紅、綠、藍LED組合光源的色彩管理

　　三色光反饋是一種經過驗證的顏色管理解決方案，但它的實現可能很復雜。它不需要。

　　摘要

　　結合紅色、綠色和藍色發光二極管（發光二極管）形成光源是一個吸引人的建議。這種多色光源可以產生各種各樣的顏色。發光二極管本身堅固耐用，效率高。LED光源將改善許多現有的應用，如LCD背光，并啟用新的，如自適應汽車內部照明。然而，在生產高質量的多色LED光源之前，還有許多挑戰需要克服。本文介紹了一種特殊應用標準產品（ASSP）集成電路，解決了許多挑戰。

　　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.