Lens Material Development for Improved Halogen Headlamp Visibility

Automobile headlamps are highly controlled products that must meet various performance standards to be commercialized. The combination of the bulb and lens must emit acceptable color and light output. Commercially available headlamps use different types of bulbs but usually a clear or slightly tinted lens. In the past few years, high performance bulbs have been used. These are known as HID or xenon lamps and are characterized by their bluer color compared to standard halogen bulbs.

This paper explores some of the possibilities that new lens material can offer in terms of design and aesthetics with little or no impact on lighting performance as tested per the Society of Automotive Engineers (SAE) J1383 [1]. Light stability of these new lens materials is also discussed. In addition, this paper illustrates the possibility of creating a system based on halogen bulbs in which the beam chromaticity appears to be similar to a HID system in all angles of the beam pattern that are not in direct view. The potential benefits of such systems with regard to improved road visibility and glare is also discussed.