Vacuum fluorescent display device with circular polarizer

摘要

A vacuum fluorescent display has a filament heated below incandescence and phosphor coated anodes. A foraminous charge-control electrostatic lens between the filament and the viewer both controls uniform illumination of the anodes and also comprises part of a contrast-enhancement element. An embodiment of the invention with a linear array of anodes and an analog-to-digital power supply forms a linear scale indicator.