Autofocusing zoom lens

Claim 2

A zoom lens comprising from the object end, a first positive stationary group, a second variator group of negative power, manual means for axially moving said second group to vary the equivalent focal length of said lens, a third compensator group, and a fourth positive objective lens group, a prism for reflecting a portion of the light passing through said zoom lens, an automatic focus detector responsive to reflected light from said prism, a motor for moving said compensator group axially of said lens, said automatic focus detector being effective to operate said motor to move said compensator group axially of said lens to maintain the image created by said lens at the focal plane of the lens, said compensator group having a movement of a distance d between a first position corresponding to the longest equivalent focal length of the lens where the lens is focused at infinity, and a second position corresponding to an equivalent focal length of the lens where the lens is focused at the closest focusing position, in which d<mF where m is the magnification of the lens at its closest focusing position and F is the longest equivalent focal length of the lens.

Claim 3

The lens of claim 1 where said compensator group is of positive power.

Claim 4

The zoom lens of claim 1 where said fourth group comprises two widely air spaced sub groups and said prism is positioned between said subgroups.

Claim 5

A lens according to claim 1 scaled to an image frame of 24×36 mm defined substantially as follows: __________________________________________________________________________ SURFACE AXIAL DISTANCE LENS RADII (mm) BETWEEN SURFACES (mm) N.sub.D V.sub.D __________________________________________________________________________ S1 89.600 L1 3.00 1.805 25.46 S2 58.300 L2 9.000 1.487 70.44 S3 -1215.000 0.200 S4 92.200 L3 6.000 1.487 70.44 S5 -1215.000 Z1 S6 820.500 L4 1.500 1.697 55.46 S7 44.682 5.400 S8 -51.997 L5 1.500 1.697 55.46 S9 42.087 L6 5.300 1.785 25.70 S10 2199.200 Z2 S11 138.690 L7 7.500 1.518 58.96 S12 -37.060 L8 1.200 1.805 25.46 S13 -60.172 Z3 S14 35.135 L9 6.400 1.518 58.96 S15 233.400 0.100 S16 41.157 L10 6.000 1.487 70.39 S17 -250.000 L11 1.500 1.806 40.74 S18 58.684 4.810 APERTURE 10.403 S19 PLANO PRISM 13.200 1.517 64.20 S20 PLANO 19.500 S21 -19.100 L12 1.800 1.773 49.63 S22 -37.300 0.200 S23 74.114 L13 3.500 1.581 40.89 S24 -305.000 __________________________________________________________________________ ZOOM SPACING DATA EFL M Z1 Z2 Z3 __________________________________________________________________________ 81.844 mm 0.0 1.982 mm 34.637 mm 14.504 mm 136.996 0.0 24.045 19.142 7.936 195.092 0.0 34.510 1.520 15.092 143.157 -0.1 34.510 15.342 1.270 __________________________________________________________________________ BFL = 40.0 mm F/N = 3.5 where the lens comprises elements L1-L13 from the object end, the lens surfaces are designated S1-S24 from the object end, N d is the index of refraction of the lens elements, and V d is the dispersion of the lens elements as expressed by the Abbe number of the lens.

Claim 6

A lens according to claim 1 scaled to an image frame of 24×36 mm defined substantially as follows: __________________________________________________________________________ SURFACE AXIAL DISTANCE RADII (mm) BETWEEN SURFACES (mm) N.sub.D V.sub.D __________________________________________________________________________ S1 91.632 L1 3.000 1.785 26.06 S2 54.537 L2 7.340 1.517 64.20 S3 4989.260 0.300 S4 94.866 L3 5.150 1.517 64.20 S5 -570.634 Z1 S6 599.211 L4 1.500 1.806 40.65 S7 69.969 3.100 S8 -66.080 L5 1.500 1.697 55.47 S9 26.680 L6 4.510 1.785 25.71 S10 83.175 Z2 S11 76.458 L7 6.700 1.487 70.39 S12 -32.500 L8 1.200 1.785 26.06 S13 -53.748 Z3 S14 29.548 L9 6.100 1.522 59.46 S15 -80.198 L10 1.500 1.743 49.21 S16 233.381 4.810 APERTURE 2.000 S17 PLANO PRISM 22.000 1.517 64.20 S18 PLANO 18.994 S19 -17.538 L11 1.600 1.743 49.21 S20 -51.056 0.300 S21 143.799 L12 3.400 1.517 52.1 S22 -58.905 __________________________________________________________________________ ZOOM SPACING DATA EFL M Z1 Z2 Z3 __________________________________________________________________________ 82.015 mm 0.0 1.730 mm 33.756 mm 15.511 mm 135.020 0.0 23.684 18.312 9.000 195.001 0.0 33.516 1.480 16.000 136.674 -0.1 33.516 15.280 2.200 __________________________________________________________________________ BFL = 39.0 mm F/N = 4.5 where the lens comprises elements L1-L12 from the object end, the lens surfaces are designated S1-S22 from the object end, N d is the index of refraction of the lens elements, and V d is the dispersion of the lens elements as expressed by the Abbe number of the lens.

Claim 7

A zoom lens comprising from the object end a first positive group, a second negative group, a third positive group, a fourth compensator group, and a fifth rear group, said first and third groups being movable in fixed relation to vary the equivalent focal length of said lens while said second group remains stationary, manual means for axially moving said first and third groups, a prism in said fifth group for reflecting a portion of the light passing through said zoom lens, a motor operatively connected to said compensator group for moving said compensator group axially of said lens, an automatic focus detector responsive to light reflected by said prism, said automatic focus detector being effective to operate said motor to move said compensator group axially of said lens to maintain an image created by said lens at the focal plane of said lens, said compensator group having a movement of a distance d between a first position corresponding to the longest equivalent focal length of the lens where the lens is focused at infinity, and a second position corresponding to an equivalent focal length of the lens where the lens is focused at the closest focusing position, in which d<mF where m is the magnification of the lens at its closest focusing position and F is the longest equivalent focal length of the lens.

Claim 8

A zoom lens comprising from the object end a first positive group, a second negative group, a third positive group, a fourth compensator group, and a fifth rear group, said first and third groups being movable in fixed relation to vary the equivalent focal length of said lens while said second group remains stationary, manual means for axially moving said first and third groups, a prism in said fifth group for reflecting a portion of the light passing through said zoom lens, a motor operatively connected to said compensator group for moving said compensator group axially of said lens, an automatic focus detector responsive to light reflected by said prism, said automatic focus detector being effective to operate said motor to move said compensator group axially of said lens to maintain an image created by said lens at the focal plane of said lens, said compensator group having a movement of a distance d between a first position corresponding to the longest equivalent focal length of the lens where the lens is focused at infinity, and a second position corresponding to an equivalent focal length of the lens where the lens is focused at the closest focusing position, in which d<mF where m is the magnification of the lens at its closest focusing position and F is the longest equivalent focal length of the lens.

Claim 9

The lens of claim 6 where said compensator group is of positive power.

Claim 10

The zoom lens of claim 6 where said fifth group comprises two widely air spaced rub groups and said prism is positioned between said subgroups.

Claim 11

A lens according to claim 6 scaled to an image frame of 24×36 mm defined substantially as follows: __________________________________________________________________________ SURFACE AXIAL DISTANCE RADII (mm) BETWEEN SURFACES (mm) N.sub.D V.sub.D __________________________________________________________________________ S1 72.323 L1 3.000 1.784 26.06 S2 51.619 L2 9.000 1.517 64.20 S3 -360.772 Z1 S4 -137.086 L3 1.500 1.720 50.34 S5 1440.597 3.500 S6 -77.924 L4 1.500 1.699 53.9 S7 37.610 L5 4.510 1.785 25.70 S8 109.887 Z2 S9 517.353 L6 4.000 1.483 70.2 S10 -122.307 0.200 S11 130.331 L7 9.000 1.654 60.2 S12 -42.523 L8 1.200 1.784 26.02 S13 -82.613 Z3 S14 40.021 L9 5.000 1.583 54.9 S15 -115.999 L10 1.300 1.723 37.99 S16 265.106 Z4 S17 77.423 L11 4.800 1.788 26.3 S18 209.204 1.300 S19 -942.720 L12 3.000 1.834 37.34 S20 30.954 5.800 S21 PLANO PRISM 22.000 1.519 64.20 S22 PLANO 4.147 S23 -25.682 L13 1.600 1.640 60.15 S24 -31.854 0.200 S25 -77.583 L14 3.800 1.673 32.17 S26 -44.208 __________________________________________________________________________ ZOOM SPACING DATA EFL Z1 Z2 Z3 Z4 M FVD __________________________________________________________________________ 82.132 mm 1.059 mm 38.246 mm 1.454 mm 11.010 mm 0.0 181.2 mm 135.057 20.702 18.602 23.533 8.588 0.0 200.8 194.803 34.461 4.843 41.057 4.824 0.0 214.4 167.972 34.461 4.843 35.815 10.068 -0.1 214.4 __________________________________________________________________________ BFL [-] = 39.0 mm F/N = 4.0 where the lens comprises elements L1-L15 from the object end, the lens surfaces are designated S1-S27 from the object end, N d is the index of refraction of the lens elements, and V d is the dispersion of the lens elements as expressed by the Abbe number of the lens.

Claim 12

A zoom lens of the type where one or more variator lens groups move to vary the equivalent focal length of said lens and a compensator lens group moves to compensate for change in the position of the focal plane of the lens with change in equivalent focal length, each of said variator and compensator lens groups having a mount therefor, a plurality of guide rods mounted longitudinally in said lens, said variator and compensator lens groups mounts slidably mounted to said rods, said mount for said compensator lens group having a threaded connection to one of said rods whereby upon rotation of said one of said rods said compensator lens group moves axially of said lens, said zoom lens including a prism and an automatic focus detecting system, said prism reflecting a portion of the light passing through said zoom lens, said automatic focus detector being responsive to light from said prism, a motor operative to rotate said one rod, said automatic focus detector being effective to operate said motor too move said compensator lens group on said rods axially of said lens to maintain an image created by said lens in focus at the focal plane of said lens as said one or more variator lens groups are moved to vary the equivalent focal length of said lens, and means for moving said one or more variator lens groups, said compensator lens group having a movement of a distance d between a first position corresponding to the longest equivalent focal length of the lens where the lens is focused at infinity, and a second position corresponding to an equivalent focal length of the lens where the lens is focused at the closest focusing position, in which d<mF where m is the magnification of the lens at its closest focusing position and F is the longest equivalent focal length of the lens.

Claim 13

A zoom lens of the type where one or more variator lens groups move to vary the equivalent focal length of said lens and a compensator lens group moves to compensate for change in the position of the focal plane of the lens with change in equivalent focal length, each of said variator and compensator lens groups having a mount therefor, a plurality of guide rods mounted longitudinally in said lens, said variator and compensator lens groups mounts slidably mounted to said rods, said mount for said compensator lens group having a threaded connection to one of said rods whereby upon rotation of said one of said rods said compensator lens group moves axially of said lens, said zoom lens including a prism and an automatic focus detecting system, said prism reflecting a portion of the light passing through said zoom lens, said automatic focus detector being responsive to light from said prism, a motor operative to rotate said one rod, said automatic focus detector being effective to operate said motor too move said compensator lens group on said rods axially of said lens to maintain an image created by said lens in focus at the focal plane of said lens as said one or more variator lens groups are moved to vary the equivalent focal length of said lens, and means for moving said one or more variator lens groups, said compensator lens group having a movement of a distance d between a first position corresponding to the longest equivalent focal length of the lens where the lens is focused at infinity, and a second position corresponding to an equivalent focal length of the lens where the lens is focused at the closest focusing position, in which d<mF where m is the magnification of the lens at its closest focusing position and F is the longest equivalent focal length of the lens.