The physical properties of liquid crystal is: when the electric conduction, arranged orderly, make the light easy through;Without power arrangement chaos, prevent light through.Allow light liquid crystal as gate block or allow to pass through.Technically, in a nutshell, the LCD panel contains two quite delicate without sodium glass material, known as the Substrates, with a liquid crystal layer between them.When the beam through the layer of liquid crystal, liquid crystal itself can stand in rows or reverse the irregular shape and thus cut off or make light beam pass.Most LCD belong to organic compounds, made up of long rod molecules.Under the natural state, the parallel to the long axis roughly rod-shaped molecules.To pass through the fine processing of liquid crystal pour into a slotted plane, the liquid crystal molecules will line up along the trough, so if the slot is parallel, each molecule is completely parallel.(2) single color LCD LCD LCD technology is pumped into the principle of the two columns have grooves between the plane.The two slots in the plane of the perpendicular cut (at 90 degrees c).That is to say, if a molecule in the plane of the north and south, are the other molecules in the plane of the east-west, and lies between two surfaces of molecules is forced into a state of 90 - degree turn.Because of the light spread along the molecular orientation of the light passes through liquid crystal was also turn 90 degrees.But when add a voltage applied to the liquid crystal molecules will be back in vertical arrangement, can make the light point-blank out, and nothing to reverse.

LCD is dependent on polarization filter (film), and the light itself.Natural light is random scatter in every direction.Polarization filter is actually a series of parallel lines more and more thin.These lines form a net, blocking all the light is not parallel to the line.Polarization filter line coincide with the first vertical, so have can completely block the polarization of light.Only two filter line completely parallel, or the light itself is reverse to match the second polarizing filter, light to penetrate.LCD is composed of such two perpendicular polarization filter, so under normal circumstances should block all trying to penetrate the light.However, due to full of distortion between two filter liquid crystal, so wear out after the first filter in the light, will be the liquid crystal molecules turn 90 degrees, finally from the second through the filter.On the other hand, if the LCD and a voltage, molecular rearrangement and completely parallel, make the light no longer turn, so just is blocked by the second filter.All in all, plus electric will block light, without electricity, make the light.However, can change the LCD liquid crystal alignment, make the light in, electric fires, but without electricity is blocked.But because almost always on a computer screen, so only "add electricity to light blocking" scheme can achieve the goal of most save electricity.