RGB LED backlight module with individual area control for LCD panels

Higher luminance efficacy, local dimming capability, wider color gamut, faster response, longer operation life and fewer environmental issues make RGB LED backlight driving systems suitable for large scale LCD TVs. For these applications, area dimming control is often adopted to reduce power consumption and enhance the image contrast ratio. In this paper, an RGB backlight driving system for LCD panels with individual area control is proposed. Using the topology proposed in this paper, the backlight can be divided into 96 areas and the brightness of each area can be individually controlled according to its corresponding dimming command. This technique can also be expanded to a higher number of areas easily. In order to verify the correctness of the proposed system, a prototype is presented and experiments are carried out. According to the experimental results, the measured power conversion efficiencies of the proposed backlight driving system are all higher than 90% under all load conditions and individual area control can be achieved.