PROCEEDINGS ARTICLE | April 28, 2008
Proc. SPIE. 7003, Optical Sensors 2008
KEYWORDS: Optical components, Light sources, Light emitting diodes, Roads, Lamps, Legal, Refraction, Headlamps, Optimization (mathematics), Electrochemical etching
The automotive lighting technology is in considerable progress due to new components, e.g., High-Power-LEDs and
light guides, and new sophisticated production techniques. Furthermore, great importance is being attached to the
appearance of front and tail lamps. White High-Power-LEDs have reached a development stage that affords its
reasonable application to low beam headlamps. This challenging illumination function requires sophisticated design
techniques in order to preserve the advantages associated with this source type. Thus, high efficiency and stylish
appearance have to be reconciled, e.g., with the use of freeform surfaces. Beside the demands from manufacturers and
customers, car lamps have to meet several regulations (ECE, SAE, etc.). This contribution describes the illumination
design of a LED-based low beam headlamp using advanced mathematical methods, e.g., 3D-Tailoring, automatic
optimization, and Virtually Reflecting/Refracting Surfaces (VRS). We propose this new surface type with non
conventional reflection/refraction properties as an advantageous design tool for the first layout and for automatic
optimization, as well. For efficiency reasons, special attention will be paid to the creation of the cut-off line without
using additional stops.
