白光LED色彩渲染的光谱设计考虑

　　白光LED色彩渲染的光谱设计考虑

　　在这篇文章中，国家标准与技术研究所（NIST）的专家们分析了各种白光LED模型，通过模拟它们的显色性能和发光效率。结果多芯片和荧光粉型白光LED的设计提供一定的指导。

　　介绍

　　一般照明光源最重要的特点之一是显色。颜色渲染是光源的特性，它告诉物体在给定照明下的颜色是多么自然。如果渲染效果不佳，光源对一般照明不起作用。1992美国能源政策法案规定的最低要求的发光效率（流明每瓦）和显色指数（CRI）2几种常见灯具产品销往美国。这是白光LED用于一般照明的一个重要方面的类型。

　　White light from LEDs is realized by a mixture of multicolor LEDs or by combinations of phosphors excited by blue or UV LED emission， and thus they have greater freedom in spectral design than conventional sources. Questions arise on how the spectra of white LEDs should be designed for good color-rendering performance， e.g.， whether RGB white LEDs can satisfy the need or a four-color mixture is needed， or whether much broader， continuous spectra are required. To evaluate the color-rendering performance of light sources， the CRI，2 recommended by the Commission Internationale de l’Éclairage （CIE）， is available and widely used， but it is known to have deficiencies，3，4 especially when used for sources having narrowband spectra. A poor correlation between visual evaluation of RGB white LEDs and the CRI is reported.5 The color-rendering problems of white LEDs are being investigated by the CIE Technical Committee 1-62 with a future plan to develop a new metric.