为了快速确定白光LED相关色温与黄色荧光粉浓度的关系, 提出“中间参数A”的方法, 以达到减少工作量, 缩短工作时间, 提高精度的目的。首先, 通过理论分析推导出色品坐标与“中间参数A”的关系公式。然后, 制备6组不同黄色荧光粉浓度的白光LED样品, 计算出每个浓度对应的A值, 拟合A值与荧光粉浓度的关系公式。在色品图上查找目标色温对应的色坐标, 就可以利用“中间参数A”的方法预测目标色温对应的黄色荧光粉浓度。实验结果表明：利用“中间参数A”的方法生产的白光LED的色温与目标色温的误差在50 K以内。在预测高色温时, 该方法比“直接探索色温与荧光粉浓度的关系”的方法的精度高一个数量级。而且利用该方法, 采用2组不同荧光粉浓度样品相比于6组样品, 在预测目标色温对应的荧光粉浓度时的相差量低于0.5%。因此, 该方法具有耗时短、工作量少, 精度高的优点。

In order to quickly determine the relationship between the correlated color temperature (CCT) of white LEDs and the corresponding yellow phosphor concentration, a method of ‘intermediate parameter A’ was proposed in this paper, which can reduce the workload, shorten the working time and improve the precision. First, the formula of the chromatic coordinate and the ‘intermediate parameter A’ was deduced by theoretical analysis. Then, six groups white LED samples with different yellow phosphor concentration were fabricated. After that, the ‘A value’ of each concentration was calculated. It is found that the relationship between the A value and the phosphor concentration is linear. The chromatic coordinates of the target CCT can be found on the chromaticity diagram, so the yellow phosphor concentration of the target CCT can be predicted by using this method. The experimental results show that the deviation between the CCT of white LED and the target CCT is less than 50 K by using this method. In the prediction of a high CCT, this method is more accurate by one order of magnitude than the method of ‘direct exploration of the relationship between CCT and phosphor concentration’. And in predicting the phosphor concentration of a target CCT, the difference of phosphor concentration between the two groups of phosphor concentration samples and the six groups of samples is less than 0.5% by using this method. Therefore, the method of ‘intermediate parameter A’ has the advantages of short time, less workload and more accurate in determining the phosphor concentration of the white LED with target CCT.