Zoom lens system

Claim 2

A zoom lens system comprising, from the object to the image side: a front lens group; a zooming lens group including at least a movable lens group; and a rear lens group including a fixed lens unit and a variable aperture stop located within the fixed lens unit towards the object side and a focusing lens unit movable on the image side of the fixed lens unit, wherein the lens system fulfills the following condition: ##EQU4## wherein: f F represents the focal length of the focusing lens unit in the rear lens group; f III represents the focal length of the whole rear lens group upon infinity focusing; and γ represents the zoom ratio of the zoom lens system.

Claim 3

The invention of claim 1, wherein the focusing lens unit is of a positive refractive power and movable from the image side to the object side upon focusing from the infinity toward the closer object distance.

Claim 4

The invention of claim 2, wherein the focusing lens unit includes at least a positive lens with the stronger refractive surface facing the object side.

Claim 5

The invention of claim 3, wherein the zooming lens unit consists of a variator lens unit and a compensator lens unit moving in different speeds from each other.

Claim 6

The invention of claim 1, wherein the focusing lens unit is of a negative refractive power and movable from the object to the image side upon focusing from the infinity toward the closer object distance.

Claim 7

The invention of claim 5, wherein the focusing lens unit includes at least a negative lens with the stronger refractive surface facing the image side.

Claim 8

The invention of claim 6, wherein the zooming lens unit consists of a variator lens group and a compensator lens unit moving in different speeds from each other.

Claim 9

The invention of claim 1, wherein the aperture stop is located between lens elements of the fixed lens unit.

Claim 10

The invention of claim 1, wherein the fixed lens unit is led by the aperture stop.

Claim 11

The invention of claim 1, wherein the focusing lens unit is of a lightweight and simple construction.

Claim 12

The invention of claim 1, wherein the focusing lens unit is movable in a portion of the rear lens group inclining towards the image side.

Claim 13

The invention of claim 1, wherein the front lens group is of a positive refractive power.

Claim 14

The invention of claim 1, wherein the zooming lens unit consists of a variator lens group of a negative refractive power and a compensator lens unit of a negative refractive power.

Claim 15

The invention of claim 1, wherein the zooming lens group consists of a variator lens group of a negative refractive power and a compensator lens group of a positive refractive power.

Claim 16

The invention of claim 1, wherein the front lens group is fixed.

Claim 17

The invention of claim 1 wherein the rear lens group includes a second fixed lens unit on the image side of the focusing lens unit.

Claim 18

A zoom lens system comprising the following construction data, wherein F represents a movable focusing lens group: __________________________________________________________________________ Radius of Axial Refractive Abbe Curvature Distance Index Number __________________________________________________________________________ r.sub.1 95.563 d.sub.1 4.300 N.sub.1 1.51823 ν.sub.1 58.96 r.sub.2 720.269 d.sub.2 0.120 I 105.410 d.sub.3 1.680 N.sub.2 1.75450 ν.sub.2 32.83 r.sub.4 45.765 d.sub.4 7.770 N.sub.3 1.61272 ν.sub.3 58.52 r.sub.5 1470.976 d.sub.5 42.916˜26.280˜5.050 r.sub.6 115.780 d.sub.6 1.200 N.sub.4 1.72000 ν.sub.4 50.31 r.sub.7 41.103 d.sub.7 5.623 r.sub.8 -45.187 d.sub.8 1.500 N.sub.5 1.60000 ν.sub.5 64.38 II r.sub.9 42.526 d.sub.9 3.200 N.sub.6 1.78472 ν.sub.6 25.70 r.sub.10 220.131 d.sub.10 4.213˜14.273˜39.536 r.sub.11 -123.721 d.sub.11 1.500 N.sub.7 1.67000 ν.sub.7 57.07 r.sub.12 843.056 d.sub.12 1.459˜8.035˜4.002 r.sub.13 223.538 d.sub.13 2.800 N.sub.8 1.74000 ν.sub.8 28.26 r.sub.14 -58.573 d.sub.14 0.120 r.sub.15 62.726 d.sub.15 3.300 N.sub.9 1.51763 ν.sub.9 53.47 r.sub.16 -65.386 d.sub.16 1.950 N.sub.10 1.80518 ν.sub.10 25.43 r.sub.17 290.458 d.sub.17 2.800 (Aperture stop) r.sub.18 40.612 d.sub.18 5.828 N.sub.11 1.48749 ν.sub.11 70.15 r.sub.19 -55.165 d.sub.19 1.523 N.sub.12 1.72342 ν.sub.12 37.99 r.sub.20 44.160 III d.sub.20 0.351 r.sub.21 41.659 d.sub.21 3.990 N.sub.13 1.48749 ν.sub.13 70.15 r.sub.22 -111.200 d.sub.22 25.960 r.sub.23 98.244 d.sub.23 2.500 N.sub.14 1.78472 ν.sub.14 25.75 r.sub.24 -1153.801 d.sub.24 1.500 N.sub.15 1.51680 ν.sub.15 64.12 r.sub.25 26.452 d.sub.25 22.000 r.sub.26 45.668 d.sub.26 4.000 N.sub.16 1.72000 ν.sub.16 50.31 F r.sub.27 2749.518 d.sub.27 1.000 N.sub.17 1.71736 ν.sub.17 29.42 r.sub.28 88.147 __________________________________________________________________________

Claim 19

A zoom lens system comprising the following construction data, wherein F represents a movable focusing lens group: __________________________________________________________________________ Radius of Axial Refractive Abbe Curvature Distance Index Number __________________________________________________________________________ r.sub.1 95.563 d.sub.1 4.300 N.sub.1 1.51823 ν.sub.1 58.96 r.sub.2 720.269 d.sub.2 0.120 I 105.410 d.sub.3 1.680 N.sub.2 1.75450 ν.sub.2 32.83 r.sub.4 45.765 d.sub.4 7.770 N.sub.3 1.61272 ν.sub.3 58.52 r.sub.5 1470.976 d.sub.5 42.916˜26.280˜5.050 r.sub.6 115.780 d.sub.6 1.200 N.sub.4 1.72000 ν.sub.4 50.31 r.sub.7 41.103 d.sub.7 5.623 r.sub.8 -45.187 d.sub.8 1.500 N.sub.5 1.60000 ν.sub.5 64.38 II r.sub.9 42.526 d.sub.9 3.200 N.sub.6 1.78472 ν.sub.6 25.70 r.sub.10 220.131 d.sub.10 4.213˜14.273˜39.536 r.sub.11 -123.721 d.sub.11 1.500 N.sub.7 1.67000 ν.sub.7 57.07 r.sub.12 843.056 d.sub.12 1.459˜8.035˜4.002 r.sub.13 223.538 d.sub.13 2.800 N.sub.8 1.74000 ν.sub.8 28.26 r.sub.14 -58.573 d.sub.14 0.120 r.sub.15 62.726 d.sub.15 3.300 N.sub.9 1.51763 ν.sub.9 53.47 r.sub.16 -65.386 d.sub.16 1.950 N.sub.10 1.80518 ν.sub.10 25.43 r.sub.17 290.458 d.sub.17 2.800 (Aperture stop) r.sub.18 40.612 d.sub.18 5.828 N.sub.11 1.48749 ν.sub.11 70.15 r.sub.19 -55.165 d.sub.19 1.523 N.sub.12 1.72342 ν.sub.12 37.99 r.sub.20 44.160 III d.sub.20 0.351 r.sub.21 41.659 d.sub.21 3.990 N.sub.13 1.48749 ν.sub.13 70.15 r.sub.22 -111.200 d.sub.22 25.960 r.sub.23 98.244 d.sub.23 2.500 N.sub.14 1.78472 ν.sub.14 25.75 r.sub.24 -1153.801 d.sub.24 1.500 N.sub.15 1.51680 ν.sub.15 64.12 r.sub.25 26.452 d.sub.25 22.000 r.sub.26 45.668 d.sub.26 4.000 N.sub.16 1.72000 ν.sub.16 50.31 F r.sub.27 2749.518 d.sub.27 1.000 N.sub.17 1.71736 ν.sub.17 29.42 r.sub.28 88.147 __________________________________________________________________________

Claim 20

A zoom lens system comprising, from the object to the image side: a front lens group; a zooming lens group including at least a movable variator lens unit and a compensator lens unit; and a rear lens group consisting of a fixed lens unit with a variable aperture stop included therein and a movable focusing lens unit, for focusing the zoom lens system from infinity to a close distance, on the image side of the aperture stop, wherein the lens system fulfills the following condition: ##EQU5## wherein: f F represents the focal length of the focusing lens unit in the rear lens group; f III represents the focal length of the whole rear lens group upon infinity focusing; and γ represents the zoom ratio of the zoom lens system.

Claim 21

A zoom lens system comprising, from the object to the image side: a front lens group; a zooming lens group including at least a movable variator lens unit and a compensator lens unit; and a rear lens group consisting of a fixed lens unit with a variable aperture stop included therein and a movable focusing lens unit, for focusing the zoom lens system from infinity to a close distance, on the image side of the aperture stop, wherein the lens system fulfills the following condition: ##EQU5## wherein: f F represents the focal length of the focusing lens unit in the rear lens group; f III represents the focal length of the whole rear lens group upon infinity focusing; and γ represents the zoom ratio of the zoom lens system.

Claim 22

A zoom lens system comprising, from the object to the image side: a front lens group; a zooming lens group including at least a movable lens group; and a rear lens group including a fixed lens unit and a variable aperture stop fixed with the fixed lens unit in an object side portion of the rear lens group and a focusing lens unit movable on the image side of the fixed lens unit and the aperture stop, wherein the lens system fulfills the following condition: ##EQU6## wherein: f F represents the focal length of the focusing lens unit in the rear lens group; f III represents the focal length of the whole rear lens group upon infinity focusing; and γ represents the zoom ratio of the zoom lens system.

Claim 23

A zoom lens system comprising, from the object to the image side: a front lens group; a zooming lens group including at least a movable lens group; and a rear lens group including a fixed lens unit and a variable aperture stop fixed with the fixed lens unit in an object side portion of the rear lens group and a focusing lens unit movable on the image side of the fixed lens unit and the aperture stop, wherein the lens system fulfills the following condition: ##EQU6## wherein: f F represents the focal length of the focusing lens unit in the rear lens group; f III represents the focal length of the whole rear lens group upon infinity focusing; and γ represents the zoom ratio of the zoom lens system.