Dynamic Prediction of Correlated Color Temperature and Color Rendering Index of Phosphor-Coated White Light-Emitting Diodes

Abstract

Light-emitting diode (LED) technology is a multidisciplinary subject that involves photometry, electric power, heat, and chromaticity which are interdependent on one another. So far, the photoelectrothermal (PET) theory has linked up the first three aspects. This research includes chromaticity into the dynamic PET theory so that even the correlated color temperature (CCT) and color rendering index (CRI) of phosphor-coated white LEDs can be dynamically predicted, thus overcoming the low bandwidth problem of some light measurement equipment. This dynamic modeling of CCT and CRI has been verified with favorable agreements between theoretical predictions and measurements of several LED samples. The outcome of this project offers a new research and development tool for practicing LED system designers to predict the instantaneous variations of CCT and CRI when the power varies in a LED system.