实现白光LED阵列色温分布均匀化技术研究

本文通过优化白光LED阵列的结构,实现在目标面上产生均匀的色温分布。通过收集系统中每颗LED的色温坐标矩阵与照度矩阵,根据色温叠加公式,计算LED阵列在目标面上叠加后的色温分布,构建目标面上色温均匀度评价函数,评价函数反应目标面上色温分布的均匀性。通过优化阵列中LED的位置,使得评价函数的值最小,即目标面上色温均匀度最高。运用这种方法我们优化设计了两个实例:(1)相同规格的9颗白光LED方形阵列;(2)不同规格16颗圆形白光LED阵列,优化后色温均匀度均达到了95%以上。利用这种方法同样可以在目标面上同时实现均匀的色温分布与照度分布,设计9颗相同规格的白光LED以3×3方形阵列方式排布,优化后色温均匀度从78%提升到88.7%,照度的均匀度从42%提升到87.6%。分析实际加工制造过程产生的误差对色温均匀度的影响,随着制造误差的增大优化后色温均匀度下降,但均优于优化前色温分布均匀性。

Design of white LED array for uniform correlated color temperature distribution

In this paper, an algorithm is proposed to design white LED array for uniform distribution of the correlated color temperature (CCT) on the target surface. The color temperature distribution of LED array on the target surface can be calculated by superposition of color temperature superposition from different LEDs in the array. A merit function is constructed which reflects the uniformity of CCT distribution. The value of the merit function depends on all LED positions. By optimizing all LED positions, the merit function achieves the minimal value. When merit function achieves the minimal value, the uniformity of the CCT distribution will reaches the highest. By the method, two LED arrays are designed:(1) Square array consisting of 9 identical white LEDs (2) Circular array consisting of 16 white LEDs. After optimization, the two LED arrays both produce uniform CCT distribution with a uniformity of higher 95%.In addition, we also design another LED array which controls the uniformity of irradiance and CCT distribution simultaneously by constructing a special evaluation function. By optimizing the configuration of the LED array, the uniformity of the CCT is increased from 78% to 88.7% and the uniformity of the irradiance distribution is increased from 42% to 87.6%. Finally, the influence of the CCT errors of LEDs on the uniformity is analyzed. The results show that the uniformity of LED array will decrease with the increasing of the CCT errors of each LED. Also the algorithm is still quite effective for designing the LED array in which each LED has different CCT error.