Ultra-wide-angle lens with 2.8mm fixed focus

Abstract

The invention relates to an ultra-wide-angle lens with a 2.8mm fixed focus. An optical system of the lens is provided with a front set A, a diaphragm C and a rear set B in the incidence direction of light from left to right in sequence. The front set A is sequentially provided with a negative meniscus lens A-1, a negative meniscus lens A-2 and a double convex lens A-3, wherein the focus fA of the front set A is -9.8mm. The rear set B is sequentially provided with a double convex lens B-1 and a gluing set, wherein a double convex lens B-2 is connected with a positive meniscus lens B-3 in a sealed mode to form the gluing set, the focus fB of the rear set B is 5.67mm. The ultra-wide-angle lens with the 2.8mm fixed focus has the advantages of having an ultra-wide angle, high resolution, a large relative aperture, the focus which is fixed all day long and the like. The ultra-wide-angle lens with the 2.8mm fixed focus can be matched with a CCD camera with the 3-million-pixel high resolution or a CMOS camera with the 3-million-pixel high resolution, is generally used in places with a small visibility range and a large view angle such as elevator cages and halls, and is a mainstream product of a miniature monitoring image pickup system.

Description

technical field [0001] The invention relates to a camera lens device of a monitoring system, in particular to a 2.8 fixed-focus ultra-wide-angle lens. Background technique [0002] There have been various fixed-focus lenses on the market for a long time, which are used in surveillance systems. However, its optical performance index is low. Although some can meet the high-definition requirements, there are many defects in the high-definition wide-angle when monitoring a small space. Contents of the invention [0003] In order to overcome the defects of existing fixed-focus lenses, the technical problem to be solved by the present invention is to provide a 2.8 fixed-focus ultra-wide-angle lens, which can ensure clear images and ultra-wide angles in a small space while possessing excellent sensitivity; , Even in low light or night conditions, it can ensure the high quality of the image, reaching megapixels. [0004] In order to solve the above technical problems, the techni...

AI Technical Summary

Problems solved by technology

However, its optical performance index is low. Although some can meet the high-definition requirements, there are many defects in the high-definition wide-angle when monitoring a small space. It cannot have the advantages of ultra-wide angle, high resolution, large relative aperture, and day and night confocal

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