Halogen, xenon and LED bulbs are more and more durable and reliable lamps for use in cars, motorcycles, trucks and other vehicles to illuminate the road in a better way. The Economic Commission for Europe (ECE) regulates the use of automotive lighting for improved road safety. They provide guidelines regarding automotive lighting that products must fulfil.
Light is an electromagnetic wave such as radio waves and X-rays. However, the human eye can only perceive a part of the light spectrum between 380nm and 780nm, from blue to red.
Headlights project the luminous surface of the bulb onto the road, thanks to reflector and projector systems. This projection leads to a typical beam pattern with bright light in the center of the lane, low cut-off on the opposite lane to avoid glaring oncoming traffic and a high cut-off on the road border to perceive for example traffic signs.
The reflector and the lens are the two main elements of the headlight. The reflector is a mirror that concentrates the light of the bulb towards the lens, which finally shapes the light in the right direction.