We all know the state of material existence are three common " solid, liquid , gaseous ," but there are some unusual states of matter , the LCD is one of them . In the liquid crystal has a fluidity and an orderly arrangement of a solid . For example , a nematic liquid crystal phase is composed of columnar elongated molecules , is at 118-136 掳 C are nematic form. In this state, the molecule has a fluidity of liquid , but they ( within limits ) can only point to the same direction, and can not twist freely . The liquid crystal is in a great technological purposes ,

When the liquid crystal phase to have a special shape of the molecule combinations will produce , they can flow , but also has the optical properties of crystals . The definition LCD , which has now been relaxed to include a certain temperature range can be achieved in the liquid crystal phase , at a lower temperature crystalline substance was normal . And the liquid crystal composition of the material is an organic compound , a carbon compound composed of the center it is . While two substances having a liquid crystal , is the combination of forces between molecules , their special optical properties and sensitive to electromagnetic fields , it is highly practical .

LCD screen is the use of liquid crystal electromagnetic sensitive this feature. The liquid crystal molecules are arranged sequentially in accordance with the rotation direction of the film to the thin groove , if the electric field is not formed , the light incident from the polarizer will be smooth , the liquid crystal molecules rotate according to its traveling direction and then the other side is emitted . If, after two conductive glass energized, will cause an electric field between two pieces of glass , and thus the liquid crystal molecules are arranged therebetween effects to molecular torsion bar , the light can not penetrate , and thus cover the light source . Thus the resulting light and dark contrasting phenomenon called twist nematic field effect , referred TNFE (twisted nematic field effect). The LCD display is such a basic principle described above .