1. A brief history of the liquid crystal
A. Discovery phase
It was discovered in 1888 by Austrian botanist F. Reinitzer
In 1889, it was named “Liquid Crystal” by the German physicist Otto Lehmann.
B. Stage of development
In 1963, the U.S. company RCA made a proposal to apply liquid crystal to the display.
1969, Synthetic Ambient Liquid Crystal (MBBA).
C. Application phase
In 1973, clocks, desktops appeared.
In 1979, game consoles, 1-6mm card motors appeared.
In 1982, detectors appeared.
1984, applied to 2inch TFT color LCD TVs.
1986, applied to the STN typewriter.
1988, for 3-14inch TFT color LCD TVs.
1989, applied to 100inch color LCD TV, laptop.
1990, applied to a 10inch color LCD laptop.
In 1994, 21 inch TFT was put into trial production (Sharp). 14-inch color STN LCD was put into trial production.
Now: LCD technology has seen unprecedented development and widespread application.
2. Types of liquid crystal
A. Status of liquid crystal
Liquid crystal is a substance between a liquid and a solid, which develops between the liquid phase and the solid phase with temperature change.
The main structure is the intermediate part of the benzene ring with -CN, -F, attached at both ends.
B. Molecular structure of liquid crystals
C. Types of liquid crystal
There are three states of the existing LCD, and the current LCD is mainly used in the Nematic state.
I. Nematic phase liquid crystals
Nematic molecular species have a disordered center of gravity that allows them to behave like ordinary liquids flowing, but the pointing vectors of the molecular rods are roughly the same.
II. Intra-crystalline liquid crystal
Smectic LC molecules form a layer-by-layer structure with a molecular layer thickness of approximately one. The length of a molecule; the molecules are arranged perpendicular to the plane of the molecular layer and the center of gravity of the molecule is disordered in the molecular layer of, forming a layer of two-dimensional fluid.
III. Cholesteric liquid crystals
The gravity arrangement of Cholesteric molecules is disordered, but the molecules point at a vector. The plane is roughly pointing in one direction. In the direction perpendicular to this plane, the molecule’s pointing vector. It rotates the spiral structure of the stroke.