Light emitting diodes are coming to car headlights, and the changes are going to be a lot more radical than you think.
Think of a car. What mental picture do you conjure up? Probably something that resembles a face: a mouth (the grill) balanced by two eyes (the headlights) at its edge.
With LEDs, those eyes can go away or at least shrink, said Jonathan Dunlap, a project manager at Osram, who is overseeing a project to bring a modular LED headlight element to market. The Joule, Osram’s module, consists of five white light LEDs on a puck. A single unit, which measures only about an inch in diameter, can substitute in for a low-beam headlight. Put in two or three, and you have high beams, more light and other lighting effects.
The small size will give designers freedom they haven’t had since the dawn of the auto age. Traditional bulbs rely on burning filaments, glass globes and reflectors. Many car makers, of course, will continue on with traditional styles. A car without head lamps might look like a mole to a lot of customers.
Others, however, will likely experiment. You could do a completely smooth surface, punctuated only by a few points of light. Wraparound lights? Smaller ones? Why not? Unlike traditional bulbs, light from LEDs can be directed with a great deal of precision.
“With traditional lights, you need a large exit aperture. With HID or halogens, you were limited in size,” he said.
While red LEDs have become standard equipment for car tail lights, only a few manufacturers put LEDs on the front of their cars. Of these few, most only use LEDs as auxiliary lights on high-end models like the Audi A8.
Early adopters are already using LEDs to create design signatures. Audi’s LEDs are arranged to create a pointillist eyebrow. Mercedes uses LEDs to form a bar of light.
Joule light units will be made in such a way that car designers will be able to buy basic units and design around them. In other words, Osram will just have to make a few basic models to satisfy a lot of customers. It's no coincidence that the Joule name also sounds like 'jewel.' (Note to that this is another example of a company promoting a light fixture, not an LED.)
Yes, LEDs will extend the range of electric vehicles or improve gas mileage. The LED headlights in car like the Nissan Leaf consume only 21 watts of power, compared to the standard 55 watts consumed by a standard halogen headlight.
That translates into nine extra kilometers, he said. Osram is working on a light module containing five LEDs that will cut the power down to 14 watts. (Osram, he added, does not make the headlights for the Leaf.)
“It has a major impact on batteries and electric vehicles,” he said.
In a gas car, LED headlights can save 9 gallons of gas a year, he added. Increased mileage standards around the world will require car makers to curb power consumption any way they can. Panasonic has retrofitted a home air conditioner for cars that runs on waste heat. Ioxus is promoting ultracaps for starts and stops.
LED headlights provide an easier path to mileage improvements than a new engine design.