Miniature short-focus fixed focal lens with ultra-wide angle

Abstract

The invention relates to the technical field of lenses, in particular to a miniature short-focus fixed focal lens with an ultra-wide angle. The miniature short-focus fixed focal lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are arranged in the light incidence direction, wherein the lenses and the whole lens have the relationship shown as follows: the absolute value of the quotient obtained by dividing f2 by f is larger than 1.15 and smaller than 1.42; the absolute value of the quotient obtained by dividing f4 by f is larger than 1.34 and smaller than 1.62; the absolute value of the quotient obtained by dividing f5 by f is larger than 0.94 and smaller than 1.22; the absolute value of the quotient obtained by dividing f6 by f is larger than 1.31 and smaller than 1.65; f represents the focal length of the lens, f2 represents the focal length of the second lens, f3 represents the focal length of the third lens, f4 represents the focal length of the fourth lens, f5 represents the focal length of the fifth lens, and f6 represents the focal length of the sixth lens. The day and night confocal function is realized, and a clear image can be formed under infrared light without focusing under the condition that a clear image is formed under visible light; besides, the miniature short-focus fixed focal lens has the temperature compensation function and has the characteristic of no focus shift when used in the environment at subzero 30 DEG C to 80 DEG C.

Description

technical field [0001] The invention relates to the technical field of lenses, in particular to a small fixed-focus lens with a short focus and an ultra-wide angle. Background technique [0002] With the rapid development of social economy and technology, security monitoring system has become more and more popular and high-end. Chips are being updated, and all aspects of performance of surveillance lenses, including field of view, clear aperture, pixels, and image size, are also being optimized. Among them, ultra-wide-angle fixed-focus lenses are one of the lenses that account for a large proportion of demand. Their characteristics are The focal length is short, the field of view is large, and the monitoring range is very wide. The existing fixed-focus wide-angle lens generally has a focal length of about 2.8mm, a maximum field of view of about 140 degrees, large distortion, and insufficient resolution at the edge of the image plane. Contents of the invention [0003] The...

AI Technical Summary

Problems solved by technology

Chips are being updated, and all aspects of performance of surveillance lenses, including field of view, clear aperture, pixels, and image size, are also being optimized. Among them, ultra-wide-angle fixed-focus lenses are one of the lenses that account for a large proportion of demand. Their characteristics are The focal length is short, the field of view is large, and the monitoring range is very wide. The focal length of the existing fixed-focus wide-angle lens is generally about 2.8mm, the maximum field of view is about 140 degrees, the distortion is large, and the resolution at the edge of the image plane is not high enough.

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