Zoom lens
AssigneeAsia Optical Co., Inc.
InventorMing-chung Chen
Life of this patent
Estimating the term…
Abstract
Disclosed is a zoom lens, which includes, in sequence from an object side to an image side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, a fifth lens group, a negative sixth lens group and a positive lens group. The first, third, fifth and seventh lens groups are fixed. When the zoom lens is made to zoom from a wide-angle end to a telephoto end, the second and fourth lens groups move toward the third lens group, while the sixth lens group moves toward the seventh lens group. The absolute value of the ratio of the focal distance of the second lens group to that of the sixth lens group is within a range between 0.1 and 0.5.
Claims16
A zoom lens comprising:
- an object-side fixed lens group having a positive refraction power and comprising a reflection element for folding an optic axis of the zoom lens;
- an image-side fixed lens group having a positive refraction power;
- and
- a moving lens subsystem arranged between the object-side fixed lens group and the image-side fixed lens group, the moving lens subsystem comprising an object-side moving lens group and an image-side moving lens group, both having a negative refraction power, and an intermediate lens unit arranged between the object-side moving lens group and the image-side moving lens group and comprising an intermediate moving lens group of positive refraction power located between an object-side internal fixed lens group of positive refraction power and an image-side internal fixed group.
Dependencies are inferred from the claim text.