Four-lens type photography optical lens group

Abstract

The invention discloses a four-lens type photography optical lens group, which comprises a first lens with positive refractive power, a second lens with negative refractive power, a third lens, a fourth lens and an optical ring, wherein a dispersion coefficient of the first lens is V1 which is more than 50 and less than 60; the front surface of the second lens is a concave surface; the rear surface of the second lens is a convex surface; the front surface of the third lens is a convex surface; the rear surface of the third lens is a concave surface; at least one surface of the third lens is set to be an aspheric surface; at least one surface of the fourth lens is set to be an aspheric surface; and the optical ring is arranged in front of the second lens.

Description

technical field [0001] The invention relates to an optical mirror group, in particular to a four-piece photographic optical mirror group applied to a miniaturized photographic lens. Background technique [0002] In recent years, with the rise of mobile phone cameras, the demand for miniaturized photographic lenses has been increasing, and the photosensitive elements of general photographic lenses are nothing more than photocoupled devices (Charge Coupled Device, CCD) or complementary metal oxide semiconductors (Complementary Metal -Oxide Semiconductor, CMOS) two types, due to the advancement of semiconductor manufacturing technology, the pixel area of ​​the photosensitive element is reduced, and the miniaturized photography lens is gradually developing into the high-pixel field. Therefore, the requirements for imaging quality are also increasing. [0003] Common mobile phone lenses mostly use a three-piece lens group. The lens group consists of a first lens with positive ref...

AI Technical Summary

Problems solved by technology

[0004] As the pixel area of ​​the photosensitive element gradually shrinks, the system's requirements for imaging quality increase, and the common three-piece lens group will not be able to meet the use of higher-end photographic lens modules.

[0005] U.S. patent specification US7365920B2 (announced on April 29, 2008) discloses a four-piece lens group, but wherein the first lens and the second lens are bonded to each other with two spherical mirrors to form a Doublet to eliminate chromatic aberration, but This method has its disadvantages. First, too many spherical mirror configurations make the system less free, which makes it difficult to shorten the overall length of the optical system. Second, the glass lens bonding process is not easy, resulting in difficulties in manufacturing.

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