红、绿、蓝LED组合光源的色彩管理

　　红、绿、蓝LED组合光源的色彩管理

　　三色光反馈是一种经过验证的颜色管理解决方案，但它的实现可能很复杂。它不需要。

　　摘要

　　结合红色、绿色和蓝色发光二极管（发光二极管）形成光源是一个吸引人的建议。这种多色光源可以产生各种各样的颜色。发光二极管本身坚固耐用，效率高。LED光源将改善许多现有的应用，如LCD背光，并启用新的，如自适应汽车内部照明。然而，在生产高质量的多色LED光源之前，还有许多挑战需要克服。本文介绍了一种特殊应用标准产品（ASSP）集成电路，解决了许多挑战。

　　Figure 1： CIE 1931 Color Space. The triangle represents the color gamut formed by red， green， and blue LEDs. W—white， R—red， G—green and B—blue. The x， y coordinate defines the chromaticity of a light source. A third axis （not shown）， Y， is needed to define the brightness of the light source.

　　Using RGB LEDs

　　The simplest multi-color LED light source consists of three sets of LEDs—red， green， and blue—with each set driven by a separate driver module. The resultant color of the light source is dependent on the ratio of light intensity between the red， green， and blue sets of LEDs. The light intensity of an LED can be controlled by varying its drive current， or by varying the duty cycle of the LED using pulsewidth modulation （PWM）。 The PWM method is popular because the relationship between duty factor and light intensity is more linear than that of current vs. intensity.