Fiber-Based Headlamp Lights Road to the Future

Daniel C. McCarthy

If you want the prestige of a luxury sedan combined with the higher road clearance of a sport-utility vehicle, check out Mitsubishi Motors Corp.'s SSS. But don't look for the SSS on the highway -- it's not even road-legal. Mitsubishi designed it strictly for exhibition at car shows, where it will demonstrate futuristic technologies and gauge the public's reaction to new designs. Show cars also give manufacturers an idea of how feasible new technologies are for mass production.

A high-intensity discharge headlamp developed for the SSS by Visteon Automotive Systems achieved all of these aims, according to Jon Hull, designer of the SSS. "Right now, the biggest restriction for Visteon's system is price; namely, the [high-intensity discharge] lamp," he said. However, the lamp design should last longer than standard vehicle lifetimes, enabling car buyers to eliminate the cost of replacing bulbs, he added.

As body-colored bumpers reduce the options for bright exterior trim, few stylistic features remain to distinguish one car from another. One exception is the headlamp. Most lamps illuminate the road by reflecting light from a halogen source, but complex reflector designs also are limited in what they can do differently.

"There are things with this lamp design that are more modular and that you can't do with halogen lamps," said Jeff Erion, manager of Visteon's advanced lighting group. "We have five designs that can be driven from the same remote light generator. The only way we could have done this is with the high-intensity discharge remote lighting system."

Fiber-optic-based headlamp systems could be lighting up the road within three years. Courtesy of Mitsubishi Motors.

Visteon designers assembled the SSS' headlamp using three basic components: a compact light generator, standard fiber optic cables and the lamp. The custom-made light generator measures 8 × 5 × 3 in., but it emits twice as much light as current halogen sources and uses half the energy, Erion said. Fiber optic cables deliver light to the lamp, which, unlike traditional designs that rely on reflection, uses an acrylic lightguide to shape the beam through refraction.

It has been several years since high-intensity discharge lamps began appearing on the road, said Erion, who predicted that in another three years vehicles will be lighting up the highway using fiber-based systems that should be comparable in cost.