Optical and thermal designs of LED matrix module used in automotive headlamps

Abstract

With higher efficiency, brightness and reliability than traditional light sources, LED has been widely applied in automotive headlamps. The smaller volume and higher power density of a LED package drive the design of automotive headlamps with LED matrix model, such as adaptive driving beam (ADB) system. This paper proposed a matrix automotive headlamp module with rectangle lens array to balance the contradiction between improving the visual condition of driver in the nighttime driving and reducing the impact of glare on others from the opposite direction. Firstly, according to the requirements on light distribution provided by the GB 25991 regulation, the optimized optical design, including configuration of LEDs and structure of optical system, was developed based on the optical simulations. Secondly, the thermal management of the module was conducted by using the fluid finite element simulation through considering both the natural and forced convections. The results show that: 1) a LED matrix with specially designed rectangle lens array that contains different size of lenses can produce the independent and nonoverlapping rectangular light spots as required; 2) the heatsink with optimal designed pin fins can provide more effective thermal dissipation in convection.