沿黑体辐射线类太阳光LED调光系统调配及优化

Coordination and Optimization for Dimming System of Sunlight-Like LED Along Black Body Radiation Line

为了使发光二极管(LED)光源光谱在可见光波段更接近太阳光光谱,且相关色温实现沿黑体辐射线连续可调,选取不同峰值波长LED芯片及荧光粉,覆盖可见光波段;采用相应LED芯片激发相应荧光粉,获得多个调光光源并记录色点及相对光谱;根据光谱叠加性原理,混合光源色点位于调光光源在CIE 1931色坐标图中围成的区域内。对四色光源混合调光进行了系统的调配优化,基于脉宽调制(PWM)调光模式,使用LED驱动模块控制各调光LED的光通量,实现了光源沿黑体辐射线色温可连续调节。模拟与实测结果显示,在常用照明色温2700~6500 K时,LED光源的一般显色指数大于98,且各特殊显色指数均大于90。光谱特性与太阳光类似,填补了LED白光中青光波段的凹陷,去除了短波长蓝光危害。

To make the spectrum of light-emitting diode(LED)light sources in the visible light range closer to the solar spectrum,and to achieve continuously adjustable correlated color temperature along the black body radiation line,LED chips and phosphors with different peak wavelengths were selected to cover the visible light range.By using the corresponding LED chips to excite the corresponding phosphors,multiple dimmable light sources were obtained,and their color points and relative spectra were recorded.According to the principle of spectral superposition,the color points of the mixed light source fell within the area enclosed by the dimmable light sources in the CIE 1931 color coordinate chart.The mixing and dimming of four-color light sources were systematically coordinated and optimized.Based on the pulse width modulation(PWM)dimming mode,the LED driver module was employed to control the luminous flux of each dimmable LED,achieving continuous adjustment of the color temperature of the light source along the black body radiation line.Simulation and measurement results show that,in the commonly used lighting color temperature range from 2700 K to 6500 K,the general color rendering index of the LED light source is greater than 98,and various special color rendering indices are greater than 90.The spectral characteristics are similar to those of sunlight,filling the dip in the cyan band of LED white light and eliminating the hazards of short-wavelength blue light.