整合觸碰技術及顯示功能之雙邊掃瞄驅動技術研究

Abstract

投射面電容觸碰技術(Projected Capacitive Touch technology)的工作原理即是設計兩個方向的電極，一個方向稱為信號傳輸電極：Tx(Transmissive Line)；另一個方向為信號接受電極：Rx(Receive Line)。手指的觸碰與否，將會改變Tx 傳送到Rx 的信號，藉此，可做為判斷手指觸碰的與否。 就目前的智慧型手機及平板電腦的市場，觸碰面板已經是現有的趨勢，而這樣的使用介面，因為使用上簡單、可節省傳統鍵盤的空間、更符合人們使用上的直觀感受，因此可預期的，未來將會逐步取代全面鍵盤界面，甚而更滲透於所有的中大型顯示器。而觸碰面板介面中，投射式電容因為具有穿透率高且輕碰即可反應的特性，目前也逐漸成為市場上的主流觸碰介面。但也因為多了一塊觸碰面板，使的重量更重、模組更厚、價格更高、光學特性犧牲。因此，如何將觸碰面版與顯示器做整合以減少玻璃使用數，一直都是許多面板廠致力開發的。研究了文獻及市場或展覽中開發出的整合式架構，在整合液晶面板及觸碰面板時，兩個技術製程道數的累加似乎是難以避免，而這卻也造成了製造過程的難度。抑或因為須另外設計觸碰元件，因此影響了液晶面板顯示器最重要的特性指標-開口率。另有些整合技術，則是利用液晶面板既有的結構，改以壓力式的方式來感測電容變化，但這樣的方式除了有極低的製造偏移容忍度外，也失去了目前電容觸碰面板風行主要的特性-輕碰即能感應。綜合以上，整合觸碰及顯示功能雖是技術發展的趨勢，但應需在兼顧良率及既有重要特性的前提下。 在本篇論文中，即是依此提出新的整合式技術架構。在此新架構設計中，即是利用LCD(liquid-crystal display) 設計本身就已有的信號線(data line)，做為觸碰面板的傳輸訊號電極，如此不僅節省了觸碰面板的製程道數，對於製作生產的良率上，更是有相對實現的效益，也因為不須額外製作觸碰元件，因此可維持既有的開口率，其感觸原理也仍是投射式電容感應，因此輕碰感應的優點仍存有。為了能確切驗證此新技術架構的可行性、技術挑戰及整合後的特性，包含顯示光學、電性、驅動，及觸碰能力表現，將在本論文研究做基礎的實驗設計及數據驗證，並架構模擬上的等效電路，以作為後續產品實現的先期技術研究。

The operational concept of projected capacitive touch technology is as follows: there are two electrodes in different directions. One is called Tx: Transmissive Line, and the other is called Rx: Received Lines. The Rx signal conveyed from Tx will change as fingers touch, and it will be the judged signal. Touch panel is the main stream interface as for present market in PDA (Personal Digital Assistant) and Tablet computer. The interface has many advantages：easy-use、saving space compared to conventional keyboard、fitter with the people’s habit. We can predict that touch panel interface will totally replace keyboard interface, and even permeate into middle and high size display screen. Among all touch panel interfaces, projected capacitive technology gradually becomes the main stream one in the market because it has crucial characteristics: high transmittance and feather touch. Unavoidably, the display is getting heavier, thicker, higher cost, and worse optical performances because of extra touch panel glass. Therefore, how to integrate LCD (liquid-crystal display) panel and touch panel is what the panel manufacturer devoted to developing all the time. After studying lots of papers and the developed integrated structures in market and technology shows, as touch panel and LCD panel are integrated into one, the process flow accumulation is unavoidable. The manufacture challenges become drastically hard to be overcome because of the process flow accumulation. There are some integrated technologies designing touch sensor in the panel, which decrease the important target in LCD panel: aperture ratio. Some structures and electrical characteristics in LCD are utilized for pressure touch sensing. In this kind of method, there is not only small process margin, but also users have to lose the crucial point of projective touch panel- leather touch. Above all, although developing integrated technology of LCD and touch panel is the trend, giving consideration to yield and the crucial characteristics is very important. In this thesis, we propose a New-concept integrated TP (touch panel) technology structure. In this new structure, we make use of the data traces of LCD design to be the transmissive traces of touch panel. Therefore, not only steps of process could be decreased but also yield in manufacture could be raised. Since extra sensor is not needed, aperture ratio could be kept. And we also retain the characteristic of feather touch. To verify the possibility、technology challenges and the performances of this New-concept integrated TP technology, there are basic experiments and data verification including optical and electrical characteristics、driving methods and touch performance in this thesis. And simulation effective circuit is built as well. With the solid data, we could make sure that he productive accomplishment could be achieved.