應用於液晶顯示器面板之多輸出閘極驅動電路技術

Abstract

在現今的科技生活中，人們對於顯示器的品質需求越來越多，無論是畫面品質或是產品外觀。因此System-on-panel的技術已成為發展的重點，此技術不但可節省製造成本與提高良率並且具有縮減產品模組、實現高可靠度與高解析度顯示器等特性。而在薄膜電晶體液晶顯示器(thin-film transistor liquid-crystal display，簡稱TFT-LCD)驅動系統中，閘極驅動電路，gate drivers(或稱掃描驅動電路，scan drivers)，主要負責將畫面上一列列的電晶體依序打開，讓資料電壓能夠進入到液晶及儲存電容內。近來，在消費性產品中，閘極驅動電路部分已高度整合於下層玻璃基板，而非傳統使用IC晶片的型式。目地在於降低成本與使LCD模組更輕薄，雖然非晶矽薄膜電晶體(a-Si TFTs)的電子遷移率低，但其高均勻性及低成本，適合閘極驅動電路的實現。

在此篇論文中，提出兩種應用在顯示器上的閘極驅動電路，第一種為雜訊抑制分享(Noise Prevent Sharing)機制的閘極驅動電路，主要是利用四組驅動訊號可實現單一路徑充放電並可得到低雜訊，窄邊框的優點。 第二種則為了未來產品化能有更靈活的應用，而做出了具有雙向掃描(Bi-direction scan)的閘極驅動電路，而其未來發展則朝向共享雜訊抑制機制來達到面積縮減以及低雜訊的方向進行。

It is popular and inevitable for us to have many instruments with display screens in our life. The requirements of qualities whatever in image or appearance of apparatus have become more sophisticated. A revolutionary technology of TFT LCDs has been developed quickly which is system-on-panel (SOP) applications. However, SOP application has the potential to realize compact, highly reliable, and high resolution display by integrating functional circuits within a display. Besides, the cost of panel becomes lower, as well as the higher yield rate can be achieved.In the driver system of thin-film transistor liquid-crystal display (TFT-LCD), gate drivers (or scan drivers) are the essential parts that sequentially control the gates of pixel TFTs. Therefore, the pixel TFTs can transfer correct data and store in the liquid crystal and storage capacitors. Recently, in the consumer electronic display products, the gate driver circuits have been integrated into the bottom plate glass of LCD module rather than providing form the conventional ICs. Although the electron mobility in a-Si TFTs is extremely low (≈0.3cm2/V-s), the traits of high uniformity and low cost of manufacturing a-Si TFTs have created the trend towards gate driver on array (GOA). Moreover, the application of GOA decreases the cost of ICs and results in the module lighter and thinner. In this thesis, we have proposed two main kinds of gate driver the for the flat panel application. First multiple outputs gate driver by sharing noise prevent mechanism has proposed. The main design concept is using four clock signals to achieve single path conduction for low noise performance and narrow bezel purpose. Second, we will offer another theory of gate driver design which includes bi-direction scanning and use the “Noise prevent share” mechanism to keep the integrity of circuits when it be commercialized. Furthermore, we hope this design can develop toward the way not only sharing more noise prevent units for the purpose of size reduction, but lower the unnecessary noise in the future.