Economical high resolution day and night fixed focus lens

Abstract

The invention relates to an economical high resolution day and night fixed focus lens. A front group with a negative focal power and a back group with a positive focal power are orderly arranged along a light incident direction. The front group is orderly provided with a positive crescent lens A-1 and a negative crescent lens A-2. The focal length fA of the front group is -21.996mm. The back group B is orderly provided with a gluing group with the closed connection of a biconcave lens B-1 and a biconvex lens B-2 and a biconvex lens B-3, and the focal length fB of the back group is 6.792mm. According to the lens, the total number of lends is reduced in the condition of ensuing performance, besides the high resolution, large relative aperture, day and night confocal performance, low distortion and short shooting distance of an 8mm fixed focal lens, the economical high resolution day and night fixed focus lens is more economical and is generally used in a dark or no-light place with the requirement of high definition picture quality such as a road, a warehouse, an underground parking place, a bar, a pipe, a corridor and a park, and the economical high resolution day and night fixed focus lens is a mainstream product of a micro monitoring camera system.

Description

technical field [0001] The invention relates to a camera lens device of a monitoring system, in particular to an economical high-resolution day and night dual-purpose fixed-focus lens. Background technique [0002] Various fixed-focus lenses have been used in surveillance systems in the market, and the emergence and application of small TV surveillance cameras have a history of 20 to 30 years. There are various specifications and models of miniature camera lenses to match them. Their performance indicators are mixed, most of them are low-end products, and their performance indicators are low. Although some can meet the requirements of high-definition, there are many defects in high-definition and wide-angle monitoring in small spaces. Day and night confocal, low distortion and other advantages often require higher cost; and the spectral range to be adapted is narrow, and can only be used under daytime light conditions of 480nm to 700nm; the image distortion is large, and the...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the defect of high cost of the existing fixed-focus lens, the purpose of the present invention is to provide an economical high-resolution day and night dual-purpose fixed-focus lens. At the same time, by changing the optical structure, the number of lenses in the optical structure is reduced, that is, the cost is reduced under the premise of ensuring high performance

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