Car headlights have changed a lot over the years. In the early days of the automobile, the road conditions themselves were so bad. That most people didn’t even want to drive at night. So, the early cars didn’t even have a dedicated lighting system.
With time cars became more reliable, and road infrastructure started meeting public demand. This led to people venturing out even after sundown.
Seeing this shift, car manufacturers started including headlamps in their vehicles. But during those early days, those headlamps were still not an essential part of the car’s design.
In fact, until the start of the 1900s, most vehicles features old-school gas or oil lamps. This was a big problem, as these lamps couldn’t operate in adverse weather conditions. Moreover, they needed to be refueled each time you took your car out.
This changed in the early 1900s when acetylene gas lamps started becoming popular. They were built better, and the flame could resist wind and rain. They also featured concave mirrors and magnifying lenses to augment the light.
This remained the standard for car lighting until the 1920s. When electric headlights finally started becoming a viable alternative. What sealed the deal was the, at that time, innovative feature of electric lights. Which for the first time allowed drivers to switch between low and high beams. without actually having to stop and get out of the vehicle.
This change to electric lighting made vehicles more reliable and safer. While also making it possible to standardize the headlight designs. It also kicked off the evolution of car headlights. Which started from filament bulbs, and has gradually evolved to the LED lights we see today.
Let us take a look at all the different types of headlights, and how they are improving upon nighttime vision.
Filament Headlights
As we all know, the first electric headlamp light source was the tungsten filament. It operated in a vacuum or near-vacuum state. Where inert gas was essentially sealed inside the headlight along with the filament.
The filament used a lot of power to create light, which was often too low compared to the input required. Moreover, the tungsten used to boil off the surface of the filament and condenses on the bulb glass.
This resulted in the glass becoming blackened, essentially rendering the headlight assembly useless. This could also happen if the seal broke, as the filament would oxidize and burn up.
This meant that you had to replace the entire headlight assembly altogether. Since, in those days, replaceable bulbs were not yet invented. This problem was eventually solved, by moving to a tungsten-halogen combination.
Halogen
Halogen truly changed the game for car headlight systems. Not only were the new bulbs cheaper to produce. They also produced way more light, while using way less energy.
This was initially made possible, by replacing the vacuum inside the bulb with gas. More specifically, pressurized halogen gas, usually iodine or bromine.
The use of these gases prevented the blackening of the bulb assembly. While also making it possible for them to burn brighter.
Moreover, since the bulbs themselves contained the halogen gas. The entire headlight assembly didn’t have to be vacuum sealed. So, in the case of failure, you could just replace the bulb.
This revolutionized the way car manufacturers approached car lighting. As well as the design of the headlights themselves. Since now, car manufacturers didn’t need to worry about having a standardized headlight assembly for all models.
They could simply standardize the bulb itself. Which gave them almost unlimited freedom to change the design of the housing. This is part of the reason why standard reflector style halogen bulbs have remained the universal standard for car lighting for so long.
Brands like OSRAM continue to support and even advance this technology. With new and exciting products, like the high-intensity Night Breaker series. Which provides a light output that almost matches modern HID’s.
Or the more rugged Super Bright series focused on off-road performance. Even the standard halogen bulbs have been heavily updated for a longer lifespan. As seen in the Ultra Life series, which boasts a working lifespan of over 100,000 km. In this way, halogen technology still remains a relevant source of lighting.
Xenon or HID
The next evolution of headlights came in the form of High-intensity discharge bulbs. More commonly known as HID or Xenon headlights.
They work on a similar principle as the CFL bulbs that we use in our homes. This means there is no need for a filament anymore. Instead, the system works by creating a high voltage area between two electrodes.
The remaining space is then filled with a combination of Xenon and Argon gases. Along with the gases, the headlight also contains vaporized metals, which actually emit the light.
The good thing about this system is that it produces an extremely powerful and bright light. This light can be even brighter than LEDs, even though it takes some time to reach this peak brightness.
The bad part of using this system is that it is a lot more expensive than halogen bulbs. Moreover, due to the limited amount of metal present, the lights also burn out sooner than modern LEDs.
Which means you don’t necessarily get a longer lifespan than standard halogens. Even if the lighting performance is miles ahead.
This is why such systems are only used in more expensive cars. Where they can be easily supplemented by other additional lights. That don’t suffer from these limitations. A good example of a usable HID light is OSRAM’s XENARC series. Which features similar sub-categories, like the Night Breaker, the Super Bright, and the Ultra Life.
LED
Another reason why HID’s never really took off in mass-market applications was due to LEDs. LEDs basically sidestepped all the problems associated with using gas-based lighting. By instead focusing on electroluminescence.
This is just a fancy word for what happens when electrons are basically fired towards positively charged holes in a semiconductor. As a result of this action, they release energy as photons, which are the building block of light.
Since all the complicated components are essentially replaced by a light-emitting diode. It makes it possible to fit the whole setup in a smaller size. Thus, allowing for more compact bulb and headlight designs.
All this, while delivering almost the same levels of light output as HID’s. Without the same high-energy requirements. The system doesn’t even produce excess heat when compared to the older systems. Which allows it to last longer and perform better.
Once again, this system is a lot more expensive than halogens but offers a lot more value than even HID’s. This is part of the reason why it has been mostly adopted as the new standard of car lighting.
Companies like OSRAM have started to create their own versions of these LED lights. With the famous Night Breaker series witnessing an LED upgrade. Along with the LEDriving XTR series for off-road performance, or the HL series for highway use.
Laser
Even as carmakers have barely started adopting LEDs as the standard across the board. We are already witnessing the next big leap in lighting technology.
Interestingly, this evolution is coming with a step back in terms of the science itself. As the new laser light systems once again use gas to produce light.
This new system is basically based on the already established principle of chemiluminescence. Where phosphorus gas is essentially energized with the help of lasers. Instead of an electric current.
The lasers are initially focused with the help of special lenses. Which directs the laser light to the gas chamber. The light produced as the result is then directed using a standard reflector setup. In this manner, this technology combines the best of both worlds.
This hybrid system is truly revolutionary. As it can produce up to 1000 times the amount of light as standard LEDs. While consuming barely half the energy.
This translates to laser lights being able to illuminate almost twice the distance. When compared to standard LED lights used today. While being almost 10 times smaller than LEDs.
As you can expect, this level of performance and design upgrade comes at a high cost. Which is part of the reason why we have yet to see laser systems go mainstream.
Brands like OSRAM are working on creating their own solutions for this category. We can expect it to get more widespread acceptance, once those come to market. For now, we will just have to wait and see how long that takes. And whether we see another new type of headlight system emerge in the meantime.