How an LCD TV works

The competition among TVs is very high. One of the current requirements is the ability to process digital signals. Due to the specifics of their origin, LCD TVs initially have a number of serious advantages.
In the modern world, a person relies heavily on numerous technical "assistants" - cars, computers, GPS systems, mobile phones and other electronics. LCD - technology has managed to prove its usefulness in all areas of human activity. It is hard to imagine anything technologically advanced without an informational LCD display, which is convenient for monitoring the operation of any device. LCD technology finds new applications every day. Not surprisingly, she conquered the IT market and, in the end, revolutionized the production of televisions.
LCD TVs are flat, stylish devices that are growing in demand day by day.
Principle of operation
"Liquid" crystals were discovered in 1888 by an Austrian botanist. Under different conditions, they have different degrees of transparency. In the 60s of the last century, scientists managed to create the first experimental models of liquid crystal screens, but they were too unstable to be put into production. Only relatively recently, the developers have achieved acceptable results.
In modern TVs, TFT LCD technology is most often used - a thin-film transistor liquid crystal display. It consists of two sheets of glass-like polarized material, one of which is covered with TFT film. The film contains crystals, how many crystals - so many pixels. Thin Film Transistors regulate the flow of current, causing their crystals to change and deform, providing transparency/opacity.
The crystals themselves do not glow, so there is a fluorescent lamp behind the display. The display and the lamp are separated by a white screen that evenly distributes the light.
To obtain a color image, a special filter is used. It adds red, green and blue colors. Any other color can be created by combining them. Since the pixels are very small, the viewer ends up seeing a "whole" picture.
Due to the features of LCD technology, the screen does not emit radiation.
The diagonal of the screen in LCD-TVs reaches 50 inches, and in some models - and more. Until now, manufacturers have not been able to completely solve the problem of increasing the size. For each pixel added, three transistors are required, and in models over 37 inches, light distribution is problematic. Fortunately, leading manufacturers have been able to solve this problem to a large extent. Sony, Samsung, Sharp, LG - these are the brands under which high-quality LCD TVs with a large diagonal are sold.
The screen aspect ratio of some models is 16:9, this format is best suited for watching DVD and HDTV, however, many models retain the traditional 4:3 that most TV channels still support. The discrepancy between the signal formats and the TV is usually compensated by various algorithms.
The picture on an LCD TV is usually much brighter and more contrast than on a conventional CRT. It gives a good "picture" in any light. Neither daylight nor artificial light can interfere with its correct operation.
You can watch TV from any position, since the viewing angle is usually from 160 degrees, in the latest models - up to 178 degrees. It used to be that "plasma" has a better viewing angle, however, the corresponding performance of both technologies is almost equal. As a rule, the viewing angle is not least affected by the "grain" of the screen, the so-called. "dot pitch" - it is desirable that it be less than 0.28 mm.
One of the most important characteristics of an LCD is the response time - the smaller it is, the better (it shows how quickly the transparency of an individual pixel can change without losing image quality). The response time is measured in milliseconds, the optimal value is 20 ms or less. Fast response times are very important when watching DVDs and HDTVs on large screens, especially in action scenes.
Unlike plasma and CRT TVs, the image in the LCD does not "burn out", so it is very good for working with a computer or connecting a video set-top box. The display quality of text and graphics is very high.
One of the common misconceptions is "the higher the resolution, the bigger the picture." It is not always so. In most conventional CRT TVs, the resolution is VGA (640X480 pixels), while LCDs can also have XGA (1024X768) or W-XGA (1280X768). Before studying the numbers, it is better to compare the "picture" itself.
Technical features
Usually LCD TVs are sold with a built-in audio system, tuners, etc., but it's better to find out in advance what is included in the kit. For example, TVs of some manufacturers do not support PC connections, which may come as a surprise to an inattentive buyer, sometimes, in order to work in a home theater system, the TV is not equipped with speakers.
It is important that the TV supports HDTV signal. A high-resolution digital image is much better than a normal one. Today, some cable and pay-satellite channels work with HDTV, in the future conventional TV will also work with it.

How an LCD TV works
How an LCD TV works
How an LCD TV works
How an LCD TV works How an LCD TV works How an LCD TV works

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May 28, 2024 01:20:20 +0300 GMT
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