Sequential-color voltage-adaptable RGB-LED backlight driving system with local dimming control for LCD panels

Higher luminance efficacy, faster response, lower power consumption, longer operation life, wider color gamut and environmental issues makes RGB LED backlight driving system suitable for high end LCD applications. In this paper, a sequential-color voltage-adaptable RGB LED backlight driving system with local dimming control for LCD panels is proposed. Using the topology proposed in this paper, the panel can be divided into 4 individual areas. A digitally-controlled multi-phase driving system for RGB LED lamp, a current sharing method, and a human machine interface (HMI) for dimming the backlight module will be presented. The output voltage is adjustable so that RGB LED maintains the desired string current and maximizes the efficiency. Finally, experimental results are presented to validate the effectiveness and correctness of the proposed system. Besides the presented system can successfully drive the RGB LED backlight module, and the color-mixing can be achieved using the developed HMI and driving system.