Is your Plasma TV HDTV-enabled?
July 10, 2007
When you go for a Plasma TV, you should know how native resolution of a Plasma TV counts most in displaying the resolution of the original input signal that it receives.
Based on the native pixels that a Plasma TV has, it can be classified into a HDTV or HDTV Ready which actually refer to the capabilities of a Plasma TV to display HDTV resolutions. Any resolution that ranges between 720p and 1080p is called HDTV resolution. A TV that comes with a native resolution of 480p or below can not display the HDTV resolutions with a desirable picture quality
Generally most high end plasma TVs come with native resolution of 1024×768 pixels which means the screen will have 768 lines vertically from top to bottom. There is another higher resolution 1080i or 1920×1080 pixels which can show images of the same resolution without any scaling of the pictures to fit them on their screen. While Plasma TVs of native resolution 1080i are not so many in the market and they are generally much more expensive presently, the Plasma TV makers come with plasma TVs with lesser resolution and even some of the cheaper Plasma TV are incapable of showing pictures of resolution above 480p.
When you buy a Plasma TV with 720p resolution or higher, and you want it to display input signals of 1080i, the original pixels of the input have to be scaled down so that the image can be accommodated on the screen. For example, your plasma TV has a native resolution of 1024×768 pixels but needs to show images of 1080i resolution, the original pixels of the input have to be scaled down to match the native resolution of your plasma TV. This will prevent you from viewing the resolution of the original input signal.
It is highly recommended that you choose your Plasma TV after studying its native resolution, especially when you receive HDTV broadcast via your cable television network. Plasma TVs with lesser resolution of 480p are incapable of showing HDTV pictures and they are suitable for viewing EDTV signals.
How does a Plasma TV work?
May 18, 2007
Both Plasma TV and the conventional CRT-type display use phosphors to produce the display. The screen of these display systems is made up of tiny spots known as pixels which have a phosphor coat on their back.
We can also compare a Plasma TV with a fluorescent lamp although on a superficial level. Not only they use the luminous properties of phosphors, they also use inert gases like argon, neon, xenon which in a plasma state, emit invisible, ultra-violet photons. In a fluorescent bulb, these emitted photons strike the phosphorous coating of the inner wall of the bulb resulting in a radiant glow, which fills our rooms.
However, a Plasma TV, which works on the same principle, has innumerable tiny fluorescent lamps, which are called pixels. Each Pixel, in its turn, has three tiny sub-pixels coated with red phosphor, green phosphor and blue phosphor. The pixels or cells are filled with rare gases like neon and xenon and the entire network of pixels is placed between two sheets of glass.
Two sets of electrodes address electrodes and display electrodes form two separate grids, one along the rear glass plate and another along the front glass plate. Once electric current is passed between the electrodes, it excites the noble gases to release the electrons thereby producing ions and free flowing electrons in the mixture. These charged particles rush towards electrically opposite charged electrodes, collide with each other and emit invisible, ultra violet photons. These photons react with the colored phosphors (RGB) in the sub-pixels and give visible light.
The overall shade of the pixel depends on the intensity of each sub-pixel which is proportionate with the level of electricity passing though it. To show a gamut colors, these three basic colors, RGB, are blended in different combinations by varying the intensity of each color. Plasma display Panels have a special feature, PCM (pulse code modulation) which modulates the electric pulse at a rapid rate and enable the production of more than 17 million colours.
HDTV guide for Plasma TV buyers
May 17, 2007
High Definition Television is the new buzzword in the world of television. More often, the word HDTV is in a sense analogous to higher resolution. As a result, we indulge in a simple calculation: the greater the resolution, the better the picture quality will be. As a result, we go for flat panels which have high native resolution like 720p or 1080p. But, is the resolution only one criteria for judging the picture quality of a display? It is true that the higher resolution ensures sharper pictures. However, there are also other features like colour reproduction, brightness and contrast which are equally, may be, more important than resolution as the over-all picture quality is the hybrid of all these features.
While you go through plasma reviews, the specification of the TV often provides you with essential information like resolution, contrast ratio, response time etc. If you are already familiar with these terms, you may often find yourself in a better position to choose the best Plasma TV to suit your taste. It is also a good idea to navigate through the features listed in the review. Double check, whether the plasma TV which lures your attention with its stylish design and excellent specs, has been provided with anti-glare technology as the plasma screens have a natural tendency to reflect light in ambient conditions. Especially, when you plan to install your plasma tv in a bright room, this feature is often useful.
Well, how to evaluate the performance of a plasma TV? As a thumb of rule, branded Plasma TVs often render great pictures. However there is a maze of specification which may often bewilder you if you are not so familiar with. Fortunately, it is not be- all and end-all.
You may still become a better judge of plasma TV than a reviewer using these simple techniques:
• Check how the colours look on the screen. Do they look natural and accurate? How is the colour saturation? How do the nearest hues appear distinct?
• Next important consideration is the black levels achieved by the TV. Play a DVD and watch dark scenes on the screen. You should be able to see the darkest objects without graying. It is a good idea to test this feature in a little dark room instead of bright room.
• Test the sharpness the pictures by reducing the brightness settings as the maximum brightness may often hide the flaws. Reducing the brightness and contrast to 50 % of their original settings often help you to judge the picture quality.
• Most Plasma TVs boast of their HDTV capabilities. It is wise to put them under a test before you invest money. If the retailers cannot provide HDTV broadcast, a Blue ray disc or a DVD often makes best video material to test the performance of the TV.
• Be familiarized with the remote and meddle with all the pre-sets which modify how the images look on the screen. Some of the Plasma TVs have come up with a myriad of useful presets which may add greater value to your money
The History of Plasma TV
May 10, 2007
Plasma TV is one of the most sophisticated products available in the electronics market in recent times. Originally developed as a technology for big-sized televisions, plasma display has revolutionized every aspect of TV viewing with its excellent picture quality, image depth and most importantly, its exact facsimile of real world with billions of colours.
Today, we have a wide range of digital video devices like HDTV, DTV, and DVD that boast high quality image production but require excellent output devices like Plasma Display or LCD (Liquid Crystal Display). The larger Plasma Display Panels (PDP) with their excellent brightness, their faster response time, wider viewing angle and greater colour range has an edge over LCDs in terms of affordable price.
The concept of Plasma Display Panel dates back to 1964 when Donald L. Blitzer, H.Gene Slottow and a graduate student Robert Wilson designed the first single colour plasma display panel at University of Illinois for Plato Computer System.
Plasma display Panels were originally monochrome and had either green or orange display for the next two decades. Although Plasma display Panels were popular in the early 1970s for their huge screen size and sleek profile, they were generally used in multi-viewers environment like stock exchanges or big halls.
Fujitsu, a Japanese company designed the worlds first multi-colour display with 21 screen in 1992. In 1996, Panasonic, another Japanese electronics company bought Plasma co, an American based company and its technical expertise in plasma technology and started to manufacture Plasma Display Panels. However, only in 1997, the first commercial Plasma Display Panel entered the market and began to gain popularity in the subsequent years. In 1998, Plasma Display Panel was used for televising Olympic events and it turned out to be a great success. The electronic giant Panasonic built worlds largest Plasma TV in
Plasma Displays have better compatibility with almost all video formats - VCR, DVD, DTV and HDTV and even digital DVI connectors. They make excellent display devices for home theatres, video presentations in schools, colleges, training centers and video conferencing in business.
The use of plasma TV in public display system is immense. Larger plasmas make excellent display systems in stadiums, highway terminals, big halls in hotels or banks, advertising panels etc. Larger Plasmas (above 42 inches) are certainly cheaper as the LCD of the similar size will cost almost thrice.
What is Plasma?
May 10, 2007
Plasma is a special form of matter, which is unique from solid, liquid and gaseous states of matter. Although plasmas have a few common, fundamental properties with gases like indefinite volume and size, they significantly differ from gases by their electrical properties. A typical gas, like air, is electrically neutral, as the number of positive charged particles and negative charged particles in their atoms are equal in number. However, when a source of energy like heat or electricity is introduced into this state of equilibrium, it makes some or all negative particles (electrons) get loose, added or lost, thus making the gas ionized or electrically charged. It is the degree of ionization which actually determines the state of plasma. Thus, plasma refers to an ionized gas with unique properties like good electrical conductivity and their strong interactive nature in the electromagnetic fields.
Plasma has a wide range of applications in the present world. For example, neon signs and fluorescent lamps use noble gases like argon, neon, and xenon, which become plasmas when the electric current is passed in the tubes containing these gases.
