Passive electrical Components

On the liquid crystal display LCD

LCD liquid crystal display panel is a kind used for information on electronic road show, such as text, images and video. His / her consumption, such as computer monitors, televisions, sheets instruments and other devices that space in the cockpit of aircraft is on-board computers of cars that use devices on daily rates, such as video-player device, games, clocks, computation and Mobiles.

An LCD consists of a polarizador liquid light, electrically controlled, so that he / she is inside the cells between two transparent plates polarizadoras tablet. The axes of the two plates are polarizadores perpendicularmente aligned with each other. Each cell is provided by contacts eléctricos an electric field, can be applied in liquid.

Among its main features, it is leves his / her his / their portability, and his / her capacity in amounts much larger than the tubes of the catódicos radiation (CRT) product. His / their low power consumption allows it / it in devices be used by portable battery powered electronics. This is an electro-optical modulation device that has a number of pixels together, and prepared with liquid crystal light filled to generate images in color or black and white.

The oldest discovery as it took to develop LCD technology was the discovery of liquid crystals, 1888.

In 2008, worldwide sales of TVs LCDs with the sale of shares topped CRT.

Monitor the LCD screen is very light and thin, without supporting mobile.

LCD technology is already in use time. As an example can be cited, portable consoles, the Game Boy (Nintendo), digital watches, calculation, MP4, MP3, portable DVD started, digital cameras and mobile.

Benefits

First monitors of the LCD type screen that has a really flat, so that the distortion of the picture tube monitors radiation type Catódicos or CRT (you / they have their curved screens);

They tire less second perspective;

Third, they use less energy;

4th They emit little pollutants (some models are not emit harmful radiation, but a few) of radiation;

The fifth new models have distortion corrections, so that the images in a harmonious state and real, even in motion.

Disadvantages

First you have the limited angle about a vertical (90) vision, suffering with the problem of black light and white light, although the one chance in the older models. Now comes the more LCD-178. to see.

The persistence of the second logic state of pixel LCD can "pull" the impact of I in the exhibition of photos taken with the movement.

The third resolution is not constant, with losses of 50% in moving images (in older models).

4th / he has not a good definition with SDTV sources: Open TV analog cable TV, DVD, SKY SD (480i).

General Vision

Each pixel of an LCD screen is generally consists of a layer of molecules aligned between two transparent electrodes and two polarizadores filters. The axes are perpendicular to each other in most cases.

The electrode surface that you / they are aligned in contact with the material liquid of how molecules liquid crystal treated in a certain direction. This treatment is usually based on polymers in a thin layer which is separated unidirecionalmente. The direction of liquid crystal alignment is then defined by the direction of friction.

The electrodes are made from a driver called transparent indium tin corroded (ITO). Before applying an electric field orientation of the molecules of liquid, it is safe for approximation of the electrode surface.

In a device "twisted nematic" (Common Unit of liquid crystals) in surface alignment directions of the two electrodes are perpendicular to each other and how to organize molecules in a spiral structure.

It reduces the rotation of the polarization direction of incident light, and the device appears ashes. When the voltage applied to the surface is large, the molecules liquid crystal in the middle of the layer to the almost completely helical shape, and polarization of the incident light does not turn as through the layer of liquid passes, so that the light is mainly polarized perpendicular to the second filter, and therefore he / she will be the black pixels are displayed.

By controlling the voltage applied across the liquid crystal layer in each pixel, the light may be entitled, in different form various amounts of ash to pass the levels.

The visual effect of a twisted nematic device in the train and condition where it is much less dependent on fluctuations in the thickness of the device when the voltage is turned off.

For this reason, these devices are generally among the polarizadores crossed in a way that they were operating without tension diamond (the eye is more sensitive to changes the dark state, as provided bright) appear.

These devices can also be operated in parallel under polarizadores I get married in this light and dark states are reversed. The power of darkness off state in this configuration is blind, but because of small variations in the thickness of the whole.

How much liquid crystals as the material of the alignment layer containing ionic compound. When an electric field of a particular polarity is applied through a long period of time, this ionic material is attracted to the surface and increases the action of the device.

This is avoided by applying an alternating current or reverse the polarity of the electric field, as the device to the receiver (the response of the liquid crystal layer is the same regardless of the polarity of the applied field).

Short Story

1888: Frédéric Reinitzer (1858 -1927), he / she discovers the nature of the core extracted (in other words, two points and coalition generation of color crystal) fluid cholesterol and published their findings at a meeting of the Chemical Society, Vienna, May 3, 1888 (F. Reinitzer: Articles to give the knowledge of cholesterol, Monatshefte für Chemie (Wien) 9, 421-441 (1888)).

• 1904: Otto Lehmann publishes his / her work "Liquid Crystals (LC)."

• 1911: Charles Manguin performs the first test liquid crystal confined by the plates of thin films.

• 1922: Georges Friedel described the structure and properties of liquid crystals and class into three categories (nemáticos, smectic and cholesteric).

• 1936: Marconi Wireless Telegraph patented the first practical application Technology ", the Liquid Crystal Light valve".

• 1962: The first major publication in English on Molecular "Structure and properties of liquid crystals ", including Dr. George W. Gray.

• 1962: Richard Williams of RCA found that liquid crystals had some interesting electro-optical characteristics, generating scratches in a thin layer of liquid crystal material by applying a voltage. This effect is being train eletro hydrodynamic instability, resulting from the "Williams domains" of the liquid crystal-based call.

• 1964: George H. Meier healing, working in the laboratories of RCA to the discovery of Williams is to change the colors for the field, which induces dicróicos coloring realinhamento conducted in a homeotropic liquid crystal, which generates the completion of the LCD first operational base, the it's like a dynamic dispersion (DSM).

By applying a voltage to a DSM display changes to the original layer of liquid protein transparent in a state of clouding leitosa. He / she shows that DSM and how transmissivo could be studied and considered, but it requires a current considerable speed for his / her operation. George H. Meier healing was included in the National Inventors Hall of Fame and credited with the invention the LCD.

• 1960: I work in pioneering the liquid was at the end of 1960 with the Constitution of the Royal Radar Reino made Malvern, England. Team TRE support the work during the George Gray and his / her team from the University of Hull, was finally discovered that the liquid cyanobiphenyl (he / she is the stability and properties of the correct temperature has been for use in crystal displays liquid) crystals.

• 1970: December 4, 1970 twisted, the field effect in nematic liquid crystals was developed by Hoffmann-La Roche in Switzerland (Patent No. 532,261), patented listed with Wolfgang Helfrich and Martin Schadt as the inventor [9]. Hoffmann-La Roche, soon after, a led to the invention the Swiss manufacturer Brown Boveri & Cie, which produces the display of watches in the decade of 1970. This sector produced the Japanese soon first steps of Quartz digital pulse with TN-LCD and many other products. James Fergason when he / she worked with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute presented an identical patent in the EEA, April 22, 1971. [13] in 1971, Fergason ILIXCO (now LXD Incorporated) produced the basis of the first company to the effect that the TN-LCDs soon replaced Types of DSM, due to improvements in tension operation and low power consumption.

• 1972: The first panel of the main advantages of the LCD viewfinder was produced in the United States by T. Peter Brody.

• 2007: 4 for the first quarter of 2007, sales of LCD TVs topped her / it of CRT at an international level.

• 2008: LCD TVs, most with a market share of 50% of the 200 million TV sets.

About the Author

Carla Sofia adores technology especially the technology LCD.Televisores LCD and see the Televisor Samsung LCD TV de 32 polegadas