2.8 mm high-definition day-and-night confocal lens

Abstract

The invention relates to a 2.8 mm high-definition day-and-night confocal lens. The 2.8 mm high-definition day-and-night confocal lens comprises a main lens cone and an optical system arranged in the main lens cone, wherein the optical system comprises a front group of lenses A, diaphragms and a rear group of lenses B which are successively arranged from left to right in a light incidence direction; the focal power of the front group of lenses A is negative; the focal power of the rear group of lenses B is positive; the front group of lenses A comprise a falcate negative lens A-1, a plastic aspheric lens A-2 and a falcate positive lens A-3; and the rear group of lenses B comprise a plastic aspheric lens B-1, a plastic aspheric lens B-2 and a biconvex lens B-3. Two optical elements are adopted, the three diaphragms are arranged on the front while the two diaphragms are arranged at the rear, and one of the lenses has negative focal power while the other lens has positive focal power. The2.8 mm high-definition day-and-night confocal lens has the advantages that a field angle is large, the confocal lens can be used in daytime and at night, the optical structure is simple, the cost of the materials is low and the like; the resolution ratio can reach 8 MP, and thus, the 2.8 mm high-definition day-and-night confocal lens can be matched with the corresponding CD or CMOS.

Description

Technical field: [0001] The invention relates to a 2.8mm high-definition day and night confocal lens. Background technique: [0002] At present, there are a variety of 2.8mm fixed-focus lenses used in security systems in the market, and the market demand is large. The traditional 2.8mm lens is usually an all-glass lens, and because of the large field of view, the cost is relatively high. With the development of technology, people's requirements for clarity are getting higher and higher, and high-resolution chips are incomplete. However, in the current security industry, there are few real low-cost, high-quality, wide-angle fixed-focus lenses; at the same time , according to the traditional way of thinking, in order to improve the resolution, there are generally two ways: one is to use less lenses to reduce the clear aperture, and the other is to use more lenses. The use of more lenses will certainly improve the performance of the lens, but it will also increase the cost; a...

AI Technical Summary

Problems solved by technology

The use of more lenses will certainly improve the performance of the lens, but it will also increase the cost; although the reduction of the clear aperture can reduce the cost, it will lead to a decrease in the image quality of the lens

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