Design And Analysis Of High-definition Athermal Automotive Fisheye Lenses

As the main medium for vehicles to obtain external information,vehicle lens plays an important role in the auto drive system.Modern vehicle lenses need to have higher optical performance to get clearer road environment information,improving driving safety and comfort.Therefore,the current development trend of vehicle lens is to have a larger aperture and a larger field of view.Due to the small field angle of view of ordinary lenses,which cannot meet the current demand for a large field of view,vehicle lenses based on fish-eyes structure have gradually attracted the attention of designers.Based on the development trends of automotive lenses in recent years,this thesis designs a high-definition automotive fish-eye lens with a large field of view.The maximum field Angle was 178.6° and the FNO is 1.5.The Chief Ray Angle(CRA)at the maximum field of view of the system is less than 13°.Equipped with AR0330 CM sensor,the system can meet the size of 1/3 inch image plane without dark corners.At the 0.5 Nyquist frequency,the Modulation Transfer Function(MTF)value of the center field of view is greater than 0.7,the MTF value of the edge field of view is greater than0.25.Due to the harshness of the use scene of the vehicle lens,the athermal design and stray light suppression of the lens are carried out respectively.The system uses the optical passive athermal method to find out the optimal material collocation scheme.The final design meets the working temperature requirements of-30℃～80℃.In the stray light analysis,firstly,the optical system is structurally designed,followed by stray light suppression.Finally,combined with the current common machining scheme and machining accuracy,the tolerance sizes is determined,and the sensitivity analysis and Monte Carlo analysis of the system are carried out.The Monte Carlo results show that at the0.78 Nyquist frequency,the average diffraction MTF of 90% of optical systems decreases by less than half of the initial value,which meets the imaging requirements and mass production requirements of vehicle lenses.