LED光谱特性及其在中间视觉下的应用

为了研究中间视觉下LED的光度特性,运用LED光色电综合分析仪测量了不同电流下五种颜色多个LED的光谱,然后计算了不同中间视觉亮度下的光通量,并分析和研究了中间视觉修正系数Rm随电流和亮度的变化。研究表明:电流在12～24mA范围内,同一颜色LED的相对光谱整体变化小于8%,因此在普通照明要求下,可以用平均光谱来描述LED的相对光谱。在中间视觉下,绿、白这两种颜色LED的中间视觉修正系数Rm的对数与亮度的对数存在线性关系,红、黄、蓝LED的Rm的对数与亮度的对数存在二次曲线关系。其中,蓝、绿、白LED的Rm随亮度增大而减小,红、黄LED的Rm随亮度增大而增大。该研究为中间视觉下LED灯具的设计提供了理论基础。

The LED＇s Spectral Characteristics and Its Application in Mesopic Vision

To investigate the photometric characteristics of LED under mesopic vision, photoelectric spectrum analyzer is used to measure five different colors and several spectrums of LEDs under different electric currents. Then the luminous flux under different brightness of mesopic vision is calculated as well as the changes of mesopic vision correction coefficient Rm, which is varied with electric current and brightness, are analyzed and studied. The study shows that the whole spectral relative variation of the same color of LED is less than 8% within the electric current range from 12 mA to 24 mA. Therefore, the relative spectrum of LED can be represented by the average spectrum in general illumination requirement. Under mesopic vision, there is a linear relationship between the logarithm of mesopic vision correction coefficient Rm of the color blue or white LED and the logarithm of brightness. There is a quadratic curve relationship between the logarithm of the Rm of red, yellow or blue LED and the logarithm of brightness. The Rm of blue, green or white LED decreases as the brightness increases while the Rm of red or yellow LED increases as the brightness increases. This research provides a theoretical basis for the design of the LED lamps under mesopic vision.