Electronic visual displays Active displays Passive displays present visual information by emitting light present visual information by modulating light Principle Liquid crystal display (LCD) + backlight (this combination is considered an active display) LCD Example LCD TV screen, LCD computer monitor LCD watch (reflective) see LCD classification Principle Cathodoluminescence Electrophoresis also see Electronic paper Example Cathode ray tube (CRT) Field emission display (FED) Vacuum fluorescent display (VFD) Surface-conduction electron-emitter display (SED) Research & manufacturing: Principle Electroluminescence Electrochromism Example (thin or thick film) electro-luminescence (EL) (inorganic or organic) light emitting diode (LED, OLED) gas discharge display (Nixie tube) Research & manufacturing: Principle Photoluminescence Electrowetting Example Plasma display panel (PDP) Research & manufacturing: Principle Incandescence Electromechanical modulation Example Numitron, a 7-segment numerical display tube Numitron website flap display flip-disk display digital micromirror device (DMD) Interferometric modulator display (IMOD) FTIR (unipixel)