Recently, as the light‐emitting diodes (LEDs) technology has improved, especially LED brightness is remarkable increased, the brightness of LCD panel is enough even if LED sources are located in only short edge sides (left and right) of the LCD module. As a result, the smart local dimming system is needed to use the invented LED back light unit (BLU) efficiently. In this paper, we proposed the new local dimming system to reduce power consumption and enhance motion picture quality for a new edge LED BLU. The proposed system is applied to active 2D local dimming algorithm and scanning technique at the same time. Our local dimming system has 3 advantages, 25% power saving, 1:100,000 contrast ratio and average MPRT 3.9ms with 240Hz panel. We verified performances by measurement. Finally, our 2D dimming technique was developed as AISC IP type which was merged in timing controller (TCON), so we can apply our system for mass product in 2011 year.