vacuum fluorescence display (VFD)
Vacuum Fluorescence Display(VFD) is a self-emitting display technology that realizes the principle of cathode ray tube( CRT) in each pixel.
Light is emitted by electrons released in a heated cathode and accelerated toward the anode in a cathode-grid-anode construction. On the anode are phosphors that emit light when struck by the electrons. The grid between the cathode and anode has a voltage of about 50 V, which is used for control and acceleration. The anode voltage is 100 V.
Since the phosphors are on the side facing the viewer, the luminance is very high, reaching values of 10,000 cd/m2. In addition to the high luminance, VFD displays have a large viewing angle and excellent contrast.