Methods of extrapolation of the LED life time and their comparison based on some LED degradation curves

Abstract

The degradation of luminous flux of LEDs is dependent on the type of LED and its operation conditions. That is why a prediction of lifetime often differs from case to case. Mostly, the testing times are too short to reach 70 or 80% of the beginning luminous flux. So extrapolation has to be used to predict the lifetime. In this study different methods and mathematical functions are compared.