快速超扭轉向列液晶顯示控制器之製作與測量

Abstract

在本篇論文裡,我們提出適用於快速超扭轉向列(STN)液晶顯示(LCD)控制 器的設計,此種驅動方式稱為"主動尋址方式(Active Addressing Method)",它是一種新的驅動技術,能使快速超扭轉向列液晶顯示器傳送全 動態畫面而不致於喪失亮度與對比度,首先,我們解釋利用傳統多工尋址 (Conventional Multiplexed Addressing)技術來驅動快速超扭轉向列液 晶顯示器在畫面顯示上所造成的" 幀響應(Frame Response)" 現象,其次, 解釋主動尋址方法的原理,我們如何選擇主動尋址方法的列信號和推導對 於想要顯示圖形行信號的演算式,實現主動尋址方法的電路設計,其包含積 體電路設計,此控制器利用0.8μm單層多晶矽(Single-poly),雙層金屬 (Double-metal),雙井(Twin-well),CMOS技術被製作在39mm^2面積上,整個 電路的電晶體數約37萬且最低的工作頻率是3.932 MHz,其顯示的畫像 (Pixel)數是255*256,因為快速超扭轉向列液晶顯示器比薄膜電晶體(TFT) 顯示器有較低製造成本的優點,所以主動尋址方法被預測能使液晶顯示器 具有低成本,高性能的特點而適用於眾多的影像產品。 This thesis introduces the design of a CMOS controller suitable for application in high speed supertwisted nematic (STN) liquid crystal displays (LCDs). The driving method is called "Active Addressing Method". The active addressing method is a new electronic driving technology that makes it possible for fast- responding STN LCDs to deliver full-motion video images without loss of brightness or contrast. First, we explain the conventional multiplexed addressing techniques at video rate, and describe the " Frame Response " phenomenon resulting from the conventional multiplexed addressing method when fast- responding STN LCD is used. Then, we explain the theory of the active addressing method. We address how to choose the active addressing row signals and derive the algorithms for generating column signals to display the desired patterns. Circuit design for implementing the active addressing method is presented, including an integrated circuit design. This controller has been fabricated in a 0.8μm CMOS single-poly double-metal twin- well technology with an area of 39mm^2. The approximate transistor count of this controller is 370 thousand. This circuit operates at more than 3.932MHz clock rate. The pixel numbers of STN LCD are 255*256. Because of the low manufacturing cost in STN displays as compared with the thin film transistor (TFT) displays, the active addressing method is expected to make low cost, high-performance video rate LCDs for the wide variety of application products.