多基色LED的照明通信光源显色性研究

可见光无线通信(visible light communication,VLC)是将LED照明技术和光通信技术相结合的一种新兴技术。针对目前LED照明通信光源显色性差、光效低且色温不可调等问题,依据多基色LED白光通信原理进行了相关研究,以Yoshi等提出的高斯分布形式作为基色LED的光谱模型,利用国际照明委员会(CIE)推荐的一般显色指数(R_a)和美国国家标准与技术研究所(National Institute of Standards and Technology,NIST)推荐的一般色质指数(Q_a)评价光源的显色性。采用遗传算法,在2 700~6 500K色温范围内优化出单个色温以及色温可调光源满足显色性最优的光谱组合,并基于R_a和Q_a大于80的原则优化出色温可调光源光视效能(luminous efficacy of radiation,LER)最优化的光谱组合。最后根据实验结果分析了光源的显色性、光视效能和色温可调性三者之间的关系。结果表明:三基色色温可调白光LED满足显色性最优的峰值波长组合为613nm/541nm/464nm,此时R_a和Q_a的最小值分别为81.2和81,可以满足一般条件下的照明通信需求;四基色色温可调白光LED满足显色性最优的峰值波长组合为620nm/562nm/505nm/449nm,此时R_a和Q_a的最小值分别为96.7和92.2。在特殊照明场所或要求较高的通信速率时,应采用四基色白光LED作为照明通信光源。仿真得到了三基色和四基色白光LED的最佳光谱组合,为宽通道可见光通信光源的设计提供了参考依据。

Study on Color Rendering of Light Communication Source Based on Multi-Chromatic LED

Visible Light Communication (VLC) is an emerging technology which combines LED lighting engineering and optical communication technique .In this article ,we aim at the problems of bad color rendering ,low luminous efficacy and non-adjusta-ble color temperature of white LED lighting communication source .We did some researches according to the multi-chromatic white LED communication theory .Meanwhile ,we used the Gaussian distribution put forward by Yoshi as the spectral model of chromatic LED ,and made use of the general color rendering index (Ra ) which is recommended by CIE and the general color quality scale (Qa ) recommended by National Institute of Standards and Technology (NIST ) to evaluate the color rendering of light source .We adopted Genetic Algorithm to optimize single color temperature and adjustable color temperature scope 2700 to 6500 K based on principle that Ra and Qa are greater than 80 to optimize the best combination of spectra of adjustable color tem-perature light source .At last ,according to the result of the experiment ,we analyzed the relationship among the color rendering , luminous efficacy of radiation (LER) and adjustable color temperature of the light source .It turned out that tri-chromatic adjust-able color temperature white LED's peak wavelength combination which satisfies the best color rendering is 613 nm/541 nm/464 nm .Meanwhile ,when the minimum of Ra and Qa are 81.2 and 81 respectively ,it can meet the demand of lighting communication in the general situation .And the tetra-chromatic adjustable color temperature white LED's peak wavelength combination which meets the best color rendering is 620 nm/562 nm/505 nm/449 nm .The minium of Ra and Qa are 96.7 and 92.2 at the same time . When in a spot which requires special lighting or higher communication rate ,we should use tetra-chromatic LED white light as the lighting communication source .In the article ,we have simulated the best spectral combination of LED .And it can provide some references for the design of visible communication light source used in the wide channels .