The end is coming for the long-serving electric light bulb -- in the automotive industry at least. But that creates a dilemma for lighting suppliers which have spent millions developing high-tech systems that use traditional bulbs.

Electronic semiconductors called light emitting diodes (LEDs) have been in use for rear light systems on cars since 2000. Now competitors in the sector believe LEDs may start replacing bulbs for low-beam headlights by 2006.

LEDs are smaller and draw much less power than bulbs. They have a long lifespan, and provide very 'pure' colour.

"Within five years we should have at least one function with LEDs at least on 50% of the vehicles," says Philippe Hidden, Valeo's Group Director, Sales and Business Development.

Hidden says the current installation rate for LED on rear light clusters is around 10%, but will grow rapidly.

LEDs light up around 250 milliseconds quicker than bulbs. That doesn't sound like much, but at 100kph, it's about seven meters in distance -- easily the difference between stopping safely and crashing.

"Now we have many applications of LEDs for rear lighting, especially for the tail section, which is a more useful function," says Hidden.

What's really driving LED development is the integration potential. Light emitting diodes are a true electronic component, rather than electronically-controlled electrics. This means that they can be integrated into the vehicle's electronic architecture, giving lighting systems a degree of intelligence for adaptive lighting systems.
Possible applications include: automatic fog lighting, which activates when the car detects fog conditions; brake force display, which illuminates a brighter and bigger area when the brake pedal is pushed hard; automatic reverse lights.

Diodes are equally significant for adaptive front lighting systems (AFS). They lead to a substantial reduction in the number of moving parts, and can be controlled more precisely and simply.

For example, a small number of LEDs can make up one light beam, any of which can be angled, dimmed or brightened according to requirements.

It all sounds good, but there may be an elephant trap ahead for suppliers. Across the globe, leading auto lighting suppliers have already spent millions developing adaptive lighting -- with bulbs providing the source.

Hella and Valeo in Europe, and Koito-owned North American Lighting have all reached series production of AFS of one form or another with various customers.

But the trend is less than a year old. Although the innovation has penetrated as far as German supplier Hella's application on the 2004 Opel Astra, it's far from being standard. Hella, with turnover around EUR2 billion, spent about EUR30 million getting its first AFS system on the road on the Audi A8 sedan in autumn 2002. Last year, Hella also launched its bi-xenon projector front light, which eliminates the need for headlights to come in pairs.
Hella engineered the world's first standard xenon front light in 1992, giving the high-end technology around a decade as one of only two options -- halogen or xenon. If LED headlights hit volume production by 2007, then these latest expensive breakthroughs have only a few years to generate returns.

Halogen still accounts for up to 75% of the European original equipment market. Hella's financial situation means the company looks to make money on every contract and can't really afford 'loss leaders'. The supplier anticipates 50% fitment of a bi-xenon/AFS combination in the premium and luxury segments in 2-3 years. It needs to make the most of it -- if nothing else to boost funding for R&D spending on the next generation.

Schefenacker, a German high-end lighting supplier, led the way with LED rear lights on DaimlerChrysler cars and currently doesn't compete in the front lighting market.
However, the company believes there is so much potential in LED front lights they too will join the party come 2006.