Color quality of white LEDs

Abstract

This chapter provides an overview of the fundamentals of chromaticity and color rendering, the two important aspects of color quality of light sources for general illumination. There is a special focus on the use of solid-state light sources. The section on chromaticity discusses chromaticity coordinates and diagrams, correlated color temperature (CCT), Duv, and specifications for color differences. The section on color rendering discusses object color evaluation, the color rendering index (CRI) and the shortcomings thereof, and color quality beyond CRI, introducing the color quality scale (CQS) as a design tool. The chapter also discusses luminous efficacy of radiation and the color characteristics used for single-color LEDs. Finally, future considerations on color quality for white LED developments are given.