Today’s high-tech headlights explained
From LEDs to lasers we’ve gathered the very best here
Headlights are hugely important for cars as they not only serve an important safety function (i.e. lighting the road ahead to make driving in darkness possible) but they also need to be integrated into the overall design in a way that doesn’t jar. But it’s the technology that makes night driving a breeze and how it works is the topic of this piece.
Currently the most advanced type of headlight uses lasers instead of traditional halogen or xenon bulbs. After headlight lasers the next most advanced are what are called the LED matrix headlights which feature dozens of diodes that grant them great precision when projecting light.
Now while full LED headlights are becoming increasingly common even among affordable cars, the most advanced kinds with the largest number of diodes is reserved for high end motors. The same applies for laser lights which can currently only be specified on the BMW i8 and 7-Series, as well as the Audi R8 LMX edition; no other car has them yet.
So how do laser lights work? Well, they do use diodes to emit light - three separate beams, in fact, which are guided by mirrors into a prism which merges them into a single beam. Said beam afterward passes through a yellow phosphorus-filled lens thus activating the phosphorus inside which in turn emits white light and that light is reflected yet again, then passed through a clear lens before it illuminates the road ahead.
Sounds pretty complicated because it is, but BMW, one of the two proponents of the technology, says these lights use 30 percent less power than full LED headlights and provide double the light distance compared to them. They also offer superior packaging compared to LED headlights too.
However, laser lights have several downsides, only one of which is their prohibitive cost. They also don’t work for low and high beams so they need to be backed up by a more conventional system and they require serious constant cooling - that’s not strange when you’re talking about high-powered lasers, but in the realm of automotive headlights it is a bit much.
That’s why full LED lights are far more popular these days, even with their added cost compared to Xenon lights. Their growing popularity is due the fact that they allow manufacturers to make the headlight any shape they see fit, plus they also use a lot less energy than halogens or xenons. Plus they’re also brighter than halogens and almost as bright as Xenons.
There are also matrix-style LED headlights too, which do away with the necessity to switch from low to high beam - they offer great light dispersion precision and can effectively block light hitting an oncoming vehicle all while using the full illumination capability they offer (i.e. driving with high beams all the time). If you haven’t driven a car with active high beam assist yet, we advise you to try it and be amazed by just how much more relaxed it makes night driving knowing you always have maximum visibility and the system does the work for you. Still, they are not perfect: price for an LED system is still quite high (higher than an equivalent Xenon solution) and they too emit quite a bit of heat and require heatsinks to keep cool.
We’re not yet sure laser headlights will take the automotive world by storm in the manner LEDs are now doing and replacing Xenons. We are, however, very curious to see how current technology progresses and what new developments will shake the sector in the future. Maybe the next step is not necessarily radically different technology, but smarter application of what we have today through the use of clever software.
Volkswagen, for instance, has its own LED lights it offers on the new Arteon, and they are adaptive and curve around corners to give you maximum visibility just like everybody else’s. The difference here is VW’s solution (called Active Light System) offers a predictive option in that it doesn’t change the light’s direction only based on steering wheel input - it uses a combination of images from the forward-facing camera and sat-nav data to further improve cornering visibility.
This kind of idea, which blends using several features the car already has in new ways (the forward-facing camera and sat-nav) is the way to go as modern cars are chockfull of electronic gadgets that could definitely do more than one job since they’re already there. What will the next big advance in auto headlights be and how will it affect the industry?