The LCD screen is a flat, thin display device consisting of a number of colored or black and white pixels placed in front of the light source or reflector. LCD display low power consumption, so much favored by engineers, suitable for the use of battery electronic equipment.
To trace the source of liquid crystal display, you must start with the "LCD" began to start. In 1888, an Austrian botanist, Fidelberg. Friedrich Reinitzer found a special substance. He extracted from the plant a compound called spiroxyl toluate, in this compound for heating experiments, accidentally found that the compound has two different temperatures melting point. And its state is between the well-known liquid and solid matter, somewhat similar to the soapy water-like solution, but it is in a certain temperature range has both liquid and crystalline nature of the material, but also because of its unique State, and later named it "Liquid Crystal", is the meaning of liquid crystalline material. However, although the LCD as early as 1888 was found, but really useful in life around the supplies, but it is in the 80 years after the things.
In 1968, at the Shannov R & D center of RCA (Radio & TV Inventor), engineers found that liquid crystal molecules were affected by voltage, changing the state of their molecules, and allowed the incident light to be deflected The phenomenon. Using this principle, RCA invented the world's first use of liquid crystal display screen. Later, liquid crystal display technology is widely used in general electronic products, where the calculator, electronic form, mobile phone screen, the hospital used by the instrument (because of radiation measurement considerations) or digital camera above the screen and so on. It is interesting to note that liquid crystal discovery is earlier than vacuum tubes or cathode ray tubes, but the world is not much aware of this phenomenon until 1962 only the first, by the RCA research group chemist Joe. Described by Joe Castellano, a book published by Mr. Joe Castellano. And the same as the image tube, although these two technologies are developed by the US RCA company, but were Japan's Sony (Sony) and Sharp (Sharp) two companies to carry forward.
LCD display, according to the drive to classify can be divided into static drive (Static), simple matrix drive (Simple Matrix) and active matrix drive (Active Matrix) three. Among them, the passive matrix type can be divided into twisted nematic (TN), super twisted nematic (STN) and other passive matrix driven liquid crystal display; and active matrix type can be divided into Thin Film Transistor (TFT) and two-terminal diode type (Metal / Insulator / Metal; MIM) two ways.
TN, STN and TFT-type liquid crystal display because of the use of liquid crystal molecules to reverse the different principles, in the viewing angle, color, contrast and animation display quality on the high and low range of the difference, so that the scope of application of the product classification is also significant segment. With the current range and level of application of liquid crystal display technology, active matrix drive technology is based on thin film transistor (TFT) as the mainstream, and more used in notebook computers and animation, image processing products. The simple matrix drive technology is currently twisted nematic (TN), and super twisted nematic (STN) based, the current application of more paper processors and consumer products based. Among them, TFT liquid crystal display required capital investment and technical requirements are high, and TN and STN required technical and capital requirements are relatively low.