Zoom lens including a wide angle of view

Claim 2

A zoom lens including a wide angle of view and having a wide magnification change area, said zoom lens having, in succession from the object side, a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power and a fourth lens group of positive refractive power and wherein when zooming is to be effected from the wide angle end to the telephoto end, said first lens group and said fourth lens group are monotonously moved toward the object side and at the same time, said third lens group is monotonously moved toward the object side by an amount of movement 0.4-0.8 as great as the amount of movement of said first and fourth lens groups and said second lens group is moved toward the object side in the vicinity of at least the wide angle end, said zoom lens satisfying the following condition:

Claim 3

5<f 1 /-f 2 <6.5 where f 1 is the focal length of said first lens group and f 2 is the focal length of said second lens group.

Claim 4

5<f 1 /-f 2 <6.5 where f 1 is the focal length of said first lens group and f 2 is the focal length of said second lens group.

Claim 5

A zoom lens according to claim 1, wherein numerical data are as follows: __________________________________________________________________________ Focal length f = 35˜200 Zoom ratio 5.7 F-number 3.5˜4.5 Image height y = 21.6 __________________________________________________________________________ Radius of Center thickness Refractive Abbe curvature and air space index number __________________________________________________________________________ r1 219.97 d1 1.3 n1 1.805 ν1 25.4 L.sub.1 r2 69.27 d2 8.0 n2 1.498 ν2 82.3 G.sub.1 r3 -129.41 d3 0.1 r4 50.60 d4 4.0 n3 1.797 ν3 45.5 L.sub.2 r5 129.98 d5 (variable) r6 121.12 d6 1.3 n4 1.903 ν4 35.8 L.sub.3 r7 23.54 d7 2.8 r8 301.35 d8 4.2 n5 1.861 ν5 23.0 L.sub.4 r9 -28.77 d9 1.1 n6 1.877 ν6 38.1 G.sub.2 r10 189.86 d10 2.7 r11 -25.19 d11 1.0 n7 1.713 ν7 54.0 L.sub.5 r12 32.36 d12 2.8 n8 1.861 ν8 23.0 r13 682.84 d13 (variable) r14 -260.75 d14 3.3 n9 1.517 ν9 64.1 L.sub.6 r15 -41.85 d15 0.1 r16 37.74 d16 4.5 n10 1.519 ν10 70.1 L.sub.7 G.sub.3 r17 -59.29 d17 1.0 r18 -41.97 d18 1.0 n11 1.861 ν11 23.0 L.sub.8 r19 -93.35 d19 (variable) r20 74.81 d20 3.0 n12 1.517 ν12 64.1 L.sub.9 r21 -108.74 d21 0.1 r22 42.60 d22 3.9 n13 1.620 ν13 60.3 L.sub.10 r23 86.90 d23 7.0 r24 -103.53 d24 2.0 n14 1.796 ν14 41.0 L.sub.11 r25 37.43 d25 2.5 G.sub.4 r26 -253.20 d26 2.5 n15 1.517 ν15 64.1 L.sub.12 r27 -49.39 d27 0.1 r28 81.93 d28 6.5 n16 1.518 ν16 59.0 L.sub.13 r29 -23.95 d29 1.0 n17 1.788 ν17 47.5 r30 -45.57 Bf __________________________________________________________________________ f.sub.W = f.sub.M = 84.0 f.sub.T = 193.96 d5 2.30 21.71 36.79 d13 18.92 9.25 0.54 d19 19.11 9.37 3.00 Stop: ahead of L.sub.9 0.8 0.8 0.8 Back focal length: Bf 53.15 78.12 94.41 __________________________________________________________________________ where the values are shown in succession from the object side and the suffix numbers represent the order from the object side.

Claim 6

A zoom lens according to claim 1, wherein numerical data are as follows: __________________________________________________________________________ Focal length f = 35˜200 Zoom ratio 5.7 F-number 3.5˜4.5 Image height y = 21.6 __________________________________________________________________________ Radius of Center thickness Refractive Abbe curvature and air space index number __________________________________________________________________________ r1 158.9 d1 1.5 n1 1.805 ν1 25.4 L.sub.1 r2 64.1 d2 3.0 n2 1.498 ν2 82.3 G.sub.1 r3 -138.8 d3 0.1 r4 47.2 d4 4.3 n3 1.670 ν3 47.1 L.sub.2 r5 127.2 d5 (variable) r6 133.1 d6 1.3 n4 1.903 ν4 35.8 L.sub.3 r7 23.6 d7 2.9 r8 154.6 d8 4.2 n5 1.805 ν5 25.4 L.sub.4 r9 -32.5 d9 1.1 n6 1.804 ν6 46.4 G.sub.2 r10 117.2 d10 2.7 r11 -25.4 d11 1.0 n7 1.713 ν7 54.0 L.sub.5 r12 30.8 d12 2.8 n8 1.861 ν8 23.0 r13 483.9 d13 (variable) r14 -486.8 d14 3.3 n9 1.517 ν9 64.1 L.sub.6 r15 -39.4 d15 0.1 r16 36.2 d16 4.5 n10 1.519 ν10 70.1 L.sub.7 G.sub.3 r17 -84.7 d17 0.8 r18 -47.7 d18 1.0 n11 1.861 ν11 23.0 L.sub.8 r19 -121.8 d19 (variable) r20 72.5 d20 3.0 n12 1.517 ν12 64.1 L.sub.9 r21 -115.7 d21 0.1 r22 46.8 d22 3.9 n13 1.620 ν13 60.3 L.sub.10 r23 107.7 d23 7.0 r24 -89.7 d24 2.0 n14 1.796 ν14 41.0 L.sub.11 r25 37.6 d25 2.5 G.sub.4 r26 -298.2 d26 2.5 n15 1.567 ν15 64.1 L.sub.12 r27 -47.4 d27 0.1 r28 93.5 d28 6.5 n16 1.518 ν16 60.3 L.sub.13 r29 -24.6 d29 1.3 n17 1.788 ν17 47.5 r30 -43.4 Bf __________________________________________________________________________ f.sub.W = 36.1 f.sub.M = 84.0 f.sub.T = 194.0 d5 1.27 20.68 35.76 d13 19.27 9.60 0.89 d19 17.34 7.60 1.23 Stop: ahead of L.sub.9 0.8 0.8 0.8 Back focal length: Bf 54.2 79.17 95.46 __________________________________________________________________________ where the values are shown in succession from the object side and the suffix numbers represent the order from the object side.

Claim 7

A zoom lens according to claim 1, wherein numerical data are as follows: __________________________________________________________________________ Focal length f = 35˜ 200 Zoom ratio 5.7 F-number 3.5˜4.5 Image height y = 21.6 __________________________________________________________________________ Radius of Center thickness Refractive Abbe curvature and air space index number __________________________________________________________________________ r1 268.4 d1 1.3 n1 1.805 ν1 25.4 L.sub.1 r2 69.1 d2 7.5 n2 1.498 ν2 82.3 G.sub.1 r3 -122.2 d3 0.1 r4 49.8 d4 3.6 n3 1.840 ν3 43.3 L.sub.2 r5 122.4 d5 (variable) r6 101.9 d6 0.9 n4 1.903 ν4 35.8 L.sub.3 r7 24.4 d7 3.4 r8 153.4 d8 4.4 n5 1.861 ν5 23.0 L.sub.4 G.sub.2 r9 -21.9 d9 0.9 n6 1.877 ν6 38.1 r10 88.3 d10 3.1 r11 -25.5 d11 0.9 n7 1.744 ν7 45.1 L.sub.5 r12 38.5 d12 3.7 n8 1.861 ν8 23.0 r13 -591.6 d13 (variable) r14 -4145.0 d14 3.8 n9 1.498 ν9 82.3 L.sub.6 r15 -40.1 d15 0.1 r16 36.3 d16 4.1 n10 1.498 ν10 82.3 L.sub.7 G.sub.3 r17 -114.4 d17 1.5 r18 -44.1 d18 1.0 n11 1.861 ν11 23.0 L.sub.8 r19 -80.9 d19 (variable) r20 119.0 d20 1.3 n12 1.767 ν12 46.8 L.sub.9 r21 37.3 d21 4.2 n13 1.517 ν13 64.1 r22 -79.6 d22 0.1 r23 36.9 d23 4.5 n14 1.620 ν14 60.3 L.sub.10 r24 0.0 d24 7.0 r25 -96.8 d25 1.0 n15 1.773 ν15 49.4 L.sub.11 G.sub.4 r26 34.9 d26 4.2 r27 -179.9 d27 3.4 n16 1.518 ν16 60.3 L.sub.12 r28 -41.3 d28 0.1 r29 66.8 d29 8.0 n17 1.518 ν17 58.9 L.sub.13 r30 -34.5 d30 1.0 n18 1.797 ν 18 45.5 r31 -103.5 Bf __________________________________________________________________________ f.sub.W = 36.1 f.sub.M = 84.0 f.sub.T = 194.0 d5 2.46 21.87 36.95 d13 18.37 8.70 -0.01 d19 19.08 9.34 2.97 Stop: ahead of L.sub.9 0.8 0.8 0.8 Back focal length: Bf 48.53 73.50 89.79 __________________________________________________________________________ where the values are shown in succession from the object side and the suffix numbers represent the order from the object side.

Claim 8

A zoom lens according to claim 1, wherein said first lens group has a positive first lens component comprising a negative meniscus lens and a biconvex positive lens cemented together, and a second lens component which is a positive meniscus lens having its convex surface facing the object side.

Claim 9

A zoom lens according to claim 5, satisfying the following condition: 80<ν.sub.2, where ν 2 is the Abbe number of the positive lens forming the cemented first lens component in said first lens group.

Claim 10

A zoom lens according to claim 1, wherein said second lens group has, in succession from the object side, a third lens component which is a negative meniscus lens having its convex surface facing the object side, a fourth lens component which is a cemented negative lens component, and a fifth lens component which is a negative lens comprising cemented lenses and having its surface of sharper curvature facing the object side.

Claim 11

A zoom lens according to claim 7, satisfying the following conditions: n.sub.5 >1.8 n.sub.6 >1.8, where n 5 and n 6 are the refractive indices of the positive lens and the negative lens, respectively, forming the fourth lens component as the cemented negative lens in said second lens group.

Claim 12

A zoom lens according to claim 1, wherein said third lens group has, in succession from the object side, a sixth lens component which is a positive lens having its surface of sharper curvature facing the image side, a seventh lens component which is a biconvex positive lens, and an eighth lens component which is a negative meniscus lens having its convex surface facing the image side.

Claim 13

A zoom lens according to claim 9, satisfying the following condition: -3.6<q.sub.6 <-0.5, where q 6 is the shape factor of the sixth lens component of said third lens group which is positioned most adjacent to the object side and the shape factor q is defined by ##EQU3## where ra and rb are the radii of curvature of the lens surfaces of that lens which are adjacent to the object side and the image side, respectively.

Claim 14

A zoom lens according to claim 1, wherein said fourth lens group has a ninth lens component which is a biconvex positive lens, a tenth lens component which is a positive lens having its surface of sharper curvature facing the object side, an eleventh lens component which is a biconcave lens having its surface of sharper curvature facing the image side, a twelfth lens component which is a positive lens having its surface of sharper curvature facing the image side, and a thirteenth lens component which is a positive lens comprising a biconvex positive lens and a negative meniscus lens having its convex surface facing the image side cemented together.

Claim 15

A zoom lens according to claim 11, satisfying the following conditions: 0.5<q.sub.10 <5 -1<q.sub.11 <0.0, where q 10 and q 11 are the shape factors of the tenth lens component and the eleventh lens component, respectively, in said fourth lens group and the shape factor q is defined by ##EQU4## where ra and rb are the radii of curvature of the lens surfaces of that lens which are adjacent to the object side and the image side, respectively.

Claim 16

A zoom lens including a wide angle of view, said zoom lens having, in succession from the object side, a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power and a fourth lens group of positive refractive power, said first, second and third lens groups together forming a substantially afocal system, characterized in that when the zoom lens is to be focused to a short distance object, said first lens group is moved toward the object side along the optic axis relative to the image plane and said second lens group and said third lens group are moved together toward the image side along the optic axis.

Claim 17

A zoom lens including a wide angle of view, said zoom lens having, in succession from the object side, a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power and a fourth lens group of positive refractive power, said first, second and third lens groups together forming a substantially afocal system, characterized in that when the zoom lens is to be focused to a short distance object, said first lens group is moved toward the object side along the optic axis relative to the image plane and said second lens group and said third lens group are moved together toward the image side along the optic axis.

Claim 18

A zoom lens according to claim 13, satisfying the following condition: 0.1 S≦ΔT≦0.35 S, where S is the amount of movement of said first lens group for focusing and ΔT is the amount of integral movement of said second lens group and said third lens group.

Claim 19

A zoom lens according to claim 14, wherein numerical data are as follows: TABLE 4 __________________________________________________________________________ Focal length f = 35˜105 Zoom ratio 3 F-number 3.5˜4.5 Image height y = 21.6 __________________________________________________________________________ Radius of Center thickness Refractive Abbe curvature and air space index number __________________________________________________________________________ r1 150.69 d1 1.3 n1 1.805 ν1 25.3 L.sub.1 r2 58.13 d2 0.4 r3 66.23 d3 6.2 n2 1.603 ν2 60.6 L.sub.2 G.sub.1 r4 -128.09 d4 0.1 r5 33.14 d5 3.9 n3 1.603 ν3 60.6 L.sub.3 r6 67.54 d6 (variable) r7 62.79 d7 1.0 n4 1.796 ν4 45.5 L.sub.4 r8 17.07 d8 3.0 r9 -213.87 d9 3.5 n5 1.805 ν5 25.3 L.sub.5 r10 -20.49 d10 1.0 n6 1.796 ν6 45.5 G.sub.2 r11 -194.15 d11 2.7 r12 -21.48 d12 1.0 n7 1.713 ν7 53.9 L.sub. 6 r13 17.23 d13 3.5 n8 1.796 ν8 40.9 r14 -696.58 d14 (variable) r15 122.05 d15 4.0 n9 1.713 ν9 53.9 L.sub.7 r16 -24.80 d16 0.4 r17 -21.54 d17 1.0 n10 1.805 ν10 25.3 L.sub.8 G.sub.3 r18 -38.91 d18 0.1 r19 35.07 d19 2.0 n11 1.568 ν11 56.0 L.sub.9 r20 72.08 d20 (variable) r21 21.96 d21 4.0 n12 1.563 ν12 60.8 L.sub.10 r22 34.58 d22 1.5 n13 1.796 ν13 45.5 r23 20.50 d23 2.0 r24 104.25 d24 4.0 n14 1.518 ν14 60.3 L.sub.11 G.sub.4 r25 -31.38 d25 0.1 r26 -95.95 d26 5.5 n15 1.563 ν15 60.8 L.sub.12 r27 -16.37 d27 1.4 n16 1.796 ν16 40.9 r28 -45.88 Bf __________________________________________________________________________ f.sub.W = 36.2 f.sub.M = 60 f.sub.T = 103 d6 0.98 10.62 19.77 d14 12.52 6.77 1.49 d20 10.84 6.96 3.08 Stop: ahead of L.sub.9 0.8 0.8 0.8 Back focal length: Bf 52.36 65.30 78.24 __________________________________________________________________________ where the values are shown in succession from the object side and the suffix numbers represent the order from the object side.