Pixelated-LEDs Car Headlight Design for Smart Driving and CO ₂ Reduced Emissions 2020-37-0018

The advent of Electroluminescent Diode (LED) technologies has been one of the major sources of energy reduction in the domestic lighting sector as well as in the automotive and aerospace fields. In vehicles, the use of LEDs allows a reduction of 110W to 40W useful for the function Dipped beam is a gain of about 350W in energy consumption of the vehicle with a combustion engine (from 2 to 5g of CO₂ per kilometer) [1]. In 2010, Adaptive Driving Beam (ADB (also called glare-free high beam) appeared. The objective of the ADB is to adapt the beam to the presence of vehicles in both directions to improve the driver's long-range visibility without causing discomfort, distraction or glare to other road users. The ADB is a lighting function with high added value in terms of comfort and road safety [2]. The new lighting technologies make this function more and more efficient and effective with a resolution and the number of pixels that increases. Pixelated LEDs, by offering various advantages over other architectures, are gaining market shares. They are more efficient and then they will contribute to reduce CO₂ emissions because in the case of pixelated LED we only turn on the necessary pixels as opposed to DMD and LCD beam solutions. Besides these advantages, LEDs also have longer lifetime. Today, the pixels number per headlight does not exceed 100 pixels and soon, in 2022 this number will go over thousands of pixels per headlight for dynamic and high definition beams for new application such as glare free and high beam road marking functions. Several architectures allow pixelation -- LCD beam, DMD, Laser Scan, Pixelated LED -- are presented and studied in this work. The main selection criteria for choosing the optimal architecture presented here are road safety, reduction of CO₂ emissions, reliability and robustness.