Zoom lens and imaging apparatus
AssigneeFUJIFILM Corporation
InventorsTetsuya Ori, Michio Cho
Life of this patent
Estimating the term…
Abstract
A zoom lens is constituted essentially by six lens groups, in order from the object side to the image side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a positive refractive power; a fifth lens group having a negative refractive power; and a sixth lens group having a positive refractive power. The distances between all pairs of adjacent lens groups change when changing magnification from the wide angle end to the telephoto end, and Conditional Formula (1) below is satisfied: −5<f1/f2<−1.5 (1) wherein f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group.
Claims18
A zoom lens consisting of six lens groups, which are, in order from the object side to the image side:
- a first lens group having a positive refractive power;
- a second lens group having a negative refractive power;
- a third lens group having a positive refractive power;
- a fourth lens group having a positive refractive power;
- a fifth lens group having a negative refractive power;
- and
- a sixth lens group having a positive refractive power;
- the distances between all pairs of adjacent lens groups changing when changing magnification from the wide angle end to the telephoto end;
- the distance between the third lens group and the fourth lens group being shortest at the wide angle end throughout the entire magnification range;
- and
- Conditional Formula (1) below being satisfied:
- −5<f1/f2<−1.5 (1)
- wherein f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group;
- and
- wherein the first lens group consists of, in order from the object side to the image side, a positive lens and a cemented lens formed by cementing a negative lens and a positive lens provided in this order from the object side to the image side together.
A zoom lens consisting of six lens groups, which are, in order from the object side to the image side:
- a first lens group having a positive refractive power;
- a second lens group having a negative refractive power;
- a third lens group having a positive refractive power;
- a fourth lens group having a positive refractive power;
- a fifth lens group having a negative refractive power;
- and
- a sixth lens group having a positive refractive power;
- the distances between all pairs of adjacent lens groups changing when changing magnification from the wide angle end to the telephoto end;
- the distance between the third lens group and the fourth lens group being shortest at the wide angle end throughout the entire magnification range;
- and
- Conditional Formula (1) below being satisfied:
- −5<f1/f2<−1.5 (1)
- wherein f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group;
- and
- wherein the third lens group has a negative meniscus lens with a concave surface toward the image side as the lens most toward the image side.
A zoom lens consisting of six lens groups, which are, in order from the object side to the image side:
- a first lens group having a positive refractive power;
- a second lens group having a negative refractive power;
- a third lens group having a positive refractive power;
- a fourth lens group having a positive refractive power;
- a fifth lens group having a negative refractive power;
- and
- a sixth lens group having a positive refractive power;
- the distances between all pairs of adjacent lens groups changing when changing magnification from the wide angle end to the telephoto end;
- the distance between the third lens group and the fourth lens group being shortest at the wide angle end throughout the entire magnification range;
- and
- Conditional Formula (1) below being satisfied:
- −5<f1/f2<−1.5 (1)
- wherein f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group;
- and
- wherein the fourth lens group consists of a single positive meniscus lens with a convex surface toward the object side.
Dependencies are inferred from the claim text.