A five-megapixel surveillance camera

Abstract

The invention discloses a 5-megapixel monitoring lens. The 5-megapixel monitoring lens sequentially comprises a first lens L1, a second lens L2, a vignetting diaphragm r5, a third lens L3, an aperture r8, a fourth lens L4, a fifth lens L5, a sixth lens L6, a color filter GF and an imaging surface IMA from the object side, wherein the first lens L1 meets condition that Nd is less than or equal to 1.55, Vd1 is more than or equal to 63, Nd is the optical index of d light of a first lens material, and Vd is the Abbe constant of the d light of the first lens material; the third lens L3 meets the condition that Nd is less than or equal to 1.85 and more than or equal to 1.7, Vd is more than or equal to 45 and less than or equal to 55, Nd is the optical index of d light of a third lens material, and Vd is the Abbe constant of the d light of the third lens material; the fourth lens L4 meets the condition that Nd is more than or equal to 1.7, Vd is less than or equal to 30, Nd is the optical index of d light of a fourth lens material, and Vd is the Abbe constant of the d light of the fourth lens material; the aperture value F# of the lens structure is less than or equal to 2.1; and the central thickness t and the focal length f of the lens of the second lens L2 and the third lens L3 meet the following relationship that t / f is more than or equal to 0.4 and less than or equal to 0.5.

Description

technical field [0001] The invention relates to a monitoring lens, in particular to a monitoring lens with 5 million pixels. Background technique [0002] With the rapid rise of the security monitoring market in recent years, the optimization and improvement of digital processing and network transmission speed, the quality requirements for security monitoring lenses have been greatly improved, from ordinary monitoring requirements to high-definition identification. In order to facilitate installation, the BFL (back focal length) needs to be increased. The traditional method is to increase the TTL (total lens length) to increase the BFL (back focal length) for installation, and when using multiple lenses, it is necessary to increase the tooling to produce different curvatures. The cost of the lens increases. Mass production requires higher production costs. Cost reduction has always been the goal of designers. The cost of lens glass lenses comes from the number of production ...

AI Technical Summary

Problems solved by technology

In order to facilitate installation, the BFL (back focal length) needs to be increased. The traditional method is to increase the TTL (total lens length) to increase the BFL (back focal length) for installation, and when using multiple lenses, it is necessary to increase tooling to produce different curvatures. The lens increases the cost. Mass production requires higher production cost. Cost reduction has always been the goal of designers. The cost of lens glass lens comes from the number of production tools and lenses.

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