The requirement to reduce the vertical frontal area of motor vehicles to improve aerodynamics and styling has prompted the development of headlamps having narrower vertical apertures. This paper describes the development work which has been carried out jointly by Lucas in England and Carello in Italy with the objective of maintaining the photometric performance achieved by conventional large headlamp systems. Various design possibilities including projector systems and reflector designs employing an unshielded bulb are considered but the Lucas/Carello work has led to the conclusion that the multifaceted reflector offers the greatest advantages. By employing these high efficiency multifaceted reflector forms it can be shown that the performance objective can be achieved from a reflector having a 75 mm vertical aperture.
