Plasma displays, like cathode ray tube (CRT) televisions, are phosphor-based,
meaning they rely on glowing phosphor to create their images.
Let's start with how a plasma display is actually constructed. A plasma panel
starts with two sheets of 1/16" glass. Between the sheets of glass are spacers
that create individual cells within the two glass sheets. Transparent electrodes
are then coated inside the front and back pieces of glass (the rear electrode
is called the "address electrode"), so that there are two electrodes per cell
on the front piece of glass and one electrode per cell on the rear piece of glass.
Figure 1
Next, each cell is coated with phosphor and filled with a mixture of neon and
xenon gases as shown in Figure 1. Note that the entire structure is sealed so
that the gas will not escape.
Now let's talk about how this works to create an image. When an electrical
charge is added to the front and back electrodes, a voltage differential is
created, adding energy to the gas mixture and changing the gas to a plasma state.
Once the gas changes into a plasma state, it releases ultraviolet energy which
excites the phosphor coated inside each cell, causing it to emit visible light.
This is how each cell emits light. The plasma display is structured so that three
cells are arrayed - side by side - in close proximity to each other. These three
cells represent one pixel (picture element) on the plasma. How many pixels a
plasma display has depends on the resolution of the display. A 1280 x 720
resolution plasma display has 921,600 pixels. Each pixel has three cells, so
a 1280 x 720 resolution plasma has 3 x 921,600, or 2,764,800 individual cells.
Each cell within a pixel is phosphor coated with one of the three primary colors
of red, green and blue. All other colors that we see are made up of a combination
of the three primary colors.
The three cells per pixel then work in conjunction to produce color. For example,
if a pixel needs to be white, all three cells will be turned on. Your eyes see
the combination of the three primary colors, in such close proximity to one
another, in the form of white light.
If the pixel needs to be blue, for an area of an image that will be displayed
as sky, only the blue cell of that pixel will be turned on.
In this way, each pixel can be a different color, and all pixels working
together on the plasma display can paint a picture in much the same way a
printer uses individual dots to make a color image on paper.
We hope this straightforward explanation is enough. If you have further
questions, please email us at
info@theprojectorpros.com.