Liquid crystal display refers to a lot of use of LCD produced by the display. Graphic LCD Display Today, the name of the liquid crystal display, mostly refers to the use of notebook computers, or desktop computer applications in the display. That is, thin film transistor liquid crystal display. Graphic LCD Display Its English name for the Thin-film transistor liquid crystal display, referred to as the TFT LCD. From its English name, we can know that this kind of display its main structure has two characteristics, one is the thin film transistor, Graphic LCD Display the other is the LCD itself. Let's talk about the LCD itself.
We generally believe that things like water have three states, respectively, solid state with the gas state. In fact, the three-state substance is for water, for different substances, Graphic LCD Display there may be other different states exist. In the liquid crystal state we are talking about, it is a state between the solid and the liquid. In fact, this state is only a phase change process of the material , Graphic LCD Display as long as the material has the above Of the process, that is, between the solid and liquid state exists, Graphic LCD Display the physicist will call it liquid crystal.
The first discovery of this liquid crystal, Graphic LCD Display has been spent more than 100 years old. In 1888, discovered by Austrian botanist Friedrich Reinitzer, it was found that when the compound was heated to 145.5 ° C, it was found that when the compound was heated to 145.5 ° C, Graphic LCD Display the solid was judged to be isolated from the purified cholesteryl benzoate Melting, showing a liquid and liquid phase between the semi-molten flow of white turbid liquid. This condition will always maintain the temperature rise to 178.5 degrees Celsius, to form a clear isotropic liquid (isotropic liquid). The next year, in 1889, the study of phase transfer and thermodynamic equilibrium of the German physicist O. Lehmann, this compound for more detailed analysis. Graphic LCD Display He found under the polarized light microscope that this viscous semi-fluid white turbid liquid compound had the optical properties of the birefringence, which is characteristic of the anisotropic crystal, that is, optical anisotropic. Graphic LCD Display So this crystal-like liquid called liquid crystal. Since then, scientists have this new discovery of the nature, known as the fourth state of the material - liquid crystal (liquid crystal). It will have both liquid and solid properties within a certain temperature range.
Generally in terms of water, the lattice in the solid because of heating, began to absorb heat and destroy the lattice, when the temperature exceeds the melting point will dissolve into a liquid. The thermotropic liquid crystal is not the same, when its solid heat, and will not directly into a liquid, will dissolve the formation of liquid crystal state. When you continue to heat, will be re-dissolved into liquid (isotropic liquid). This is the so-called secondary dissolution phenomenon. The liquid crystal as the name suggests, it will have a solid lattice, and liquid flow. When the liquid crystal has just been discovered, because of the many types, Graphic LCD Display so people in different areas of the LCD will have different classification methods. In 1922 by G.
Its structure is composed of liquid crystal rod-like molecules together to form a layer of a layer of structure. The longitudinal axes of the molecules of each layer are parallel to each other. And the direction of the major axis is vertical or has an inclination angle for each layer of the plane. Graphic LCD Display Because of its structure is very similar to the crystal, it is also known as the smectic phase. Its order parameter S (order parameter) approaches 1. The bond between the lamellar liquid crystal layer and the interlayer is broken due to the temperature, so that the layer and the interlayer are easier to slide. But each layer of the molecular bond is strong, Graphic LCD Display so easy to be interrupted. So the single layer of view, its arrangement is not only orderly and sticky. If we use the giant phenomenon to describe the physical properties of the liquid crystal, we can put a group of regional liquid crystal molecules as the average point of the director (director), which is the group of regional LCD molecules in the average direction. In the case of lamellar liquid crystal, because of its lamellar structure, Graphic LCD Display the liquid crystal molecules form a layered structure, so that different layered liquid crystals can be reclassified for different fingers. When the long axis of its liquid crystal molecules are standing vertically, it is called "Sematic A phase". If the long axis of the liquid crystal molecules have a certain tilt angle, it is called "Sematic C phase". Graphic LCD Display To A, C and other letters to name, which is in accordance with the order of discovery to call, and so on, there should be a "Sematic B phase" is. But later found that B phase is actually a deformation of the C phase only, Graphic LCD Display because the C phase if the structure with chiral is B phase. That is, Chiral sematic C phase is Sematic B phase. And the structure of a layer of liquid crystal molecules, in addition to each layer of liquid crystal molecules have a tilt angle, Graphic LCD Display the layers of the tilt angle between the layers will form a spiral structure.