Vehicle headlamp construction for a well defined lower beam pattern

摘要

A vehicular headlamp has a reflector which is so optically designed as to provide, by reflecting light from a light source, a basic beam pattern of approximately semicircular shape wholly disposed below the horizon, with a top edge cutoff extending horizontally. A front lens is stepped to produce a lower beam pattern by raising part of the basic beam pattern and by horizontally expanding the rest of the basic beam pattern. The top edge cutoff of the lower beam pattern is as clearcut as that of the basic beam pattern. Either of two different lower beam patterns required for vehicles keeping to the right and for those keeping to the left is producible merely by changing the optical design of the front lens.