０．１５ （ア−３）前記第３レンズ群は、前記第３Ｎレンズ群の
物体側に正の屈折力を有する第３１レンズ群、前記第３
Ｎレンズ群の像面側に正の屈折力を有する第３３レンズ
群を有することである。In order to further improve the optical performance, it is preferable that the numerical range of the conditional expression be as follows. 0.3 <f1 / fTL <0.45-0.15 <f3N / fTL <-0.08-0.35 <f3C / fTL <-0.15 (A-3) The third lens group is A 31st lens unit having a positive refractive power on the object side of the 3N lens unit;
The third lens group having a positive refractive power is provided on the image plane side of the N lens group.
【００６０】このように全体として正の屈折力を持つ第
３レンズ群内を、負の屈折力を持つ第３Ｎレンズ群を挟
む形で正の屈折力を持つレンズ群を配置した構成とする
ことで、ブレ補正用のレンズ群である第３Ｎレンズ群に
入射する光束の径が小さくなりブレ補正レンズ群自体の
小型化に有効であり、また収斂光束がブレ補正用のレン
ズ群に入射する形となるため、少ない移動量で結像位置
のズレの補正が可能となり、ブレ補正レンズの駆動機構
の負荷軽減、小型化に有利となる。As described above, the third lens unit having a positive refractive power as a whole is configured such that the lens unit having a positive refractive power is arranged so as to sandwich the third N lens unit having a negative refractive power. Thus, the diameter of the light beam incident on the third N lens group, which is a lens group for blur correction, is reduced, which is effective in reducing the size of the blur correction lens group itself, and the form in which a convergent light beam enters the lens group for blur correction. Therefore, the deviation of the imaging position can be corrected with a small amount of movement, which is advantageous for reducing the load on the drive mechanism of the blur correction lens and reducing its size.
【００６１】（ア−４）ΦＤを前記回折光学面の設計波
長で、かつ設計回折次数の回折光に対する屈折力、ΦＴ
Ｌを全系の屈折力としたとき ０．００５ ＜ ΦＤ/ΦＴＬ ＜ ０．１ （６） の条件式を満足することである。(A-4) ΦD is the refractive power for the diffracted light of the design diffraction order and the design wavelength of the diffractive optical surface, ΦT
When L is the refractive power of the entire system, the conditional expression 0.005 <ΦD / ΦTL <0.1 (6) is satisfied.
【００６２】条件式(６)は主に倍率色収差を良好に補正
するためのものである。The conditional expression (6) is mainly for favorably correcting lateral chromatic aberration.
【００６３】（６）式の上限を超えて前記回折光学面の
屈折力が強まると、第２レンズ群以降で発生する軸上、
倍率色収差に対して補正不足となり、逆に下限を超えて
屈折力が弱まると第２レンズ群以降で発生する軸上、倍
率色収差に対して補正過剰となる。When the refractive power of the diffractive optical surface is increased beyond the upper limit of the equation (6), the on-axis generated in the second and subsequent lens groups becomes
When the chromatic aberration of magnification is insufficiently corrected, and conversely, when the refractive power is weakened below the lower limit, the chromatic aberration of magnification on the axis generated in the second and subsequent lens units is overcorrected.
【００６４】上記のように回折光学面の屈折力を適切に
設定することで、全長を短縮しながらも軸上、倍率色収
差が良好に補正されたコンパクトで高性能な撮影光学系
を実現することを容易にしている。By appropriately setting the refractive power of the diffractive optical surface as described above, it is possible to realize a compact and high-performance photographing optical system in which the axial chromatic aberration of magnification is well corrected while shortening the overall length. Is easy.
【００６５】尚、更に好ましくは条件式（６）の数値範
囲を次の如く設定するのが良い。It is more preferable to set the numerical range of conditional expression (6) as follows.
【００６６】 ０．０１５ ＜ ΦＤ/ΦＴＬ ＜ ０．０５ （ア−５）第３Ｎレンズ群は物体側より順に両レンズ面
が凸面の正レンズと両レンズ面が凹面の負レンズとから
なる接合レンズ、両レンズ面が凹面の負レンズを有する
ことである。0.015 <ΦD / ΦTL <0.05 (A-5) The third N lens group includes, in order from the object side, a cemented lens composed of a positive lens with both lens surfaces convex and a negative lens with both lens surfaces concave. And both lens surfaces have a concave negative lens.
【００６７】これによれば防振時の収差変動を少なくす
ることが容易となる。According to this, it becomes easy to reduce the fluctuation of aberration during image stabilization.
【００６８】（ア−６）第２レンズ群は像面側に凹面を
向けた負レンズの１つのレンズで構成することである。(A-6) The second lens group is composed of one negative lens having a concave surface facing the image plane side.
【００６９】これによればフォーカスを高速に行うこと
が容易となる。According to this, it becomes easy to perform focusing at high speed.
【００７０】（ア−７）回折面を第１レンズ群中の物体
側に凸面を向けた正レンズと像面側に凸面を向けた正レ
ンズとから成る接合レンズの接合面に設けることであ
る。(A-7) The diffractive surface is provided on the cemented surface of the cemented lens of the first lens unit, which is composed of a positive lens having a convex surface facing the object side and a positive lens having a convex surface facing the image surface side. .
【００７１】これによれば回折面の回折効果による色収
差の補正を効果的に行うことが容易となる。According to this, it becomes easy to effectively correct the chromatic aberration due to the diffraction effect of the diffraction surface.
【００７２】次に、本発明の撮影光学系を用いた一眼レ
フカメラシステムの実施形態を、図１５を用いて説明す
る。図１５において、１０は一眼レフカメラ本体、１１
は本発明による撮影光学系を搭載した交換レンズ、１２
は撮影光学系１１を通して得られる被写体像を記録する
フィルムや撮像素子などの記録手段、１３は撮影光学系
からの被写体像を観察するファインダー光学系、１４は
撮影光学系からの被写体像を記録手段１２とファインダ
ー光学系１３に切り替えて伝送するための回動するクイ
ックリターンミラーである。ファインダーで被写体像を
観察する場合は、クイックリターンミラー１４を介して
ピント板１５に結像した被写体像をペンタプリズム１６
で正立像としたのち、接眼光学系１７で拡大して観察す
る。撮影時にはクイックリターンミラ１４が矢印方向に
回動して被写体像は記録手段１２に結像して記録され
る。Next, an embodiment of a single-lens reflex camera system using the photographing optical system of the present invention will be described with reference to FIG. In FIG. 15, reference numeral 10 denotes a single-lens reflex camera main body;
Is an interchangeable lens equipped with the taking optical system according to the present invention;
Is recording means such as a film or an image sensor for recording a subject image obtained through the photographing optical system 11, 13 is a finder optical system for observing the subject image from the photographing optical system, and 14 is a means for recording the subject image from the photographing optical system. This is a rotating quick return mirror for switching and transmitting to the finder optical system 12 and the finder optical system 13. When observing the subject image with the viewfinder, the subject image formed on the focus plate 15 via the quick return mirror 14 is
Then, the image is magnified by the eyepiece optical system 17 and observed. At the time of photographing, the quick return mirror 14 rotates in the direction of the arrow, and the subject image is formed on the recording means 12 and recorded.
【００７３】このように本発明の撮影光学系を一眼レフ
カメラ交換レンズ等の光学機器に適用することにより、
高い光学性能を有した長焦点距離でありながらも非常に
コンパクトな光学機器が実現できる。As described above, by applying the photographing optical system of the present invention to an optical apparatus such as a single-lens reflex camera interchangeable lens,
A very compact optical device having a long focal length with high optical performance can be realized.
【００７４】以下に、本発明による撮影光学系の実施例
の数値データを示す。これらの数値実施例において、ｒ
ｉは物体側から順に第ｉ番目の面の曲率半径、ｄｉは物
体側から順に第ｉ番目の面と第ｉ＋１番目の面のレンズ
厚又は空気間隔、ｎｉとνｉはそれぞれ物体側から順に
第ｉ番目の光学部材のｄ線における材質の屈折率とアッ
ベ数である。The numerical data of the embodiment of the photographing optical system according to the present invention will be described below. In these numerical examples, r
i is the radius of curvature of the i-th surface in order from the object side, di is the lens thickness or air gap between the i-th surface and the (i + 1) -th surface in order from the object side, and ni and νi are i-th in order from the object side. The refractive index and Abbe number of the material at the d-line of the second optical member.
【００７５】各実施例は共にＤで示す面に回折光学面が
設けられている。ここで、各数値実施例の回折面の位相
形状ψは、次式によって定義している。In each embodiment, a diffractive optical surface is provided on the surface indicated by D. Here, the phase shape の of the diffraction surface in each numerical example is defined by the following equation.
【００７６】ψ（ｈ，ｍ）＝（２π／ｍλ0）（Ｃ1ｈ2
＋Ｃ2ｈ4＋Ｃ3ｈ6…） 但し、ｈは光軸に対して垂直方向の高さ、ｍは回折光の
回折次数、λ0は設計波長、Ｃｉは位相係数（ｉ＝１，
２，３…）である。Ψ (h, m) = (2π / mλ 0 ) (C 1 h 2
+ C 2 h 4 + C 3 h 6 ...) where h is the height in the direction perpendicular to the optical axis, m is the diffraction order of the diffracted light, λ 0 is the design wavelength, and Ci is the phase coefficient (i = 1,
2,3 ...).
【００７７】また、任意の波長λ、任意の回折次数ｍに
対する回折面Ｄの屈折力φDは、最も低次の位相係数Ｃ1
を用いて次のように表すことができる。The refractive power φ D of the diffraction surface D for an arbitrary wavelength λ and an arbitrary diffraction order m is the lowest-order phase coefficient C 1.
Can be expressed as follows.
【００７８】φD（λ，ｍ）＝−２Ｃ1ｍλ／λ0 各実施例において、回折光の回折次数ｍは１であり、設
計波長λ0 はｄ線の波長（５８７．５６ｎｍ）である。Φ D (λ, m) = − 2C 1 mλ / λ 0 In each embodiment, the diffraction order m of the diffracted light is 1, and the design wavelength λ 0 is the d-line wavelength (587.56 nm). .
【００７９】[0079]
【外１】 [Outside 1]
【００８０】[0080]
【外２】 [Outside 2]
【００８１】[0081]
【外３】 [Outside 3]
【００８２】[0082]
【外４】 [Outside 4]
【００８３】[0083]
【発明の効果】本発明によれば光学系が振動したときの
像ブレを補正することができ、しかも無限遠物体から近
距離物体に至る広範囲の物体距離において高い光学性能
を有したレンズ全長の短いコンパクトな撮影光学系及び
それを用いた光学機器を達成することができる。According to the present invention, it is possible to correct image blur when the optical system is vibrated, and to provide a lens having a high optical performance over a wide range of object distances from an object at infinity to a close object. A short and compact photographing optical system and an optical device using the same can be achieved.
【００８４】この他本発明によれば、色収差を始めとす
る諸収差が良好に補正されていながら望遠比０．７程度
と非常にコンパクトであり、さらに光学系に振動が加わ
ったときの撮影画像のブレを良好に補正できる防振機能
をも有した、取り扱い易く高い光学性能をも備えた撮影
光学系及びそれを用いた光学機器を実現することができ
る。In addition, according to the present invention, while the various aberrations including chromatic aberration are well corrected, the telephoto ratio is about 0.7, and the image is very compact. It is possible to realize a photographing optical system having an anti-vibration function capable of satisfactorily correcting blurring, an easy-to-handle and high optical performance, and an optical apparatus using the same.
【図１】 本発明の撮影光学系の数値実施例１のレンズ
断面図。FIG. 1 is a lens cross-sectional view of Numerical Example 1 of an imaging optical system according to the present invention.
【図２】 本発明の撮影光学系の数値実施例１の基準状
態と防振時の収差図。FIGS. 2A and 2B are aberration diagrams of a photographing optical system according to a numerical example 1 of the present invention in a reference state and in image stabilization.
【図３】 本発明の撮影光学系の数値実施例２のレンズ
断面図。FIG. 3 is a lens cross-sectional view of Numerical Example 2 of the photographing optical system of the present invention.
【図４】 本発明の撮影光学系の数値実施例２の基準状
態と防振時の収差図。FIGS. 4A and 4B are aberration diagrams of a photographing optical system according to a second embodiment of the present invention in a reference state and in image stabilization.
【図５】 本発明の撮影光学系の数値実施例３のレンズ
断面図。FIG. 5 is a lens cross-sectional view of a numerical example 3 of the photographing optical system of the present invention.
【図６】 本発明の撮影光学系の数値実施例３の基準状
態と防振時の収差図。FIG. 6 is a diagram illustrating aberrations in a reference state and image stabilization in Numerical Example 3 of the imaging optical system of the present invention.
【図７】 本発明の撮影光学系の数値実施例４のレンズ
断面図。FIG. 7 is a lens cross-sectional view of a numerical example 4 of the imaging optical system of the present invention.
【図８】 本発明の撮影光学系の数値実施例４の基準状
態と防振時の収差図。FIG. 8 is a diagram illustrating aberrations in a reference state and image stabilization according to Numerical Example 4 of the imaging optical system of the present invention.
【図９】 本発明における単層回折格子の断面模式図。FIG. 9 is a schematic cross-sectional view of a single-layer diffraction grating according to the present invention.
【図１０】 本発明における単層回折格子の回折効率を
示すグラフ。FIG. 10 is a graph showing the diffraction efficiency of a single-layer diffraction grating according to the present invention.
【図１１】 本発明における積層回折格子の断面模式
図。FIG. 11 is a schematic cross-sectional view of a laminated diffraction grating according to the present invention.
【図１２】 本発明における積層回折格子の回折効率を
示すグラフ。FIG. 12 is a graph showing the diffraction efficiency of the multilayer diffraction grating in the present invention.
【図１３】 本発明における３積層回折格子のの断面模
式図。FIG. 13 is a schematic cross-sectional view of a three-layer diffraction grating according to the present invention.
【図１４】 本発明における３積層回折格子の回折効率
を示すグラフ。FIG. 14 is a graph showing the diffraction efficiency of a three-layer diffraction grating according to the present invention.
【図１５】 本発明の光学機器の要部概略図。FIG. 15 is a schematic diagram of a main part of the optical apparatus of the present invention.
ＳＰ ： 絞り ＩＰ ： 像面 １ ： 回折格子のベース面の基材 ２ ： 回折格子を形成する光学材料 ３ ： 回折格子 ４ ： 積層回折格子における第１の回折格子 ５ ： 積層回折格子における第２の回折格子 ６ ： ３積層回折格子における第１の回折格子 ７ ： ３積層回折格子における第２の回折格子 ８ ： ３積層回折格子における第３の回折格子 １０ ： ビデオカメラ本体 １１ ： 撮影光学系 １２ ： 撮像素子 １３ ： 記録手段 １４ ： ファインダー Ｙ ： 像高 SP: Aperture IP: Image plane 1: Base material of diffraction grating base surface 2: Optical material forming diffraction grating 3: Diffraction grating 4: First diffraction grating in stacked diffraction grating 5: Second diffraction grating in stacked diffraction grating Diffraction grating 6: First diffraction grating in three-layer diffraction grating 7: Second diffraction grating in three-layer diffraction grating 8: Third diffraction grating in three-layer diffraction grating 10: Video camera body 11: Imaging optical system 12: Image sensor 13: Recording means 14: Viewfinder Y: Image height
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2H087 KA02 KA03 LA02 MA07 NA07 NA14 PA11 PA16 PA20 PB14 PB15 QA02 QA07 QA14 QA21 QA26 QA34 QA42 QA45 RA32 RA42 RA46 UA01 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H087 KA02 KA03 LA02 MA07 NA07 NA14 PA11 PA16 PA20 PB14 PB15 QA02 QA07 QA14 QA21 QA26 QA34 QA42 QA45 RA32 RA42 RA46 UA01
Claims (6)
レンズ群、負の屈折力を有する第２レンズ群、正の屈折
力を有する第３レンズ群を有し、無限遠物体から近距離
物体へのフォーカシングに際し、前記第２レンズ群を光
軸上像側へ移動させる撮影光学系において、 前記第１レンズ群は、正の屈折力を有し、光軸に対して
回転対称な回折光学面を有し、 前記第３レンズ群は負の屈折力を有する第３Ｎレンズ群
を有し、該第３Ｎレンズ群を光軸に対し略垂直方向に移
動することにより画像ブレの補正を行うことを特徴とす
る撮影光学系。1. A first lens having a positive refractive power in order from the object side.
A lens group, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. In focusing from an object at infinity to an object at a short distance, the second lens group is imaged on the optical axis. In the imaging optical system moved to the side, the first lens group has a positive refractive power, has a diffraction optical surface rotationally symmetric with respect to an optical axis, and the third lens group has a negative refractive power. An imaging optical system, comprising: a third N lens group that moves the third N lens group in a direction substantially perpendicular to an optical axis to correct image blur.
レンズ１枚からなる接合レンズを有し、ν３ｐ、ν３ｎ
を前記接合レンズの正レンズと負レンズの材質のアッベ
数、Ｎ３ｐ、Ｎ３ｎを前記接合レンズの正レンズと負レ
ンズの材質の屈折率としたとき ν３ｎ − ν３ｐ ＞ １５ Ｎ３ｎ、Ｎ３ｐ ＞ １．７ の条件式を満足することを特徴とする請求項１の撮影光
学系。2. The 3N lens group has a cemented lens composed of one positive lens and one negative lens, and has ν3p, ν3n
Is the Abbe number of the material of the positive lens and the negative lens of the cemented lens, and N3p and N3n are the refractive indices of the material of the positive lens and the negative lens of the cemented lens. Ν3n−ν3p> 15 N3n, N3p> 1.7 2. The photographing optical system according to claim 1, wherein a conditional expression is satisfied.
ンズ1枚からなる接合レンズを有し、ｆ１、ｆ３Ｎ、ｆ３
Ｃを順に前記第１レンズ群、第３Ｎレンズ群、接合レン
ズの焦点距離、ｆＴＬを全系の焦点距離としたとき ０．２５ ＜ ｆ１/ｆＴＬ ＜ ０．５５ −０．２５ ＜ ｆ３Ｎ/ｆＴＬ ＜ −０．０３ −０．４０ ＜ ｆ３Ｃ/ｆＴＬ ＜ −０．１０ の条件式を満足することを特徴とする請求項１又は２の
撮影光学系。3. The third N lens group has a cemented lens composed of one positive lens and one negative lens, and includes f1, f3N, and f3.
When C is the focal length of the first lens group, the 3N lens group, the cemented lens, and fTL is the focal length of the entire system, 0.25 <f1 / fTL <0.55-0.25 <f3N / fTL < The imaging optical system according to claim 1, wherein the following conditional expression is satisfied: −0.03 −0.40 <f3C / fTL <−0.10.
の物体側に正の屈折力を有する第３１レンズ群、前記第
３Ｎレンズ群の像面側に正の屈折力を有する第３３レン
ズ群を有していることを特徴とする、請求項１、２又は
３の撮影光学系。4. The third lens group includes a 31st lens group having a positive refractive power on the object side of the 3N lens group, and a 33rd lens group having a positive refractive power on the image plane side of the 3N lens group. The photographing optical system according to claim 1, further comprising a lens group.
設計回折次数の回折光に対する屈折力、ΦＴＬを全系の
屈折力としたとき ０．００５ ＜ ΦＤ/ΦＴＬ ＜ ０．１ の条件式を満足することを特徴とする請求項１、２、３
又は４の撮影光学系。5. The condition of 0.005 <ΦD / ΦTL <0.1, where ΦD is the design wavelength of the diffractive optical surface, the refractive power for the diffracted light of the design diffraction order, and ΦTL is the refractive power of the entire system. 4. The method according to claim 1, wherein the following expression is satisfied.
Or the imaging optical system of 4.
系を有していることを特徴とする光学機器。6. An optical apparatus comprising the photographing optical system according to claim 1.
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| CN104094156A (en) * | 2012-02-06 | 2014-10-08 | 富士胶片株式会社 | Wide-angle lens and imaging device |
| CN105527700A (en) * | 2014-10-17 | 2016-04-27 | 奥林巴斯株式会社 | Telephoto Lens and Image Pickup Apparatus Using the Same |
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| JPH11160617A (en) * | 1997-12-01 | 1999-06-18 | Canon Inc | Inner focusing optical system having vibration-proof function |
| JPH11295590A (en) * | 1998-04-14 | 1999-10-29 | Canon Inc | Optical system provided with diffraction optical element |
| JP2000089101A (en) * | 1998-09-11 | 2000-03-31 | Canon Inc | Inner focus type optical system |
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| JP2008096656A (en) * | 2006-10-11 | 2008-04-24 | Canon Inc | Photographic optical system and imaging apparatus having the same |
| 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 |
| CN102789042A (en) * | 2011-05-20 | 2012-11-21 | 索尼株式会社 | Internal focus lens |
| CN104094156A (en) * | 2012-02-06 | 2014-10-08 | 富士胶片株式会社 | Wide-angle lens and imaging device |
| CN104094156B (en) * | 2012-02-06 | 2016-05-25 | 富士胶片株式会社 | Wide-angle lens and camera head |
| CN105527700A (en) * | 2014-10-17 | 2016-04-27 | 奥林巴斯株式会社 | Telephoto Lens and Image Pickup Apparatus Using the Same |
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