This
explanation has been designed in a way to make it meaningful to human beings. If you are are doing a science degree this explanation is not for you. I have taken the liberty of
slightly simplifying a few aspects, like the actual reactions between
gases and electrical current. However you should be safe giving this
explanation down the pub or at the office without fear of some clever dick pointing out what you got wrong.
What Is A Plasma
A plasma is a gas. It is made up of an equal number of positively and negatively charged electrons which means it has no actual electrical charge. However if you supply an electrical current to one of these plasmas then it becomes positively charged and produces light.
What Is A Phosphor and How Does it React To a Plasma
A phosphor is a colored substance coated to the screen. On a plasma screen they are either Red, Green or Blue. Light from the electrically charged plasma causes the phosphor to produce a color, Red, Green or Blue depending upon the color of the phosphor.
Sub Pixels Are Phosphors
Red Green & Blue phosphors known as sub pixels are lit in the manner described above. It is the combination of the three colors at varying intensities, caused by varying electrical currents, that can produce any color. Well almost any color (about 16 million different ones). Now just remember that a sub pixel is a phosphor and is either Red, Green or Blue and that by mixing Red, Green and Blue you can make any color.
Pixels (picture elements)
A pixel is made of 3 sub pixels(phosphors), It is the dot you can actually see if you put your face really close to the screen. Combinations of dots (pixels) make a picture, Refreshed (redrawn) quickly (50 times a second or more) makes the moving picture that we see.
Summary
Fine so all this is great but how does a Plasma TV know where and how to light these millions of sub pixels at millions of different combinations and intensities to light about a million(depending on the specific TV) pixels, that form a picture, so damn quickly?!
The Electrode Lattice
This is a lattice or net of circuits (One for each sub pixel phosphor) that can be accessed individually one after the other with a current of varying voltage. The circuits connect to electrodes which fire the plasma to light each individual sub pixel phosphor at (depending on the voltage) the required intensity. They of course then light the pixel at the precise color required. This happens between 50 & 60 times per second per sub pixel phosphor (WOW!). Creating the moving image.
The Processor and Plasma's
What controls this is a computer processor. Not unlike, but never the less different from a PC processor. It is the inclusion of a processor and a relatively flat lattice of electrical circuits which alleviates the need for an electron gun which is what produces the picture in a conventional TV. The absence of an electron gun and its large space requirements is why Plasmas are so thin.
