US 4,046,459 A · Retrofocus wide angle objective lens system

Abstract

A retrofocus wide angle objective lens system of seven air-spaced lenses, the first and second lenses, counting in the order of the entrant light beam, being negative meniscus lenses of forward convexity, the third lens being a positive lens, the fourth lens being a bi-convex lens, the fifth lens being a bi-concave lens, and the sixth and seventh lenses being positive lenses. The third and fourth lenses are separated by a large axial air space, and the third lens has a larger diameter than the fourth lens.

Claims8

Dependent claims

A retrofocus wide angle objective lens system comprising seven axially aligned lenses including, in the order of the entrant light beam:

negative meniscus first and second lenses of forward convexity;
a positive third lens;
a bi-convex fourth lens;
a bi-concave fifth lens;
and
positive sixth and seventh lenses;
and
wherein axial air space between said third lens and said fourth lens is larger than the axial thickness of said third lens, said third lens having a diameter larger than the fourth lens.

5 more elements

Dependencies are inferred from the claim text.

Abstract

Claims8

Dependent claims

A retrofocus wide angle objective lens system comprising seven axially aligned lenses including, in the order of the entrant light beam:

negative meniscus first and second lenses of forward convexity;
a positive third lens;
a bi-convex fourth lens;
a bi-concave fifth lens;
and
positive sixth and seventh lenses;
and
wherein axial air space between said third lens and said fourth lens is larger than the axial thickness of said third lens, said third lens having a diameter larger than the fourth lens.

5 more elements

Dependencies are inferred from the claim text.

Retrofocus wide angle objective lens system

Life of this patent

Abstract

Claims8

Retrofocus wide angle objective lens system

Life of this patent

Abstract

Claims8