The technology of Plasma display Panels, or PDPs, is a very new one. The
release of these flat paneled televisions began around 1996. There isnt yet a company
who has come out with a display panel with the contrast and/or color quality of the
regular CRT displays. PDPs are hoped to obtain this quality through more advanced
research, to allow them to lower prices and have them hang on the walls of all homes.
This would eliminate the need for TV stands and the extremely heavy, large screen
CRT TVs, thus also cutting down on shipping charges for mail order. PDPs have a
somewhat similar function to that of the CRT with the process of exciting Phosphors,
to glow and produce an image.
Plasma Displays are very unique machines. They combine the large screen of a
retro projection monitor, the pixel structure of an LCD panel, and the color-generation
system of a conventional, CRT-equipped television. Each individual pixel in a plasma
display contains red, green, and blue phosphors, along with a series of electrodes. The
structure somewhat resembles that of a light-emitting diode (LED). (Putman )
When voltage is applied to one of the three terminals in an individual pixel, it
discharges through the pixel to a second electrode, ionizing a rare gas (plasma) in the
process. This ionization creates ultraviolet light, which in turn strikes a red, green, or
blue phosphor and causes it to glow. Depending on the level of voltage applied and the
duration of the charge/discharge cycle, the phosphor will either glow dimly or brightly.
(Putman )
In theory, each color has 256 levels that can be expressed this way, resulting in a
24-bit (16.7 million) color palette. The use of a third electrode provides faster and
more accurate control of the charge/discharge cycle, which in turn allows for faster
picture refresh rates. (Putman ) As a result, moving images from video can be
displayed with picture refresh rates up to 75Hz. For the future of computer monitors,
this will be helpful for producing ones that are less painful to the eyes when stared at
for long periods of time.
The plasma displays do show off bright colors due to this excited-phosphor
system which is basically the same way a CRT monitor produces color. But PDPs do
not produce the radiation or high voltage produced by the electron beam. They just
have a small pixel structure which is why they can be manufactured so thin.
Because of the thin profile, Plasma Display Panels are manufactured with a
considerably lighter weight than regular CRT monitors. Although, they are often
heavier than they look. A 40 inch plasma display typically weighs about 60-70 pounds.
Still, this is a good improvement from the CRTs where a 40inch monitor could weigh
up to three hundred.
At this point, there is a big misconception about PDPs resolution. All PDPs
currently being marketed in the 33 inch to 42 inch range have a vertical resolution of
480 pixels and no more. For 4:3 panels that translates to a resolution of 640x480; for
16:9 panels the pixel count is 852x480. Some models have been demonstrated with a
higher resolution (768 vertical pixels), but they are considerably larger - typically
weighing well over 100 pounds with screens as large as 50 inches diagonal. (Putman )
The current 480-pixel limit means that any signal you connect to a PDP with
a resolution exceeding 640x480 will be scaled or remapped down in size, resulting in
pixel decimation and plenty of dithering. (Zenger) These remapped images will make
the quality of small text and fine image details, reduce somewhat dramatically. NTSC
and VGA computer graphics are the only types of signal that all PDPs are compatible
and work well with. They will be read line for line and pixel for pixel. This opens
plenty of doors in the commercial, industrial, corporate, and consumer retail markets.
The PDPs do have many advantages though. Often many big screen TVs have a
problem with the viewing angle. When one walks to a side of the screen, it usually
blacks out and they can no longer see a clear picture. Plasma display panels can
produce a very large image and still maintain a 160 degree viewing angle. PDPs also
are capable of displaying more than 16 million different colors, where as CRTs can only
display about 1 million.
Being that PDPs are still a very new technology, the price of them has yet to
come down. PDPs once packaged into a monitor start at least at $10,000 and can range
from $15-20,000. Most PDPs are used in