The Vacuum Fluorescent Display

VFD emits a very bright light with high contrast and can support display elements of various colors. VFDs can display  numerals, multi-segment alpha-numeric characters or can be made in a dot-matrix to display different alphanumeric characters and symbols.

The Vacuum Fluorescent Display 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 which are coated with alkaline earth metal oxides which emit electrons.

The Grids are a thin metal mesh which control and diffuse electrons emitted from the Cathode.  The Anodes are conductive electrodes on which the phosphor is printed and indicate characters, icons or symbols.

Electrons emitted from the Cathode are accelerated with positive potential applied to both the Grid and Anode, which upon collision with the Anode excites the phosphor to emit light.  The desired illuminated patterns can be achieved by controlling the positive or negative potentials on each Grid and Anode.  This voltage can be as low as 10VDC.