LEDs may lead to new car lighting

Light-emitting diodes, or LEDs, are almost as old as transistors. But technological advances in recent years have paved the way for a new generation of high-powered LED headlamps that will change auto styling and possibly improve safety.

Lumileds Lighting, a Silicon Valley firm that has pioneered high-intensity LEDs, announced last month that it would provide LEDs for daytime-running lights in the new Audi A8.

LED headlamps will begin appearing by 2006 or 2007 on new vehicles, most probably luxury and other high-end models, said Doug Silkwood, director of marketing at Lumileds.

Because LEDs are so much thinner than traditional headlamps, they will give automotive stylists new flexibility in designing front ends. Already, concept cars are being designed with all-LED lamps for exterior uses.

LEDs would offer several other advantages. Typically, they operate many times longer than traditional lights before needing replacement, and they are about twice as energy efficient. Japanese automakers have estimated that LED headlights alone could improve fuel efficiency by half a mile per gallon; I take that with a grain of salt because some people rarely drive at night.

Still, one big benefit of LEDs could come in the area of glare reduction, though they are such an unknown commodity that it’s probably much too soon to say they will solve the growing safety problem of nighttime glare.

Thousands of motorists have complained to the federal government in recent years about headlight glare, a problem most often blamed on high-intensity discharge lamps, or HIDs. Owners of the luxury cars that have HIDs love their ability to provide better illumination of the road, but other motorists say their bluish glare is so intense that they can impair night vision.

The National Highway Traffic Safety Administration is conducting a multiyear program to reduce headlamp glare, saying the three primary causes of complaints are HIDs, high-mounted lamps on light trucks (sport utility vehicles, pickups and minivans) and fog lamps. The agency aims to create new federal rules next year to reduce glare.

LEDs could help, Silkwood said, because the shape of their beams and their optical brightness can be controlled more precisely. A cluster of eight LEDs would be needed for a headlight. Eventually, designers could develop dynamic lighting -- so that when a car makes a tight turn, the LEDs would provide additional light to the side.

LEDs are essentially semiconductor devices that produce light when photons are excited between force fields. So they emit less heat than lamps with filaments, and they don’t contain gases like fluorescent lights.

Lumileds, which produces its devices in San Jose, has led the way in developing higher-powered LEDs, which also are showing up in flashlights and eventually could outperform compact fluorescent lights for home use, Silkwood said.

LEDs already have overtaken the traffic signal market. You can see them in traffic lights with clusters of red or green dots. Conventional incandescent lamps consume 10 times more power and last only six months, compared with seven years for LEDs.

But LEDs aren’t cheap. They will probably cost about as much as HIDs, which run as $500 options on new vehicles. Is $500 too much for a new headlight?

Well, I’d hate to be driving behind uncovered gravel trucks on Southern California freeways with that much dough invested in the front end of my car.

Ralph Vartabedian can be reached at ralph.vartabedian@latimes.com.