Greater Safety Through Optimized Light Dispersion in Less Space - Obtained by the Consistent Use of Plastics in Producing Headlamps 870302
Aerodynamic styling is playing an increasing role in the design of today's passenger cars. The profile sections of the frontends of cars imply that the available installation space for the headlamps - particularly its overall depth and height is decreased in size. New types of headlamps had to be developed.
One result of extensive investigations are stepped reflectors with up to six paraboloids with different focal lengths arranged around the same focal point. This type of reflector (called homofocular reflector) cannot be formed from sheet steel but from plastic by injection molding. Depending on thermal, mechanical and geometric boundary conditions three different reflector materials can be used: lacquered thermosets, unlacquered thermoplastics by one or two material injection moldings.
Similar to sheet steel the use of glass lenses reduces considerably the freedom of the designer. This disadvantage of offset by the use of plastic lenses. In addition there are advantages in weight and greater optical accuracy. Lack of hardness of plastics will be compensated for by coating the lenses in different ways.
Citation: Haack, W., "Greater Safety Through Optimized Light Dispersion in Less Space - Obtained by the Consistent Use of Plastics in Producing Headlamps," SAE Technical Paper 870302, 1987, https://doi.org/10.4271/870302. Download Citation