How A Plasma TV Works.
This
explanation requires a few sub explanations so please bare with me. I
promise it will all make sense in the end. 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 smarty
pants chipping in about anything you missed or got wrong.
What Is A Plasma and What Can It Do
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 colour, Red, Green or
Blue depending upon the colour 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 colours at
varying intensities, caused by varying electrical currents, that can
produce any colour. Well almost any colour (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
colour.
Pixels
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) makes the moving picture that we see.
Summary So Far:-
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 Grid
This is a lattice 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 colour required. This happens between 50 & 60 times per
second per sub pixel phosphor (WOW!). Creating the moving image.
The Processor and Plasma's are not TV's At All?
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 it also technically speaking
means that Plasma TV's are not really TVs at all but more like monitors.