一种评估LED蓝光危害的方法

提出了一种估算荧光粉转换型LED的蓝光危害方法。先选择同型号普通照明用白色LED样品21只,用光谱仪测量其正常发光下的归一化光谱分布,然后计算光源的色温和蓝白比,以及在蓝光危害限值范围内可以容许的亮度,最后得到在蓝光危害限值内,容许亮度与色温和容许亮度与蓝白比的关系。研究表明：对于该类型的荧光粉转换型LED,当色温小于7500K时,亮度在100,000 Cd/m₂以下不会引起蓝光危害,如果LED的荧光粉失效,只要亮度小于31400 Cd/m₂,也不会对人眼造成蓝光危害。色温和容许亮度曲线及蓝白比和容许亮度曲线随温度变化很小,对于同一类型白色LED,这两条曲线均可用来评估LED灯具是否对人眼构成蓝光危害。

A method to evaluate the blue light hazard of phosphor converted LED

A method for estimating blue light hazard of phosphor converted LEDs is developed. 21 LED samples of the same type for general lighting are selected, and then the relative spectra of these LEDs are measured. The color temperatures and the ratios of blue light to white light (B/W ratios) are calculated, and then the irradiance of LED while the blue light hazard reaches the maximum value are got. Finally, the relationship among maximal irradiances, color temperatures and B/W ratios are obtained. It is shown that there is no blue light hazard when the irradiance is less than 100,000 Cd/m2 for the phosphor converted LEDs with color temperature less than 7000K. The blue light is no harmful effect when the irradiance is less than 31400 Cd/m2 even the phosphor is useless. Color temperature-irradiance curve and B/W ratio-irradiance curve show good regularities, which can be used to evaluate the blue light hazard of LED lamps.