P‐88: Active Local Dimming System for Low Power and Motion Blur Enhancement

Abstract

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.

Effects of Light-Emitting Diode (LED) Configuration on Luminance and Color of an Edge-Lit Backlight Unit

“…Direct-lit BLUs have provided significant reduction of power consumption and meaningful improvement of the contrast ratio, by applying the local dimming technology [24], [25]. There have been technical reports on corresponding technologies for the edge-lit BLUs by individually controlling the luminance of the LEDs arranged in a row along the edges of an LGP [26], [27]. However they showed less effective performances than those for the direct-lit BLU.…”