LED Headlights: Lexus LS600h, Audi R8

LED light sources have become common in automotive taillight applications. For taillights, the light does not have to project and need to be simply bright enough for other drivers to see when daytime running lights (DRLs) and/or the brakes are engaged. Because of the low brightness requirements, LEDs have been able to replace regular bulbs for taillight applications. With continued advances in LED technology, brightness has increased considerably over the last few years and now we see LED technology begin to penetrate automotive headlight applications, especially for in forward lighting.

Audi’s luxury sports car, the R8, will have LED DRLs standard with LED headlamps as an option. Although five other Audi models have LED-based DRLs, the R8 will be the first Audi to use white LEDs for both high-beams and low-beams. In Audi’s case, the LEDs are manufactured by Philips Lumileds and integrated into a headlamp by Automotive Lighting in Germany.

Toyota is also introducing LED technology for its headlights, but only to function as a low-beam projector. Toyota’s luxury division, Lexus, will introduce LED low-beam projectors on its ultra-luxury LS600h saloon. Halogen and Xenon lamps will also be offered as standard and optional items, respectively, on the LS600h. Why the shift to LED power? There are several advantages. LEDs can last about 100,000 hours, or more than 11 years. Although some might incorrectly think think brightness levels do not decrease for LEDs, they do in fact decrease. The 100,000-hour lifetime specification is actually the time it takes for the LED brightness to hit 50% of its original brightness. Still, 11 years is a very long time, and much longer than conventional light sources. LEDs are also solid-state, meaning there are no moving parts and therefore are very durable and somewhat more resistant to shocks and bumps relative to halogen or Xenon. The picture above shows a three-LED powered low-beam headlamp. We will most likely see more LED technology being applied to all automotive headlamps as LED chip and packaging technologies continue to advance.

Update 2008.05.30
Autoblog is reporting that the Audi R8 will be sporting a full LED headlamp and that includes high and low beams, turn signals in addition to the DRLs. The DRLs alone took 24 LEDs so you would think the entire LED headlamp would require quite a bit more. Nope. the entire LED headlamp requires just 54 LEDs. The light coming out of the LEDs are said to be really close to the color of daylight, instead of the yellowish stuff most of us are used to. The LED headlamp option will take a big toll: £3,590 or $7,100 USD, enough to purchase a used A4!!!

Source: LEDs Magazine, Motor Authority, Autoblog

[tags]Lexus, Audi, R8, LS600h, Automotive, LED Headlight, LED, LED Headlamp[/tags]

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