Zhang Fuzheng, Xu Haisong, Wang Zhehong
Appl Opt. 2017 Mar 1;56(7):1962-1971. doi: 10.1364/AO.56.001962.
The trade-off between the color fidelity index (R) released recently by the Illuminating Engineering Society of North America (IES) and luminous efficacy of radiation (LER) was investigated by adjusting the peak wavelengths, spectral widths, and intensities of four-channel LEDs utilizing a multiobjective optimization algorithm based on differential evolution in the correlated color temperature (CCT) ranging from 2800 to 6500 K for general lighting. The results indicate that R at a specific LER value decreases with the increasing CCT, and vice versa, and that R has significant improvements over the Commission Internationale de l'Eclairage (CIE) color rendering index (CRI) in avoiding spectral gaming and evaluating the light sources even with negative CIE general CRI (R). Further, the optimal peak wavelengths with regard to R were identified as 629 nm, 568 nm, 504 nm, and 447 nm, yielding high color rendering in terms of R(93∼94) and R(95∼97) and relatively excellent LER (299 lm/W∼339 lm/W) over a wide range of CCTs from 2800 to 6500 K. This suggests that R can be compatible with R, making it possible to obtain a common set of optimal peak wavelengths for R and R. Besides, the IES method could assess saturated red and skin tones more fairly than the CIE CRI. With a practical 17-channel LED array covering the resulted four optimal peak wavelengths, the improvements of the IES method over the CIE CRI were validated further.
通过基于差分进化的多目标优化算法，调整四通道发光二极管（LED）的峰值波长、光谱宽度和强度，研究了北美照明工程协会（IES）最近发布的颜色保真度指数（R）与辐射发光效率（LER）之间的权衡关系，该研究针对一般照明中2800至6500 K的相关色温（CCT）范围。结果表明，在特定LER值下，R随CCT的增加而降低，反之亦然，并且在避免光谱博弈和评估即使具有负国际照明委员会（CIE）一般显色指数（CRI）的光源方面，R比CIE显色指数有显著改进。此外，关于R的最佳峰值波长被确定为629 nm、568 nm、504 nm和447 nm，在2800至6500 K的宽CCT范围内，产生了R（93∼94）和R（95∼97）的高显色性以及相对优异的LER（299 lm/W∼339 lm/W）。这表明R可以与R兼容，从而有可能获得一组适用于R和R的共同最佳峰值波长。此外，IES方法在评估饱和红色和肤色方面比CIE CRI更公平。通过一个覆盖所得四个最佳峰值波长的实用17通道LED阵列，进一步验证了IES方法相对于CIE CRI的改进。
