高显色指数白光LED光源的研究

根据光源混合原理和模拟黑体轨迹的Chebyshev法，推导了三通道脉冲宽度调制(PWM)占空比与色坐标、光通量、相对色温之间的关系式，同时确定调光约束条件。在上述推导公式基础上，设计出一种智能调光控制系统，该系统通过手机客户端分别控制暖白/绿/蓝3种LED光源模组，实现高显色指数R_a下混合白光的调光调色。实验结果表明:设置光源色温为3 600 K时，光通量在600 lm之内，设定值与测试值最大误差为0.74%；当光源光通量设定为300 lm时，色温在3 200, 7 600]之间连续可调，其最大误差为1.82%，且光通量波动小于4%；混合光源具有较高的显色指数，在调光范围内，一般Ra在90以上，最大可达95.3。

White-light LED clusters with high color rendering index

Based on light-mixing technology and Chebyshev method of simulating Planckian locus, the relationships between chromaticity coordinate, luminous flux, relative color temperature and duty ratio of three-channel pulse width modulation (PWM) are derived in the paper, and limitation of three channels' PWM dimming is established. On the basis of this method, intelligent light-control system is designed, which can realize dimming and tunable color temperature of white-light LED clusters the warm white/green/ blue (WW/G/B)] with high color rendering index (CRI) Ra by mobile client. Experiments show that maximum flux error between the setting value and the test value is 0.74% while the correlated color temperature (CCT) of the LED clusters is 3 600 K and the luminous flux is less than 600 lm. The deviation mean of CCT is less than 1.82% and luminous flux fluctuation is no more than 4% while the luminous flux is 300 lm and the range of CCT is from 3 200 K and 7 600 K. Meantime, CRI is generally more than 90, and the maximum value is 95.3 in the tunable range of the white-light LED clusters.