Gas zoom lens

Claim 2

A gas zoom lens system consisting essentially of a first lens group and a second lens group, each group consisting of two elements, the first lens group consisting, from the front to the rear, a first positive meniscus element convex to the front and a second negative meniscus element convex to the front, said second group consisting from the front to the rear, a first negative meniscus element concave to the front and a second positive meniscus element concave to the front, said second element of said first group and said first element of said second group defining, between their opposed surfaces, a cavity filled with a gas having a characteristic index of refraction, said lens system further including means to vary the pressure of said gas thereby causing a corresponding variation in the focal length of the system.

Claim 3

A gas zoom lens system made substantially according to the following specifications: ______________________________________ Lens Radius Thickness Spacing n.sub.d v ______________________________________ S.sub.1 = 269.55 A R.sub.1 = 27.0104 t.sub.1 = 9.79 1.487 70.41 R.sub.2 = 53.2409 S.sub.2 = 1.59 B R.sub.3 = 21.3087 t.sub.2 = 4.0 1.755 27.58 R.sub.4 = 15.5397 S.sub.3 = 25.93 Gas C R.sub.5 = -26.8834 t.sub.3 = 4.0 1.755 27.58 R.sub.6 = -35.1491 S.sub.4 = 1.68 D R.sub.7 = -60.3301 t.sub.4 = 10.98 1.487 70.41 R.sub.8 = -29.0170 S.sub.5 = 264.41 ______________________________________ Note All dimensions being in millimeters, positive radius indicating center of curvature is to right, negative radius indicating center of curvature is to left.

Claim 4

A gas zoom lens system made substantially according to the following specifications: ______________________________________ Lens Radius Thickness Spacing n.sub.d v ______________________________________ S.sub.1 = 269.55 A R.sub.1 = 27.0104 t.sub.1 = 9.79 1.487 70.41 R.sub.2 = 53.2409 S.sub.2 = 1.59 B R.sub.3 = 21.3087 t.sub.2 = 4.0 1.755 27.58 R.sub.4 = 15.5397 S.sub.3 = 25.93 Gas C R.sub.5 = -26.8834 t.sub.3 = 4.0 1.755 27.58 R.sub.6 = -35.1491 S.sub.4 = 1.68 D R.sub.7 = -60.3301 t.sub.4 = 10.98 1.487 70.41 R.sub.8 = -29.0170 S.sub.5 = 264.41 ______________________________________ Note All dimensions being in millimeters, positive radius indicating center of curvature is to right, negative radius indicating center of curvature is to left.

Claim 5

A gas zoom lens system consisting essentially of a first, and second lens group, the first lens group consisting, from the front to the rear of a first negative meniscus element convex to the front, a first doublet element comprising a double convex element cemented to a negative meniscus element, a third negative meniscus element convex to the front, said second group consisting, from the front to the rear, of a first negative meniscus element concave to the front, a first doublet comprising a positive meniscus element cemented to a second negative meniscus element both elements concave to the front and a thick positive meniscus element having a substantially flat front surface, said second negative meniscus element of said first group and said first negative meniscus element of said second group defining, between their opposed surfaces, a cavity filled with a gas having a characteristic index of refraction, said lens system further including means to vary the pressure of said gas thereby causing a corresponding variation in the focal length of the system.

Claim 6

A gas zoom lens system consisting essentially of a first, and second lens group, the first lens group consisting, from the front to the rear of a first negative meniscus element convex to the front, a first doublet element comprising a double convex element cemented to a negative meniscus element, a third negative meniscus element convex to the front, said second group consisting, from the front to the rear, of a first negative meniscus element concave to the front, a first doublet comprising a positive meniscus element cemented to a second negative meniscus element both elements concave to the front and a thick positive meniscus element having a substantially flat front surface, said second negative meniscus element of said first group and said first negative meniscus element of said second group defining, between their opposed surfaces, a cavity filled with a gas having a characteristic index of refraction, said lens system further including means to vary the pressure of said gas thereby causing a corresponding variation in the focal length of the system.

Claim 7

A gas zoom lens system made substantially according to the following specification: __________________________________________________________________________ Lens Radius Thickness Spacing n.sub. d v __________________________________________________________________________ S.sub.1 = 379.18 A R.sub.1 = 187.3280 t.sub.1 = 8.40 1.651 55.8 R.sub.2 = 78.6647 S.sub.2 = 31.8409 B-C R.sub.3 = 68.7752 Doublet t.sub.2 = 11.28 1.651 55.8 R.sub.4 = -147.8520 t.sub.3 = 7.20 1.526 51.0 R.sub.5 = 385.7787 S.sub.3 = .5 D R.sub.6 = 35.0314 t.sub.4 = 6.480 1.633 57.7 R.sub.7 = 30.6058 S.sub.4 = 25.941 Gas E R.sub.8 = -70.4804 t.sub.5 = 6.4800 1.746 27.9 R.sub.9 = 1518.4936 S.sub.5 = 4.4984 F-G R.sub.10 = -4192.0727 Doublet t.sub.6 = 7.20 1.591 39.7 R.sub.11 = -25.5272 t.sub.7 = 11.680 1.645 37.0 R.sub.12 = -67.6515 S.sub.6 = 0.500 H R.sub.13 = -2415.7485 t.sub.8 = 8.4 1.651 55.8 R.sub.14 = -294.0486 S.sub.7 = 451.1833 __________________________________________________________________________ Note: All dimensions being in millimeters, positive radius indicating center of curvature is to right, negative radius indicating center of curvature is to left.

Claim 8

A gas zoom lens system made substantially according to the following specification: __________________________________________________________________________ Lens Radius Thickness Spacing n.sub. d v __________________________________________________________________________ S.sub.1 = 379.18 A R.sub.1 = 187.3280 t.sub.1 = 8.40 1.651 55.8 R.sub.2 = 78.6647 S.sub.2 = 31.8409 B-C R.sub.3 = 68.7752 Doublet t.sub.2 = 11.28 1.651 55.8 R.sub.4 = -147.8520 t.sub.3 = 7.20 1.526 51.0 R.sub.5 = 385.7787 S.sub.3 = .5 D R.sub.6 = 35.0314 t.sub.4 = 6.480 1.633 57.7 R.sub.7 = 30.6058 S.sub.4 = 25.941 Gas E R.sub.8 = -70.4804 t.sub.5 = 6.4800 1.746 27.9 R.sub.9 = 1518.4936 S.sub.5 = 4.4984 F-G R.sub.10 = -4192.0727 Doublet t.sub.6 = 7.20 1.591 39.7 R.sub.11 = -25.5272 t.sub.7 = 11.680 1.645 37.0 R.sub.12 = -67.6515 S.sub.6 = 0.500 H R.sub.13 = -2415.7485 t.sub.8 = 8.4 1.651 55.8 R.sub.14 = -294.0486 S.sub.7 = 451.1833 __________________________________________________________________________ Note: All dimensions being in millimeters, positive radius indicating center of curvature is to right, negative radius indicating center of curvature is to left.