In the middle of 2006, the first car equipped with an intelligent AFS (Adaptive Front-lighting System) headlamp went into serial production and has, until now, generated a very positive reaction in the press all over the world. The different AFS beam patterns in this car are generated by a Xenon AFS projector module, which works in combination with a swiveling actuator system.
One of the big innovative steps in automotive front-lighting technology that is soon to be released is the introduction of the LED (Light Emitting Diode) as a new light source for headlamp applications.
The benchmark for this new light source technology is of course the well accepted performance level of today's HID headlamp systems.
On the one hand, it is very important to achieve the HID performance level in terms of luminous flux, peak intensities, distribution characteristics, homogeneity and other positive attributes. On the other hand, the flexible functionality of modern headlamp systems like dynamic bend lighting and the realization of the AFS beam pattern will be the target for the next steps in the development of an LED-based headlamp system.
In this paper we will describe the different technology and strategy aspects which enable us to achieve the aforementioned HID performance level and modern AFS functionality when using the LED as a light source.
Due to the special characteristics and behavior of the LED light source, there are big challenges which have to be solved, particularly in terms of:
flexible addition of singular beam pattern elements generating the AFS light functions, like town light, country light, adverse weather light and the motorway light.
realizing a system behavior similar to dynamic bend lighting simply through intelligent switching of different beam pattern elements and without using mechanically moving elements in the headlamp.