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LCD technology

It was in the closing decades of the 20th century that the large screen television technologies began to develop and with the progress of time and the introduction of new technological innovations, one could see the emergence of flat screen televisions. There were several different technological tools which were used in the formation of these flat screen devices, the foremost among them being the LCD technology. Primitive technologies like the CRT or the use of cathode ray tubes moved into oblivion as the flat screen techniques took centre stage and at present is the prevalent form used in the manufacture of television sets. The LCD or the liquid crystal technique is dependent on the pixels on the LCD which are again comprised of certain constituent factors. These include two glass plates with molecules, two polarizing filters and the liquid crystal molecules.

There are also different kinds of LCD display technologies which play a major role in the flat screen technologies. These include the Multi-Domain Vertical Alignment or MVA and it is preferred at times because of its swifter response times and higher contrast ratios compared to many of the other techniques. However its reduced brightness is a setback. Another technique is the Twisted Nematic or TN which is among the commonest forms used for flat screen techniques. The other procedures include In-Plane Switching or IPS and Patterned Vertical Alignment or PVA. The use of these LCD techniques in the manufacture of flat screens are beneficial for several reasons like firstly it is space saving and also looks smarter and stylish and are slimmer versions. Moreover they do not suffer from burn-ins like the bulky television sets of earlier times.

However it must be pointed out that the presence of small film transistors in case of LCDs often lead to the formation of defective pixels thus affecting visibility and blurring or distortion of images. Sony, Samsung, Panasonic, LG, Toshiba, Akai are premier manufacturers of flat screens.

Is plasma a safe buy?

In the present times, it has been noticed that the wide range of bulky television sets are slowly fading into oblivion and they have paved the way for a newer and sleeker version known as the flat screen technology. Since the beginning of experimentations with the flat screen techniques, several technological tools have been devised for the proper functioning of these wide screen devices. A very prominent technical tool used for this purpose has been the plasma display technique. The plasma display is constituted by several components like scores of gas filled cells which are placed between the glass plates, dielectric materials, two sets of electrodes and certain protective layers. These protective layers are constituted by Magnesium Oxide. In the plasma display itself the pixels are made up of a series of subpixel cells totaling three in number. The three subpixel cells are constituted by the three primary colors which are visible to the human eye i.e. red, blue and green and therefore the plasma display pixels are made up of subpixel cells of red, green and blue phosphorus. The total effect of colors in a pixel is created by a combination of the light rays emitted by the subpixel cells.

Plasma displays are quite popular and widely used as they have several merits. An important advantage that can be noted in this case that compared to the LCD screens, it is easier and also less expensive to manufacture these flat screens and unlike the liquid crystal displays or LCDs they can provide better angles of viewing. They are also sleeker and slimmer. It is interesting to note that since the pixels in a plasma display can be turned off completely, it is possible to attain better display resolution, contrast and brightness.

However, one must be aware that plasma screens, unlike LCDs are prone to burn-ins and they are available in larger display sizes, the minimum being around 37 inches and run the risk of producing defective pixels.

DLP in flat screen projection televisions

One of the most prominent flat screen technologies used and released world wide apart from the liquid crystal displays or LCDs are the DLP or projection through digital light processing which are widely used in projection televisions which refer to those televisions having flat screen and those which employ video projectors for their functioning. This technological process was devised by Dr. Larry Hornbeck in 1987 for use in the video projectors and it was registered as a product exclusively copyrighted by the Texas Instruments. The image is produced by the digital light processing technology with the help of the Digital Micromirror Device or the DMD and it is integral to the functioning of the DLP projector. The matrix of the semiconductor chip is composed of tiny microscopic mirrors and these comprise what is known as the Digital Micromirror device. In the flat projection screens of the digital light processing projectors these microscopic mirrors help in the projection of the image where each mirror represents different pixels which of course combine to form the final image on the projector screen. In case of the usage of the DLP technology there are three prominent means by which the colored images are produced and projected in the flat screen displays.

In some of the projectors it is found that only a single DLP chip is used and in these cases it can be observed that the projectors spin the color schemes in the wheels of a spinning color wheel which is located in between the lamp and the digital micromirror device. This color wheel is made up of the three primary colors visible to the human eye i.e. red, green and blue. There is also the ‘rainbow effect’ which is observed in some of the DLP single chip projectors which at times cause side effects like headaches to the audience. Three chip projectors having DLP technology emit color through the lens after having split the rays via a prism.