基于发光二极管环形阵列与漫反射表面的均匀照明光源研究

Uniform Illumination Study by Light-Emitting Diode Ring Array and Diffuse Reflection Surface

均匀的照明条件与光源良好的混色效果是彩色视觉的重要组成部分。基于发光二极管(LED)环形阵列与高漫反射率表面,研究了一种间接照明的均匀光源,建立了数学模拟算法。根据单个LED的朗伯体特性,讨论了LED环形阵列在半球形内表面上的辐照分布。半球形内表面是高漫反射率表面,可近似看作朗伯表面,将光均匀地反射到检测平面上。通过半球形内表面的双向反射分布函数(BRDF),仿真了检测平面的照度均匀性。并通过实验证实了该照明方式与数学模拟算法的正确性。实验所得的多波段LED阵列混光图像效果良好,光照均匀度95.5%满足彩色视觉测量的需要。证实了该方法设计均匀照明光源的有效性。

Well mixed-color distribution of illumination and uniform illuminated environment are the common requirements in color vision applications.Using three-ring light-emitting diode（LED） array and diffuse reflection surface,an indirection method for the uniform illumination is proposed,and a mathematic simulation algorithm is constructed.Based on the Lambertian characteristic of a sing LED,the irradiance distribution over a sphere inner surface to the three-ring LED array is discussed.Then light is reflected to the detected surface by sphere inner surface.The sphere inner surface with high diffuse reflectance can be seemed as a Lambertian surface.According to bi-directional reflectance distribution functions（BRDF） of sphere inner surface,the uniformity of irradiance distribution of detection surface is simulated.Experimentd are implemented to check the validity of simulation results and the indirection method.Some experimental images show uniform mixed-color distribution and the illumination uniformity of 95.5% can fulfill the meets of color vision applications.The experimental results confirm that this method is useful for the uniform illumination design.