Schumacher, T., Fratty, H., and Dorleans, G., "Improvements in Low Beam Lighting Achieved By Complex Surface Reflectors," SAE Technical Paper 870059, 1987, doi:10.4271/870059.
A newly developed technology for headlamp system design utilizing reflectors of a continuous complex surface, results in headlamp performance and design flexibility previously unachievable. Beam pattern homogeneity, gradients and intensity are significantly improved and at the same time. The physical parameters of the lens can now include vertical and horizontal angles up to 3 times current limits. Current standards can easily be met with light emmitting surfaces of 50 mm in height and 135 mm in width. Larger dimensions would permit corresponding increases in performance. The results of these developments are outlined in this paper.