Zoom lens
AssigneeYoung Optics Inc.
InventorsYu-Hung Chou, Pei-Ching Liu
Life of this patent
Estimating the term…
Abstract
A zoom lens including a first lens group and a second lens group is provided. Refractive powers of the first lens group and the second lens group are respectively negative and positive. The first lens group includes a first lens, a second lens, and a third lens arranged in sequence from an object side to an image side. The second lens group is disposed between the first lens group and the image side, and includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side to the image side. The zoom lens satisfies −2.4<f1/fw<−1.0, wherein f1 is the effective focal length of the first lens group, and fw is the effective focal length of the zoom lens at a wide end.
Claims27
A zoom lens, comprising:
- a first lens group, having a negative refractive power and comprising a first lens, a second lens and a third lens arranged from an object side to an image side, wherein an Abbe Number of at least one of the first lens, the second lens and the third lens is greater than 70, and the first lens has a concave surface facing the object side, wherein the first lens is a lens with a refractive power closest to the object side of all lenses within the zoom lens;
- and
- a second lens group, having a positive refractive power, disposed between the first lens group and the image side and comprising a fourth lens, a fifth lens, a sixth lens, a seventh lens and a eighth lens arranged from the object side to the image side, wherein the zoom lens satisfies −2.4<f1/fw<−1.0, where f1 is an effective focal length of the first lens group, and fw is an effective focal length of the zoom lens at a wide end.
A zoom lens, comprising:
- a first lens group, having a negative refractive power and comprising a first lens, a second lens and a third lens arranged in order from an object side to an image side, wherein an Abbe Number of at least one of the first lens, the second lens and the third lens is greater than 70, and the first lens has a concave surface facing the object side, wherein refractive powers of the first lens, the second lens, the third lens are positive, negative and negative, respectively;
- and
- a second lens group, having a positive refractive power, disposed between the first lens group and the image side and comprising a fourth lens, a fifth lens, a sixth lens, a seventh lens and a eighth lens arranged from the object side to the image side, wherein the zoom lens satisfies −2.4<f1/fw<−1.0, where f1 is an effective focal length of the first lens group, and fw is an effective focal length of the zoom lens at a wide end.
A zoom lens, comprising:
- a first lens group, having a negative refractive power and comprising a first lens, a second lens and a third lens arranged from an object side to an image side, wherein an Abbe Number of at least one of the first lens, the second lens and the third lens is greater than 70, and the first lens has a concave surface facing the object side;
- a second lens group, having a positive refractive power, disposed between the first lens group and the image side and comprising a fourth lens, a fifth lens, a sixth lens, a seventh lens and a eighth lens arranged from the object side to the image side, wherein the zoom lens satisfies −2.4<f1/fw<−1.0, where f1 is an effective focal length of the first lens group, and fw is an effective focal length of the zoom lens at a wide end;
- and
- a third lens group, disposed between the object side and the first lens group, and having at most two lenses, wherein the third lens group has a fixed position in the zoom lens and is in the fixed position when the zoom lens switches between the wide end and a tele end, wherein an Abbe Number of each lens of the third lens group is less than or equal to 53.9 and greater than or equal to 18.9.
Dependencies are inferred from the claim text.