Night and day dual-purpose monitoring prime lens

Abstract

The invention discloses a night and day dual-purpose monitoring prime lens, adopting five lenses and reducing quantity of lens, wherein three lenses are aspheric surface lenses which are made of plastics materials, which effectively reduces the weight of the lens and the manufacture cost and improves the product competiveness. The night and day dual-purpose monitoring prime lens enables the lens image difference to be effectively corrected through optimizing and configuring the positive and negative focal length of various lenses and overcomes the defects of the plastic aspheric surface lenses that the focal point drift easily happens under the high or low temperature environment due to the big expansivity. Through the usage of the configuration, the lens focal point drift shift of the product is controlled in the reasonable range, and the night and day dual-purpose monitoring prime lens has an advantage of good analysis under the low or the high temperature, increases the lens usage occasions and the environment condition range, and improves the lens product quality and the competiveness.

Description

【Technical field】 [0001] The invention relates to an optical lens, in particular to a day and night monitoring fixed-focus lens. 【Background technique】 [0002] Day and night dual-purpose fixed-focus monitoring lenses generally use glass lenses. For example, patent documents CN203311083U and CN203311082 disclose lenses that use glass lenses. Since each lens is made of glass, the cost of the lens is relatively high. [0003] With the development of science and technology, more precise plastic lenses that can replace glass lenses can be produced through molds. Because the price of plastic lenses is relatively low, in order to improve the price competitiveness of lenses and reduce production costs, many optical lenses use plastic lenses. , to replace the glass lens; however, the plastic lens has a large thermal expansion coefficient, which makes the lens have the defect of focus drift, resulting in unstable performance of the lens. [0004] The present invention studies and pr...

AI Technical Summary

Problems solved by technology

[0002] Day and night dual-purpose fixed-focus monitoring lenses generally use glass lenses. For example, patent documents CN203311083U and CN203311082 disclose lenses that use glass lenses. Since each lens is made of glass, the cost of the lens is relatively high.

[0003] With the development of science and technology, more precise plastic lenses that can replace glass lenses can be produced through molds. Because the price of plastic lenses is relatively low, in order to improve the price competitiveness of lenses and reduce production costs, many optical lenses use plastic lenses. , to replace the glass lens; however, the plastic lens has a large thermal expansion coefficient, which makes the lens have the defect of focus drift, resulting in unstable performance of the lens

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