Design And Analysis Of High Definition CCTV Wide Angle Fixed Focus Lens

As the most effective means of security,Closed Circuit Television surveillance system(CCTV)is widely used in all walks of life,CCTV wide-angle prime lens because it has the characteristics of large range of monitoring is also widely used in CCTV system,so it has great research value.This paper designs three CCTV wideangle lenses that reach million-level HD pixels according to different usage scenarios.The first is a CCTV fisheye lens with a field of view Angle of 200°,a target surface size of 12.92 mm,and a total optical length of 40.45 mm.It has the advantages of large field of view,large target surface monitoring and small size,and is suitable for monitoring in a wide range of places.The second type is SWIR wide-angle CCTV lens,whose field of view Angle reaches 150°,working wavelength is 0.9～ 1.7 um,F number is 2.2,and total optical length is only 35.02 mm.It achieves the effect of infrared short-wave band widefield imaging,and is suitable for places with poor light conditions at night,foggy areas and other places requiring large-scale monitoring.The third type is an ultra-short focal underwater CCTV wide-angle lens,whose field of view reaches 120°,F number is 2.2,and focal length is 2.63 mm.The total optical length including the water window is only 35 mm,which realizes the monitoring effect of large field of view of underwater lens.Meanwhile,the lens has the advantages of total optical length and small volume.It is suitable for rivers,lakes,fishery ponds and other waters requiring large field of view monitoring.After the image quality analysis and tolerance analysis,it is shown that the three lenses can achieve good HD imaging effect when combined with the image sensor with megapixels,and have the feasibility and practical machinability of the subsequent opto-mechanical structure design.The temperature analysis of the three lenses shows that the three lenses can adapt to the temperature change of the working environment.Finally,the stray light of underwater lens is analyzed and the solution is given.