Vehicle Lamp Light Guide With Dual Reflection for Cut-Off Beams

The light guide is divided into multiple functional regions: a light receiving region with asymmetric curvature (different radii of curvature in vertical and horizontal directions), a light emitting region, and a reflective region. This segmentation allows each region to perform its specific function optimally, with the asymmetric light receiving region focusing light efficiently while the reflective region redirects blocked light, thereby reducing overall light loss without requiring a completely complex structure.

The light receiving region is designed with asymmetric curvature where the radius of curvature in the vertical direction differs from that in the horizontal direction. This local variation in geometric properties enables differential light control: the vertical curvature controls the cut-off line formation while the horizontal curvature optimizes light collection, reducing light loss in specific directions without affecting the overall beam pattern definition capability.

The reflective region, positioned at the lower end of the light guide, captures light that would otherwise be blocked to form the cut-off line. By reflecting this previously wasted light back toward the light emitting region, the system converts the harmful light blockage into a beneficial secondary light path, thereby maintaining beam pattern quality while improving overall light efficiency and reducing energy loss.

The asymmetric light receiving region is designed in advance with specific curvature radii to pre-focus light before it reaches the light emitting region. This preliminary optical conditioning ensures that light is efficiently directed toward the emission area, reducing the need for subsequent blocking and minimizing light loss before the light even reaches the point where cut-off line formation would occur.