Glossary A–ZLetter B
Brightness degradation (ageing)
Brightness degradation is the gradual decline in a screen's luminous output as operating time increases.
It affects the diodes in LED walls and backlights as well as OLED screens. Ageing is normal and cannot be prevented, only slowed down.
How quickly a screen loses brightness depends mainly on the brightness used and on temperature. An outdoor screen that runs permanently at full power in the sun ages faster than a dimmed screen indoors. Diodes of different colours also age at different rates, so the colour of the picture can shift slightly over time as well.
Ageing becomes noticeable mainly when new and old devices hang side by side: a replaced screen in a video wall or a new module in an LED wall looks brighter than its neighbours. Operators should plan brightness reserves, let an ambient light sensor control brightness and order spare parts early. Many LED walls can be recalibrated so that the surface looks even again.