Automotive Lighting, the company responsible for the headlight design of the new F80/F82 M3/M4 and new 4 Series, has provided a complete picture showcasing the LED technology.
Hussein Al-Attar, the designer responsible for the headlight design of the BMW 4 Series Coupe, described the design thinking behind these beautiful lights.
The LED lighting technology used in the BMW 4 Series Coupe Concept is essentially the same as in the BMW 6 Series models, but it changes from round lines to open hexagons. Al-Attar pointed out that connecting the light elements with the completely enclosed air intake grille is a new idea. In fact, it looks better in person than the LEDs on the current BMW 3 Series sedan, and will likely be retained on the production BMW 4 Series Coupe.
"We had a very clear idea from the beginning," Al-Attar said when designing the lighting for the 4 Series Coupe concept car. "In the end it was just a matter of fine-tuning and discussing whether the lines connecting the lights to the grille should be placed slightly higher or lower. Location."
But what is the actual technology behind these headlights?
LED technology in headlights
In rear lights, red and yellow LEDs are already the state of the art in lighting technology. In headlights, white LEDs that provide better light efficiency are particularly needed. White LEDs are already used in several series projects for signaling functions such as position lights or daytime running lights. The automotive lighting company has created a world debut by developing the Audi R8's first fully LED headlights. For the first time, all lighting functions of a series of headlights use LED technology, including high and low beams, daytime running lights, turn signals and position lights.
Advantages of LED
The light temperature of LED almost reaches daytime light quality.
Extremely long life, lasting the entire vehicle life.
Energy consumption is significantly reduced.
Utilize the headlight installation space more efficiently.
In the development of the headlights, unique freedom and diversity were provided to develop design elements characteristic of the brand.
LED function
LEDs are based on semiconductor technology. When a forward voltage is applied, light is emitted directly from the semiconductor substrate. The color depends on the energy gap energy of the conduction and valence bands of the material that forms the semiconductor. Through a luminescence conversion process, white light can be produced. By combining a blue diode with an applied conversion material, the combination of blue and yellow is perceived as white light.
Technology implementation in headlights
To achieve the target light pattern required for LED applications in headlights, there are two traditional options, already implemented in filament and gas discharge lamps. Either redirect the LED's light through reflectors to achieve light patterns on the road. Alternatively, a compact system could be applied using lenses to project light onto the road. Due to the small size of LEDs, there is an opportunity to combine these two light systems together for the first time.
Temperature management
Unlike halogen lamps or xenon systems, LEDs emit "cold" light, that is, they do not produce infrared radiation. Due to their high efficiency, LEDs convert up to 20% of the input energy into visible light in LED lighting systems (compared to only 5% for filament bulbs). The rest of the energy generates heat within the semiconductor chip. Luminous flux, color and forward voltage are temperature dependent. Once the allowable temperature is exceeded, the life of the LED will be seriously affected, and in the worst case, it may even be damaged. In order to protect the hottest part - the chip, a cooling element with a controlled air flow delivery system was developed. Directs warm air to the bezel of the headlights for both de-icing and defogging.
Reduction in energy consumption
The application of LED technology significantly reduces carbon dioxide emissions and fuel consumption. This aspect is particularly important when implementing daytime running lights (DRL). DRLs using LEDs require 14 watts of energy, while traditional vehicle lighting (low beam, rear lights, position lights) consumes 300 watts during the day.