Surveillance camera

Abstract

The present invention provides a monitor lens including a first lens group, a second lens group and a diaphragm. The first lens group includes a first lens with negative refractive power, a second lens with positive refractive power from the object side lens and a third lens with negative power; the second lens group includes a fourth lens with positive power, a fifth lens with positive power, and a sixth lens with negative power from the object side to the imaging surface ; The first lens, the second lens and the fifth lens all use glass spherical lenses, the third lens, the fourth lens and the sixth lens all use plastic aspheric lenses, and the optical centers of each lens are located on the same straight line. The present invention reduces the number of lenses by using three plastic aspherical lenses, reduces the length and weight of the lens, and lowers the manufacturing cost; through the matching combination of lenses of different materials, reasonable focal power and air interval distribution, the aberration of the lens is reduced It is effectively corrected and has the advantages of small focus drift caused by high and low temperatures.

Description

technical field [0001] The invention relates to the field of camera lens technology, in particular to a monitoring lens. Background technique [0002] With the rapid development of science and technology, people have a higher level of understanding of security, and surveillance cameras were born immediately. In recent years, surveillance cameras have become a major force in the security industry, driving the continuous advancement and rapid development of the security industry. , People pay more and more attention to performance issues such as the quality of its imaging effect and the size of the field of view. [0003] The existing monitoring lens includes a first lens group, a diaphragm and a second lens group in sequence from the object side to the imaging surface along the optical axis, and through the optical combination of different lenses in the first lens group, diaphragm and second lens group, In order to achieve different imaging display effects. [0004] Existi...

AI Technical Summary

Problems solved by technology

[0004] Existing surveillance cameras generally have defects such as overall length, small viewing angle, large temperature influence, low resolution quality, small target surface, and high cost.

As the day and night confocal lens of patent document CN105301739A uses three plastic material aspheric lenses and 2 glass lenses, its field of view angle is too small and the total length is too long; as the large target surface day and night confocal monitoring lens of patent document CN105388591A is used The number of lenses is as many as 12, which increases the cost, and the field of view angle is too small, and the resolution quality is poor; such as the patent document CN102323657A security day and night dual-use lens, although the lens resolution is improved and the total length is reduced by using multiple aspheric plastic material lenses , but the field of view angle of the lens is not large enough, and the target surface is too small

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