JAJU617A October 2018 – May 2022
In general, HUD systems have a low transmission percentage, due to only a small percentage of HUD lumens being reflected by the windshield to the driver’s eyebox. A lot of electrical power is required to overcome this low transmission and to generate enough brightness in day-time driving conditions. Higher LED power consumption requires robust thermal designs in order to dissipate the heat and keep the LED junction temperatures at reasonable levels.
Additionally, HUDs are typically enclosed inside the vehicle dashboard with minimal airflow. This exacerbates the issue with higher power consumption, since the heat is recycled and further increases the temperature of all components. LEDs are sensitive at higher temperatures, so this results in an power-to-brightness efficiency decrease as well.
Therefore, it’s important to select LEDs which are efficient in order to simplify the thermal solution and total HUD volume.