A Study On Color Temperature Distribution of LED Headlamp

Zhuang Meilin^{1, 2}, Li Shuizhi², Lin Yandan^1*

¹ Department of Illuminating Engineering and Light Sources，Fudan University; Shanghai, P.R.China

² Shanghai Research Center of Soild-State Lighting Engineer and Technology; Shanghai, P.R.China

*Contact email address: ydlin@fudan.edu.cn

Abstract—The illuminating effect and visual comfort of LED headlamp exert a powerful influence on driving safety. In this study, we found that the color temperature uniformity of high beam and low beam of LED headlamp are not ideal by testing the distribution of color temperature on the lamp and on the test screen. This phenomenon mainly occurs at the edge of light distribution, meanwhile, the color temperature in the intermediate region is higher than in the edge. The near-field light distribution of four LED devices with different packages were tested and used in headlamp optical simulation. The result explained the cause of the color temperature non-uniformity. Moreover, we proposed several suggestion in LED device and headlamp development.

Keywords- LED;Headlamp;Color temperature distribution; uniformity;