Spencer, C., "Headlamp Developments with DMC Reflectors Including Homofocal Arrangements," SAE Technical Paper 840041, 1984, doi:10.4271/840041.
This paper reviews headlamp developments that have taken place in Europe and particularly in the UK. It outlines the changes which occoured due to the requirement for greater styling and aerodynamic design freedom and resulted in the introduction of headlamps having a rectangular frontal aspect. These headlamp design changes dictated a move away from the twin transverse filament approach of the SAE beam distribution to the more controllable shielded axial filament system used to achieve the ECE beam pattern. The relevence of the UK experience is discussed in view of the changes that have been introduced to permit replaceable bulb headlamps in the USA.