應用人眼視覺特性之低功耗液晶顯示技術

Abstract

液晶顯示器由於其輕薄之特性，已大量被應用在可攜式產品中，但由於電池容量與尺寸限制，可攜式產品一般都不能長時間的連續使用；在近幾年研究中得知，液晶顯示器的背光模組所消耗能量將近整體系統的五成；為了延長電池的使用時間，如何降低背光模組的耗電變成重要的課題。我們研究的目標是利用人眼視覺的視頻特性─感知亮度增強效應(Brücke effect)，提出新的背光源驅動技術，透過調整背光強度、閃爍頻率及發光週期，來降低背光源的功率消耗並保持在液晶顯示器上所感受的亮度。實驗結果顯示，在相同的感知亮度及有限的畫面閃爍下，可以降低背光模組之功率消耗。

This paper presents a novel backlight driving technique for liquid crystal displays. By scaling the intensity, frequency, and duty cycle of the backlight, this technique not only increases the perceived brightness but also saves the power. The increased brightness comes from a perceptual effect of temporal vision – a brief flash appears brighter than a steady light of the same intensity, called Brücke brightness enhancement effect. Due to the experimental data, the backlight power consumption decreases at the cost of flickering. We performed visual experiments to parameterize the Brücke effect and derived an optimization algorithm accordingly. To demonstrate the potential power savings of this technique, we profiled the power consumption of an Apple iPod and fabricated an LED driving module.