针对光生物效应重要性及复杂性问题, 提出一种生物节律因子的调光计算方法。给定三通道LED工作在额定条件下的光谱分布就能够实现任意比例的混合光源的照度、相关色温、节律因子的便捷计算。实验选用三种色温白光LED组成三通道光源, 基于脉冲宽度调制(PWM)原理进行三通道分时调光。在某一照明测试空间距离下, 先测得单通道独立工作时的光谱分布, 并通过调光计算方法得到三通道在任意比例下混合光源的理论照度、相关色温、节律因子; 再测得三通道光源在不同混合比例下的实际照度、相关色温与节律因子。然后将理论与实际计算所得的照度、相关色温、节律因子进行比较, 并分析误差。实验结果表明,照度、相关色温、节律因子的多条拟合直线与调光计算式所描述直线的斜率差异分别在6%、2%、3%以下, 截距差异分别在2%、5%、3%以下。用显著性差异检验来检验实际节律因子与理论计算所得节律因子的正态分布特性, 结果显示并无明显差异, 表明在给定各LED光源光谱分布的情况下, 调光计算方法不用通过测量混合光源光谱分布, 便能快速有效地计算出混合光源照度、相关色温、节律因子。

A dimming and calculation method of circadian factor is proposed in view of the importance and complexities of non-visual biological effects. When the spectral distribution of each of the three channels under the rated conditions is given, the illuminance, CCT and circadian factor of hybrid light at any ratio can be calculated easily. In test, three-channel hybrid light source is composed of three color temperature LEDs, and dimming with PWM on the principle of time sharing. At one testing distance, the spectral distribution of each single channel is measured independently first, and the theoretical illuminance, CCT and circadian factor of hybrid light in continuous gradient are obtained by the dimming and calculation method. Then, the actual illuminance, CCT and circadian factor of hybrid light are measured. Finally, the two illuminances, CCT and circadian factors got by theoretical and actual are compared along with an error analysis. The results show that the fitting line of the illuminance, CCT and circadian factor and the line described by the dimming and calculation method show a low difference in slope, which is below 6%, 2%, 3% ,respectively, and the difference in intercept is below 2%, 5%, 3%, respectively. And there is no significant difference between the actual rhythm factor and the theoretical calculated rhythm factor under the significant difference test. It is shown that the dimming and calculation method can calculate the illuminance, color temperature and circadian factor of the hybrid light easily and effectively without measuring the spectral distribution of hybrid light when the spectral distribution of each single LED is given.