JP2011081111A5

JP2011081111A5 -

Info

Publication number: JP2011081111A5
Application number: JP2009232225A
Authority: JP
Filing date: 2009-10-06
Publication date: 2012-11-08
Anticipated expiration: 2029-10-06

Description

本発明のリアアタッチメントレンズは、主レンズ系の像側に着脱可能に装着され、該主レンズ系単独の焦点距離に比べて長い方へ焦点距離を変化させるリアアタッチメントレンズにおいて、前記リアアタッチメントレンズの最も物体側のレンズ面から最も像側のレンズ面までの距離をＬとするとき、前記リアアタッチメントレンズの最も物体側のレンズ面からの距離が０．５Ｌから１．０Ｌまでの間に負レンズGn1を有しており、前記負レンズGn1は材料のｄ線に対するアッベ数をνdn1、ｇ線とＦ線に対する部分分散比をθgFn1とするとき、
10＜νdn1＜23
0.020＜θgFn1−0.6438＋0.001682×νdn1＜0.100
なる条件を満足することを特徴としている。 The rear attachment lens of the present invention is detachably attached to the image side of the main lens system, and the rear attachment lens changes the focal length in a longer direction than the focal length of the main lens system alone. When the distance from the lens surface closest to the object side to the lens surface closest to the image side is L, a negative lens is used when the distance from the lens surface closest to the object side of the rear attachment lens is 0.5L to 1.0L. When the negative lens Gn1 has an Abbe number of the material with respect to the d-line νdn1 and a partial dispersion ratio with respect to the g-line and the F-line θgFn1,
10 <νdn1 <23
0.020 <θgFn1−0.6438 + 0.001682 × νdn1 <0.100
It is characterized by satisfying the following conditions.

各数値実施例において、ｉは物体側から数えた順序を示す。ｒｉは第ｉ番目の光学面の曲率半径、ｄｉは第ｉ面と第（ｉ＋１）面との間の軸上間隔、ｎｄｉとνｄｉはそれぞれｄ線に対する第ｉ番目と第（ｉ＋１）面との間の媒質の屈折率、アッベ数を示す。Redはエクステンダーの倍率を示す。また、ｆは焦点距離、ＦｎｏはＦナンバー、ωは半画角（度）であり、リアアタッチメントレンズの数値実施例においては、全て主レンズ系に装着した状態での値を示す。また前述の各条件式と数値実施例における諸数値との関係を（表１）に示す。表１において負レンズＧｎ１の位置とは最も物体側のレンズ面から負レンズＧｎ１の物体側のレンズ面までの長さをいう。これは以下同様である。
In each numerical example, i indicates the order counted from the object side. ri is the radius of curvature of the i-th optical surface, di is the axial distance between the i-th surface and the (i + 1) -th surface, and ndi and νdi are the i-th and (i + 1) -th surfaces with respect to the d-line, respectively. The refractive index and Abbe number of the medium in between are shown. Red indicates the magnification of the extender. In addition, f is a focal length, Fno is an F number, and ω is a half angle of view (degree). In the numerical examples of the rear attachment lens, all values are shown when mounted on the main lens system. Table 1 shows the relationship between the above-described conditional expressions and numerical values in the numerical examples. In Table 1, the position of the negative lens Gn1 refers to the length from the most object side lens surface to the object side lens surface of the negative lens Gn1. The same applies hereinafter.

Claims

In a rear attachment lens that is detachably attached to the image side of the main lens system and changes the focal length in a longer direction than the focal length of the main lens system alone, the rear attachment lens is the most from the lens surface on the most object side. When the distance to the image-side lens surface is L, the rear attachment lens has a negative lens Gn1 when the distance from the most object-side lens surface is 0.5 L to 1.0 L, and The negative lens Gn1 has a Abbe number of the material with respect to the d-line as νdn1, and a partial dispersion ratio with respect to the g-line and F-line as θgFn1.
10 <νdn1 <23
0.020 <θgFn1−0.6438 + 0.001682 × νdn1 <0.100
A rear attachment lens characterized by satisfying the following conditions.

The rear attachment lens has a positive lens Gp1 within a distance from the most object-side lens surface of 0 to 0.5 L, and the positive lens Gp1 has a refractive index and an Abbe number for the d-line of the material, respectively. When the partial dispersion ratio for Ndp1, νdp1, g-line and F-line is θgFp1,
1.90 <Ndp1 + 0.0125νdp1 <2.24
0.001 <θgFp1−0.6438 + 0.001682 × νdp1 <0.020
Rear attachment lens according to claim 1, characterized by satisfying the following condition.

The rear attachment lens has a positive lens Gp2 within a distance of 0.5L to 1.0L from the lens surface closest to the object side. The positive lens Gp2 has a refractive index and an Abbe number with respect to the d-line of the material. Is Ndp2, νdp2, and the partial dispersion ratio for g-line and F-line is θgFp2, respectively.
1.90 <Ndp2 + 0.0125νdp2 <2.24
−0.010 <θgFp2−0.6438 + 0.001682 × νdp2 <0.003
Rear attachment lens according to claim 1 or 2, characterized by satisfying the following condition.

An imaging optical system comprising: a main lens system; and the rear attachment lens according to claim 1 detachably attached to an image side of the main lens system.

An imaging apparatus comprising: the imaging optical system according to claim 4; and a light receiving unit that receives an image formed by the imaging optical system.