How Do Plama TVs Work?

If you've been keeping an eye on TVs in recent years, you've noticed that there are two big competitors: plasma TVs and LCD TVs. But to the average consumer these two terms can be confusing. What is a plasma TV anyway? Why do they call it that? How does it work? Well, let's tale a look at it.

What are plasma TVs?

Plasma TVs are super thin, very bright, have a very wide range of color that they can produce, and they also have amazingly dark blacks, unlike the more grey-black of LCD screens. This blackness creates amazing contrast that makes the picture appear much better and can be measured by contrasts of up to 1:1,000,000. Plasma screens tend to have about 100,000 hours of display time before the screen loses half of its brightness. This is about 27 years if you're watching 10 hours a day. Plasma screens also have virtually no motion burn because of their great response times and refresh rates. Early plasma screens had problems burning out much earlier and this has given plasma a bad reputation for reliability. Some plasma screens have also experienced screen burn-in, which is where an old image remains on the screen as new ones appear. Plasma TVs also contribute to climate change due to the release of nitrogen trifluoride (a powerful greenhouse gas) during production of them. Plasma screens use glass instead of plastic like LCD screens. This makes them a little heavier and more susceptible to glare, but recent plasma TVs are coated with an anti-glare solution.

How do plasma TVs work?

Plasma TVs contain three gases: xenon, helium and neon. These gasses, if you remember from your high school chemistry class, are three of the "noble gases" which means that do not react to any other chemicals. This makes them great for many jobs that other elements simply can't do. In a plasma TV, these three gases are kept in chambers between thin layers of glass. The chambers have long electrodes on either side of them. When charge is put into one of the electrodes, but not the other, a difference in voltage causes the gasses to ionize and rush towards the electrodes. As they hit, they release photons, or light particles. These end up making the light for the screen. If a segment is supposed to be black, the TV gives the area no charge.

To create color, the back of these little boxes are covered in phosphors (chemicals that give off colored light in certain situations). When the excites plasma formed noble gases give off photons, part of that light is ultraviolet. This ultraviolet light causes the release of colored light from the phosphors. This is similar to the way a fluorescent lamp works. Within each pixel, there are three subpixels. These are made up of a green phosphor, a blue phosphor, and a red phosphor. The combination of these three colors in different amounts is what causes all of the colors on your TV screen. This combination of RGB (Red Green Blue) is also how LCD screens and computer animated coloring work.

Source: http://en.wikipedia.org/wiki/Plasma_tv