GotFrag Hardware explains what SED displays are and why they are the future.
SED works a lot like a CRT monitor. In a CRT monitor, an electron gun (made up of a cathode and some anodes) shoots electrons through a large glass tube (cathode ray tube) at a large flat surface (screen) that is coated in phosphor. When the negatively charged electrons collide with the phosphor-coated surface, they excite the material, causing electrons to drop valence rings, and give off visible light photons. If you’ve ever seen inside a monitor, you will have seen something glowing at the skinny end of the big glass tube. This is the cathode filament, which heats up the cathode and causes it to emit a bunch of electrons.