Ligjt Displays Flashcards
Electroluminescemce
Process of transforming electrical energy directly into light
Consumes much less energy
LED
Light emitting diode
Electroluminescent light source made out of semi conductors material that can be made to change how well it conducts electricity
Can be made to emit light with small electric current
Parts of lED
No filament made of solid material very rugged
Efficient little heat
Lasts long
Uses of LEDs
Electronic billboards
Traffic lights
Decorative lights
Handheld displays
OLEDs
Organic light emitting diodes
A light source made of several extremely thin layers of organic molecules that use an electric current use less energy as they do not require a backlight
Properties of OLEDs
Thinner lighter brighter
More flexible as they can be rolled
Uses of OLEDS
Potential in small and large screens Cellphones medical equipment Head mounted displays Tv Computers
OLED disadvantages
Expensive easily damaged by water
Plasma displays advantages
Producer brighter images than LCD
Plasma display disadvantage
Requires much more electrical power
Plasma display work
Each had tiny fluorescent light colour
Electric signal causes gas to release ultra violet radiation
Ultraviolet radiation is absorbed by phosphors radiate light
Liquid crystal display examples
Laptops digital watches cell phones iPods
Flat panel TVs
LCD function
White light behind liquid crystal a solid that can change the orientation of its mollecule like a liquid but only when electricity is applied
Crystals can block or transmit light depends on amount of electricity
Red blue green filters to produce colours
Polarizing filter blocks certain lights to make colours
White light is always on crystal do not block all light not completely black is it gray
