Audi has been at the forefront of LED (Light Emitting Diode) technology since 2003 when they showed a slat-shaped LED fog light on the 2003 Pikes Peak Concept at Detroit and an all LED headlight on the Audi Nuvolari quattro at the Geneva Motor Show in that same year. In 2003 Audi also helped set up a working party to speed up EU approval for advanced and powerful lighting technology. Now, the EU has granted a special permit to Audi to start offering the all LED headlight on the R8 sports car.
Audi is quick to point out they are the first car manufacturer to develop this “revolutionary technology of the future”, however, they cannot take all of the credit. Also involved in the research and development were LED manufacturers Philips Lumileds Lighting of California and Automotive Lighting from Reutlingen Germany.
The all LED headlight is fully functional for daytime running lights (which is already available on the R8, A5/S5, S6 and since 2004 on the A8 W12 quattro), turn signals, dipped low beam and high beam lights. Each headlight unit uses 54 LED light sources and is especially remarkable for its low energy consumption (50 watts for the low beam headlights, 6 watts for the daytime running lights). The LEDs are arranged in clusters or “arrays” which function together as a single light source. In reference to the page photo above, the LED lamp assembly is separated into four areas:
LED low-beam headlight module: basic light distribution by an array of four LEDs for each of the upper and lower reflector shells, range and light/dark boundary via the plastic lens from three arrays of two LEDs.
LED high-beam headlight reflectors: one array of four LEDs per reflector shell.
LED turn signal: eight yellow high-performance LEDs.
LED daytime running light strips: 24 white Advanced Power TopLEDs with optical fibers for homogeneous illumination.
In addition to these four sections, there are also two cooling fans, one for each low and high beam. According to Audi, since the amount of heat generated by the LEDs is low, the fans serve to circulate heat forward to the plastic lens in order to melt ice or snow instead of acting as a cooling device for the high and low beams.
LEDs are a type of semiconductors (1 square millimeter) which are silicon based and convert electricity to light by electronic means. The light that is given off is known as electroluminescence which is 10 times faster than a conventional filament bulb which gives off incandescent light. Compared to the conventional halogen and xenon bulb, reflector/housing and lens assemblies, LED lighting technology has major advantages. Due to their smaller size, increased durability, increased lifespan and low energy consumption, LED lighting systems will undoubtedly take over as the primary lighting source in future vehicles.
However, despite revolutionary technology aspects, there are also major design implications. As a result, car designers now have increased flexibility to explore alternative headlamp shapes and configurations which beg the question: is the conventional headlamp a thing of the past? Andreu Sola Gomfaus, Head of Lighting Design at Audi, suggests, no. “Because the LED light no longer comes from a single light source, the LED arrays are very flat and compact and occupy much less space than conventional headlights, it will in future be possible to transform the face of a car much more easily. Several LEDs can moreover be combined in all manner of shapes, for a striking look.” However, Gomfaus goes on to explain that the headlamp shape is not going to disappear. Cars are still consumer products which are the slaves of human emotions and virtues. In addition to many other components, designers depend on headlamp design to give vehicles soul and identity. The challenge now is to find a balance between function and aesthetics which is nonetheless an exciting aspect of future car design.