The roles of EL displays and plasma panels are changing because of their lack of full color. In the case of EL, suitable phosphors have not been demonstrated. In the case of plasma, suitable phosphors have been available, but, because of the plasma/UV excitation of the phosphor, there are problems in terms of life, efficiency, and background illumination from Hg visible line emissions. The production of LC HIC FPDs now exceeds the worldwide production of plasma panels by over an order of magnitude and the production of EL displays by two orders of magnitude. Several companies such as Fujitsu, Hitachi, NEC, and NTT have stopped R&D on EL. Also, NEC and DNP have stopped production on plasma panels.

The proponents of these two technologies point out that they have several advantages over LCDs that will ensure their continued use. Both technologies are used in the custom marketplace, have existing factory capacity, will benefit from product inertia and reputation, and offer wide viewing angle, self-luminance, and fast response. Electroluminescence is made in the thinnest form factor, and plasma is made in the largest form factor. NHK is presently making 33-inch full- color experimental plasma panels with HDTV resolution.

Until the primary problems with both techniques--cost and lack of full color--are solved, these two technologies will lose FPD market share. At the Japan Electronics Show '91, no demonstrations indicated that these techniques were making any significant advances in color.

In spite of the lack of color, the manufacturers (Sharp in the case of EL and Matsushita in the case of plasma) predict a growth in production volume. EL is considered to be most suitable for the industrial and computer workstation market because of its wide viewing angle, brightness, ruggedness, and high information content. Plasma is unique in being the largest FPD in size, and it is considered to have the greater promise as a full-color display.

Published: June 1992; WTEC Hyper- Librarian