A full-spectrum imaging lens with super large aperture

Abstract

A full spectrum imaging lens with a super large aperture is disclosed. From an object side to an image side and along an optical axis, the lens successively comprises a diaphragm, a first glued lens L1 possessing negative optical power, a second concave and convex lens L2 possessing the negative optical power; a third bi-convex lens L3 possessing positive focal power, a fourth glued lens L4 possessing the positive focal power, a fifth bi-convex lens L5 possessing the positive focal power and a sixth glued lens L6 possessing the positive focal power. The first glued lens L1 possesses the negative optical power so that the diaphragm images a diameter at a front end, which means that an entrance pupil diameter is large. An aperture is effectively increased and a light entering amount is increased too. A second lens of the fourth glued lens L4 and the fifth bi-convex lens L5 satisfy the following conditions that (1) Vd42>75; and (2) Vd5>70, wherein the Vd42 represents an abbe number of the second lens of the fourth glued lens L4 and the Vd5 represents an abbe number of the fifth bi-convex lens L5.

Description

technical field [0001] The invention relates to the technical fields of monitoring and security, in particular to a full-spectrum imaging lens with a super large aperture. Background technique [0002] Surveillance cameras are quasi-cameras used in security. Its pixel and resolution are higher than those of computer video heads, but lower than professional digital cameras or dv. Surveillance cameras are mostly single video capture devices, and rarely have data storage functions. Surveillance cameras are mainly divided into gun type, hemispherical, and high-speed dome in terms of appearance. In addition, there are analog monitoring and IP network monitoring. They are widely used in many security fields such as schools, companies, banks, transportation, and safe cities. [0003] In recent years, with the rapid development of my country's economy, people increasingly need high-quality life and a safe and reliable environment. Major projects are being carried out across the cou...

AI Technical Summary

Problems solved by technology

However, due to the relatively small aperture, FNO is around 1.8, and it cannot be imaged at night without auxiliary light sources, so it cannot be used in some specific environments where auxiliary lighting equipment cannot be installed; in addition, this lens can only achieve visible light It is not defocused when switching with infrared light, so the axial chromatic aberration of infrared light and visible light cannot be completely overlapped, which is not true full-spectrum imaging

[0006] For the lens described in Patent Document 2 (103969817A), although the FNO is below 1, the aperture of the lens reaches 31.25mm, so the lens is huge in size, and the cost of materials and processing is extremely expensive, which is not conducive to mass production and cannot meet the requirements of small surveillance lenses. requirements of modernization and low cost

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