Small ultra-wide low-distortion prime lens

Abstract

The invention discloses a small ultra-wide low-distortion prime lens. The prime lens sequentially comprises, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens. The first lens and the fourth lens are glass spherical lenses. The second lens, the third lens, the fifth lens and the sixth lens are plastic aspheric lenses. The first lens is a plane-concave glass lens with negative focal power. The second lens is a convex-concave plastic lens with negative focal power. The third lens is a concave-convex plastic lens with positive focal power. The fourth lens is a biconvex glass lens with positive focal power. The fifth lens is a biconcave plastic lens with negative focal power. The sixth lens is a biconvex plastic lens with positive focal power. According to the invention, by combining and optimizing the glass lenses and the plastic lenses reasonably, the maximum image plane of the prime lens can be over 1 / 2.7'', the field angle is larger than 130 degrees, the maximum aperture F is 1.8, TV distortion is less than 8%, and image distortion is reduced greatly. Moreover, the prime lens has a day-night confocal function and a temperature compensation function.

Description

technical field [0001] The invention relates to the field of lens technology, in particular to a small ultra-wide-angle low-distortion fixed-focus lens. Background technique [0002] Fixed-focus lenses occupy a large proportion of the market for security surveillance lenses. Due to their different optical parameters such as field of view, focal length, and F-number, there are various types of lenses, and lenses with different performance parameters can be selected for different occasions. Among them, the ultra-wide-angle lens with a wide field of view can monitor a wider range. It is suitable for elevators, shopping malls and other occasions. The field of view is generally above 90 degrees. However, this type of lens has relatively large distortion, and TV distortion exceeds 16%, resulting in image distortion. Obviously, at the same time, the image quality at the edge of the image plane is poor, which limits the application of ultra-wide-angle lenses in some fields that requ...

AI Technical Summary

Problems solved by technology

Among them, the ultra-wide-angle lens with a wide field of view can monitor a wider range. It is suitable for elevators, shopping malls and other occasions. The field of view is generally above 90 degrees. However, this type of lens has relatively large distortion, and TV distortion exceeds 16%, resulting in image distortion. Obviously, at the same time, the image quality at the edge of the image plane is poor, which limits the application of ultra-wide-angle lenses in some fields that require high image deformation

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