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LEDs have been used in exterior lighting since the late 1990s in the form of customized LED arrays. Typically for those applications, each LED had a lens or reflector optic. The future styling trends explore the use of light guides or fibers to create transparent three dimensional structures. Light guides allow the designer to create lamps of various shapes with one standard light module without the need to rearrange the LEDs. However the design of those light guides can be inefficient and has its optical and mechanical limitations. Therefore the optical coupling efficiency to the light source is a key element in the design of the system. Key features for a LED light source module (here called DVO for Direct View Optic module) are proposed and advantages over standard LEDs in light guide applications are discussed.

Halogen light sources for automotive forward lighting applications are designed for a nominal DC voltage and power, typically in the range of 13 volts and 55 to 65 watts. However some applications attempt multifunctional use, such as a high beam – day time running lamp (DRL) combination, by regulating the power. This can be done by pulse width modulation (PWM) or by simply lowering the applied DC voltage. More advanced applications, such as smart headlamps or advanced forward lighting systems, might also operate the bulb only for a short period of time. This can have a similar effect as PWM. In either case the halogen bulb will perform differently than at the DC design voltage. The valid power or voltage ranges do not only depend on the light source itself, but strongly on environmental conditions. Thermal management and external temperatures of the system can influence or prevent the halogen cycle activation and cause problems, such as bulb wall blackening.

This paper discusses the use of a new double filament light source in reflector optic designs of headlamps for ECE and US VOA applications. An explanation of the development of the bulb is offered and the unique features intrinsic are examined. Methodology for using this source to produce low glare and a sharp gradient cut-off in headlamps is discussed. Factors, which must be taken into consideration with this new bulb, are presented for review. Experimental results of the bulb analysis and headlamp photometric performance are included.