Abstract Headlamps are essential for safe night driving, as they must provide sufficient brightness to illuminate the road while minimizing glare for other drivers.Designing low-beam optics is more complex than general lighting optics due to the need for a high-contrast cutoff dea eyewear line, with the brightest point positioned near its edge.This challenge becomes even greater when working with compact optical systems.
In this paper, we propose a robust optical design to address this issue effectively.We develop low-beam optics for bicycle headlamps using a cylindrical lens array (CLA) combined with reflective optics to create a specialized light pattern.The CLA spreads the optical pattern horizontally to form the cutoff line; however, this alone does not ensure optimal performance.
To overcome this limitation, we here introduce a novel design principle: the light pattern generated by the reflector, before passing through the CLA, should be inverse-triangular or trapezoidal.This approach enables the CLA to shift the brightest point upward and closer to the cutoff line, solving a key challenge in previous designs.