Wide-angle type zoom lens

Claim 2

A wide angle type zoom lens comprising, from the direction in which light enters, a first lens group consisting of negative, positive, positive and positive lenses, and having a positive refractive power, said group being axially movable for focusing; a second lens group consisting of a negative meniscus lens of forward convexity and a negative cemented lens of negative and positive lenses and having a negative refractive power; a third lens group consisting of a negative cemented lens of negative and positive lenses, whereby when said second lens group is axially moved to effect zooming, said third lens group performs image shift compensating movement; a fourth lens group having a positive refractive power and having a function of making substantially afocal the light bundle existing therefrom; and a fifth lens group having a positive refractive power and having an image forming function, said wide angle type zoom lens being characterized by the following relationships: ##EQU2## wherein Fw is the focal length of the entire system in the wide angle side; F1 is the focal length of the first lens group; F2 is the focal length of the second lens group; R1 is the radius of curvature of the first surface in the first lens group; R6 is the radius of curvature of the front surface of the last lens in the first lens group; R8 is the radius of curvature of the first surface in the second lens group; N6 is the refractive index for the spectral d line of the negative lens of the cemented lens in the second lens group; N7 is the index of refraction for the spectral d line of the positive lens of the cemented lens in the second lens group; ν5 is the Abbe number for the spectral d line of the negative meniscus lens in the second lens group; ν6 is the Abbe number for the spectral d line of the negative lens of the cemented lens in the second lens group; and ν7 is the Abbe number for the spectral d line of the positive lens of the cemented lens in the second lens group.

Claim 3

A wide angle type zoom lens as in claim 1, satisfying the following data for the radii of curvature, R, the axial separations between the surfaces, D, the refractive indices, N, and Abbe numbers, ν, for the spectral d line ______________________________________ No. R D N ν ______________________________________ 1 -66.9639 0.5084 1.80518 25.4 2 16.6244 1.4983 1.60311 60.7 3 -18.5615 0.0224 4 14.8846 0.8427 1.60311 60.7 5 ∞ 0.0224 6 6.4009 0.9515 1.60311 60.7 7 13.6142 variable 8 8.4250 0.1944 1.71300 53.9 9 2.1745 0.8646 10 -3.2902 0.1944 1.71300 53.9 11 2.4903 0.6742 1.80518 25.4 12 27.2391 variable 13 -3.2651 0.1495 1.76200 40.2 14 4.2084 0.3681 1.80518 25.4 15 ∞ variable 16 25.9631 0.4468 1.60311 60.7 17 -5.2782 0.0150 18 8.6093 0.4610 1.60311 60.7 19 -13.9780 0.1047 20 ∞ 1.6449 1.51633 64.1 21 ∞ 0.8972 22 4.2149 0.4336 1.60311 60.7 23 -179.6943 0.0224 24 5.2289 0.4037 1.60311 60.7 25 -19.3257 0.1298 26 -4.8322 0.1495 1.80518 25.4 27 9.0354 1.7346 28 11.3451 0.4486 1.64850 53.0 29 -3.2344 0.2243 30 4.1072 0.4187 1.63636 35.4 31 -6.7594 0.0603 32 -3.5498 0.1495 1.80518 25.4 33 14.6707 0.1944 34 ∞ 1.0168 1.63854 55.4 35 ∞ ______________________________________ ______________________________________ Variable Separation Focal length f = 1 - 9.5 ______________________________________ F 1.0 4.1863 9.5964 d7 0.1438 4.3472 5.5996 d12 6.0267 1.4222 0.6429 d15 0.3992 0.8004 0.3273 ______________________________________ A block of R20 and R21 and a block of R34 and R35 are beam splitters.

Claim 4

A wide angle type zoom lens as in claim 1, satisfying the following data for the radii of curvature, R, the axial separations, D, the refractive indices, N, and the Abbe numbers, ν, for the spectral d line ______________________________________ No. R D N ν ______________________________________ 1 ∞ 0.2986 1.80518 25.4 2 9.6276 1.2691 1.60311 61.0 3 -29.7967 0.0224 4 21.7056 0.6719 1.69350 53.2 5 -54.4699 0.0224 6 5.7892 0.9704 1.69350 53.2 7 15.9189 variable 8 6.5665 0.1493 1.77250 49.6 9 1.8067 0.6719 10 -2.6730 0.1493 1.71300 53.9 11 2.2232 0.5226 1.80518 25.4 12 31.5507 variable 13 -3.8480 0.1493 1.77250 49.6 14 10.2036 0.2986 1.80518 25.4 15 -35.3124 variable 16 32.8391 0.4180 1.60311 61.0 17 -6.2361 0.0149 18 4.8319 0.4180 1.60311 61.0 19 272.2644 0.1493 20 ∞ 1.6423 1.51633 64.1 21 ∞ 0.9257 22 5.2951 0.4628 1.60311 61.0 23 -12.1817 0.0224 24 4.0138 0.4180 1.60311 61.0 25 51.7578 0.2086 26 -3.9179 0.1642 1.80518 25.4 27 8.8859 1.5784 28 -19.0651 0.4479 1.71300 53.2 29 -2.7638 0.0224 30 2.9272 0.4778 1.63636 35.4 31 -3.8049 0.0269 32 -3.2541 0.1493 1.80518 25.4 33 7.6137 0.1941 34 ∞ 1.0152 1.63854 55.4 35 ∞ ______________________________________ ______________________________________ Variable Separation Focal length f = 1- 9.5 ______________________________________ F 1.0 3.3456 9.5000 d7 0.1459 3.2813 4.6751 d12 5.0751 1.2755 0.5460 d15 0.3632 1.0274 0.3632 ______________________________________ A block of R20 and R21 and a block of R34 and R35 are beam splitters.

Claim 5

A wide angle type zoom lens as in claim 1, satisfying the following data for the radii of curvature, R, the axial separations, D, the refractive indices, N, and the Abbe numbers, ν, for the spectral d line ______________________________________ No. R D N ν ______________________________________ 1 -70.5253 0.5234 1.80518 25.4 2 16.5940 1.4177 1.60311 60.7 3 -18.9263 0.0224 4 14.4711 0.8569 1.60311 60.7 5 -538.3921 0.0224 6 6.4879 0.9277 1.60311 60.7 7 13.4032 variable 8 8.6984 0.1869 1.71300 53.9 9 2.1072 0.8832 10 -2.9966 0.1869 1.60311 60.7 11 2.6637 0.6554 1.80518 25.4 12 12.1432 variable 13 -3.2554 0.1346 1.76200 40.2 14 3.9659 0.3627 1.80518 25.4 15 -11706.58 variable 16 26.4307 0.4510 1.60311 60.7 17 -5.2251 0.0150 18 8.7499 0.4696 1.60311 60.7 19 13.8382 0.1047 20 ∞ 1.6449 1.63854 64.1 21 ∞ 0.8972 22 4.2149 0.4336 1.60311 60.7 23 -179.6943 0.0224 24 5.2289 0.4037 1.60311 60.7 25 -19.3257 0.1298 26 -4.8322 0.1495 1.80518 25.4 27 9.0354 1.7346 28 11.3451 0.4486 1.64850 53.0 29 -3.2344 0.2243 30 4.1072 0.4187 1.63636 35.4 31 -6.7594 0.0603 32 -3.5498 0.1495 1.80518 25.4 33 14.6707 0.1944 34 ∞ 1.0168 1.63854 55.4 35 ∞ ______________________________________ ______________________________________ Variable Separation Focal length f = 1- 9.5964 ______________________________________ F 1.0 4.1863 9.5964 d7 0.1438 4.3472 5.5996 d12 6.0267 1.4222 0.6429 d15 0.3992 0.8004 0.3273 ______________________________________ a block of R20 and R21 and a block of R34 and R35 being beam splitters.