Rear conversion lens

Claim 2

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a biconvex positive lens component, a biconcave negative lens component and a positive lens component with its more curved surface facing the object side, said converging group consisting of, in the order from the object side, a positive lens component with its more curved surface facing the image side and a biconcave negative lens component with its more curved surface facing the image side.

Claim 3

A rear conversion lens system according to claim 1, wherein said positive lens component in said converging group is a doublet lens component including a negative meniscus lens convex to the object side and a biconvex positive lens.

Claim 4

A rear conversion lens system according to claim 1, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.7613 r.sub.1 =84.84 d.sub.1 =3.0 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-67.022 d.sub.2 =2.3 r.sub.3 =-65.251 d.sub.3 =1.0 n.sub.2 =1.74443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =16.493 d.sub.4 =1.4 r.sub.5 =35.215 d.sub.5 =18.9 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =-658.806 d.sub.6 =0.514 r.sub.7 =877.266 d.sub.7 =1.2 n.sub.4 =1.50137 ν.sub.4 =56.5 f.sub.2 r.sub.8 =-21.399 d.sub.8 =0.1 r.sub.9 =-332.183 d.sub.9 =1.0 n.sub.5 =1.80454 ν.sub.5 =39.5 r.sub.10 =47.332 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 5

A rear conversion lens system according to claim 1, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =1.5423 r.sub.1 =179.709 d.sub.1 =3.7 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-90.827 d.sub.2 =2.0 r.sub.3 =-109.097 d.sub.3 =2.1 n.sub.2 =1.74443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =32.52 d.sub.4 =2.1 r.sub.5 =40.56 d.sub.5 =4.2 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =99.049 d.sub.6 =66.24 r.sub.7 =317.64 d.sub.7 =6.2 n.sub.4 =1.50137 ν.sub.4 =56.5 f.sub.2 r.sub.8 =-55.266 d.sub.8 =0.2 r.sub.9 =-195.754 d.sub.9 =1.8 n.sub.5 =1.80454 ν.sub.5 =39.5 r.sub.10 =267.716 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 6

A rear conversion lens system according to claim 2, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.52644 r.sub.1 =187.587 d.sub.1 =3.0 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-47.144 d.sub.2 =3.3 r.sub.3 =-36.794 d.sub.3 =1.0 n.sub.2 =1.74443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =19.353 d.sub.4 =2.3 r.sub.5 =44.11 d.sub.5 =3.4 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =-110.232 d.sub.6 =11.275 r.sub.7 =114.19 d.sub.7 =2.0 n.sub.4 =1.6968 ν.sub.4 =55.6 r.sub.8 =34.505 d.sub.8 =11.1 n.sub.5 =1.50137 ν.sub.5 =56.5 f.sub.2 r.sub.9 =-21.903 d.sub.9 =0.1 r.sub.10 =-92.338 d.sub.10 =1.4 n.sub.6 =1.80454 ν.sub.6 =39.5 r.sub.11 =80.765 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 7

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a positive lens component, a negative lens component with its more curved surface facing the image side, a biconvex positive lens component and a biconcave negative lens component with its more curved surface facing the object side, said converging group consisting of, in the order from the object side, a positive lens component with its more curved surface facing the image side and a biconcave negative lens component with its more curved surface facing the image side.

Claim 8

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a positive lens component, a negative lens component with its more curved surface facing the image side, a biconvex positive lens component and a biconcave negative lens component with its more curved surface facing the object side, said converging group consisting of, in the order from the object side, a positive lens component with its more curved surface facing the image side and a biconcave negative lens component with its more curved surface facing the image side.

Claim 9

A rear conversion lens system according to claim 6, wherein said positive lens component in said converging group is a doublet lens component including a negative meniscus lens convex to the object side and a biconvex positive lens.

Claim 10

A rear conversion lens system according to claim 7, wherein said positive lens component and said negative lens component disposed on the object side of said diverging group are cemented to each other.

Claim 11

A rear conversion lens system according to claim 7, wherein said positive lens component foremost in said diverging group is a positive meniscus lens component convex to the image side and said negative lens component with its more curved surface facing the image side is a negative meniscus lens component convex to the object side, and said biconvex positive lens component and said biconcave negative lens component of said diverging group are cemented to each other.

Claim 12

A rear conversion lens system according to claim 6, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.8448 r.sub.1 =7602.182 d.sub.1 =2.5 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-85.234 d.sub.2 =0.1 r.sub.3 =111.37 d.sub.3 =1.0 n.sub.2 =1.74443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =16.963 d.sub.4 =1.0 r.sub.5 =27.323 d.sub.5 =4.9 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =-27.976 d.sub.6 =1.1 r.sub.7 =-25.116 d.sub.7 =1.0 n.sub.4 =1.79668 ν.sub.4 =45.4 r.sub.8 =439.936 d.sub.8 =2.645 r.sub.9 =1743.856 d.sub.9 =28.23 n.sub.5 =1.50137 ν.sub.5 =56.5 f.sub.2 r.sub.10 =-22.944 d.sub.10 =0.1 r.sub.11 =-294.545 d.sub.11 =1.0 n.sub.6 =1.80454 ν.sub.6 =39.5 r.sub.12 =54.449 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 13

A rear conversion lens system according to claim 7, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =1.954 r.sub.1 =87.4 d.sub.1 =2.5 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-576.216 d.sub.2 =1.0 n.sub.2 =1.74443 ν.sub.2 =49.4 r.sub.3 =17.692 d.sub.3 =1.4 f.sub.1 r.sub.4 =36.939 d.sub.4 =5.2 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.5 =-20.532 d.sub.5 =2.0 r.sub.6 =-19.333 d.sub.6 =1.0 n.sub.4 =1.79877 ν.sub.4 =44.3 r.sub.7 =-79.971 d.sub.7 =8.469 r.sub.8 =86.861 d.sub.8 =1.5 n.sub.5 =1.79877 ν.sub.5 =44.3 r.sub.9 =30.221 d.sub.9 =13.9 n.sub.6 =1.50137 ν.sub.6 =56.5 f.sub.2 r.sub.10 =-20.432 d.sub.10 =0.1 r.sub.11 =-188.213 d.sub.11 =1.0 n.sub.7 =1.80454 ν.sub.7 = 39.5 r.sub.12 =53.325 ______________________________________ wherein r represents the curvature radius of each lens surface, d represent the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 14

A rear conversion lens system according to claim 8, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =1.2278 r.sub.1 =-167.947 d.sub.1 =2.5 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-51.604 d.sub.2 =0.1 r.sub.3 =97.027 d.sub.3 =1.0 n.sub.2 =1.7443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =16.21 d.sub.4 =1.8 r.sub.5 =23.202 d.sub.5 =7.9 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =-17.735 d.sub.6 =1.0 n.sub.4 =1.79631 ν.sub.4 =40.8 r.sub.7 =182.618 d.sub.7 =13.16 r.sub.8 =104.359 d.sub.8 =1.5 n.sub.5 =1.7335 ν.sub.5 =51.0 r.sub.9 =34.774 d.sub.9 =9.2 n.sub.6 =1.50137 ν.sub.6 =56.5 f.sub.2 r.sub.10 =-22.416 d.sub.10 =0.1 r.sub.11 =-160.252 d.sub.11 =1.0 n.sub.7 =1.80454 ν.sub.7 =39.5 r.sub.12 =61.571 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 15

A rear conversion lens system according to claim 9, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.9271 r.sub.1 =36.295 d.sub.1 =1.0 n.sub.1 =1.79668 ν.sub.1 =45.0 r.sub.2 =17.706 d.sub.2 =1.2 r.sub.2 =32.624 d.sub.3 =4.7 n.sub.2 =1.59507 ν.sub.2 =35.6 f.sub.1 r.sub.4 =-28.183 d.sub.4 =1.2 r.sub.5 =-27.231 d.sub.5 =1.0 n.sub.3 =1.77279 ν.sub.3 =49.4 r.sub.6 =55.411 d.sub.6 =1.0 r.sub.7 =58.841 d.sub.7 =1.55 n.sub.4 =1.59507 ν.sub.4 =35.6 r.sub.8 =117.020 d.sub.8 =4.12 r.sub.9 =1086.312 d.sub.9 =25.3 n.sub.5 =1.50137 ν.sub.5 =56.5 r.sub.10 =-24.049 d.sub.10 =0.1 f.sub.2 r.sub.11 =-185.481 d.sub.11 =1.0 n.sub.6 =1.80454 ν.sub.6 =39.5 r.sub.12 =65.497 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which rerepresents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 16

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a negative meniscus lens component convex to the object side, a biconvex positive lens component, a biconcave negative lens component and a positive meniscus lens component convex to the object side said converging group consisting of, in the order from the object side, a positive lens component and a biconcave negative lens component.

Claim 17

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a negative meniscus lens component convex to the object side, a biconvex positive lens component, a biconcave negative lens component and a positive meniscus lens component convex to the object side said converging group consisting of, in the order from the object side, a positive lens component and a biconcave negative lens component.

Claim 18

A rear conversion lens system according to claim 14, wherein said positive lens component in said converging group is a doublet lens component including a negative meniscus lens convex to the object side and a biconvex positive lens.

Claim 19

A rear conversion lens system according to claim 15, wherein said biconvex positive lens component and said biconcave negative lens component in said diverging group are cemented to each other.

Claim 20

A rear conversion lens system according to claim 14, wherein said biconcave negative lens component and said positive meniscus lens component in said diverging group are cemented to each other.

Claim 21

A rear conversion lens system according to claim 14, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.96135 r.sub.1 =∞ d.sub.1 =2.5 n.sub.1 =1.59507 ν.sub.1 =35.6 r.sub.2 =-81.319 d.sub.2 =0.1 r.sub.3 =401.867 d.sub.3 =1.0 n.sub.2 =1.74443 ν.sub.2 =49.4 f.sub.1 r.sub.4 =18.181 d.sub.4 =1.4 r.sub.5 =28.13 d.sub.5 =5.3 n.sub.3 =1.59507 ν.sub.3 =35.6 r.sub.6 =-24.535 d.sub.6 =1.5 r.sub.7 =-21.934 d.sub.7 =1.0 n.sub.4 =1.79668 ν.sub.4 =45.4 r.sub.8 =-472.423 d.sub.8 =11.728 r.sub.9 =88.894 d.sub.9 =1.5 n.sub.5 =1.79877 ν.sub.5 =44.3 r.sub.10 =33.579 d.sub.10 =12.6 n.sub.6 =1.50137 ν.sub.6 =56.5 f.sub.2 r.sub.11 =-22.556 d.sub.11 =0.1 r.sub.12 =-152.552 d.sub.12 =1.0 n.sub.7 =1.80454 ν.sub.7 =39.5 r.sub.13 =64.571 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 22

A rear conversion lens system according to claim 15, wherein numerical data are shown in the following table: ______________________________________ d.sub.0 =1.02869 r.sub.1 =37.224 d.sub.1 =1.0 n.sub.1 =1.79668 ν.sub.1 =45.4 r.sub.2 =17.855 d.sub.2 =1.15 r.sub.3 =31.0 d.sub.3 =4.8 n.sub.2 =1.59507 ν.sub.2 =35.6 r.sub.4 =-27.118 d.sub.4 =1.1 f.sub.1 r.sub.5 =-26.049 d.sub.5 =1.0 n.sub.3 =1.77279 ν.sub.3 =49.4 r.sub.6 =41.192 d.sub.6 =1.0 r.sub.7 =45.961 d.sub.7 =2.6 n.sub.4 =1.59507 ν.sub.4 =35.6 r.sub.8 =165.452 d.sub.8 =13.1 r.sub.9 =98.846 d.sub.9 =1.5 n.sub.5 =1.79631 ν.sub.5 =40.8 r.sub.10 =36.72 d.sub.10 =10.0 n.sub.6 =1.51823 ν.sub.6 =59.0 f.sub.2 r.sub.11 =-23.342 d.sub.11 =0.1 r.sub.12 =-91.709 d.sub.12 = 1.0 n.sub.7 =1.78797 ν.sub.7 =47.5 r.sub.13 =83.740 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 23

A rear conversion lens system according to claim 16, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =3.093 r.sub.1 =24.242 d.sub.1 =1.0 n.sub.1 =1.744 ν.sub.1 =44.9 r.sub.2 =14.539 d.sub.2 =7.36 r.sub.3 =40.75 d.sub.3 =2.7 n.sub.2 =1.59507 ν.sub.2 =35.6 f.sub.1 r.sub.4 =-73.12 d.sub.4 =1.0 n.sub.3 =1.77279 ν.sub.3 =49.4 r.sub.5 =25.676 d.sub.5 =0.1 r.sub.6 =26.376 d.sub.6 =5.1 n.sub.4 =1.59507 ν.sub.4 =35.6 r.sub.7 =129.070 d.sub.7 =6.25 r.sub.8 =116.7 d.sub.8 =1.5 n.sub.5 =1.79631 ν.sub.5 =40.8 r.sub.9 =41.2 d.sub.9 =11.0 n.sub.6 =1.51823 ν.sub.6 =59.0 f.sub.2 r.sub.10 =-21.21 d.sub.10 =0.1 r.sub.11 =-152.348 d.sub.11 =1.0 n.sub.7 =1.78797 ν.sub.7 =47.5 r.sub. 12 =53.434 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 24

A rear conversion lens system according to claim 17, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.6917 r.sub.1 =37.545 d.sub.1 =1.0 n.sub.1 =1.79668 ν.sub.1 =45.4 r.sub.2 =17.681 d.sub.2 =1.3 r.sub.3 =33.0 d.sub.3 =4.8 n.sub.2 =1.59507 ν.sub.2 =35.6 f.sub.1 r.sub.4 =-26.174 d.sub.4 =1.0 r.sub.5 =-25.59 d.sub.5 =1.0 n.sub.3 =1.77279 ν.sub.3 =49.4 r.sub.6 =40.631 d.sub.6 =2.75 n.sub.4 =1.59507 ν.sub.4 =35.6 r.sub.7 =136.497 d.sub.7 =14.29 r.sub.8 =100.545 d.sub.8 =1.5 n.sub.5 =1.79631 ν.sub.5 =40.8 r.sub.9 =37.535 d.sub.9 =10.0 n.sub.6 =1.51823 ν.sub.6 =59.0 f.sub.2 r.sub.10 =-23.269 d.sub.10 =0.1 r.sub.11 =-87.1 d.sub.11 =1.0 n.sub.7 =1.78797 ν.sub.7 =47.5 r.sub.12 =87.1 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.

Claim 25

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a positive meniscus lens component convex to the object side, a positive meniscus lens component convex to the object side, a negative meniscus lens component convex to the object side and a positive lens component with its more curved surface facing the object side, said last three lens components being cemented to each other, said converging group consisting of, in the order from the object side, a positive doublet lens components with its more curved surface facing the image side and a biconcave negative lens component with its more curved surface facing the image side.

Claim 26

A rear conversion lens system for mounting on the image side of a photographic lens to make the composite focal length of the rear conversion lens and the photographic lens greater than the focal length of the photographic lens, comprising, in the order from the object side, a diverging group and a converging group, said diverging group consisting of, in the order from the object side, a positive meniscus lens component convex to the object side, a positive meniscus lens component convex to the object side, a negative meniscus lens component convex to the object side and a positive lens component with its more curved surface facing the object side, said last three lens components being cemented to each other, said converging group consisting of, in the order from the object side, a positive doublet lens components with its more curved surface facing the image side and a biconcave negative lens component with its more curved surface facing the image side.

Claim 27

a rear conversion lens system according to claim 22, wherein numerical data are as shown in the following table: ______________________________________ d.sub.0 =0.9054 r.sub.1 =29.797 d.sub.1 =1.0 n.sub.1 =1.79668 ν.sub.1 =45.4 r.sub.2 =17.897 d.sub.2 =1.7 f.sub.1 r.sub.3 =53.982 d.sub.3 =8.4 n.sub.2 =1.59507 ν.sub.2 =35.6 r.sub.4 =133.503 d.sub.4 =1.0 n.sub.3 =1.77279 ν.sub.3 =49.4 r.sub.5 =14.218 d.sub.5 =5.4 n.sub.4 =1.59507 ν.sub.4 =35.6 r.sub.6 =304.772 d.sub.6 =11.6 r.sub.7 =113.566 d.sub.7 =1.5 n.sub.5 =1.84042 ν.sub.5 =43.3 r.sub.8 =41.622 d.sub.8 =11.1 n.sub.6 =1.56384 ν.sub.6 =60.8 f.sub.2 r.sub.9 =-22.559 d.sub.9 =0.1 r.sub.10 =-160.483 d.sub.10 =1.0 n.sub.7 =1.78797 ν.sub.7 =47.5 r.sub.11 =48.426 ______________________________________ wherein r represents the curvature radius of each lens surface, d represents the center thickness of each lens or the air space between adjacent ones of the lenses, excepting d 0 which represents the air space between the rear conversion lens and the standard lens, n represents the refractive index of each lens, ν represents the Abbe number of each lens, the subscript numbers represent the order from the object side, and f 1 and f 2 represent the focal lengths of the diverging group and the converging group respectively.