綠色顯示系統之色彩優化與節能研究

Abstract

隨著顯示技術的日益提升，低耗電率、高對比度且廣色域之綠色顯示科技成為下一波發展趨勢，採用光效率高的發光二極體作為背光光源，包含背光分區調變的高動態範圍顯示系統，以及不需彩色濾光片之場序型液晶顯示系統。然而彩色動態背光增加色彩複雜度，以致於影像產生色彩偏差現象，降低影像品質，因此提出色彩優化模型實際驗證在高動態範圍液晶顯示器與色序型顯示器，達到準確的色彩色度重現，維持影像細節並降低功率消耗，可廣泛的應用在顯示科技。 在紅(R)、綠(G)、藍(B)三色發光二極體分區調變光源下，考慮背光分佈與影像本身色彩亮度，建立色彩優化模型已經成功地應用在37吋高動態範圍顯示器上，使得整體色差可以小於2.5∆E00(為人眼可接受的色差範圍)，並且成功地維持畫面細節。此外，在紅(R)、綠(G)、藍(B)、白(W)四色發光二極體背光模組，提出考慮色彩模型優化色序型演算法RGBWw與RGBDw，已成功在15.4”色序型顯示器驗證，尤其以高效率RGBDw演算法整體色彩表現與原始影像之色差僅為0.6∆E00，相對於傳統RGB循序法影像品質，該方法大幅抑制77%色分離現象，其功率消耗降低至77%。 應用色彩優化模型於綠色能源顯示技術，除了維持節能廣色域之目的，也提供觀賞者良好的影像品質，極具發展未來高影像品質顯示技術之潛力。

Recently, there has been a tremendous wave of interest in the relationship between power consumption and image quality. The use of LED-backlight systems has increasingly been proposed: High Dynamic Range LCD (HDR-LCD) with local dynamic backlight technology and Field Sequential Color LCD (FSC-LCD) without color filters. However, the colorful backlight distribution increases chromaticity complexity while color shift is caused on perceived image. Therefore, color optimization models were proposed for HDR-LCD and FSC-LCD to maintain image quality and reduce power consumption. In RGB-LED backlight system, this method was demonstrated on 37” HDR-LCD. The color accuracy was achieved with ∆E00 <2.5 and image details were maintained. On the other hand, the proposed FSC methods, RGBWw and RGBDw, were proposed for RGBW-LED backlight system using color optimization model. The results were demonstrated on 15.4” FSC-LCD. Comparing to conventional RGB-driving sequence, the RGBDw method yielded color accuracy with ∆E00 <0.6, suppressed 77% CBU and reduced 77% power dissipation. Therefore, the color optimization models were proposed and designed to achieve high image quality and low power dissipation in green technologies.