Chromaticity Maintenance in LED Devices

With the recent improvements in LED luminous efficacy that have been achieved by the lighting industry, greater attention is being devoted to understanding the long-term performance of LEDs. Specifically, there is a need to understand and predict the ability of LEDs to maintain luminous flux and chromaticity over time. The issue of chromaticity maintenance (aka, chromaticity stability and color shift) is especially important for LED devices since they may be used for 10 years or more without replacement of the light source. The characteristics of LEDs have a significant impact on chromaticity maintenance for LED-based lamps and luminaires. However, other components of an LED device, including lenses, reflectors, and device design, can also have an impact on chromaticity. Understanding the aging characteristics of LEDs, lenses, and reflectors is critical to designing and building LED-based products for long-term use.