Zoom lens

Abstract

A zoom lens includes a first lens group with negative diopter and a second lens group with a positive diopter; wherein, the second lens group is arranged between the first lens group and an image side; and the first lens group and the second lens group are suitable for moving between an object side and the image side. Besides, the first lens group includes a first lens with negative diopter; while the first lens is a meniscus lens with a convex surface facing to the object side and an Abbe number larger than 50. Furthermore, the focus of the zoom lens is F, the focus of the first lens group is F1, a curvature radius of the first lens facing to the surface of the second lens group is R2 and F / F1 is more than 0.6 below zero and less than 0.2 below zero and R2 / F is more than 0.7 and less than 1.8.

Description

technical field [0001] The present invention relates to a lens, and in particular to a zoom lens. Background technique [0002] With the advancement of modern video technology, imaging devices such as projectors, digital video cameras (Digital Video Camera, DVC) and digital cameras (Digital Camera, DC) have been widely used. One of the core components of these imaging devices is a zoom lens. The optical zoom of the zoom lens can make the image clearly formed. Therefore, the optical quality of the zoom lens is closely related to the quality of image formation. In the fiercely competitive market, various manufacturers are committed to improving the quality of the zoom lens and reducing its production cost, so as to enhance the competitive advantage of the above-mentioned imaging devices. [0003] In traditional technology, the zoom lens is designed to be composed of two lens groups, wherein the first lens group near the object side has negative refractive power, and the secon...

AI Technical Summary

Problems solved by technology

[0004] However, the f-number (fnumber) of the traditional zoom lens consisting of two lens groups and having five to six lenses is greater than 3.5, and its aperture is relatively small, such as: U.S. Patent No. 6,324,014 or U.S. Patent No. 5,541,772, So it is difficult to achieve a large relative aperture (relative aperture)

In addition, this type of zoom lens uses an aspherical lens to eliminate aberration, and the high price of the aspheric lens leads to high production costs of the traditional zoom lens.

And if this type of zoom lens needs to achieve a large relative aperture, it needs to use more lenses and match aspheric lenses to eliminate aberrations, which will also lead to high production costs of traditional zoom lenses

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