Constrained optimization of multi-color LED light sources for color temperature control

Abstract

Color temperature is one of the most significant characteristics for light sources due to its influence on human visual perception, circadian rhythm, emotion, work efficiency, and etc. Currently, it is common for LED light sources to render or tune color temperatures by mixing various color LEDs with different intensity. Existing methods can hardly take into consideration all the lighting requirements, including power consumption, luminous flux, spectrum components, and etc. In this paper, we first make a brief introduction on the significance of color temperature and emphasize the hazard of excess blue light. Then an optimization algorithm of light chromaticity is proposed for the design and control of LED light sources based on linear programming. Objective functions and constraints are described in details. In the optimal color rendering design, we simultaneously restrain the luminous flux, color temperature and the spectrum components of blue light. An example of LED light source design is taken to verify our approach. Results show that the proposed algorithm is able to fulfill the requirement of color temperature, while maintaining satisfied photometric and electrical performance comparing with conventional methods. The optimization algorithm is suitable for both color temperature control and rendering color light with targeted spectral components.