Blue light hazard optimization for white light-emitting diode sources with high luminous efficacy of radiation and high color rendering index. (1st September 2017)

• Record Type: Journal Article
• Authors: Zhang, Jingjing; Guo, Weihong; Xie, Bin; Yu, Xingjian; Luo, Xiaobing; Zhang, Tao; Yu, Zhihua; Wang, Hong; Jin, Xing
• Is Part Of: Optics & laser technology. Volume 94(2017)
• Page Start: 193
• Page End: 198
• Publication Date: 2017-09-01
• Subjects: Light-emitting diode -- Spectral optimization -- Blue light hazard -- Color rendering -- Color temperatures; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2017.03.031
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: An algorithm was proposed to minimize blue hazard and maximize LER simultaneously. Spectra with low blue hazard, high LER and CRI were achieved at different CCTs. After optimization, the maximum permissible exposure duration increases by 14.9%. It is found that the minimum hidden blue hazard increases with LER increases. It can be used to guide the fabrication of LED in line with photobiological safety. Abstract: Blue light hazard of white light-emitting diodes (LED) is a hidden risk for human's photobiological safety. Recent spectral optimization methods focus on maximizing luminous efficacy and improving color performances of LEDs, but few of them take blue hazard into account. Therefore, for healthy lighting, it's urgent to propose a spectral optimization method for white LED source to exhibit low blue light hazard, high luminous efficacy of radiation (LER) and high color performances. In this study, a genetic algorithm with penalty functions was proposed for realizing white spectra with low blue hazard, maximal LER and high color rendering index (CRI) values. By simulations, white spectra from LEDs with low blue hazard, high LER (≥297 lm/W) and high CRI (≥90) were achieved at different correlated color temperatures (CCTs) from 2013 K to 7845 K. Thus, the spectral optimization method can be used for guiding the fabrication of LED sources in line with photobiological safety. It is also found that the maximum permissible exposure duration of the optimized spectra increases by 14.9% than that of bichromatic phosphor-converted LEDs with equal CCT.