In the past all of these were low resolution, text only CRTs. They are currently being upgraded to graphics displays capable of showing charts. However, most people asked estimated the gas plasma displays to be larger than what they really are. Other applications include kiosks, in-wall mounted control and information consoles, and fast food restaurants, which are converting their cash registers from PCs with CRTs to touch sensor entry flat panels, in a constant struggle to improve their productivity as measured by income per square foot. Flat panel technologies can be divided into emissive and non-emissive types.
Emissive displays emit their own light, while the non-emissive ones use external light sources.
Among the emissive displays, the most common are gas plasma and electroluminescent displays. Individual pixels are excited to emit photon when cumulative currents flow through horizontal and vertical leads. Main disadvantage include the difficulties to achieve 256 gray levels, linearity across the screen, and color. Their main disadvantages are that it is difficult to achieve 256 gray levels, full color, and high resolution, as they suffer from pixel density and linearity problems. Their main applications are in the industrial market, where their raggedness is their main asset.