Overview

Optoelectronic displays are acquiring increasing importance as interfaces between people and computers, cellular telephones, pagers, and other communications devices. These displays, ranging from cathode-ray tubes to liquid-crystal, light-emitting diode, and electroluminescent panels, have been steadily improved. They now present larger, brighter images than earlier versions, are more reliable, and draw less power. These displays are now integral parts of a wide variety of products from desktop and notebook computer monitors to test equipment, TV receivers, automotive and aircraft instruments, and electronic games. They can be found in homes, offices, factories, stores, travel agencies, financial institutions, and airline terminals, and even in the passenger sections of airliners. Some optoelec-tronic displays have reached monumental billboard size in cities, where they provide news bulletins as colorful, moving "zippers." The latest automobiles now include three or four different kinds of indicators and displays, and more are in the offing.

Of all the display technologies, liquid-crystal displays have shown the most conspicuous improvement within the past 10 years. They first appeared as black segmented digits on white backgrounds in watches and calculators, but they have now morphed into multicolor flat panels. With increasing resolution and wider color palettes, LCDs are now challenging CRTs as the leading computer monitor displays and they are now in TV receivers, camcorders and digital cameras.

The charge-coupled device (CCD) camera is also replacing traditional video camera tubes inside and outside of TV studios and in industrial and consumer still and video cameras.

The standard observer curve, shown in Fig.