Design of a projector headlamp without using a screen

Abstract: A design for a projector headlamp that does not use a screen for low-beam lighting is proposed in this paper. The design not only enhances the light source utilization rate but also the elimination of the screen element prevents heat accumulation. The surface of the headlamp reflector is partitioned into six zones and, since there are no steps between reflectors, the zones are smoothly connected. A design equation for the reflector that combines varied lengths for both the circumference and optical axis is proposed and utilized for the surface design of each zone. Thus the reflector has the built-in ability to control light distribution in both the circumference and optical axis directions; consequently, it is able to create a very flexible light pattern, and is able to control all light rays to be below the cut-off line. As a result, the proposed projector headlamp can create a light distribution that meets the low-beam requirements of the ECE R112 standard