Wide-angle distortionless lens based on aspheric surface

Abstract

The invention relates to a wide-angle distortionless lens based on an aspheric surface. The wide-angle distortionless lens comprises a front lens group and a rear lens group which are sequentially arranged in the light incident direction, a fixed or variable diaphragm is further arranged between the front lens group and the rear lens group, the focal length of the front lens group is 20-35 mm, andthe focal length of the rear lens group is 3-5 mm. The front lens group comprises a first lens and a second lens which are sequentially arranged along the light incident direction, the rear lens group comprises a third lens and a fourth lens which are sequentially arranged along the light incident direction; the first lens, the third lens and the fourth lens are aspheric lenses, and the second lens is a spherical lens; the first lens is a positive meniscus lens, the second lens is a negative meniscus lens, the third lens is a biconvex lens, and the fourth lens is a negative meniscus lens. According to the invention, a combined structure of an aspheric surface and a spherical surface is adopted, and the rear lens group adopts a glued structure of the aspheric surface and the aspheric surface, thereby having the characteristics that the number of the whole lenses is small, the field angle is greater than 90 degrees, and the distortion value reaches 1.2%.

Description

technical field [0001] The invention relates to an optical lens, in particular to a wide-angle distortion-free lens based on an aspheric surface. Background technique [0002] Currently on the market, the shooting angle of commonly used ordinary lenses is about 30°-60°. The wide-angle lens can achieve a shooting angle of 90°-120°. With the development of science and technology, wide-angle lenses with large fields of view are widely used in military, medical, transportation, and industrial fields to obtain scene information in larger scenes. For ordinary wide-angle lenses, due to the large field of view angle, it is inevitable to introduce distortion, which is an aberration, causing the edge of the image to be squeezed and deformed, resulting in serious image distortion. Even if the image algorithm is corrected, it will lead to a decrease in edge resolution. [0003] For a traditional lens with a viewing angle of around 90°, if no distortion correction is performed, the op...

AI Technical Summary

Problems solved by technology

[0004] Among them, the advantage of method 1: under the premise that the market consumption is not large, the cost of spherical lenses has an absolute advantage over aspheric lenses; the disadvantage of method 1: it needs to use more lenses to reduce distortion. The transmittance decreases, and the cumulative error of the number of lens components increases, resulting in sensitive tolerances and low production efficiency

[0005] The advantage of method 2: in the case of large market usage, the cost of mold opening can be shared, and the use of aspheric surface can greatly reduce the number of lenses and greatly improve the overall transmittance of the lens; the disadvantage of method 2: the design of aspheric surface is more difficult Large, high cost of mold opening, sensitive to high and low temperature deformation, etc.

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