Overview

In this chapter, flat panel technologies competing with active matrix LCDs are briefly addressed, including plasma displays, inorganic and organic electroluminescent displays, and front and rear projection. Since the topic of this book is AMLCDs, the discussion of these alternatives will not be more than cursory. These technologies each represent a large field in themselves, with numerous publications and continuing development. The purpose here is to give the reader a flavor of competing technologies and a perspective on the merits and drawbacks of AMLCDs relative to other successful and less successful flat panel display technologies.

The final decision to select a certain display technology is usually based on a careful consideration of price and performance. Since the manufacturing of AMLCDs requires expensive, semiconductor-type processing, it has been difficult to replace CRTs and PDPs with a lower manufacturing cost structure in all applications. Figure 8.1 shows an overview of the major display technologies, of which only the CRT and projection technology are not flat panel displays. LCDs are non-emissive and need external light sources (backlight or ambient light) to be legible. The self-emissive displays can be classified in plasma display panels (PDPs), field-emission displays (FEDs), and inorganic and organic electroluminescent displays.

Figure 8.1: Classification of major high information content display technologies.

Field emission displays (FEDs) may be considered a type of flat CRT, in which the electron guns are replaced with very large numbers of microtips in a vacuum cavity. Each pixel contains hundreds of these microtips emitting electrons, which...