Compact wide-angle zoom lens

Claim 2

A wide angle zoom lens comprising: a first lens group having a positive refractive power and a second lens group having a negative refractive power, with the distance between the first and second lens groups being variable for varying the magnification of the wide angle zoom lens, said first lens group, sequentially from an object, including: a front group composed of a first lens component assuming a meniscus configuration in which its convex surface is directed to said object and having a positive refractive power, a second lens component having a more intensive concave surface directed to said object and having a negative refractive power, a third lens component having either one of positive and negative refractive powers and a fourth lens component having a positive refractive power; and a rear group composed of a fifth lens component having a positive refractive power, said second lens group, sequentially from said object, including: a sixth lens component assuming a meniscus configuration in which its convex surface is directed to an image and having a positive refractive power, a seventh lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power and an eighth lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power, said wide angle zoom lens being constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.19 0.9<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.40 where f 1 is the focal length of said first lens group, f 2 is the focal length of said second lens group, Y is the maximum image height on an image surface, and β 2W is the image forming magnification of said second lens group at a wide-angle end.

Claim 3

The wide angle zoom lens according to claim 1, wherein said front group of said first lens group is so constructed as to be movable along said optical axis to vary a spacing between said front group and said rear group for focusing and is constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 4

The wide angle zoom lens according to claim 1, wherein said front group of said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.5<|f.sub.L2 /f.sub.F |<1.3,F.sub.L2< 0 0.6<f.sub.L4 /f.sub.F <1.9 1.0<|f.sub.L6 /f.sub.2 |<2.3,f.sub.L6 >0 0.7<f.sub.L7 /f.sub.2 <4.0 0.8<f.sub.L8 /f.sub.2 <2.5 32<νL.sub.1 <70 6<ν.sub.L8 -ν.sub.L6 <40 11<ν.sub.L8 -ν.sub.L7 <45 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f F : the focal length of said front group of said first lens group, f 2 : the focal length of said second lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 5

The wide angle zoom lens according to claim 1, wherein said second lens component of said first lens group is composed of a double concave negative lens and a double convex positive lens joined to said negative lens and is constructed as a junction lens assuming a meniscus configuration in which its convex surface is directed to said image on the whole, said third lens component is constructed of a positive lens in which its convex surface exhibiting a more intensive curvature is directed to said object, said fourth lens component is composed of a positive lens in which its convex surface exhibiting a more intensive curvature is directed to said image and a negative meniscus lens joined to said positive lens and having its concave surface directed to said object and also has a positive refractive power on the whole, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.11 1.03<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.32.

Claim 6

The wide angle zoom lens according to claim 4, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 7

The wide angle zoom lens according to claim 4, wherein said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.6<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.9 1.4<|f.sub.L6 /f.sub.2 |<2.3,f.sub.L6 <0 0.9<f.sub.L7 /f.sub.2 <4.0 0.8<f.sub.L8 /f.sub.2 <1.8 32<νL.sub.1 <60 6<ν.sub.L8 -ν.sub.L6 <18 11<ν.sub.L8 -ν.sub.L7 <28 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f 2 : the focal length of said second lens group, f F : the focal length of said front group of said first lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 8

The wide angle zoom lens according to claim 4, wherein said second lens component and said fourth lens component are constructed to satisfy the following conditions for correcting spherical aberration: 0.2<n.sub.L2n -n.sub.L2p 0.27<n.sub.L4n -n.sub.L4p where n L2n : the refractive index of said negative lens of said second lens component, n L2p : the refractive index of said positive lens of said second lens component, n L4n : the refractive index of said negative lens of said fourth lens component, n L4p : the refractive index of said positive lens of said fourth lens component.

Claim 9

The wide angle zoom lens according to claim 4, wherein said second lens component and said fourth lens component are constructed to satisfy the following conditions for correcting chromatic aberration: -3<ν.sub.L2n -ν.sub.L2p <7 25<ν.sub.L4p -ν.sub.L4n <50 where ν L2n : the Abbe number of said negative lens of said second lens component, ν L2p : the Abbe number of said positive lens of said second lens component, ν L4p : the Abbe number of said positive lens of said fourth lens component, ν L4n : the Abbe number of said negative lens of said fourth lens component.

Claim 10

The wide angle zoom lens according to claim 4, wherein said second lens component of said first lens group and said seventh lens component of said second lens group are constructed to satisfy the following conditions: 3<q.sub.L2 <15 2<q.sub.L7 <9 0.3<D.sub.L2 /f.sub.W where q L2 , q L7 are the shape factors, D L2 is the on-the-axis thickness of said second lens component, and f W is the focal length of said zoom lens at the wide-angle end, and a shape factor q Li of the i-th lens component is defined as follows: q.sub.Li =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said i-th lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 11

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 28.8˜49.0, F.sub.NO = 4.1˜7.0, 2ω = 72.4˜48. 0° r d υ n ______________________________________ 1 26.361 3.30 52.3 1.74810 2 42.652 2.60 3 -31.414 2.00 43.3 1.84042 4 11.592 8.60 41.4 1.57501 5 -39.382 0.60 6 25.636 2.40 52.3 1.74810 7 ∞ 0.50 8 ∞ 3.60 69.9 1.51860 9 -12.813 1.70 23.0 1.86074 10 -18.442 2.51 11 ∞ 1.20 52.3 1.74810 12 -106.230 (d12) 13 -22.651 3.30 43.3 1.84042 14 -15.995 2.50 15 -14.584 1.40 33.9 1.80384 16 -18.925 2.80 17 -12.278 1.30 60.1 1.62041 18 -141.764 (Bf) f 28.8000 35.0000 49.0001 d12 10.2529 6.7286 2.0511 Bf 4.8254 11.5881 26.8590 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01. Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = 0.1768E - 05, c.sub.6 = 0.2898E - 07 c.sub.8 = -0.3755E - 09, c.sub.10 = 0.7895E - 12 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587, 6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU5## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 12

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 28.8˜58.6, F.sub.NO = 4.1˜8.3, 2ω = 72.3˜40. 9° r d υ n ______________________________________ 1 22.706 3.30 52.3 1.74810 2 31.963 3.00 3 -32.819 2.00 43.3 1.84042 4 11.367 8.60 41.4 1.57501 5 -39.260 0.60 6 24.508 2.40 55.6 1.69680 7 ∞ 0.50 8 ∞ 3.60 60.3 1.51835 9 -12.156 1.70 23.0 1.86074 10 -17.739 2.13 11 ∞ 1.20 31.6 1.75692 12 -104.455 (d12) 13 -19.677 3.30 44.7 1.80218 14 -14.016 2.50 15 -12.984 1.40 33.9 1.80384 16 -18.925 2.80 17 -12.600 1.30 60.1 1.62041 18 -87.211 (Bf) f 28.8001 40.0003 58.6001 d12 11.6237 6.2244 1.8177 Bf 3.7307 15.3472 34.6384 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.3287E - 05, c.sub.6 = 0.8718E - 07 c.sub.8 = -0.6130E - 09, c.sub.10 = 0.1132E - 11 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587, 6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU6## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 13

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 28.8˜63.5, F.sub.NO = 4.1˜9.0, 2ω = 72.3˜38. 0° r d υ n ______________________________________ 1 21.953 3.30 52.3 1.74810 2 29.483 3.20 3 -32.528 2.00 43.3 1.84042 4 11.289 8.60 41.4 1.57501 5 -38.408 0.60 6 25.045 2.40 55.6 1.69680 7 ∞ 0.50 8 ∞ 3.60 59.0 1.51823 9 -11.569 1.70 23.0 1.86074 10 -16.990 2.44 11 ∞ 1.20 27.6 1.75520 12 -104.218 (d12) 13 -18.297 3.30 44.7 1.80218 14 -13.294 2.50 15 -12.299 1.40 33.9 1.80384 16 -18.000 2.80 17 -12.600 1.30 60.1 1.62041 18 -88.747 (Bf) f 28.8002 42.0004 63.5013 d12 11.9532 6.0443 1.6792 Bf 3.4257 16.7743 38.5169 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.7999E - 05, c.sub.6 = 0.1303E - 06 c.sub.8 = -0.7531E - 09, c.sub.10 = 0.1224E - 11 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU7## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 14

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 28.8˜68.5, F.sub.NO = 4.1˜9.8, 2ω = 72.3˜35. 4° r d υ n ______________________________________ 1 21.509 3.30 57.5 1.67025 2 30.282 3.20 3 -32.379 2.00 43.3 1.84042 4 11.335 8.60 41.4 1.57501 5 -38.801 0.60 6 24.911 2.40 55.6 1.69680 7 ∞ 0.50 8 ∞ 4.00 56.4 1.50137 9 -11.120 1.30 23.0 1.86074 10 -16.119 2.40 11 ∞ 1.20 23.0 1.86074 12 -118.782 (d12) 13 -17.401 3.30 44.7 1.80218 14 -12.731 2.50 15 -11.868 1.40 33.9 1.80384 16 -18.000 2.80 17 -12.600 1.30 60.1 1.62041 18 -77.705 (Bf) f 28.8002 44.0006 68.5013 d12 12.2254 5.8415 1.5153 Bf 3.1590 18.2675 42.6200 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.8892E - 05, c.sub.6 = 0.1322E - 06 c.sub.8 = -0.7632E - 09, c.sub.10 = 0.1216E - 11 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU8## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 15

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 68.6˜31 .0° r d υ n ______________________________________ 1 22.700 3.30 54.0 1.61720 2 41.685 2.60 3 -31.923 2.00 43.3 1.84042 4 12.161 8.60 40.7 1.58144 5 -41.581 0.60 6 27.721 2.40 50.8 1.65844 7 ∞ 0.50 8 ∞ 3.60 53.5 1.54739 9 -11.053 1.70 23.0 1.86074 10 -17.203 2.46 11 ∞ 1.20 31.6 1.75692 12 -99.156 (d12) 13 -20.200 3.30 44.7 1.80218 14 -13.351 2.50 15 -12.371 1.20 47.5 1.78797 16 -26.547 3.10 17 -13.814 1.30 60.1 1.62041 18 -56.300 (Bf) f 30.8006 50.0015 78.5039 d12 12.0097 5.2988 1.3903 Bf 3.9843 22.0427 48.8491 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.3123E - 05, c.sub.6 = 0.7469E - 07 c.sub.8 = -0.5197E - 09, c.sub.10 = 0.9731E - 12 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU9## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 16

The wide angle zoom lens according to claim 4, which is structured based on the following Table: ______________________________________ f = 30.8˜68.5, F.sub.NO = 4.1˜9.1, 2ω = 68.3˜35. 4° r d υ n ______________________________________ 1 22.677 3.30 49.4 1.77279 2 32.535 2.60 3 -34.947 2.00 43.3 1.84042 4 11.428 8.60 40.8 1.58144 5 -54.425 0.60 6 29.087 2.40 49.4 1.77279 7 ∞ 0.50 8 ∞ 3.60 53.6 1.54739 9 -10.707 1.70 23.0 1.86074 10 -16.676 2.62 11 ∞ 1.20 35.2 1.74950 12 -98.185 (d12) 13 -19.316 3.30 45.4 1.79668 14 -13.297 2.50 15 -12.755 1.20 46.4 1.80411 16 -26.000 3.60 17 -13.000 1.30 60.3 1.62041 18 -38.074 (Bf) f 30.8005 45.0013 68.5036 d12 11.7446 5.8622 1.4850 Bf 3.9190 18.1651 41.7423 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle.

Claim 17

The wide angle zoom lens according to claim 1, wherein said second lens component of said first lens group is composed of a negative lens in which its concave surface exhibiting a more intensive curvature is directed to said object, said third lens component is constructed as a junction lens having a positive refractive power on the whole by joining a negative meniscus lens having its concave surface directed to said image to a double convex positive lens, said fourth lens component is composed of a positive lens in which its convex surface exhibiting a more intensive curvature is directed to said object, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.11 1.03<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.32.

Claim 18

The wide angle zoom lens according to claim 16, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 19

The wide angle zoom lens according to claim 16, wherein said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.6<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.9 1.4<|f.sub.L6 /f.sub.2 |<2.3,f.sub.L6 >0 0.9<f.sub.L7 /f.sub.2 <4.0 0.8<f.sub.L8 /f.sub.2 <1.8 32<ν.sub.L1 <60 6<ν.sub.L8 -ν.sub.L6 <18 11<ν.sub.L8 -ν.sub.L7 <28 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f 2 : the focal length of said second lens group, f F : the focal length of said front group of said first lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 20

The wide angle zoom lens according to claim 16, wherein said second lens component and said third lens component are constructed to satisfy the following conditions for correcting spherical aberration: 1.75<n.sub.L2n 0.2<n.sub.L3n -n.sub.L3p where n L2n : the refractive index of said second lens component, n L3n : the refractive index of said negative lens of said third lens component, n L3p : the refractive index of said positive lens of said third lens component.

Claim 21

The wide angle zoom lens according to claim 16, wherein said third lens component and said fourth lens component are constructed to satisfy the following conditions for correcting chromatic aberration: 15<ν.sub.L3p -ν.sub.L3n <25 60<ν.sub.L4 where ν L3p : the Abbe number of said positive lens of said third lens component, ν L3n : the Abbe number of said negative lens of said third lens component, ν L4 : the Abbe number of said fourth lens component.

Claim 22

The wide angle zoom lens according to claim 16, wherein said second lens component and said seventh lens component are constructed to satisfy the following conditions: 0.18<D.sub.L2 /f.sub.W <0.4 1.5<q.sub.L7 <3 where D L2 is the on-the-axis thickness of said second lens component of said first lens group, f W is the focal length of said zoom lens at the wide-angle end, and q L7 is the shape factor of said seventh lens component of said second lens group, and said shape factor q L7 of said seventh lens component is defined as follows: q.sub.L7 =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said seventh lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 23

The wide angle zoom lens according to claim 16, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 68.6˜31 .0° r d υ n ______________________________________ 1 25.145 2.00 35.5 1.59507 2 40.876 2.70 3 -22.461 6.50 43.3 1.84042 4 64.158 0.20 5 17.452 2.00 40.9 1.79631 6 9.525 6.80 59.7 1.53996 7 -23.454 0.20 8 22.073 2.00 69.9 1.51860 9 -284.716 2.64 10 ∞ 1.20 49.0 1.53172 11 -69.655 (d11) 12 -22.439 3.30 45.4 1.79668 13 -13.502 2.50 14 -11.699 1.20 47.5 1.78797 15 -34.604 3.10 16 -15.949 1.30 60.1 1.62041 17 -50.276 (Bf) f 30.8005 50.0015 78.5045 d11 12.1245 5.4136 1.5051 Bf 3.7369 21.7953 48.6021 ______________________________________ 17th Surface (Nonspherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.1638E - 05, c.sub.6 = 0.7088E - 07 c.sub.8 = -0.3773E - 09, c.sub.10 = 0.4873E - 12 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, γ is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU10## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 24

The wide angle zoom lens according to claim 1, wherein said second lens component of said first lens group is composed of a negative lens in which its concave surface exhibiting a more intensive curvature is directed to said object, said third lens component is constructed as a junction lens having either one of weak positive and negative refractive powers on the whole by joining a negative lens having its concave surface directed to said image to a double convex positive lens, said fourth lens component is constructed as a junction lens having a positive refractive power on the whole by joining a double convex positive lens to a negative meniscus lens having its concave surface directed to said object, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.11 1.03<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.32.

Claim 25

The wide angle zoom lens according to claim 23, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 26

The wide angle zoom lens according to claim 23, wherein said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.6<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.9 1.4<|f.sub.L6 /f.sub.2 |<2.3,f.sub.L6 >0 0.9<f.sub.L7 /f.sub.2 <4.0 0.8<f.sub.L8 /f.sub.2 <1.8 32<ν.sub.L1 <60 6<ν.sub.L8 -ν.sub.L6 <18 11<ν.sub.L8 -ν.sub.L7 <28 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f 2 : the focal length of said second lens group, f F : the focal length of said front group of said first lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 27

The wide angle zoom lens according to claim 23, wherein said second lens component, said third lens component and said fourth lens component are constructed to satisfy the following conditions for correcting spherical aberration: 1.75<n.sub.L2 0.08<n.sub.L3n -n.sub.L3p 0.2<n.sub.L4n -n.sub.L4p where n L2 : the refractive index of said second lens component, n L3n : the refractive index of said negative lens of said third lens component, n L3p : the refractive index of said positive lens of said third lens component, n L4n : the refractive index of said negative lens of said fourth lens component, n L4p : the refractive index of said positive lens of said fourth lens component.

Claim 28

The wide angle zoom lens according to claim 23, wherein said third lens component and said fourth lens component are constructed to satisfy the following condition for correcting chromatic aberration: -2<ν.sub.L3p -ν.sub.L3n <8 20<ν.sub.L4p -ν.sub.L4n <30 where ν L3p : the Abbe number of said positive lens of said third lens component, ν L3n : the Abbe number of said negative lens of said third lens component, ν L4p : the Abbe number of said positive lens of said fourth lens component, ν L4n : the Abbe number of said negative lens of said fourth lens component.

Claim 29

The wide angle zoom lens according to claim 23, wherein said third lens component of said first lens group and said seventh lens component of said second lens group are constructed to satisfy the following conditions: -3<q.sub.L3 <-0.5 2<q.sub.L7 <3 where q L3 , q L7 are the shape factors, and a shape factor q Li of the i-th lens component is defined as follows: q.sub.Li =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said i-th lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 30

The wide angle zoom lens according to claim 23, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 69.0˜30 .9° r d υ n ______________________________________ 1 22.551 3.00 54.0 1.61720 2 49.176 2.10 3 -24.049 1.60 46.5 1.80411 4 121.580 2.00 5 -132.357 1.10 47.5 1.78797 6 10.198 4.10 50.8 1.65844 7 -32.482 0.20 8 20.505 4.00 54.6 1.51454 9 -10.498 1.10 28.6 1.79504 10 -15.980 2.72 11 ∞ 1.20 29.5 1.71736 12 -98.996 (d12) 13 -22.540 3.30 52.3 1.74810 14 -13.009 2.50 15 -10.996 1.50 46.5 1.80411 16 -24.800 0.03 55.9 1.49712 17 -29.117 2.60 18 -17.000 1.30 60.1 1.62041 19 -77.703 (Bf) f 30.8057 50.0057 78.5012 d12 12.1357 5.4248 1.5163 Bf 3.9725 22.0236 48.8141 ______________________________________ 17th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.9600E - 05, c.sub.6 = 0.2188E - 06 c.sub.8 = -0.2960E - 08, c.sub.10 = 0.6426E - 11 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing. ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU11## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 31

The wide angle zoom lens according to claim 23, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 68.9˜30 .9° r d υ n ______________________________________ 1 21.771 3.00 49.0 1.53172 2 80.103 1.90 3 -24.939 1.60 45.4 1.79668 4 94.807 2.00 5 -70.034 1.10 47.5 1.78797 6 10.420 4.10 50.8 1.65844 7 -29.415 0.20 8 20.544 4.00 54.6 1.51454 9 -10.402 1.10 28.6 1.79504 10 -15.873 2.73 11 ∞ 1.20 32.2 1.67270 12 -92.833 (d12) 13 -22.852 3.30 45.4 1.79668 14 -13.392 2.50 15 -11.286 1.50 43.3 1.84042 16 -24.800 0.03 55.9 1.49712 17 -29.117 2.60 18 -17.000 1.30 60.0 1.64000 19 -75.985 (Bf) f 30.8069 50.0090 78.5095 d12 12.1718 5.4609 1.5524 Bf 4.0166 22.0691 48.8634 ______________________________________ 17th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.8055E - 05, c.sub.6 = 0.1774E - 06 c.sub.8 = -0.2356E - 08, c.sub.10 = 0.3921E - 11 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587.6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU12## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 32

The wide angle zoom lens according to claim 23, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 69.0˜30 .9° r d υ n ______________________________________ 1 20.505 3.00 54.6 1.51454 2 46.724 2.10 3 -23.630 1.60 46.5 1.80411 4 218.298 2.00 5 -98.990 1.10 47.5 1.78797 6 10.130 4.10 50.8 1.65844 7 -31.025 0.20 8 20.414 4.00 54.6 1.51454 9 -10.751 1.10 28.6 1.79504 10 -16.341 1.94 11 ∞ 1.20 32.2 1.67270 12 -92.799 (d12) 13 -22.417 3.30 45.4 1.79668 14 -13.251 2.50 15 -11.169 1.50 43.3 1.84042 16 -25.812 0.03 55.9 1.49712 17 -28.800 2.50 18 -16.898 1.30 60.0 1.64000 19 -65.760 (Bf) f 30.8002 50.0000 78.5001 d12 12.8119 6.1311 2.2401 Bf 4.0808 22.2483 49.2160 ______________________________________ 17th Surface (Nonspherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.8158E - 05, c.sub.6 = 0.1488E - 06 c.sub.8 = -0.1631E - 08, c.sub.10 = 0.5443E - 12 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU13## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n is the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 33

The wide angle zoom lens according to claim 23, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 69.0˜31 .0° r d υ n ______________________________________ 1 19.531 2.30 55.6 1.69680 2 31.351 2.50 3 -24.151 1.60 46.5 1.80411 4 69.660 2.00 5 180.336 1.10 47.5 1.78797 6 10.019 4.10 50.8 1.65844 7 -38.949 0.20 8 21.184 4.00 54.6 1.51454 9 -10.439 1.10 28.6 1.79504 10 -15.939 2.65 11 ∞ 1.20 28.3 1.72825 12 -95.401 (d12) 13 -22.986 3.30 49.4 1.77279 14 -13.394 2.50 15 -11.549 1.20 43.3 1.84042 16 -27.441 2.60 17 -15.950 1.30 60.1 1.62041 18 -68.571 (Bf) f 30.8011 50.0032 78.5089 d12 12.1095 5.3986 1.4901 Bf 4.2036 22.2628 49.0717 ______________________________________ 18th Surface (NonSpherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c.sub.2 = 0.0 c.sub.4 = -0.5153E - 05, c.sub.6 = 0.8831E - 07 c.sub.8 = -0.5498E - 09, c.sub.10 = 0.8733E - 12 wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU14## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 34

The wide angle zoom lens according to claim 1, wherein said second lens component of said first lens group is constructed as a junction lens assuming a meniscus configuration in which its convex surface is directed to said image, said junction lens being composed of a double concave negative lens and a double convex positive lens joined to said negative lens, said third lens component consists of a positive lens in which its convex surface exhibiting a more intensive curvature is directed to said object, and said fourth lens component is constructed as a junction lens having a positive refractive power on the whole, said junction lens being composed of a positive lens in which its convex surface exhibiting a more intensive curvature is directed to said image and a negative meniscus lens joined to said positive lens and having its concave surface directed to said object, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.14<f.sub.1 /Y<1.19 1.0<|f.sub.2 /Y|<1.09,f.sub.2 <0 1.21<β.sub.2W <1.32.

Claim 35

The wide angle zoom lens according to claim 33, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 36

The wide angle zoom lens according to claim 33, wherein said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.6<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.9 1.0<|f.sub.L6 /f.sub.2 |<2.0,f.sub.L6 <0 0.7<f.sub.L7 /f.sub.2 <1.5 0.8<f.sub.L8/f 2<2.5 40<νL.sub.1 <60 18<ν.sub.L8 -ν.sub.L6 <26 15<ν.sub.L8 -ν.sub.L7 <28 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f 2 : the focal length of said second lens group, f F : the focal length of said front group of said first lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 37

The wide angle zoom lens according to claim 33, wherein said second lens component and said fourth lens component are constructed to satisfy the following conditions for correcting spherical aberration: 2.0<n.sub.L2n -n.sub.L2p 0.27<n.sub.L4n -n.sub.L4p and further satisfy the following conditions: -3<ν.sub.L2n -ν.sub.L2p <7 25<ν.sub.L4p -ν.sub.L4n <35 where n L2n : the refractive index of said negative lens of said second lens component, n L2p : the refractive index of said positive lens of said second lens component, n L4n : the refractive index of said negative lens of said fourth lens component, n L4p : the refractive index of said positive lens of said fourth lens component, ν L2n : the Abbe number of said negative lens of said second lens component, ν L2p : the Abbe number of said positive lens of said second lens component, ν L4p : the Abbe number of said positive lens of said fourth lens component, ν L4n : the Abbe number of said negative lens of said fourth lens component.

Claim 38

The wide angle zoom lens according to claim 33, wherein said second lens component of said first lens group and said seventh lens component of said second lens group are constructed to satisfy the following conditions: 3<q.sub.L2 <6 1.1<q.sub.L7 <3 0.25<D.sub.L2 /f.sub.W <0.4 where qL2, qL7 are the shape factors, D L2 is the on-the-axis thickness of said second lens component, and f W is the focal length of said zoom lens at the wide-angle end, and a shape factor q Li of the i-th lens component q Li is defined as follows: q.sub.Li =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said i-th lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 39

The wide angle zoom lens according to claim 33, which is structured based on the following Table: ______________________________________ f = 32.8˜83.0, F.sub.NO = 3.60˜9.12, 2ω = 64.7˜2 9.3° r d υ n ______________________________________ 1 24.667 3.30 50.8 1.65844 2 45.566 2.60 3 -29.557 2.00 43.3 1.84042 4 14.000 8.60 40.7 1.58144 5 -46.563 0.60 6 32.361 1.80 45.0 1.74400 7 ∞ 0.50 8 ∞ 3.60 53.5 1.54739 9 -10.957 1.70 23.0 1.86074 10 -17.338 3.24 11 ∞ 1.20 23.0 1.86074 12 -112.757 (d12) 13 -34.637 3.90 47.1 1.67003 14 -13.537 1.50 15 -12.910 1.20 44.7 1.80218 16 -37.000 3.50 17 -14.000 1.30 67.9 1.59319 18 -73.452 (B.f) f 32.8015 50.0033 83.0080 d12 12.3786 6.2070 1.5278 B.f 4.9876 20.8571 51.3055 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle.

Claim 40

The wide angle zoom lens according to claim 33, which is structured based on the following Table: ______________________________________ f = 32.8˜83.0, F.sub.NO = 3.60˜9.12, 2ω = 65.0˜29. 4° ______________________________________ r d ν n ______________________________________ 1 21.988 3.30 54.0 1.61720 2 41.048 2.60 3 -31.447 2.00 43.3 1.84042 4 14.000 8.60 40.7 1.58144 5 -51.410 0.60 6 31.859 1.80 45.0 1.74400 7 ∞ 0.50 8 ∞ 3.60 53.5 1.54739 9 -10.723 1.70 23.0 1.86074 10 -17.246 2.30 11 ∞ 1.20 23.0 1.86074 12 -112.757 (d12) 13 -24.842 3.30 45.4 1.79668 14 -14.883 2.50 15 -13.611 1.20 46.5 1.80411 16 -54.617 4.60 17 -14.000 1.30 67.9 1.59319 18 -29.539 (B.f) ______________________________________ f 32.8017 50.0038 83.0090 d12 12.7273 6.5557 1.8765 B.f 3.1636 19.0333 49.4822 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle.

Claim 41

The wide angle zoom lens according to claim 1, wherein said second lens component of said first lens group is composed of a negative lens in which its concave surface exhibiting a more intensive curvature is directed to said object, said third lens component is constructed as a junction lens having either one of weak positive and negative refractive powers on the whole by joining a negative lens having its concave surface directed to said image to a double convex positive lens, said fourth lens component is constructed as a junction lens having a positive refractive power on the whole by joining a double convex positive lens to a negative meniscus lens having its concave surface directed to said object, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.1 0.9<|f.sub.2 /Y|<1.01,f.sub.2 <0 1.21<β.sub.2W <1.32.

Claim 42

The wide angle zoom lens according to claim 40, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 43

The wide angle zoom lens according to claim 40, wherein said front group of said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.5<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.2 1.4<|f.sub.L6 /f.sub.2 |<2.0,f.sub.L6 >0 0.8<f.sub.L7 /f.sub.2 <1.5 0.8<f.sub.L8 /f.sub.2 <2.2 32<ν.sub.L1 <60 6<ν.sub.L8 -ν.sub.L6 <40 11<ν.sub.L8 -ν.sub.L7 <45 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f F : the focal length of said front group of said first lens group, f 2 : the focal length of said second lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 44

The wide angle zoom lens according to claim 40, wherein said second lens component, said third lens component and said fourth lens component are constructed to satisfy the following conditions for correcting spherical aberration: 1.75<n.sub.L2 0.2<n.sub.L3n -n.sub.L3p 0.2<n.sub.L4n -n.sub.L4p where n L2 : the refractive index of said second lens component, n L3n : the refractive index of said negative lens of said third lens component, n L3p : the refractive index of said positive lens of said third lens component, n L4n : the refractive index of said negative lens of said fourth lens component, n L4p : the refractive index of said positive lens of said fourth lens component.

Claim 45

The wide angle zoom lens according to claim 40, wherein said third lens component and said fourth lens component are constructed to satisfy the following condition for correcting chromatic aberration: 6<ν.sub.L3p -ν.sub.L3n <15 10<ν.sub.L4p -ν.sub.L4n <25 where ν L3p : the Abbe number of said positive lens of said third lens component, ν L3n : the Abbe number of said negative lens of said third lens component, ν L4p : the Abbe number of said positive lens of said fourth lens component, ν L4n : the Abbe number of said negative lens of said fourth lens component.

Claim 46

The wide angle zoom lens according to claim 40, wherein said seventh lens component of said second lens group is constructed to satisfy the following condition: 2<q.sub.L7 <3 where q L7 is the shape factor of said seventh lens component thereof, and a shape factor q L7 of said seventh lens component is defined as follows: q.sub.L7 =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said seventh lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 47

The wide angle zoom lens according to claim 45, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 69.1˜31.0 ° ______________________________________ r d ν n ______________________________________ 1 21.607 3.00 69.9 1.51860 2 53.566 2.10 3 -21.390 1.60 47.5 1.78797 4 119.647 2.00 5 -71.239 1.10 49.4 1.77279 6 9.865 4.10 48.1 1.71700 7 -29.068 0.20 8 23.924 4.00 53.5 1.54739 9 -10.680 1.10 28.6 1.79504 10 -17.795 1.86 11 -99.983 1.10 58.5 1.61272 12 -45.987 (d12) 13 -57.766 3.30 35.2 1.74950 14 -16.773 1.00 15 -17.725 1.00 39.8 1.86994 16 -278.298 6.10 17 -11.499 1.20 60.1 1.62041 18 -26.533 (B.f) ______________________________________ F 30.8000 49.9997 78.5003 d12 11.9284 5.2487 1.3583 B.f 3.6560 21.7830 48.6912 ______________________________________ wherein the numbers at the left end indicate the order from the object, the symbols r, d, ν, n sequentially indicate the radius of curvature, the lens-surface spacing, the Abbe number and the refractive index in d-line (λ=587.6 nm), 2ω is the view angle, f is the focal length of the entire system, and F NO is the F number.

Claim 48

The wide angle zoom lens according to claim 40, which is structured based on the following Table: ______________________________________ f = 29.8˜78.5, F.sub.NO = 4.1˜10.8, 2ω = 70.8°.ab out.31.1° ______________________________________ r d ν n 1 18.312 2.30 51.1 1.73350 2 28.459 2.50 3 -24.299 1.60 46.5 1.80411 4 88.659 2.00 5 747.848 1.10 47.5 1.78797 6 11.874 4.10 59.0 1.51823 7 -24.512 0.20 8 18.381 4.00 59.0 1.51823 9 -10.738 1.10 40.9 1.79631 10 -16.243 2.66 11 ∞ 1.20 57.0 1.62280 12 -81.587 (d12) 13 -21.409 3.30 47.5 1.78797 14 -12.944 2.50 15 -10.998 1.20 45.4 1.79668 16 -29.477 2.90 17 -15.950 1.30 60.1 1.62041 18 -60.131 (B.f) ______________________________________ f 29.8002 50.0008 78.5017 d12 11.9272 5.1605 1.5363 B.f 3.5037 22.2117 48.6066 ______________________________________ 18th Surface (Non-Spherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c2 = 0.0 c4 = -0.5098E - 05 c6 = 0.1095E - 06 c8 = 0.6103E - 09 c10 = 0.8906E - 12 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU15## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 49

The wide angle zoom lens according to claim 40, which is structured based on the following Table: ______________________________________ f = 28.8˜78.5, F.sub.NO = 4.1˜11.2, 2ω 72.2°.abou t.30.9° ______________________________________ r d ν n ______________________________________ 1 19.971 2.30 37.9 1.72342 2 27.854 2.70 3 -22.230 1.60 43.3 1.84042 4 51.474 2.00 5 25.157 1.10 46.5 1.80411 6 11.054 4.10 59.0 1.51823 7 -31.668 0.20 8 21.715 4.00 59.0 1.51823 9 -10.792 1.10 40.9 1.79631 10 -16.642 2.69 11 ∞ 1.20 45.9 1.54814 12 -71.806 (d12) 13 -20.681 3.30 47.5 1.78797 14 -12.645 2.50 15 -10.815 1.20 39.8 1.86994 16 -25.890 2.90 17 -15.000 1.30 82.6 1.49782 18 -114.790 (B.f) ______________________________________ f 28.8005 47.0010 78.5027 d12 11.9991 5.6215 1.5718 B.f 2.8165 19.4171 48.1498 ______________________________________ 18th Surface (Non-Spherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c2 = 0.0 c4 = -0.4350E - 05 c6 = 0.1138E - 06 c8 = -0.6877E - 09 c10 = 0.1053E - 11 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (λ=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU16## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 50

The wide angle zoom lens according to claim 40, which is structured based on the following Table: ______________________________________ f = 28.8˜78.5, F.sub.NO =4.1˜11.2, 2ω = 72.3°.abo ut.31.0° ______________________________________ r d ν n ______________________________________ 1 17.833 2.30 42.0 1.66755 2 27.414 2.70 3 -23.215 1.60 43.3 1.84042 4 70.344 2.00 5 58.313 1.10 46.5 1.80411 6 11.470 4.10 59.0 1.51823 7 -26.200 0.20 8 19.191 4.00 59.0 1.51823 9 -11.504 1.10 40.9 1.79631 10 -16.793 2.71 11 ∞ 1.20 57.0 1.62280 12 -81.587 (d12) 13 -20.365 3.30 47.5 1.78797 14 -12.525 2.50 15 -10.690 1.20 45.4 1.79668 16 -29.477 2.90 17 -15.950 1.30 60.1 1.62041 18 -58.651 (B.f) ______________________________________ f 28.8003 47.0003 78.5007 d12 12.0787 5.7011 1.6514 B.f 2.7568 19.3571 48.0888 ______________________________________ 18th Surface (Non-Spherical Surface) Cone constant k = 0.1000E + 01 Non-spherical coefficient c2 = 0.0 c4 = -0.4884E - 05 c6 = 0.1036E - 06 c8 = -0.5858E - 09 c10 = 0.8375E - 12 ______________________________________ wherein the numbers at the left end indicate the order from the object, r is the radius of curvature, d is the lens-surface spacing, ν is the Abbe number, n is the refractive index in a d-line (ν=587,6 nm), f is the focal length of the entire system, F NO is the F number, and 2ω is the view angle, the non-spherical configuration being expressed by: ##EQU17## where r is the paraxial curvature radius, h is the height from the optical axis, c 2 , c 4 , c 6 , c 8 and c 10 are the non-spherical coefficients, and k is the cone constant on condition that the X-axis is taken in the optical axis, the H-axis is taken in the vertical direction, and the light traveling direction is positive, with E+n and E-n in the non-spherical coefficient and the cone constant indicating 10 n and 10 -n , respectively.

Claim 51

A wide angle zoom lens comprising: a first lens group having a positive refractive power and a second lens group having a negative refractive power, with the distance between the first and second lens groups being variable for varying the magnification of the wide angle zoom lens, said first lens group, sequentially from an object, including: a front group composed of a first lens component assuming a meniscus configuration in which its convex surface is directed to said object and having a positive refractive power, a second lens component having a more intensive concave surface directed to said object and having a negative refractive power, a third lens component having either one of positive and negative refractive powers and a fourth lens component having a positive refractive power; and a rear group composed of a fifth lens component having a positive refractive power, said second lens group, sequentially from said object, including: a sixth lens component assuming a meniscus configuration in which its convex surface is directed to an image and having a positive refractive power, a seventh lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power and an eighth lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power, said first lens group and said second lens group being constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.19 0.9<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.40 ##EQU18## 1.15<|rc/Y|<1.30,rc<0 where f 1 : the focal length of said first lens group, f 2 : the focal length of said second lens group, Y: the maximum image height on the image surface, β 2W : the image forming magnification of said second lens group at the wide-angle end, ra: the radius of curvature of the image-side surface of said seventh lens component of said second lens group, rb: the radius of curvature of the object-side surface of said eighth lens component of said second lens group, rc: the radius of curvature of the image-side surface of said eighth lens component of said second lens group.

Claim 52

A wide angle zoom lens comprising: a first lens group having a positive refractive power and a second lens group having a negative refractive power, with the distance between the first and second lens groups being variable for varying the magnification of the wide angle zoom lens, said first lens group, sequentially from an object, including: a front group composed of a first lens component assuming a meniscus configuration in which its convex surface is directed to said object and having a positive refractive power, a second lens component having a more intensive concave surface directed to said object and having a negative refractive power, a third lens component having either one of positive and negative refractive powers and a fourth lens component having a positive refractive power; and a rear group composed of a fifth lens component having a positive refractive power, said second lens group, sequentially from said object, including: a sixth lens component assuming a meniscus configuration in which its convex surface is directed to an image and having a positive refractive power, a seventh lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power and an eighth lens component assuming a meniscus configuration in which its convex surface is directed to said image and having a negative refractive power, said first lens group and said second lens group being constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.19 0.9<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.40 ##EQU18## 1.15<|rc/Y|<1.30,rc<0 where f 1 : the focal length of said first lens group, f 2 : the focal length of said second lens group, Y: the maximum image height on the image surface, β 2W : the image forming magnification of said second lens group at the wide-angle end, ra: the radius of curvature of the image-side surface of said seventh lens component of said second lens group, rb: the radius of curvature of the object-side surface of said eighth lens component of said second lens group, rc: the radius of curvature of the image-side surface of said eighth lens component of said second lens group.

Claim 53

The wide angle zoom lens according to claim 50, wherein said front group of said first lens group is so constructed as to be movable along said optical axis to vary a spacing between said front group and said rear group for focusing and is constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said rear group, and f R is the focal length of said rear group.

Claim 54

The wide angle zoom lens according to claim 50, wherein said front group of said first lens group and said second lens group are constructed to satisfy the following conditions: 1.7<f.sub.L1 /f.sub.F <3.8 0.5<|f.sub.L2 /f.sub.F |<1.3,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.9 1.0<|f.sub.L6 /f.sub.2 |<2.3,f.sub.L6 <0 0.7<f.sub.L7 /f.sub.2 <4.0 0.8<f.sub.L8 /f.sub.2 <2.5 32<νL.sub.1 <70 6<ν.sub.L8 -ν.sub.L6 <40 11<ν.sub.L8 -ν.sub.L7 <45 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f F : the focal length of said front group of said first lens group, f 2 : the focal length of said second lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 55

The wide angle zoom lens according to claim 50, wherein said second lens component of said first lens group is composed of a negative lens in which its concave surface exhibiting a more intensive curvature is directed to said object, said third lens component is constructed as a junction lens having either one of weak positive and negative refractive powers on the whole by joining a negative lens having its concave surface directed to said image to a double convex positive lens, said fourth lens component is constructed as a junction lens having a positive refractive power on the whole by joining a double convex positive lens to a negative meniscus lens having its concave surface directed to said object, and said first lens group and said second lens group are constructed to satisfy the following conditions: 1.0<f.sub.1 /Y<1.12 0.9<|f.sub.2 /Y|<1.16,f.sub.2 <0 1.21<β.sub.2W <1.40.

Claim 56

The wide angle zoom lens according to claim 53, wherein said front group of said first lens group is so constructed as to be movable along the optical axis to vary a spacing between said front group and said rear group for focusing and is also constructed to satisfy the following condition: 3.5<f.sub.R /f.sub.F <10 where f F is the focal length of said front group, and f R is the focal length of said rear group.

Claim 57

The wide angle zoom lens according to claim 53, wherein said front group of said first lens group and said second lens group are constructed to satisfy the following conditions: 2.0<f.sub.L1 /f.sub.F <3.0 0.6<|f.sub.L2 /f.sub.F |<1.2,f.sub.L2 <0 0.6<f.sub.L4 /f.sub.F <1.2 1.0<|f.sub.L6 /f.sub.2 |<1.5,f.sub.L6 >0 0.7<f.sub.L7 /f.sub.2 <1.2 1.2<f.sub.L8 /f.sub.2 <1.8 40<ν.sub.L1 18<ν.sub.L8 -ν.sub.L6 <30 11<ν.sub.L8 -ν.sub.L7 <28 where f L1 : the focal length of said first lens component of said first lens group, f L2 : the focal length of said second lens component of said first lens group, f L4 : the focal length of said fourth lens component of said first lens group, f L6 : the focal length of said sixth lens component of said second lens group, f L7 : the focal length of said seventh lens component of said second lens group, f L8 : the focal length of said eighth lens component of said second lens group, f F : the focal length of said front group of said first lens group, f 2 : the focal length of said second lens group, ν L1 : the Abbe number of said first lens component of said first lens group, ν L6 : the Abbe number of said sixth lens component of said second lens group, ν L7 : the Abbe number of said seventh lens component of said second lens group, ν L8 : the Abbe number of said eighth lens component of said second lens group.

Claim 58

The wide angle zoom lens according to claim 53, wherein said second lens component, said third lens component and said fourth lens component are constructed to satisfy the following conditions for correcting spherical aberration: 1.75<n.sub.L2 0.05<n.sub.L3n -n.sub.L3p 0.2<n.sub.L4n -n.sub.L4p where n L2 : the refractive index of said second lens component, n L3n : the refractive index of said negative lens of said third lens component, n L3p : the refractive index of said positive lens of said third lens component, n L4n : the refractive index of said negative lens of said fourth lens component, n L4p : the refractive index of said positive lens of said fourth lens component.

Claim 59

The wide angle zoom lens according to claim 53, wherein said third lens component and said fourth lens component are constructed to satisfy the following conditions for correcting chromatic aberration: -2<ν.sub.L3p -ν.sub.L3n <13 15<ν.sub.L4p -ν.sub.L4n <30 where ν L3p : the Abbe number of said positive lens of said third lens component, ν L3n : the Abbe number of said negative lens of said third lens component, ν L4p : the Abbe number of said positive lens of said fourth lens component, ν L4n : the Abbe number of said negative lens of said fourth lens component.

Claim 60

The wide angle zoom lens according to claim 53, wherein said third lens component of said first lens group and said seventh lens component of said second lens group are constructed to satisfy the following conditions: -3<q.sub.L3 <-0.5 1<q.sub.L7 <3 where q L3 , q L7 are the shape factors, and a shape factor q Li of the i-th lens component is defined as follows: q.sub.Li =(r.sub.b +r.sub.a)/(r.sub.b -r.sub.a) where r a is the closest-to-object radius of curvature of said i-th lens component, and r b is the closest-to-image radius of curvature thereof.

Claim 61

The wide angle zoom lens according to claim 50, which is structured based on the following Table: ______________________________________ f = 30.8˜78.5, F.sub.NO = 4.1˜10.4, 2ω = 69.0˜31.0 ° ______________________________________ r d ν n ______________________________________ 1 21.856 3.00 69.9 1.51860 2 56.752 2.10 3 -21.710 1.60 47.5 1.78797 4 131.049 2.00 5 -57.967 1.10 49.4 1.77279 6 9.708 4.10 48.1 1.71700 7 -28.234 0.20 8 23.603 4.00 53.5 1.54739 9 -10.646 1.10 28.6 1.79504 10 -17.746 1.86 11 -99.987 1.10 58.5 1.61272 12 -46.043 (d12) 13 -67.661 3.30 35.2 1.74950 14 -16.203 0.80 15 -17.198 1.20 39.8 1.86994 16 -386.612 6.10 17 -11.367 1.20 60.1 1.62041 18 -27.021 (B.f) ______________________________________ F 30.7992 50.0017 78.5023 d12 11.8781 5.2081 1.3241 B.f 3.7924 21.9161 48.8154 ______________________________________ wherein the numbers at the left end indicate the order from the object, the symbols r, d, ν, n sequentially indicate the radius of curvature, the lens-surface spacing, the Abbe number and the refractive index in d-line (λ=587.6 nm), 2ω is the view angle, f is the focal length of the entire system, and F NO is the F number.

Claim 62

The wide angle zoom lens according to claim 50, which is structured based on the following Table: ______________________________________ f = 33.0˜82.5, F.sub.NO = 4.5˜11.2, 2ω = 66.2˜29.6 ° ______________________________________ r d ν n ______________________________________ 1 21.960 2.50 69.9 1.51860 2 56.121 1.80 3 -19.191 1.60 47.5 1.78797 4 212.707 2.00 5 -47.795 1.10 49.4 1.77279 6 12.353 3.20 48.1 1.71700 7 -23.658 0.20 8 24.957 3.60 59.7 1.53996 9 -9.916 1.10 33.9 1.80384 10 -16.667 1.98 11 -79.944 1.10 49.0 1.53172 12 -38.463 (d12) 13 -54.569 3.30 35.2 1.74950 14 -16.852 1.20 15 -17.724 1.00 39.8 1.86994 16 -279.144 5.70 17 -11.679 1.20 60.1 1.62041 18 -26.800 (B.f) ______________________________________ f 32.9592 50.0023 82.4608 d12 11.1361 5.6081 1.4001 B.f 5.8951 22.0404 52.7890 ______________________________________ wherein the numbers t the left end indicate the order from the object, the symbols r, d, ν, n sequentially indicate the radius of curvature, the lens-surface spacing, the Abbe number and the refractive index in d-line (λ=587.6 nm), 2ω is the view angle, f is the focal length of the entire system, and F NO is the F number.