Industrial Electronic Engineers, Inc.
SIZE
A
CODE IDENT NO.
05464
S03601-95B-40
Van Nuys, California
SCALE N/A
REV
A
SHEET 5 of 14
08/26/02
3.0
THEORY OF OPERATION (Dot Matrix Displays)
The Vacuum Fluorescent Display array consists of three basic electrodes which are enclosed in an evacuated
glass chamber. The first electrode is the filament, which spans the entire length of the display, and is made
from a small diameter oxide coated tungsten wire. This element is common to all characters and supplies the
electron emission needed for operation. Individual grid electrodes are provided, one for each character, to
control current passing to the anodes. Each grid is a fine mesh metal screen which provides digit-select
electrical control with no visual interference. When the grid is positive with respect to the filament, electrons
are allowed to pass on to the third electrode, the anode dots, causing the fluorescent phosphor coating on
each positively charged dot to glow. Selectively energizing these fluorescent dots causes the desired
character to be displayed.
FIGURE 2
