Seeing and being seen on the road is fundamental to both your safety and that of those around you, whether they are other vehicles or pedestrians. Almost all of the information we receive when driving is captured through our eyes. Therefore, without correct lighting, we will increase the risk of accidents due to poor visibility.
How has light technology evolved in cars?
Throughout the history of the automotive industry, the technology of vehicle headlights has evolved significantly. When the car was still in its embryonic phase, the first headlights were a direct inheritance of the carriages. That is to say, oil lamps that worked on the basis of oil lamps with a wick wetted in the same compound or in oil. The light was projected onto the road through a reflector, but it was very weak.
Later, at the end of the 19th century and beginning of the 20th century, carbide lamps appeared. Carbide stones were placed on top of a container which, by means of a water dropper, generated a gas that was transported by pipes to the lighthouse. The flame emitted was whiter and brighter than the oil lamps. Shortly afterwards, incandescent bulbs appeared. Thanks to an electric current, the tungsten filament produced enough light to displace the previous two.
The latter were part of the automotive industry until the 1960s, when the first halogen headlights made their presence felt. Today, they are still in use, and it is the simplest and most economical lighting technology. Apparently, they have great similarity to incandescent bulbs. But instead of a filament “vacuum-packed”, there is an inert gas inside that allows multiplying in consideration the luminous capacity, and the useful life of the bulb (close to 500 hours).
However, at the end of the last century, new and more powerful lighting systems appeared. In 1992, the BMW 7 Series unveiled the first generation of xenon headlamps. Their whitish/blue tone resembles daylight more, and reduces eye fatigue and fatigue compared to halogen lamps. Seven years later they evolved into bi-xenon headlamps, achieving the same intensity in dipped and main beam, thus avoiding dazzling oncoming drivers.
These bulbs do not have an internal filament like the previous ones, but a pair of electrodes that generate electricity. These heat the xenon gas in a similar way to conventional fluorescent tubes. Due to the intensity of the light beam and the fact that they do not generate heat towards the outside, xenon headlamps must be accompanied by a height control system and headlamp washers. They consume less and provide up to three times the light output of halogen headlights.
Although xenon headlamps are more expensive, their service life can also be almost three times longer. But in recent years we have seen the rise of LED technology (Light Emitting Diode), simpler, more energy-efficient, more economical and more “moldable” for designers in their integration into optical groups. Their service life can exceed 20,000 hours, and they deploy their maximum capacity from practically the first moment they receive energy.
They also emit the whitest light, with a temperature close to 5,500 K as opposed to the 3,000 and 4,500 K offered by halogen and xenon bulbs, respectively. In addition, LED lighting allows car manufacturers to more precisely adjust the brightness of the drivers. Comprised of several matrix modules, the diodes can be calibrated to illuminate specific areas and adapt to track conditions.
But humans evolve, as do lighting systems. Just a decade after the landing of LED technology, with the Lexus LS 600h and Audi R8 in 2008 the first to offer them, laser technology has appeared. Since 2014, BMW as well as Mercedes-Benz and Audi have found themselves immersed in a battle to see who launched a laser headlight in a production car before. BMW finally took the cat to the water.