Development and Technical characteristics of liquid Crystal display

- Oct 16, 2019-

The liquid crystal, which originated in 1888, was a special mixed material discovered by the Austrian botanist, Lenz, which is in the normal state between the solid state and the liquid state, and it also has the dual characteristics of both solid and liquid substances, so it is called the liquid crystal. The liquid crystal composition is an organic compound, and is a compound composed of carbon. 


liquid Crystal display


The development and characteristics of liquid crystal display, the liquid crystal of the liquid crystal display in 1888, is a special mixed material discovered by the Austrian botanist, Leanz, which is in the normal state between the solid state and the liquid state, It also has the dual properties of both solid and liquid substances, and thus is referred to as a liquid crystal. The composition of the liquid crystal is an organic compound, which is a compound of carbon as the center. 


In 1963, William of the American rca company found that the liquid crystal was affected by the electric field to produce a deflection, and it was also found that the light incident into the liquid crystal would produce a refraction phenomenon.


In 1968, it was william's discovery that the light would be refracted by the liquid crystal, the rca's heil oscillator development department published the world's first screen to use liquid crystal features to display the screen. 


HTN 003


After the discovery of the liquid crystal substance for a whole period of 80 years, the "liquid crystal" and the "the display" of the two special nouns are connected together, and the "liquid crystal display (lcd)" becomes the professional term of the industry. Of course, the liquid crystal display for the first time in 1968 is not stable, and there is a distance to the practical application of daily life. Until 1973, Mr. Ge Lei, a professor of English at the University of England, found that a liquid crystal display could be produced by using a biphenyl to make the product of the liquid crystal display available for shipment, which provided a screen for the el-8025 electronic computer of the company's sharp company. Since then, the application of liquid crystal has been opened, and the rise of the lcd industry is also gradually promoted. 


TN 44


Characteristics of liquid crystal display In comparison of that characteristic of various display device, 


the liquid crystal has the following advantages


 (1) low-voltage and low-power-consumption low-power operation voltage, as long as 2-3v, the working current is only a few micro-amps, that is, the power consumption is only 10-6-10-5 W/ cm2


(2) The basic structure of the flat panel structure liquid crystal display is two pieces of conductive glass, and the middle of the liquid crystal display is provided with a thin box with liquid crystal. The structure has the advantages that the opening rate is high, the display window is most beneficial to be used, the display area is large, the making is easy, the automatic mass production is convenient, the production cost is low, the device is thin, and only a few millimeters are thick. And


 (3) the passive display type liquid crystal itself does not emit light, and the display purpose is achieved by modulating the external light, that is, different contrast is formed by different reflection and transmission of the external light to achieve the display purpose.


(4) In the liquid crystal display with large amount of information, no isolation measures need to be taken between the pixels, so that more pixels can be accommodated in the same display window area, so that the high-definition television can be made. 


(5) It is easy to color the general liquid crystal, so it is easy to realize the color by using the color filter film.


 (6) The long-life liquid crystal itself is hardly deteriorated due to the low voltage and the working current is small, and the service life is long. 


(7) There is no radiation, there is x-ray radiation in the pollution-free crt display, and there is high-frequency electromagnetic radiation in the pdp display, and the liquid crystal will not have such problems. 


 The liquid crystal display also has the following disadvantages:


 (1) the display angle is small because the principle of most liquid crystal displays depends on the anisotropy of the liquid crystal molecules, the incident light in different directions is different, the reflectivity is different, the angle of view is small, only 30-40 degrees, and as the angle of view increases, the contrast rapidly deteriorates.


 (2) The response speed and the liquid crystal display are mostly dependent on the external electric field, so the arrangement of the liquid crystal molecules is changed, so the response speed is large by the viscosity of the material, and the response speed is generally 100 to 200 ms. The quality of the liquid crystal is not good when displaying a fast moving picture. 1.2 The present liquid crystal display of the liquid crystal display device can be divided into two kinds of twisted nematic (tn), super twisted nematic (stn) and thin film type (thin film transistors). a twisted nematic liquid crystal display (tn-lcd) .