Based on new optical technologies, the next generation of headlamps will support the driver with freely programmable and adaptable light distributions. In combination with forward-looking vehicle sensors and intelligent software, it will be possible to improve the driver's perception while driving at night or in adverse weather conditions. New functionalities, such as for example marking light, glare-free high beam for oncoming traffic and driver-specific light distributions, will be feasible and thus increase safety and comfort. In order to provide these features, an active headlamp will be a complex system consisting of sensors and electronic and optical components. In this paper three different concepts for optical technologies that facilitate the generation of assisting light functions are presented. In the so-called scanning headlamp, a basic light distribution is generated by a modified free form reflector. Part of the light, emitted from the light source, is collimated and deflected by two mirrors which are attached to galvanometer motors which allow for a fast and high precision movement of the mirrors. The DMD (Digital Micromirror Device) headlamp is an array of aluminum mirrors that reflect the light of a high intensity light source. A DMD device allows the generation of a picture consisting of light and dark pixels which not only allows the generation of a large variety of light distributions, it also permits the display of characters and symbols on the street. In contrast to DMD and scanning headlamps, in a LED-array headlamp the light sources are addressed directly and light distributions are generated by creating an image of a matrix of LED-chips and the generation of different shapes of light. By means of a PWM (Pulse Width Modulation) driver, the LED-chips can even be activated at different levels of brightness. These concepts have already proven their operability under laboratory conditions.
Optical technologies for future headlamps
Optische Technologien für zukünftige Scheinwerfer
2005
10 Seiten, 8 Bilder, 7 Quellen
Aufsatz (Konferenz)
Englisch
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