Zoom lens

Claim 2

A high performance zoom lens comprising, in order from the object side, a convergent first lens group including a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a first positive meniscus lens having a surface of greater curvature on the object side and a second positive meniscus lens having a surface of greater curvature on the object side, a divergent second lens group including a negative meniscus lens having a surface of greater curvature on the image side, a biconcave lens and a positive meniscus lens having a surface of greater curvature on the object side, a convergent third lens group including a biconvex lens and a convergent fourth lens group including a cemented lens comprising a biconvex lens and biconcave lens, a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a biconvex lens, and a negative meniscus lens having a surface of greater curvature on the object side, wherein each of said lens groups is independently mechanically movable for zooming, said zoom lens satisfying the following conditions: ______________________________________ f = 35.97 ˜ 132 F No. 1: 4.1 r.sub.i d.sub.i N.sub.i ν.sub.i ______________________________________ 1 115.000 1.80 1.84666 23.9 2 67.312 8.20 1.61800 63.4 3 388.000 0.10 4 75.596 6.22 1.67000 57.3 5 325.500 l.sub.1 6 1370.000 1.11 1.74100 52.7 7 20.382 6.16 8 -108.316 1.00 1.64328 47.9 9 49.832 2.39 10 35.571 3.28 1.84666 23.9 11 126.000 l.sub.2 12 104.599 2.31 1.77250 49.6 13 -225.000 l.sub.3 14 20.500 8.07 1.54072 47.2 15 -45.300 1.21 1.80518 25.4 16 60.078 11.01 17 56.850 2.10 1.84666 23.9 18 25.920 5.63 1.66446 35.8 19 -28.750 3.37 20 -16.827 1.20 1.88300 40.8 21 -39.006 ______________________________________ overall focal length 35.97 50.00 80.00 100.00 132.00 l.sub.1 1.47 14.79 28.04 33.34 45.64 l.sub.2 34.35 26.72 15.52 10.41 4.34 l.sub.3 5.80 3.35 1.08 0.39 1.59 ______________________________________ l.sub.3S = 5.80 = 5.37l.sub.3M f.sub.1 = 109.39 = 3.04f.sub.s |f.sub.2 | = 27.98 = 0.78f.sub.s f.sub.3 = 92.72 = 2.58f.sub.s f.sub.4 = 68.38 = 1.90f.sub.s where r i is the radius of curvature of the i-th lens surface, d i is the lens thickness or distance between adjacent lenses, N i is the refractive index of the i-th lens, ν i is the Abbe number of the i-th lens, f s is the overall focal length of said zoom lens at a wide angle position thereof, l 3s is the distance between said third and fourth lens groups at f s , and l 3M is the distance between said third and fourth lens groups at 2.22f s .

Claim 3

A high performance zoom lens comprising, in order from the object side, a convergent first lens group including a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a first positive meniscus lens having a surface of greater curvature on the object side and a second positive meniscus lens having a surface of greater curvature on the object side, a divergent second lens group including a negative meniscus lens having a surface of greater curvature on the image side, a biconcave lens and a positive meniscus lens having a surface of greater curvature on the object side, a convergent third lens group including a biconvex lens and a convergent fourth lens group including a cemented lens comprising a biconvex lens and biconcave lens, a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a biconvex lens, and a negative meniscus lens having a surface of greater curvature on the object side, wherein each of said lens groups is independently mechanically movable for zooming, said zoom lens satisfying the following conditions: ______________________________________ f = 36.00 ˜ 132 F No. 1:4.1 r.sub.i d.sub.i N.sub.i ν.sub.i ______________________________________ 1 117.780 1.80 1.84666 23.9 2 68.597 8.24 1.61800 63.4 3 435.054 0.10 4 77.697 6.13 1.67000 57.3 5 344.587 l.sub.1 6 850.409 1.11 1.74100 52.7 7 20.382 6.23 8 -106.775 1.00 1.64328 47.9 9 49.710 2.13 10 35.200 3.31 1.84666 23.9 11 127.275 l.sub.2 12 98.500 2.15 1.77250 49.6 13 -208.360 l.sub.3 14 20.253 6.60 1.54072 47.2 15 -46.218 1.21 1.80518 25.4 16 61.360 12.69 17 55.409 2.10 1.84666 23.9 18 25.647 5.55 1.66446 35.8 19 -28.799 3.39 20 -16.827 1.20 1.88300 40.8 21 -43.089 ______________________________________ overall focal length 36.00 50.00 80.00 100.00 132.00 ______________________________________ l.sub.1 1.38 13.43 26.99 35.77 47.01 l.sub.2 34.36 26.13 15.14 10.77 4.29 l.sub.3 5.97 2.89 0.53 0.46 1.19 ______________________________________ l.sub.3S = 5.97 = 11.26l.sub. 3M f.sub.1 = 110.227 = 3.06f.sub.s |f.sub.2 | = 28.26 = 0.79f.sub.s f.sub.3 = 86.84 = 2.41f.sub.s f.sub.4 = 71.73 = 1.99f.sub.s ______________________________________ where r i is the radius of curvature of the i-th lens surface, d i is the lens thickness or distance between adjacent lenses, N i is the refractive index of the i-th lens, i is the Abbe number of the i-th lens, f s is the overall focal length of said zoom lens at a wide angle position thereof, l 3S is the distance between said third and fourth lens groups at f s , and l 3M is the distance between said third and fourth lens groups at 2.22f s .

Claim 4

A high performance zoom lens comprising, in order from the object side, a convergent first lens group including a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a first positive meniscus lens having a surface of greater curvature on the object side and a second positive meniscus lens having a surface of greater curvature on the object side, a divergent second lens group including a negative meniscus lens having a surface of greater curvature on the image side, a biconcave lens and a positive meniscus lens having a surface of greater curvature on the object side, a convergent third lens group including a biconvex lens and a convergent fourth lens group including a cemented lens comprising a biconvex lens and biconcave lens, a cemented lens comprising a negative meniscus lens having a surface of greater curvature on the image side and a biconvex lens, and a negative meniscus lens having a surface of greater curvature on the object side, wherein each of said lens groups is independently mechanically movable for zooming, said zoom lens satisfying the following conditions: ______________________________________ f = 36.00 ˜ 132 F No. 1:4.1 r.sub.i d.sub.i N.sub.i ν.sub.i ______________________________________ 1 117.780 1.80 1.84666 23.9 2 68.597 8.24 1.61800 63.4 3 435.054 0.10 4 77.697 6.13 1.67000 57.3 5 344.587 l.sub.1 6 850.409 1.11 1.74100 52.7 7 20.382 6.23 8 -106.775 1.00 1.64328 47.9 9 49.710 2.13 10 35.200 3.31 1.84666 23.9 11 127.275 l.sub.2 12 98.500 2.15 1.77250 49.6 13 -208.360 l.sub.3 14 20.253 6.60 1.54072 47.2 15 -46.218 1.21 1.80518 25.4 16 61.360 12.69 17 55.409 2.10 1.84666 23.9 18 25.647 5.55 1.66446 35.8 19 -28.799 3.39 20 -16.827 1.20 1.88300 40.8 21 -43.089 ______________________________________ overall focal length 36.00 50.00 80.00 100.00 132.00 ______________________________________ l.sub.1 1.38 13.43 26.99 35.77 47.01 l.sub.2 34.36 26.13 15.14 10.77 4.29 l.sub.3 5.97 2.89 0.53 0.46 1.19 ______________________________________ l.sub.3S = 5.97 = 11.26l.sub. 3M f.sub.1 = 110.227 = 3.06f.sub.s |f.sub.2 | = 28.26 = 0.79f.sub.s f.sub.3 = 86.84 = 2.41f.sub.s f.sub.4 = 71.73 = 1.99f.sub.s ______________________________________ where r i is the radius of curvature of the i-th lens surface, d i is the lens thickness or distance between adjacent lenses, N i is the refractive index of the i-th lens, i is the Abbe number of the i-th lens, f s is the overall focal length of said zoom lens at a wide angle position thereof, l 3S is the distance between said third and fourth lens groups at f s , and l 3M is the distance between said third and fourth lens groups at 2.22f s .