Field Emission Display Screen场发射显示器.pptVIP

FIELD EMISSION DISPLAY SCREEN INTRODUCTION Displays are devices by which we can view moving objects Used in television and computers They also have wide use in laboratories and in medical applications. HISTORY OF DISPLAYS Cathode ray tube Liquid crystal display Plasma displays Electro luminescent displays Field emission displays FED TECHNOLOGY The FED screen mainly contains three parts: 1.Low-voltage phosphorous plate 2.A field emission cathode using a thin carbon sheet as an edge emitter 3.FED packaging, including sealing and vacuum processing STRUCTURE OF FED LOW VOLTAGE PHOSPHOR The low voltage phosphors are the screens in which the images are displayed In the display technology the phosphor screens act as anode, which receives the electrons emitted from the cathode The phosphors are made up of layers of three primary colours -green, red and blue ?FIELD EMISSION CATHODE In the field emission display screen the cathode are electron guns which emit electrons Electron guns are called micro tips The emission of electrons is called “cold cathode emission” MICRO TIPS ARE OF DIFFERENT TYPES Wedge type emitter using silicon. Silicon tips with continuous coating of diamond particles. Single-crystal diamond particle on silicon tips. Planar diode emitter. Metal-insulator-semiconductor type planar emitter WEDGE TYPE EMITTER USING SILICON SILICON TIPS WITH CONTINUOUS COATING OF DIAMOND PARTICLES SINGLE CRYSTAL DIAMOND PARTICLE ON SILICON TIPS PLANAR DIODE EMITTER METAL INSULATOR SEMICONDUCTOR TYPE PLANAR EMITTER FED PACKAGING WORKING The field emission display works a bit like the cathode ray tube This emission of electron occurs from the cold cathode when a voltage is applied between the cathode and anode . These electrons propagate from cathode to anode They bombard with the phosphor, which is the anode and causes it to glow This reproduces the image on the screen by the mixing of colours present in the screen TWO WAYS OF WORKING Low vol