主動式的「液晶/背光」調變控制 -- 改善使用「場色序法」的液晶顯示器之色分離現象及節電技術

Abstract

使用「場色序法」的液晶顯示器(FSC-LCD, Field Sequential Color LCD)是目前最受注目的顯示科技。因為它不需要彩色濾光片(CF, Color Filter), 所以可以有效地降低顯示面板的成本、體積，提高解析度、色彩飽和度，還有高發光效率、低功率消耗的優點。 但是，使用「場色序法」的液晶顯示器有「色分離」(Color Breakup)問題 嚴重地影響了影像的顯示品質。 在這篇論文中，提出了一個新的演算法。它會自動根據目前的影像資料,決定最佳的背光模式，有效地降低色分離的現象，但卻不用大幅增加顯示器的更新頻率。另外，也可以在不影響影像品質的同時，利用「發光二極體調暗」(LED dimming)的技術，降低了功率消耗。本文使用一種『仿0-D LED 調暗技術』(pseudo zero-dimension LED dimming technique)，針對所有的影像資料，相較於原始背光模組的耗電量，至少有12.5%的節省空間。

Currently, Field Sequential Color LCD (FSC-LCD) is the most eye-catching display technology. As the FSC-LCD does not require color filter (CF), it significantly reduces the cost of panels, and has the advantages of small size, high resolution, high color saturation, low power consumption and high luminous efficiency. However, the users do not accept this product owing to the color breakup (CBU) phenomenon which affects the quality of FSC image.

The proposed “Active - liquid crystal and backlight (LC/BL) Control” algorithm presents the dynamic field sequential color (D-FSC) algorithm to reduce the CBU effect without greatly increasing frame rate. The D-FSC algorithm can intelligently select one adequate color sequence from multiple color sequences according to the image data. In other words, the scope of CBU suppression of the proposed Active -LC/BL Control algorithm is more extensive than other conventional FSCs. Besides, high-contrast and low-power image can be achieved by the two-dimension (2-D) LED dimming technique. But, the requirement of hardware is expensive. On the contrary, one pseudo zero-dimension (0-D) LED dimming technique can further reduce power dissipation with the D-FSC technique. Experimental results show the CBU suppression can be improved substantially by the proposed evaluation equation and the power dissipation can be reduced at least 12.5%.