To most people, terms such as AFS, HID, Xenon, Neon, LEDs and CHMSLs mean very little.  But to lighting engineers, they spell out a bright future. Matthew Beecham sheds some light on the future direction of vehicle lighting, based on a brand new study jointly published by just-auto.com and ABOUT Automotive.

As vehicle makers demand innovative designs and keener prices from their suppliers, the major lighting manufacturers are continually coming up with some novel concepts. And electronics are playing a major role. Headlamps that can point round curves in the road and lights that change beam pattern to suit driving conditions are already a reality.

High intensity discharge (HID) lamps (or xenon) are also changing the market. HID offers lower power consumption, higher light output and a far longer life. Compared to a halogen lamp, a HID unit uses xenon gas to produce more light for less power.

Although HID headlamps demonstrate obvious benefits, they are still an expensive option, exacerbated by the fact that they must be fitted with a self-levelling control system. Suppliers estimate that discharge headlamps typically cost five times the wholesale price of halogen lamp units. But that isn't stopping vehicle makers from offering HID. In Europe, a joint research study by just-auto.com and ABOUT Automotive estimates that 19% of all cars built in Europe in 2002 featured HID. That could reach 37% by 2007 and 50% by 2010. Current European vehicle models fitted with HID headlamps include the VW Golf, Opel Astra, Audi A3, Ford Focus, BMW Z4, DaimlerChrysler Maybach, Renault Espace, VW Phaeton and Saab 9-5.

High intensity discharge and adaptive front light systems set to grow
The study predicts that in Japan, HID headlamps will show meteoric growth, rising from 17% fitment in 2003 to 46% by 2007 reaching 56% by 2010. Although the outlook in North America is less clear cut, a conservative forecast puts fitment rates at 6% by 2007, up from 2% in 2002. Others are more optimistic, predicting fitment rates could reach 10% - 12% by 2007. There are currently 60 different models available in North America with HID. In South America, the HID market is mainly featured on imported vehicles.

In March 2003, the first stage of some long-awaited European legislation swung into force, allowing manufacturers to introduce their advanced or adaptive front light systems (AFS). Initially, the so-called fast-track solution will allow street-legal swiveling of the low beam function. These increase the range of dipped beam in curves by almost 50%. But within a few years, car headlights will play a more active role in vehicle safety. The new legislation has removed the shackles from manufacturers, enabling them to offer the first phase of adaptive lighting in Europe.

The second stage, full AFS version, with additional features such as motorway beam operation or special light distribution for bad weather conditions, is forecast for approval by 2005. These systems will use electronics and simulation technologies to programme the headlights to react to the different actions of the driver. The computer-controlled headlight system can be programmed to react to a wide range of driving situations. Looking further ahead, such adaptive lighting technology could be integrated with a vehicle's navigation system to generate anticipatory information, thereby illuminating a bend in good time. In Europe, manufacturers predict that 10% of cars produced in 2007 will feature AFS.

The Japanese lighting market is evolving, too. In October 2002, Japan's Ministry of Land, Infrastructure and Transport approved the installation of AFS. In February 2003, Koito was the first to market with AFS, introducing it on the Toyota Harrier as a standard feature.

LEDs for rear lighting, CHMSLs and - eventually - headlamps
For rear lighting, light-emitting diode (LED) light sources are gradually replacing conventional incandescent bulbs, typically for Centre High Mounted Stop Lamps (CHMSLs). Although LEDs cost more than conventional bulbs, they offer a number of benefits. Unlike incandescent bulbs that are sensitive to shock and vibration failures, LEDs typically last the life of a vehicle. For this reason, LEDs have increasingly been used in rear lighting applications. Compared with incandescent lighting, LEDs allow new styling options, reduced warranty bills and higher product reliability. LEDs also illuminate at a faster rate than conventional incandescent lamps, improving driver response and providing extra braking distance of up to five metres at 75mph.

After proving their capabilities in vehicle rear signal and CHMSLs, LEDs are finding new applications in headlamps. Manufacturers expect to see LED headlamps in Japan by 2006, in Europe by 2007, and in the US by 2008. Automotive designers at Audi and Ford are adding headlamps to the growing list of auto lighting components powered by LEDs, reflecting technology advances that have made LEDs bright enough to be incorporated in headlights for the first time. The new headlamps are being built with Luxeon LEDs from Lumileds Lighting. Each Luxeon emitter delivers up to 60-times more light than conventional 5mm LEDs. "LEDs have been used in automotive signal lighting applications for a number of years, but until recently it would have required too many emitters to produce sufficient illumination for forward lighting," said Jeff Raggio, automotive business development manager for Lumileds Lighting. At the 2003 North American motor show, Ford's Model U concept vehicle featured Luxeon-based headlamps with low-beam and high-beam functions as well as dynamic corner lighting capability.

At the 2003 Geneva motor show, the headlamps on Audi's Nuvolari also used the Lumiled's Luxeon LEDs. The extent to which LED headlamps take off will depend, among other things, on cost. The actual cost of an LED headlamp will hinge on several factors, including the light sources, drive electronics, optical elements and thermal management components. A joint venture between Agilent Technologies and Philips Lighting, Lumileds is headquartered in San Jose, California with operations in the Netherlands and Malaysia. Other lighting manufacturers also see a bright future for LED headlamps:

Michael Godwin, manager for LED Products at Osram Opto Semiconductors, responsible for automotive LED products marketing, said: "The issue is the high-beam function with LED headlamps. Will LED headlamps appear? The answer is yes - but when. We will see the same gradual process with LED headlamps as we saw with HID headlamps. We probably won't see LED headlamps before 2007 [in Europe]."

Dr Rainer Neumann, head of Visteon's European lighting development team, agrees. He said: "I am convinced that we will have LED headlamps in the future. The only question is when. There are a lot of advantages to it. We are involved in this pre-development work. The major advantage is the lifetime of this light source, as well as the [low] power consumption and the flexibility of headlamp styling that you can achieve with LED."

Jeff Mickel, executive vice president of research and development and technical marketing at Guide Corp, added: "We have working prototypes that fit in packages smaller than existing lamps. We have demonstrated this to customers and feel that there is a good chance that it will end up on a production vehicle in 2007 or 2008 model year. We feel that we are pretty far along in that technology. There is also a bigger issue about reducing mass from the front end of the vehicle in respect of pedestrian safety."

Dr Albert Heidemann, vice president of Osram Automotive Lighting, said: "Light output of white LEDs has improved considerably. We presume that the first LED headlights will be seen on the road at the end of this decade. Recently, showcars of Ford and Pininfarina have already shown the feasibility. But to gain a considerable share of the headlight market, besides the brightness, there are a lot of other issues to be solved within a LED headlight system.

In Japan, lighting manufacturers are aiming to commercialise LED headlamps in 2006. But there is still a lot more development work to do before then. Current prototype LED headlamps have only one-third of the brightness compared with HID headlamps.

Hella looks to micro-optics and 'signature lighting'
Looking ahead, Hella expect to offer long signal lamps, flat contour lighting and contour lighting which continues around the tail end using micro-optics. They also expect this technology to feature in main and auxiliary headlamps, too. According to Dr Burkard Woerdenweber, director of Hella's research and test centre, so-called signature lighting as used in the BMW 5-Series could become very popular amongst other carmakers over the next few years. He said: "Using our light guide technology, we can put any signature on any car. It won't be long before this technology will permeate down the car segments."

Expert Analysis

2nd edition - The global market for automotive lighting equipment, forecasts to 2010, 2004 edition

In this second edition reviewing the key market drivers for new vehicle lighting technologies, we extend the analysis originally published in 2001. Chapter two sets out our revised fitment forecast for HID headlamps through 2010. In extending the analysis, we add forecast fitment trends for HID by vehicle segment in Europe and Centre High Mounted Stop Lamps with LED lamps. We also include market value estimates through 2007 by major car producing region for LEDs, HIDs and interior lighting. Find out more here.

 

Further developments in sensor technology could also offer rear brake-lights that respond to road conditions such as motorway emergency stops. One problem with multiple motorway crashes is that a driver may brake suddenly to avoid the car in front, but once stopped, his brake light goes out, ridding the driver behind of a useful indicator of trouble up ahead. Other developments include brake lamps that get brighter according to the braking force being applied.

Since its first appearance on the Ford Explorer CHMSL in the 1995 model year, neon lamps have demonstrated a lot of versatility in some automotive applications. A typical neon CHMSL has an operational life of more than 2,000 hours versus 1,000 hours for an incandescent bulb. Unaffected by extremes of heat and cold and able to withstand shock and vibration damage, neon is designed to equal or exceed conventional signal lamps. In addition to its performance under extreme temperatures, neon lighting has other specific technical advantages such viewing angle and colour.

Neon suffers cost disadvantage
But, as a number of manufacturers told the authors of this study, the challenge of using neon lighting over other sources is still cost. LED costs have fallen to such a level that it is now difficult to justify neon lighting. Neon lighting is currently estimated to be between three and five times the cost of LED. Consequently, the benefits of LED have eclipsed neon. Manufacturers do not see further growth in neon lighting, as Jeff Mickel, executive vice president of research and development and technical marketing at Guide Corp, said: "I see a trend away from neon. It only had minor applications. LED output-cost ratio has improved dramatically and that has been the main driver. I don't see neon being as big a player going forward as LED." Dr Albert Heidemann, vice president of Osram Automotive Lighting, added: "Neon lamps have the advantage that they can be activated very rapidly and they are very thin. From a styling point, they might be a good fit to innovative car designs. But not being 'point like' light source, they always have to be adapted to the shape of the car body which makes them a quite costly solution. As a result, we clearly see their field of application being shifted to LED with similar performance aspects."

It is clear that the vehicle makers' demands on their supply base are becoming tougher all the time. Their calls to reduce the time taken for new developments from 42 to 18 months and for delivery times from 65 to 15 days typifies the pressures on suppliers. So how exactly are they coping with these demands? Werner Beneken, Hella's member of the management board responsible for automotive sales, said: "Requirements really have increased enormously. In the past, the life cycle of a vehicle was seven or eight years. These days, a facelift is available after an average of three or four years and Hella is nearly always involved, providing modified headlamps and combination rear lamps.

On top of this is the fact that within this significantly shortened development time we are still being continually confronted with modification requests by the customer, right up to shortly before SOP [start of production]. In order to be able to react adequately to these requests, we have to provide a lot more resources in the development stage. This again has an effect on costs, of course, and the price pressure is still enormous. But one thing must be made clear, and we tell our customers this again and again: if they do not want to become dependent on the very large mega-suppliers, the only capable alternative they have are the medium-sized, flexible and innovative suppliers and their co-operations. But they have to give us a chance to survive, which means we are not going to keep accepting orders at all costs, rather our primary objective will be to make sure we do not lose sight of our yield targets." Mr Beneken then went on to emphasise how cost and price pressure for suppliers has reached a pain threshold that can no longer be accepted. "We need models that generate the necessary cash-flow. In other words, the financial risk must be divided more fairly, for example through up-front payments for development and tools or lifetime considerations after series production has started."

This feature article has been based on a brand new research study, jointly published by just-auto.com and ABOUT Automotive. Further details on this report can be found here.

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