Liquid crystal display is a display device for letters, numbers, graphics and images, consisting of a liquid matrix of cells that become opaque or change color under the influence of an electric current or field. The form of a screen is displayed (display) that is electronically controlled by a decoder numerical and alphabetical characters. It is widely used in building digital watches (watches with those index fingers instead of a poster type LCD), displaying data on CNC machines, household machines, inscriptions and electronic signals. Just like led signs LCDs can be used for signs.
Liquid crystals are, in this case, combinations of organic chemicals in liquid form. They are able to be controlled by a corresponding voltage, so that its molecules moving from state orders “transparent” to state “not transparent”. Specifically, it is an electric polarization of liquid molecules in contrast to the rest of the “field” form a visible image.