What is Liquid crystal display?
[[File:RFE06 Arcelik.jpg|thumb|left|LCD television]] A '''liquid crystal display''' is a special thin flat panel that can let light go through it, or can block the light. (Unlike an [[light-emitting diode|LED]] it does not produce its own light). The panel is made up of several blocks, and each block can be in any shape. Each block is filled with [[liquid crystal]]s that can be made clear or solid, by changing the electric current to that block. Liquid crystal displays are often abbreviated '''LCDs'''. Liquid crystal displays are often used in [[battery]]-powered devices, such as digital watches, because they use very little [[electricity]]. They are also used for flat screen [[television|TV's]]. Many LCDs work well by themselves when there is other light around (like in a lit room, or outside in daylight). For [[smartphone]]s, [[computer monitor]], TV's and some other purposes, a back-light is built into the product. This is an LED or [[cold cathode|Cold Cathode Fluorescent Light]] (CCFL). == Construction == [[File:MA-2.JPG|right|thumb|LCD alarm clock]] The LCD uses technology called [[Electro-optic modulator|electro-optical modulation]]. This means it uses electricity to change how much light passes through it. Each pixel (block) of an LCD is made of a thin layer of [[molecule]]s between two [[electrode]]s and two [[polarization|polarizing]] [[Filter#In_optics_and_photography|filters]]. The electrodes provide electric power to the liquid crystal layer, and don't block the light. Light travels with 'polarity' or direction, and a polarizing filter only lets light with one kind of polarity to go through it, like trying to slide a ruler through a narrow opening. Only when the ruler is lined up right, will it fit. These two filters are [[Right angle|perpendicular]] to one another, so the narrow openings are in different directions. This means that without the liquid crystals between them, they would block all light from passing through – whatever light gets through the first filter will not fit through