Zoom lens system

Claim 2

A zoom lens system comprising a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, in the order from the object side, and arranged to vary the focal length of the lens system as a whole by at least moving said first, third and fourth lens groups in the direction of the optical axis, said zoom lens system being arranged to fulfill the following conditions: 0.15<|f.sub.2 /f.sub.1 |<0.3 (1) 0.5<|β.sub.3w ·β.sub.4w |<2.5 (2) 1.01<β.sub.5 <1.3 (3) where, reference symbol f 1 represents the focal length of the first lens group, reference symbol f 2 represents the focal length of the second lens group, reference symbol β 3w represents the lateral magnification of the third lens group in the wide position, reference symbol β 4w represents the lateral magnification of the fourth lens group in the wide position, and reference symbol β 5 represents the lateral magnification of the fifth lens group.

Claim 3

A zoom lens system according to claim 1 wherein said first lens group comprises a cemented doublet consisting of a negative meniscus lens and a biconvex lens cemented together, and a positive meniscus lens arranged on the image side of said cemented doublet.

Claim 4

A zoom lens system according to claim 1 wherein said second lens group comprises a negative meniscus lens convex toward the object side, a biconcave lens, a biconvex lens, and a biconcave lens whose surface on the object side has strong curvature, in the order from the object side, and arranged that an air lens with a shape like a positive meniscus lens is formed between said biconvex lens and said biconcave lens arranged on the image side of said biconvex lens.

Claim 5

A zoom lens system according to claim 1 wherein said third lens group is arranged to at least comprise one positive lens, and one cemented doublet consisting of a biconvex lens and a negative lens cemented together.

Claim 6

A zoom lens system according to claim 1 wherein said fourth lens group is arranged to at least comprise one positive lens, and one doublet.

Claim 7

A zoom lens system according to claim 1 wherein said fifth lens group comprises a positive lens, and a negative lens.

Claim 8

A zoom lens system according to claim 1 wherein said first lens group comprises a cemented doublet, which consists of a negative meniscus lens and a biconvex lens, and a positive meniscus lens, said second lens group comprises a negative meniscus lens, a biconcave lens, a biconvex lens, and a biconcave lens, said third lens group comprises a positive lens, a cemented doublet which consists of a biconvex lens and a negative lens, a positive lens, and a negative lens, said fourth lens group comprises a positive lens, a positive lens, and a negative lens, and said fifth lens group comprises a positive lens, and a negative lens, said zoom lens system having the following numerical data: ______________________________________ f = 36˜195.6, F/3.5˜F/4.5, 2ω = 62°˜12.6.de gree. ______________________________________ r.sub.1 = 265.393 d.sub.1 = 2.29 n.sub.1 = 1.80518 ν.sub.1 = 25.43 r.sub.2 = 78.3444 d.sub.2 = 7.98 n.sub.2 = 1.497 ν.sub.2 = 81.61 r.sub.3 = -179.2276 d.sub.3 = 0.2 r.sub.4 = 59.2582 d.sub.4 = 4.86 n.sub.3 = 1.744 ν.sub.3 = 44.73 r.sub.5 = 173.2891 d.sub.5 = D.sub.1 r.sub.6 = 127.9258 d.sub.6 = 1.42 n.sub.4 = 1.7865 ν.sub.4 = 50.0 r.sub.7 = 19.068 d.sub.7 = 5.0216 r.sub.8 = -48.5847 d.sub.8 = 1.39 n.sub.5 = 1.7865 ν.sub.5 = 50.0 r.sub.9 = 88.3633 d.sub.9 = 0.1905 r.sub.10 = 37.0317 d.sub.10 = 4.7 n.sub.6 = 1.84666 ν.sub.6 = 23.78 r.sub.11 = -64.4623 d.sub.11 = 1.55 r.sub.12 = -33.2011 d.sub.12 = 1.39 n.sub.7 = 1.7865 ν.sub.7 = 50.0 r.sub.13 = 804.1678 d.sub.13 = D.sub.2 r.sub.14 = ∞ (stop) d.sub.14 = 0.9524 r.sub.15 = 86.0419 d.sub.15 = 3.4714 n.sub.8 = 1.617 ν.sub.8 = 62.79 r.sub.16 = -52.5565 d.sub.16 = 0.19 r.sub.17 = 74.5381 d.sub.17 = 6.0851 n.sub.9 = 1.51821 ν.sub.9 = 65.04 r.sub.18 = -34.8404 d.sub.18 = 1.2981 n.sub.10 = 1.74 ν.sub.10 = 31.7 r.sub.19 = -514.3567 d.sub.19 = 1.4146 r.sub.20 = 30.3372 d.sub. 20 = 5.0864 n.sub.11 = 1.52542 ν.sub.11 = 64.55 r.sub.21 = 192.4854 d.sub.21 = 8.7098 r.sub.22 = -99.7097 d.sub.22 = 2.1182 n.sub.12 = 1.8061 ν.sub.12 = 40.95 r.sub.23 = 50.1429 d.sub.23 = D.sub.3 r.sub.24 = 2745.5254 d.sub.24 = 3.75 n.sub.13 = 1.51742 ν.sub.13 = 52.41 r.sub.25 = -41.1151 d.sub.25 = 0.2 r.sub.26 = 70.8046 d.sub.26 = 7.1146 n.sub.14 = 1.51742 ν.sub.14 = 52.41 r.sub.27 = -28.5245 d.sub.27 = 1.2381 r.sub.28 = -25.1132 d.sub.28 = 1.46 n.sub.15 = 1.834 ν.sub.15 = 37.16 r.sub.29 = -76.0758 d.sub.29 = D.sub.4 r.sub.30 = 1072.0189 d.sub.30 = 3.55 n.sub.16 = 1.5927 ν.sub.16 = 35.29 r.sub.31 = -75.3048 d.sub.31 = 0.135 r.sub.32 = -60.0519 d.sub.32 = 2.14 n.sub.17 = 1.7725 ν.sub.17 = 49.66 r.sub.33 = -249.2861 ______________________________________ f 36 85.8 195.6 D.sub.1 1.854 31.234 49.461 D.sub.2 26.096 14.219 2.728 D.sub.3 13.526 7.92 5.817 D.sub.4 1.634 19.102 32.508 ______________________________________ |f.sub.2 /f.sub.1 | = 0.1963, |β.sub.3 w · β.sub.4 w| = 1.272 β.sub.5 = 1.058 ______________________________________ where, reference symbols r 1 through r 33 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 32 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 17 respectively represent refractive indices of respective lenses, and reference symbols ν 1 through ν 17 respectively represent Abbe's numbers of respective lenses.

Claim 9

A zoom lens system according to claim 1 wherein said first lens group comprises a cemented doublet, which consists of a negative meniscus lens and a biconvex lens, and a positive meniscus lens, said second lens group comprises a negative meniscus lens, a biconcave lens, a biconvex lens, and a biconcave lens, said third lens group comprises a positive lens, a cemented doublet which consists of a biconvex lens and a negative lens, a positive lens, and a negative lens, said fourth lens group comprises a positive lens, a positve lens, and a negative lens, and said fifth lens group comprises a positive lens, and a negative lens, said zoom lens system having the following numerical data: ______________________________________ f = 36.03˜196.06 , F/3.5˜F/4.5, 2ω = 62°˜12 .6° ______________________________________ r.sub.1 = 338.0421 d.sub.1 = 2.29 n.sub.1 = 1.80518 ν.sub.1 = 25.43 r.sub.2 = 80.1411 d.sub.2 = 7.98 n.sub.2 = 1.603 ν.sub.2 = 65.43 r.sub.3 = -206.9613 d.sub.3 = 0.2 r.sub.4 = 61.7301 d.sub.4 = 4.86 n.sub.3 = 1.72 ν.sub.3 = 46.03 r.sub.5 = 161.6993 d.sub.5 = D.sub.1 r.sub.6 = 139.3636 d.sub.6 = 1.42 n.sub.4 = 1.84 ν.sub.4 = 46.57 r.sub.7 = 19.3118 d.sub.7 = 5.0216 r.sub.8 = -48.5652 d.sub.8 = 1.39 n.sub.5 = 1.788 ν.sub.5 = 47.38 r.sub.9 = 104.6611 d.sub.9 = 0.1905 r.sub.10 = 36.8874 d.sub.10 = 4.7 n.sub.6 = 1.84666 ν.sub.6 = 23.78 r.sub.11 = -63.2261 d.sub.11 = 1.7 r.sub.12 = -33.1461 d.sub.12 = 1.39 n.sub.7 = 1.7725 ν.sub.7 = 49.66 r.sub.13 = 742.7624 d.sub.13 = D.sub.2 r.sub.14 = ∞ (stop) d.sub.14 = 0.9524 r.sub.15 = 68.2937 d.sub.15 = 4.7662 n.sub.8 = 1.61272 ν.sub.8 = 58.75 r.sub.16 = -52.0579 d.sub.16 = 0.19 r.sub.17 = 69.9822 d.sub.17 = 5.8049 n.sub.9 = 1.51742 ν.sub.9 = 52.41 r.sub.18 = -33.1947 d.sub.18 = 1.2981 n.sub.10 = 1.7552 ν.sub.10 = 27.51 r.sub.19 = 13967.1813 d.sub.19 = 1.4146 r.sub.20 = 31.1511 d.sub. 20 = 4.9697 n.sub.11 = 1.53172 ν.sub.11 = 48.9 r.sub.21 = 163.1427 d.sub.21 = 8.7098 r.sub.22 = -96.9439 d.sub.22 = 1.6674 n.sub.12 = 1.79952 ν.sub.12 = 42.24 r.sub.23 = 47.796 d.sub.23 = D.sub.3 r.sub.24 = 22894.428 d.sub.24 = 3.75 n.sub.13 = 1.51454 ν.sub.13 = 54.69 r.sub.25 = -41.8145 d.sub.25 = 0.2 r.sub.26 = 71.2165 d.sub.26 = 7.2557 n.sub.14 = 1.51742 ν.sub.14 = 52.41 r.sub.27 = -27.6015 d.sub.27 = 1.2368 r.sub.28 = -24.8181 d.sub.28 = 1.46 n.sub.15 = 1.834 ν.sub.15 = 37.16 r.sub.29 = -71.2266 d.sub.29 = D.sub.4 r.sub.30 = 220.962 d.sub.30 = 3.55 n.sub.16 = 1.5927 ν.sub.16 = 35.29 r.sub.31 = -93.2497 d.sub.31 = 0.135 r.sub.32 = -81.3107 d.sub.32 = 2.14 n.sub.17 = 1.7859 ν.sub.17 = 44.18 r.sub.33 = 1098.844 ______________________________________ f 36.03 85.8 196.06 D.sub.1 1.838 31.599 50.29 D.sub.2 27.533 14.994 2.734 D.sub.3 13.49 8.546 6.866 D.sub.4 1.621 19.073 32.063 ______________________________________ |f.sub.2 /f.sub.1 | = 0.2, |β.sub.3 w · β.sub.4 w| = 1.236 β.sub.5 = 1.048 ______________________________________ where, reference symbols r 1 through r 33 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 32 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 17 respectively represent refractive indices of respective lenses, and reference symbols ν 1 through ν 17 respectively represent Abbe's numbers of respective lenses.

Claim 10

A zoom lens system according to claim 1 wherein said first lens group comprises a cemented doublet, which consists of a negative meniscus lens and a biconvex lens, and a positive meniscus lens, said second lens group comprises a negative meniscus lens, a biconcave lens, a biconvex lens, and a biconcave lens, said third lens group comprises a positive lens, a cemented doublet which consists of a biconvex lens and a negative lens, a positive lens, and a negative lens, said fourth lens group comprises a positive lens, a positive lens, and a negative lens, and said fifth lens group comprises a positive lens, and a negative lens, said zoom lens system having the following numerical data: ______________________________________ f = 36.03˜196.04, F/3.5˜F/4.5, 2ω = 62°˜12. 6° ______________________________________ r.sub.1 = 352.2511 d.sub.1 = 2.29 n.sub.1 = 1.80518 ν.sub.1 = 25.43 r.sub.2 = 78.5728 d.sub.2 = 7.98 n.sub.2 = 1.618 ν.sub.2 = 63.38 r.sub.3 = -221.4068 d.sub.3 = 0.2 r.sub.4 = 61.6679 d.sub.4 = 4.86 n.sub.3 = 1.72 ν.sub.3 = 46.03 r.sub.5 = 165.8793 d.sub.5 = D.sub.1 r.sub.6 = 131.4563 d.sub.6 = 1.42 n.sub.4 = 1.804 ν.sub.4 = 46.57 r.sub.7 = 19.3079 d.sub.7 = 5.0216 r.sub.8 = -48.9816 d.sub.8 = 1.39 n.sub.5 = 1.788 ν.sub.5 = 47.38 r.sub.9 = 97.3482 d.sub.9 = 0.1905 r.sub. 10 = 36.9123 d.sub.10 = 4.7 n.sub.6 = 1.84666 ν.sub.6 = 23.78 r.sub.11 = 63.4051 d.sub.11 = 1.7 r.sub.12 = -33.2626 d.sub.12 = 1.39 n.sub.7 = 1.7725 ν.sub.7 = 49.66 r.sub.13 = 933.4244 d.sub.13 = D.sub.2 r.sub.14 = ∞ (stop) d.sub.14 = 0.9524 r.sub.15 = 65.4971 d.sub.15 = 4.98 n.sub.8 = 1.60729 ν.sub.8 = 59.38 r.sub.16 = -52.3558 d.sub.16 = 0.19 r.sub.17 = 67.4426 d.sub.17 = 5.8 n.sub.9 = 1.51742 ν.sub.9 = 52.41 r.sub.18 = -33.7413 d.sub.18 = 1.4 n.sub.10 = 1.7552 ν.sub.10 = 27.51 r.sub.19 = -2224.3729 d.sub.19 = 1.4146 r.sub.20 = 31.5731 d.sub.20 = 4.95 n.sub.11 = 1.53172 ν.sub.11 = 48.9 r.sub.21 = 148.5652 d.sub.21 = 8.7098 r.sub.22 = -94.8911 d.sub.22 = 1.57 n.sub.12 = 1.8061 ν.sub.12 = 40.95 r.sub.23 = 46.4585 d.sub.23 = D.sub.3 r.sub.24 = -1836.2174 d.sub.24 = 3.75 n.sub.13 = 1.51454 ν.sub.13 = 54.69 r.sub.25 = -42.0029 d.sub.25 = 0.2 r.sub.26 = 78.329 d.sub.26 = 7.3 n.sub.14 = 1.51742 ν.sub.14 = 52.41 r.sub.27 = -27.3994 d.sub.27 = 1.2365 r.sub.28 = -24.7549 d.sub.28 = 1.46 n.sub.15 = 1.834 ν.sub.15 = 37.16 r.sub.29 = -65.7735 d.sub.29 = D.sub.4 r.sub.30 = 313.3376 d.sub.30 = 3.6 n.sub.16 = 1.5927 ν.sub.16 = 35.29 r.sub.31 = -97.1419 d.sub.31 = 0.135 r.sub.32 = -80.2502 d.sub.32 = 2.45 n.sub.17 = 1.7859 ν.sub.17 = 44.18 r.sub.33 = -625.9883 ______________________________________ f 36.03 85.83 196.04 D.sub.1 1.867 31.345 49.843 D.sub.2 27.372 14.948 2.741 D.sub.3 13.504 8.013 6.066 D.sub.4 1.622 19.595 33.4 ______________________________________ |f.sub.2 /f.sub.1 | = 0.2006, |β.sub.3 w · β.sub.4 w| = 1.264 β.sub.5 = 1.019 ______________________________________ where, reference symbols r 1 through r 33 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 32 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 17 respectively represent refractive indices of respective lenses, and reference symbols ν 1 through ν 17 respectively represent Abbe's numbers of respective lenses.