Active-Matrix Liquid Crystal Displays - Operation, Electronics and Analog Circuits Design

Abstract

For more than four decades, Cathode Ray Tube (CRT) Displays have been the dominant display technology providing very attractive performance. Brightness, contrast ratio, high image quality, speed and resolution were the main high standard specifications that CRTs were satisfied. The last two decades, there was a tremendous growth in small portable applications which required the necessary adjustment of the display technology to them. The large depth of the CRTs was the main disadvantage for preventing them to be used in these kinds of applications. Flat Panel Displays seem to be the most attractive solution to this problem. Displays engineers searched for many years in order to find the suitable flat panel display technologies that could replace CRT displays. The first successfully established flat panel technology was the plasma displays, which demonstrated to be of larger size and higher image quality compared to the CRT technology. However, the problem with the integration of plasma displays in small portable applications still exists. Finally, the inroad of the thinfilm transistors liquid crystal displays (TFT-LCD), in late 1990’s, was a milestone in the displays industry and technology. The successful development of the TFT-LCDs was achieved not accidentally. It was the sequence of the liquid crystal cell technology development, in combination with the development of semiconductors technologies for large-area microelectronics on glass, like thin-film transistors. Although, both technologies were very-well known before the 90’s, an extended research for establishing compatible fabrication processes for the materials and the manufacturing equipment has led to the TFT-LCDs realization. TFT-LCDs were rapidly grown and dominated the displays industry, especially in small portable applications. The implementation of the TFT-LCD panel peripheral driving components with low-power CMOS blocks and, therefore, the compatibility with battery operation was the main reason for the ascendance of the TFT-LCD technology in small portable applications. Today, the TFT-LCD market has been expanded. They can be used in an extremely wide range of our everyday life products, like mobile phone applications, ATMs, PDAs, navigation systems, notebook PCs and home applications, such as wide screen TVs. O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg