A spatially partitioned backlight system composed of tandem wedge‐shaped light‐guides with micro line‐prism arrays was developed for scanning field‐sequential‐color (FSC) LCD in large size. The light‐guides combined with LED light‐bars have been designed and fabricated to well distinguish each region and decrease the light leakage. By means of our approach, the volume of backlight system can be reduced down to 25 mm without sacrifice of the optical performance. As a result, 2750 nits average luminance subject to 50% duty cycle and 83% uniformity can be achieved. The leakages into the continuous adjacent blocks are well suppressed to 11.86%.