Optical Design Of Independent Free Form Surface LED Automotive Dipped And High Beam Headlamp

The automotive lamp had experienced a constantly updating with the advance of technology of automotive industry and the updating of lighting industry. LED quickly got the favor of people and became the focus of various vendors fighting for mass production use for its small volume, long service life, high security, good vibration resistance and many other advantages. Automotive headlamp especially the dipped and high beam provides the necessary guarantee for security at night, so the national standard put forward strict requirements for automotive dipped and high beam. At present, LED headlamp has been developed but the immature technology and the problem of low luminous efficiency of single LED are still the design problems of automotive dipped and high beam.The contents are listed below:1.The development course and domestic and international current situation of automotive headlamp were generalized. The advantages of LED as the vehicle light source were summarized. The theoretical basis of automotive headlamp design was elaborated. Meanwhile,the optical systems of dipped and high beam were divided into three categories which led the free form surfaces to be the final choice for the design. The national standard was introduced briefly.2. A dipped and high beam headlamp based on GB25991-2010(Automotive headlamps with LED light sources/or LED modules) was designed with high-power LED and 3 pieces of independent free form surfaces for low beam and 1 piece of independent free form surface for high beam. The area of automotive headlamp structure was calculated by CATIA. To achieve light distribution requirement, the fundamental surfaces were divided legitimately and the surface profile data of sub-surfaces were optimized and adjusted. The simulation of optical design and analysis of national standard were realized by Lucid Shape software. The results indicated that the optical system had gotten a high optical efficiency which fully met the requirements of the illumination of regulation on each test point, combined with simple structure and low cost provided all LED automotive light source possible to low configuration vehicle.3.Contrast the halogen headlamp system with the same structure with the LED’s in isolux curve simulation, road scene illumination and TC4-45 technical report to further verify the advantages of LED light source for realizing automotive dipped and high beam headlamp system and the feasibility of this design. Then the sample lamp was tested and carried out regulations validation, the sample lamp test result had achieved 73.5% of simulation value which was much higher than expected 60% and was up to the installation standard preliminarily.