We're all familiar with the common cathode-ray tube (CRT)
technology that has been the backbone of television for
decades. Inside each CRT, an electron gun similar to a laser
fires a negatively charged beam of electrons at groups of gas
molecules (the pixels), which causes them to change color;
producing the pictures we see everyday. These televisions
work well and produce very crisp pictures, but they are
notoriously bulky and heavy. This is because as the screen
gets larger, the electron gun must be moved farther back
so that it has a good angle to hit every pixel with its beam.
Thus, the larger the screen, the deeper the TV.
Enter the plasma flat panel television. Arriving with the turn
of the millennium, these televisions come in large, widescreen
models that measure only 6 or 7 inches deep; a huge
improvement over CRT. This dramatic change in shape results
from individual transistor electrodes at each pixel. We no
longer need the laser to hit every inch of the TV and, without
the laser, manufacturers can eliminate most of the traditional
bulk. The individual pixels in a plasma TV are composed of 3
fluorescent light cells: one red, one blue, and one green. The
television produces pictures by varying the intensity of each
cell to produce a unique color at every pixel without a laser.
These lights give the television its name because they contain
free flowing ions called plasma. The plasma, when hit with an
electrical charge, produces light.
Traditional CRTs used the electron gun, or laser, to charge
each pixel and create colored light. Plasma TVs instead have
two sets of electrodes, one set running vertically and one set
running horizontally. The horizontal set, which runs across
the front of the screen, and the vertical electrodes, which run
across the rear of the screen to form a grid like a checkerboard.
The computer, by sending pecific charges through a single
vertical and a single horizontal row, can color one pixel of
plasma at a time. When the various sub-pixels are charged,
the gas molecules inside release light particles called photons.
The problem here is that photons are typically in the ultraviolet
spectrum, and invisible to the naked eye. However, as they
are released, they strike the surrounding surface of the cell.
These surfaces have been specially coated with phosphors. A
phosphor is a chemical that produces light, but only after
being hit by another source of light. So, the invisible,
ultraviolet photons strike the phosphor, creating a spectrum
of light that our eyes can see.
Depending on how the three sub-pixels are charged, we may see
a greener, redder, or bluer shade. These primary colors may
combine to produce one of a million different colors. If you think
about the basics of this technology, each light cell is a miniature
fluorescent light. This produces the brilliant, flicker-less picture
we see when we watch a plasma television. Now you understand
the technology behind the plasma flat panel television.
Article written by Jakob Culver.
Author Bio::
------------
Angel Estrella
california home theater
home theater
email: bivan_dense@yahoo.com
