VFD
full spelling ： Vacuum Fluorescent Display
The Vacuum Fluorescent Display is a type of small graphic display used on consumer-electronics equipment such as video cassette recorders, microwaves, stereos, etc. The VFD emits a very bright light with clear contrast and can easily support display elements of various colors.
The VFD is composed of three basic electrodes; the Cathode (Filaments), Anodes (Phosphor) and Grids under a high vacuum condition in a glass envelope. The cathode consists of fine tungsten wires and it is coated by alkaline earth metal oxides, which emit electrons when heated by an electric current. These electrons are controlled and diffused by the grids, which are made up of thin metal. The Anodes are conductive electrodes on which the phosphor is printed to indicate characters, icons or symbols. If electrons impinge on the phosphor-coated plates, they fluoresce, emitting light.
Unlike LCDs, most VFDs continue to function normally in sub-zero temperatures, making them ideal for outdoor devices in cold climates. VFDs have been mostly used for applications requiring smaller displays with high brightness.