Photographic lens system enabling reduction in tightness of manufacturing tolerance
AssigneeSekonix Co., Ltd.
InventorsSoon Chul Choi, Ki Youn Noh
Life of this patent
Estimating the term…
Abstract
A photographic lens system enabling reduction in tightness of manufacturing tolerance of lenses, which has five lenses: a first lens, a second lens, a third lens, a fourth lens and a fifth lens sequentially arranged along an optical axis from an object, wherein the first lens has strong positive refractivity, the second lens is a meniscus type lens and has weak positive refractivity, the third lens has upward convex-shaped positive refractivity, the fourth lens has upward convex-shaped negative refractivity, and the fifth lens has negative refractivity, wherein the lens system satisfies a relation, f2/f1>10, wherein f1 is a focal distance of the first lens, and f2 is a focal distance of the second lens.
Claims16
A photographic lens system enabling reduction in tightness of manufacturing tolerance, comprising:
- a first lens, a second lens, a third lens, a fourth lens and a fifth lens sequentially arranged along an optical axis from an object, wherein
- the first lens has strong positive refractivity, the second lens is a meniscus type lens and has weak positive refractivity, the third lens has upward convex-shaped positive refractivity, the fourth lens has upward convex-shaped negative refractivity, and the fifth lens has negative refractivity;
- and
- the lens system satisfies a relation, f2/f1>10, wherein f1 is a focal distance of the first lens, and f2 is a focal distance of the second lens.
A photographic lens system enabling reduction in tightness of manufacturing tolerance, comprising a first lens, an iris, a second lens, a third lens, a fourth lens and a fifth lens sequentially arranged along an optical axis from an object, wherein
- the first lens has strong positive refractivity, the second lens is a meniscus type lens and has weak positive refractivity, the third lens has upward convex-shaped positive refractivity, the fourth lens has upward convex-shaped negative refractivity, and the fifth lens has negative refractivity, and
- the lens system satisfies relations, f2/f1>10, and |v2−v4|<5, wherein the fifth lens is an aspheric lens, f1 is a focal distance of the first lens, f2 is a focal distance of the second lens, v2 is an ABBE number of the second lens, and v4 is an ABBE number of the fourth lens.
Dependencies are inferred from the claim text.