Automotive Headlamp Concepts With Low-Beam And High-Beam Out Of A Single Led

Recent years have seen a surge in LED-based automotive headlamps including a variety of lighting functions like low-beam, high-beam, day-time running light as well as fog-light. Many of those lighting functions have been realized by designs that statically provide specific illumination patterns. In contrast, existing adaptive designs rely on either moving shutters or electronically-complex matrix sources.In this paper, alternative options will be explored for an automotive headlamp that combines low-beam and high-beam out of a single LED.The light source comprises two rows of chips arranged on a common carrier resulting in a compact LED. At the same time, electronic complexity is reduced by driving just the two rows independently.Primary optics collects the emission of the two closely-spaced chip rows and simultaneously provides a way to separate respective contributions. The subsequent secondary optics is based on facetted reflector shapes to realize low-beam and high-beam patterns.Efficiency, tolerances, system size, and cross talk will be evaluated for different primary optics based on refraction, reflection as well as TIR.