
herringbone pattern superimposed on the displayed image. If the noise is peri-
odic and synchronized with the horizontal or vertical deflection signals, it can
produce a pattern of bars. The general display quality is adequate if all noise,
random and periodic, is kept at or below one gray level in amplitude. In many
systems, it is actually somewhat worse than that. Preprocessing is not effective at
eliminating noise introduced by the display system. Only repair or replacement
will improve the situation.
4.3 Volatile Displays
The most common types of volatile display are the LCD and the TFT flat panel
monitor [6, 7], although CRT monitors are still common ...