| Light emitting diode（LED）is a new type of solid-state lighting source and considered to be the green lighting source of 21st century.Compared with traditional light sources,LED has the advantages of low power consumption,high luminous efficiency,long service life,small size,light weight,high reliability,and environmental protection.At present,LED is actively developing in general and special lighting applications,such as road lighting,LED backlight and automotive lighting and so on.High luminous efficiency,high luminance uniformity and small dimension are three key issues in the optical design of LED lighting.Based on the theory of non-imaging optics,the three main problems of low luminous efficiency,insufficient luminance uniformity and lamp bulkiness in the optical design of LED streetlights and auto lamps are studied and the optical design solutions are proposed for related problems,which can provide some new ideas for current practical engineering issues and optical design engineers.The research contents of the thesis mainly include the following three aspects:1.A freeform surface LED streetlight lens is designed and simulated by LightTools software.The results show that a rectangular spot is obtained with the longitudinal uniformity of 88.58%and the horizontal uniformity of 78.66%.The luminous efficiency is as high as 92.6%.A streetlight module with power of 160W is formed through the freeform surface LED lens arrays.In the case of the streetlight pole spacing of 45 m,the DIALux software is used to simulate the road scene.The results show that the average luminance of the illuminated roadLav（L m）=1.41cd/m2>0.75cd/m2,the total luminance uniformityU0=0.54>0.4,the longitudinal luminance uniformity UI（U L）=0.73>0.6 and the glare threshold increment TI=14<15.All of the parameters are in line with the latest road lighting standards value requirements.Compared with LED streetlights with a 40 mm pole spacing on the market,about 277 streetlights can be saved per 100 km,which has practical engineering application value.2.An ultra-thin transparent light blade of LED rear turn signal lamp is designed based on the principle of optical total internal reflection（TIR）.Each sub-surface of the light blade is optimized and adjusted using CATIA software to achieve a thickness of the light-emitting surface only 10.3mm.The simulation results of LucidShape software present that the luminous intensity values in all directions of the LED rear turn signal lamp are meet the national standard of GB17509-2008automotive and trailers turn signal lamp distribution performance requirements,and the lumina nce uniformity is as high as 77.78%.This can reduce the volume of traditional turn signal lamps and solve the problem of lighting uniformity caused by bright spot due to direct lighting in the current LED rear turn signal lamps.3.A type of smal,ultra-thin transparent light blade of LED backup lamp is designed using the TIR collimation structure.Each sub-surface of the light blade is optimized and adjusted using CATIA software and the size of the light-emitting surface only 42 mm?6mm is achieved.The simulation results of LucidShape software demonstrate that the luminous intensity values of the LED backup lamp in all directions can meet the light performance requirements of the GB15235-2007 automotive and trailer backup lamps.The optical utilization and the luminance unifor mit y of the LED backup lamp based on the TIR collimation structure are 23.9%and 87.01%,which are4.6%and 22.18%higher than that of LED backup lamp based on the principle of total interna l reflection respectively.This can reduce the volume of traditional backup lamps and solve the problem of lighting uniformity which is caused by direct lighting in the current LED backup lamps. |
