In this Q&A, just-auto talked with Dr Rainer Neumann, director of global lighting business development, Visteon, about the company’s light system innovations.
just-auto: What trends are you seeing in OEMs’ strategies with regard to vehicle lighting systems?
Visteon: Exterior lighting is extensively used by car manufacturers as a way of differentiating vehicles and brands. Daytime running lights (DRL), which was made mandatory for all new vehicles in Europe in January 2011, is a good example. More and more new configurations and shapes determine the styling of the DRLs which typically uses with LEDs.
Also, the overall trend in using LEDs as light sources for both rear lamps and headlamps is clearly visible. However, for LED headlamps it will take a few more years to achieve reasonable take rates in all vehicle segments.
What are the benefits and opportunities of LED technology in automotive applications?
Due to the long life time and the short rise time - which is a safety feature especially for rear lamps - LED light sources offer tremendous opportunities to design unique and attractive lamps. It can create a signature light, which identifies the vehicle brand and type. In the future, it will also lead to improved light performance for headlamps.
LED automotive lighting is becoming popular for a variety of applications. Yet what are the practical, constructive and regulatory challenges to consider when turning an LED idea into a product?
The main challenge is the cost of the application. Whereas the need for LED technology for rear lamps and the third stop light applications generally has been accepted, LED headlamps are still only seen on a few vehicles of the premium segment today. Visteon’s target is to develop LED modules in high volumes and with best in class performance for competitive costs.
The legislation work is principally done now. Visteon has introduced the LED light source for all applications in the ECE world.
As LED automotive headlamps gains momentum, are there concerns about the permissibility of colour fringes observed in the headlight pattern?
LED headlamps show a different colour than HID (Xenon) or halogen bulbs. Because of the physical background of the lamp, using a blue LED as the basis to create a white light creates the impression to have a bluish light rather than the yellowish halogen bulbs.
The recognition of the road obstacles illuminated by LEDs at night does not create any colour fringes or complaints with respect to visible colours. On the contrary, the driver appreciates the clear and white light impression that he can see.
For some time, the North American automotive lighting market has lagged behind that of Europe and Asia. To what extent are the Americans catching-up in terms of, say, styling and the application of LEDs?
The North American market has always been very different from Europe or Japan. In North America, styling of the lamp has always been important and in the past we have seen some very exciting and specific styling solutions which we have not seen in Europe.
Today, the availability of LEDs is supporting this approach even more. The North American market now recognises that LEDs support styling and that the lights - especially the rear lamp applications - are very much appreciated by the consumer.
While the current focus seems to be on LED, to what extent does electroluminescent systems allow for the realisation of adaptable laminar illumination for instrument panels, interior lighting, signal lamps, etc?
Electroluminescent devices are quite often used in interior lighting applications and instrument panels. For rear lights, LEDs are offering better performance in terms of illumination and light volume. With LEDs it is possible to generate pin pointed light sources in a chain but it is also possible to design a light pipe or a grained light guide to achieve optimum homogeneity.
What are the opportunities for electroluminescent technology for ambient lighting solutions?
As interior lights are getting increasingly popular, there is a need to have adaptable light colours which interacts with the vehicle’s interior features and functions (e.g. music, entertainment, driving behaviour etc). Electroluminescent technology can meet these requirements and its application is likely to expand in the short term future, starting with the premium vehicle segment.
In terms of vehicle style (and branding), to what extent are you seeing vehicle model names being incorporated within headlamps?
So far we have incorporated the name of the technology used in some headlamps (e.g. Xenon Light, Dynamic Light etc) as an explanation of the technical content. For vehicle model names or brands, I do not see a high level of interest in the market. The illuminated lights can identify the model name much easier.
Lighting regulations are now greatly reduced in number and substantially harmonised. What impact has this had on your business?
Unfortunately, we are still a long way away from reducing and harmonising regulations in the lighting business. More than one third of the current ECE regulations are dealing with lighting applications. We did see some progress in the harmonization between SAE and ECE regulations about ten years ago but this was unfortunately halted.
Today, the Group de Travail Bruessel (GTB working group) runs some initiatives that serve to summarize certain regulations with similar content with the objective of reducing the number of ECE lighting regulations, but this will take a few more years. In parallel, we need to make sure we include new technologies such as glare free high beam and other driver assistance systems into the regulation process.
What were the challenges in developing front lighting that meets pedestrian safety?
The European pedestrian protection legislation did experience some delay and phase II, which introduced more stringent requirements, is still not implemented. In the past, we therefore included technologies which focused on the need to absorb the forces generated by a crash. For more stringent requirements, which will come in to effect in the future, Visteon has production ready solutions such as flexible headlamps, which deforms in a crash situation but is pushed back into its original position after the crash without damage.