How Plasma TVs Work - Part 2

By: Jakob Culver
Submitted: 2007-01-17 16:21:08
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Before talking about plasma TVs lets talk about a technology we are already familiar with, cathode-ray tube (AKA CRT). CRT TVs work by an electron gun or laser firing negatively charged beams of electrons at gas molecules (AKA the pixels), which cause them to change color and produce very crisp and sharp pictures that most of us are used to everyday. Although these types of TVs produce great pictures they also are very bulky, this is due to the fact that as the screen of a CRT TV get larger the electron gun has to move farther back so that the gun can hit every pixel on the display. Therefore a CRT TV gets deeper in it’s behind.

In contrast to CRT televisions, plasma TVs are really the newest technology in TVs and come as widescreen TVs that are only about 6 inches deep at max. In comparison to CRTs this is a massive improvement in size and depth. Instead of having a laser to hit every single pixel like a CRT TV has a plasma TV is built with single transistor electrodes at each pixel, because of this you do not need a massive void at the rear of the TV to accommodate an electrode gun. Since plasma TVs have transistors instead of a light source each pixel contains 3 fluorescent light cells: one red, one green, and one blue. The picture on a plasma TV is created by each pixel varying in intensity to produce a different color, with this happening to every pixel a picture consisting of millions of pixels is produced. This light consists of free flowing ions called plasma and hence is why this type of TV is called a Plasma TV.

As we know CRTs use one electron gun or laser to charge a pixel and create it to light up in a certain color. Plasma TV on the contrary has two sets of electrodes, one which runs vertical and the other which runs horizontal. These two electrodes form a grid like structure by the horizontal electrode running along the front and the vertical running along the rear. The pixels on a plasma TV can be colored one at a time by the horizontal and vertical cathodes been sent a signal by the computer to do so. The pixels are colored by gas molecules releasing protons as light particles, there is however one problem with this as protons are in an ultraviolet spectrum and invisible to the human eye. To combat this, the surfaces of the cell in which these particles are released is covered with a chemical called phosphor. Phosphor has the power to produce light after been hit by another source of light, hence the protons hit this phosphor surface and show up as light visible to the human eye.

If you think about this technology on a basic level, each light source is a mini fluorescent light and means that a when you watch a plasma TV you will see a great flicker-less picture that is of high quality. Another thing to note is that this technology also contains sub-pixels and depending on how they are charged, you can see a picture that is of slight redder, greener of bluer color and as said before when they come together produce millions of pixels. All the information above is the basics of how plasma TV works and shows how a plasma TV is so thin and can produce such clear pictures.

http://electronicsexpressonline.com is a electronics information portal founded by Jakob Culver. To find out more information about this topic and more visit the website: http://electronicsexpressonline.com

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