According to statistics, the majority of accidents occur at dusk or at night – poor visibility is often the trigger. Intelligent headlights adapt to the current traffic situation, and can be a remedy. In collaboration with industry partners, Fraunhofer researchers have developed a high-resolution illumination system with more than 1,000 LED pixels: It offers considerably more options for precise light distribution than previous solutions have and is also energy efficient.

Out at night on a winding country road. It‘s raining and, to make matters worse, the headlights from the driver behind you are blinding. This is unpleasant and may, at worst, lead to an accident. Modern headlights make nighttime driving safer by adjusting the light distribution to the current traffic situation: While they illuminate specific areas in a targeted fashion, they do not blind other road users. Since light is generated on the light source only where it is needed in the traffic area. The LED chips are currently installed in headlights. Adapted to the topography of the component,“ says Oppermann. A small unevenness of a few micrometers, which inevitably occurs, can therefore be compensated for easily and quickly.

In order to be able to control each point of light independently a gold nano-sponge establishes the contact between each individual pixels and the driver chip. The nanoporous gold structure compresses like a real sponge and can be precisely adapted to the topography of the component. (Photo credit of Photo Fraunhofer IZM)

This is because previous solutions have drawbacks: LED lighting systems are relatively large and expensive: one LED is needed for each point of light. Today, up to 80 individual LEDs are commonly interconnected to form a system. In order to produce a coherent beam of light on the road, though, every LED has to have its own, precisely aligned optics. In another approach, the light source is a laser light or an LCD display with LED lighting, which fades areas of the light distribution according to the situation. Since light is produced and reabsorbed, this solution is not very energy efficient. The same applies to the method of shading certain areas by means of mechanical masks. In the latter system, moreover, only relatively large areas can be selectively illuminated and darkened.

According to the research institute, project partners of µAFS, an abbreviation standing μ-structured LEDs as smart light sources for novel adaptive headlight systems, includes Daimler, Hella KGaA Hueck & Co., Infineon Technologies, Osram,

Osram Opto Semiconductors, Fraunhofer Institute for Applied Solid State Physics IAF, Freiburg Fraunhofer Institute for Reliability and Microintegration IZM, Berlin. . The German Federal Ministry of Education and Research (BMBF) is funding the project in the field of „Integrated Microphotonics“.

•    Research News March 2016 - Better visibility when driving at night [ PDF  1.36 MB ]

•    Fraunhofer Institute for Reliability and Microintegration IZM