Day and night wide-angle fixed-focus monitoring lens

Abstract

The present invention discloses a day and night wide-angle fixed-focus monitoring lens. A first lens, a second lens, a diaphragm, a third lens, a fourth lens and an optical filter are sequentially arranged from an object side to an image side, the first lens and the fourth lens are negative-focal-power lenses, the second lens and the third lens are positive-focal-power lenses, the optical filter is a day-night dual-purpose double optical filter, the object side surface and the image side surface of the first lens are respectively a convex surface and a concave surface, the object side surface and the image side surface of the second lens are both convex surfaces, the object side surface and the image side surface of the third lens are both convex surfaces, and the object side surface and the image side surface of the fourth lens are respectively a concave surface and a convex surface; and the dual-purpose optical filter capable of being switched day and night is adopted, the use requirement for day and night resolution is met at the same time, the wide-angle monitoring requirement is met, the high and low temperature resolution variation is effectively corrected, and the stable and reliable use requirement under different temperature conditions is met by restraining the structural arrangement and optical parameters of the first lens, the second lens, the third lens, the fourth lens and the fourth lens.

Description

technical field [0001] The invention belongs to the technical field of optical imaging, and in particular relates to a day and night wide-angle fixed-focus monitoring lens. Background technique [0002] In recent years, with the increasing popularity of security monitoring facilities, the demand for the use of surveillance cameras has also increased. At the same time, the requirements for the imaging quality of surveillance cameras are also getting higher and higher. At present, the selection of surveillance cameras mainly has the following problems: [0003] (1) In the nighttime monitoring environment, the low-illuminance lighting environment will reduce the imaging clarity when the lens is imaging, and the use of light sources for supplementary light will cause overexposure caused by supplementary light reflection in some special shooting environments, and then appear The problem of unclear shooting of details; at present, the day and night resolution requirements can be ...

AI Technical Summary

Problems solved by technology

[0003] (1) In the nighttime monitoring environment, the low-illuminance lighting environment will reduce the imaging clarity when the lens is imaging, and the use of light sources for supplementary light will cause overexposure caused by supplementary light reflection in some special shooting environments, and then appear The problem of unclear shooting of details; at present, the day and night resolution requirements can be met by using the fixed-focus monitoring lens that can be used day and night. However, the current fixed-focus monitoring lens often uses glass lenses. For surveillance lenses, the cost of the lens is relatively high;

[0004] (2) The monitoring lens is a precision instrument, and its temperature requirements are very strict. Too high or too low ambient temperature will have a great impact on its shooting quality and its own performance

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