Wide angle zoom lens with high zoom ratio

Claim 2

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU15## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1 : 3.5-4.5 f = 1.0-2.36 ω = 38.4°-17.6° Surface No. r d N ν ______________________________________ 1 5.0189 0.1563 1.58913 61.1 2 -30.5650 0.0035 first 3 4.7923 0.0590 1.80610 40.9 lens 4 0.8060 0.3439 group 5 -9.3508 0.0521 1.78650 50.2 6 2.1211 0.0778 7 1.4414 0.1580 1.76180 27.1 8 25.5287 1.5274 9 3.3349 0.0858 1.77250 49.6 10 -6.2150 0.0035 11 1.1636 0.1691 1.52630 51.1 second 12 7.3634 0.0035 lens 13 0.6434 0.0973 1.51823 59.0 group 14 1.1888 0.0913 15 4.9821 0.1744 1.84666 23.9 16 0.6116 0.1688 17 3.4938 0.1320 1.54072 47.2 18 -1.2504 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 3

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU16## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1 : 3.5-4.5 f = 1.0-2.70 ω = 38.4°-15.5° Surface No. r d N ν ______________________________________ 1 23.9262 0.1021 1.61800 63.4 2 -9.4751 0.0035 3 3.9261 0.0417 1.83481 42.7 first 4 0.8307 0.2990 lens 5 -14.8346 0.0486 1.69680 55.5 group 6 2.4413 0.1038 7 1.4396 0.1483 1.76180 27.1 8 6.4718 1.7942 9 2.8732 0.0962 1.72916 54.7 10 -6.2235 0.0035 11 1.2366 0.1170 1.51633 64.1 second 12 8.4407 0.0035 lens 13 0.6543 0.1170 1.51118 51.0 group 14 1.1566 1.1014 15 4.0161 0.1816 1.84666 23.9 16 0.6109 0.1500 17 5.9169 0.0917 1.60342 38.0 18 -1.4876 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 4

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU16## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1 : 3.5-4.5 f = 1.0-2.70 ω = 38.4°-15.5° Surface No. r d N ν ______________________________________ 1 23.9262 0.1021 1.61800 63.4 2 -9.4751 0.0035 3 3.9261 0.0417 1.83481 42.7 first 4 0.8307 0.2990 lens 5 -14.8346 0.0486 1.69680 55.5 group 6 2.4413 0.1038 7 1.4396 0.1483 1.76180 27.1 8 6.4718 1.7942 9 2.8732 0.0962 1.72916 54.7 10 -6.2235 0.0035 11 1.2366 0.1170 1.51633 64.1 second 12 8.4407 0.0035 lens 13 0.6543 0.1170 1.51118 51.0 group 14 1.1566 1.1014 15 4.0161 0.1816 1.84666 23.9 16 0.6109 0.1500 17 5.9169 0.0917 1.60342 38.0 18 -1.4876 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 5

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU17## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1:4.5 f = 1.0-2.71 ω = 38.0°-15.5° Surface No. r d N ν ______________________________________ 1 2.2537 0.0694 1.81600 46.6 2 1.1609 0.1666 3 2.7666 0.2082 1.72916 54.7 4 -3.8610 0.0035 first 5 -7.2312 0.0590 1.83481 42.7 lens 6 0.8623 0.2513 group 7 -3.6135 0.0521 1.69680 55.5 8 16.1380 0.0153 9 1.4680 0.1406 1.80518 25.4 10 18.7409 1.5647 11 1.7249 0.1180 1.69680 55.5 12 -29.2377 0.0069 13 1.0075 0.1232 1.50048 65.9 second 14 2.7792 0.0035 lens 15 0.7513 0.1180 1.48749 70.1 group 16 1.3197 0.1045 17 6.2101 0.1683 1.84666 23.9 18 0.6330 0.0861 19 2.2208 0.1163 1.62538 35.7 20 -1.6372 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 6

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU17## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1:4.5 f = 1.0-2.71 ω = 38.0°-15.5° Surface No. r d N ν ______________________________________ 1 2.2537 0.0694 1.81600 46.6 2 1.1609 0.1666 3 2.7666 0.2082 1.72916 54.7 4 -3.8610 0.0035 first 5 -7.2312 0.0590 1.83481 42.7 lens 6 0.8623 0.2513 group 7 -3.6135 0.0521 1.69680 55.5 8 16.1380 0.0153 9 1.4680 0.1406 1.80518 25.4 10 18.7409 1.5647 11 1.7249 0.1180 1.69680 55.5 12 -29.2377 0.0069 13 1.0075 0.1232 1.50048 65.9 second 14 2.7792 0.0035 lens 15 0.7513 0.1180 1.48749 70.1 group 16 1.3197 0.1045 17 6.2101 0.1683 1.84666 23.9 18 0.6330 0.0861 19 2.2208 0.1163 1.62538 35.7 20 -1.6372 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 7

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU18## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1:3.5-4.5 f = 1.0-2.70 ω = 38.1°-15.5° Surface No. r d N ν ______________________________________ 1 9.5257 0.1319 1.61800 63.4 2 -9.3309 0.0035 first 3 5.2263 0.0416 1.83481 42.7 lens 4 0.8187 0.2979 group 5 17.4902 0.0486 1.84100 43.2 6 1.9875 0.0755 7 1.3272 0.1492 1.80518 25.4 8 5.9227 1.7301 9 1.3969 0.2376 1.80400 46.6 10 108.5188 0.0035 11 0.7779 0.1249 1.67000 57.4 second 12 1.8514 0.0881 lens 13 35.2537 0.2528 1.84666 23.9 group 14 0.6369 0.0867 15 1.6809 0.1145 1.59551 39.2 16 -1.6579 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.

Claim 8

In a photographic zoom lens system including relatively movable first divergent and second convergent lens groups on the object and image side, respectively, the improvements characterized by: (a) the first lens group including at least two positive and two negative lenses, with the image side lens being positive, (b) the second lens group including at least two positive lens facing the object, (c) a fixed aperture diaphragm positioned on the image side of the second lens group, and (d) the overall lens system satisfying the following conditions: ##EQU18## wherein: Z is the zoom ratio (Z=f T /f W ), f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, f W is the focal length in the wide angle position, f T is the focal length in the telescopic or narrow angle position, and r I is the radius of curvature of the lens surface facing the object of the positive lens nearest to the image in the first lens group, and (V) ______________________________________ 1:3.5-4.5 f = 1.0-2.70 ω = 38.1°-15.5° Surface No. r d N ν ______________________________________ 1 9.5257 0.1319 1.61800 63.4 2 -9.3309 0.0035 first 3 5.2263 0.0416 1.83481 42.7 lens 4 0.8187 0.2979 group 5 17.4902 0.0486 1.84100 43.2 6 1.9875 0.0755 7 1.3272 0.1492 1.80518 25.4 8 5.9227 1.7301 9 1.3969 0.2376 1.80400 46.6 10 108.5188 0.0035 11 0.7779 0.1249 1.67000 57.4 second 12 1.8514 0.0881 lens 13 35.2537 0.2528 1.84666 23.9 group 14 0.6369 0.0867 15 1.6809 0.1145 1.59551 39.2 16 -1.6579 ______________________________________ wherein: r i is the radius of curvature of the ith lens surface, d i is the thickness of the ith lens or the distance between adjacent lenses, N is the refractive index at the d-line, ν is the Abbe number, and ω is the half viewing angle.