多模式灰階與背光演算法-抑制場色序法液晶顯示器之色分離效應

Abstract

自2000年以來,LCD便逐漸取代CRT顯示器的市場，LCD的使用者每年都在增加。其中，場色序法（FSC，Field Sequential Color）是最受矚目的一種技術。FSC的原理是利用三原色(紅、藍、綠)在人眼視覺暫離的時間內把顏色混合。將影像分成紅、藍、綠三個子畫面，進而構成一個全彩影像。 由於FSC-LCD不再需要濾光片，因此可以降低了面板的成本、提高光穿透率、功率消耗降低、色彩飽和度高，由於畫素佔用的體積縮小，故也具有更佳的解析度。由於低功率與高飽和度的優勢，使FSC技術越來越普遍。然而，FSC-LCD有一個缺點：當播放動態畫面的時候會出現色分離，造成影像模糊。 本論文提出一種新的架構與演算法來消除色分離的效應。透過四個子畫面去形成一個彩色影像（紅畫面、藍畫面、綠畫面與D畫面）。降低前三個子畫面的色彩強度，並且在第四個子畫面補償回來，同時配合背光的調整去消除色分離的現象。此外，本研究共提供了四種模式：RGBM、RGBC、RGBWmin與RGBY，分別去處理各類的畫面。透過預測的方式去挑選目前畫面的最佳演算模式。這種技術叫做多模式灰階與背光演算法（Multi-LC/BL Algorithmic Technique）。

Since 2000, LCD have been released CRT at the market. The number of LCD users increased for days and days .Field Sequential Color is one kind of most attractive LCD technologies. The principle of FSC-LCD is to mix three primary colors (Red、Blue、Green) during their time of photogene in human visual system. Conventional FSC technology extracts red, blue, and green sub-frames from one image and then reconstructs a full-color image in human’s eyes. As the FSC technology does not require color filter, it has the following advantages: (1) Reduce the cost of the panel. (2) Elevate the light transmission. (3) Reduce the power consumption. (4) Reduce the pixel space with higher resolution. (5) Good saturation of the image. Thus, for a low power and high color gamut consideration, FSC technology becomes more and more popular. However, the FSC-LCD has its disadvantage: while playing moving image, there is a CBU effect which results in motion blur. A new multi-LC/BL algorithmic technique is proposed to eliminate the CBU effect. In forming a color image (R, G, B, and D) through the four sub-frames, the color intensity of the first three sub-frames is reduced. The fourth sub-frame can compensate the color intensity and adjust the backlight at the same time to eliminate the phenomenon of CBU. However, the fourth sub-frame should be adaptive according to the image data. Therefore, four modes, which include RGBWmin, RGBM, RGBC, and RGBY, are proposed to deal with various types of images, respectively. Besides, and a prediction approach is applied to select the best mode for the current frame. That is named Multi-LC/BL Algorithmic Technique.