Research On Lamp Projection Optical System Based On Micro LED

In order to meet the growing needs of people in driving safety and comfortable driving,automotive products have gradually developed in the direction of "automation,intelligence,and safety".As one of the key components of the car,the lights have gradually developed from the traditional model of a single lighting to a more intelligent,safer and more convenient modern direction,so that it can achieve the function of information display while meeting the precise lighting.In recent years,automotive lighting technology has developed rapidly as a means to improve car driving comfort and road safety.With the rise of autonomous driving,vehicle interconnection and other technologies,the development of "informatization,intelligence and safety" of automotive products puts forward higher requirements for car lights,and lamp projection has become the development direction of the next generation of car lights,playing an important role in the vehicle-car,vehicle-human interaction of intelligent cars.Due to its advantages of high brightness,long life,low power consumption,good seismic resistance and fast response,LED is widely used in the automotive field and has become the preferred light source for intelligent lights.Compared with LEDs,Micro LEDs are smaller and have higher resolution,so they have greater application potential in the field of automotive projection displays.Based on the excellent characteristics of Micro LED,this article designed a lamp projection optical system with the white light Micro LED array as the light source.According to the actual application needs,the optical structure,optical component parameters and optical properties were designed and optimized,and the problems of trapezoidal distortion and illuminance uniformity occurred during the projection of lamps were proposed.The main research content of this thesis is as follows:(1)The lamp projection optical system design scheme consisting of display light sources and projection mirrors is proposed.By coating yellow quantum dots on the blue light Micro LED array to achieve white light display,the image processing algorithm is used to correct the display image of the Micro LED array chip Regional implementation of projection image display.According to the performance requirements of the lamp,the number of pixels,pixel size,lighting area,and the parameter design of the field of viewing,focal length,and relative pores were completed by Micro LED pixels.(2)According to the design parameters of Micro LED and projection objective lens,the design and optimization of the lamp projection optical system were completed.The design method combining object tilt and optical structure optimization was adopted to solve the problem of serious deterioration of imaging quality caused by optical axis tilt in the design of lamp projection optical system,so that the modulation transfer function of the lamp projection optical system at the Nyquist frequency was better than0.6;according to the temperature range of the working environment,the imaging quality of the lamp projection optical system in the range of-20°C～80°C was analyzed,and the analysis results showed that the system still had good optical performance in a wide temperature range.The tolerance analysis of the lamp projection system is carried out by Monte Carlo method,and the error tolerance of the system is given.(3)The image distortion and illumination uniformity of the lamp projection optical system were analyzed and corrected.The reasons for trapezoidal distortion and illuminance unevenness during lamp projection were analyzed.A reverse distortion processing method is proposed to correct the distortion of the projected image.The pixel grayscale modulation method is adopted to improve the illumination uniformity of the projected image surface.The results show that the size of the keystone distortion coefficient of the corrected image decreases from 0.2896 and 0.0718 to 0.0045 and0.0117,respectively,and the illumination uniformity of the image surface before and after correction is 77.6% and 93.3%,respectively,and the image distortion and illumination uniformity are significantly improved,which meets the application requirements of the lamp projection system.