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LCD versus Plasma
Plasma and LCD
displays work in two very different ways. A
plasma TV is sometimes called an "emissive"
display while an LCD panel has a “Tran missive”
display. Let’s explore the differences in these
two technologies
How a Plasma TV
works
A plasma display
consists of two transparent glass panels with a
thin layer of pixels sandwiched in between.
Each pixel is composed of three gas-filled
cells or sub-pixels (one each for red, green
and blue). A grid of tiny electrodes applies an
electric current to the individual cells,
causing the neon and xenon gas in the cells to
ionize. This ionized gas (plasma) emits
high-frequency UV rays, which stimulate the
cells' phosphors, to glow the desired
colour.
Because a plasma panel
is illuminated at the sub-pixel level, images
are extremely accurate, and the panel's light
output is both high and consistent across the
entire screen area. Plasma TVs also provide
very wide horizontal and vertical viewing
angles. Picture quality looks sharp and bright
from virtually anywhere in the room.
Most flat-panel TVs
are progressive displays – they draw the entire
image at once. Panasonic’s 1080p plasma
displays illuminate over two million pixels for
true high-definition clarity, deeper blacks and
warmer colours.
How an LCD TV
works
Light in an LCD panel
isn't created by the liquid crystals
themselves; instead, a light source behind the
panel shines light through the display, while a
white diffusion panel behind the LCD redirects
and scatters the light evenly to ensure a
uniform image.
The display consists
of two polarizing transparent panels and a
liquid crystal solution sandwiched in between.
The screen's front layer of glass is etched on
the inside surface in a grid pattern to form a
template for the layer of liquid crystals.
Liquid crystals are rod-shaped molecules that
bend light in response to an electric current —
the crystals align so that light cannot pass
through them. Each crystal acts like a shutter,
either allowing light to pass through or
blocking the light. This pattern of transparent
and dark crystals forms the image.
LCD TVs use the most
advanced type of LCD, known as an
"active-matrix" LCD. This design is based on
thin film transistors (TFT). Their job is to
rapidly switch the LCD's pixels on and off. In
a colour LCD TV, each colour pixel is created
by three sub-pixels with red, green and blue
colour filters.
An important
difference between plasma and LCD technology is
that an LCD screen doesn't have a coating of
phosphor dots (colours are created through the
use of filters). That means you'll never have
to worry about image burn-in, which is great
news, especially for anyone planning to connect
a PC or video game system. LCD TVs are
extremely energy-efficient, typically consuming
60% less power than comparably-sized tube-type
TVs.
Which
television is right for
you?
Plasma TVs have been
around longer than LCD TVs and their technology
is a little further along. Plasma screens use a
phosphor coating like tube TVs, so they have
the natural colour we're used to with tube
models. People often describe plasma's picture
quality as richer or more "cinematic." It's a
great choice for a home theatre, or main
TV.
A plasma TV
might be for you if:
• You
want really rich, warm colours and deep
blacks
• You like to watch sports and
other fast-action TV
• You'll be sitting off-axis when
you watch TV or movies
• Your viewing room doesn't have a
lot of ambient light, or you can easily reduce
the light by closing blinds.
A flat-panel LCD
TV might be for you if:
• You watch a lot of TV
shows or play lots of video games with static
images on the screen for
extended periods of time,
multiple days a week
• Your TV room is relatively bright, or
you do a lot of daytime viewing.
LCD and
Plasma
Plasma TVs are
self-illuminating and provide wide viewing
angles. Black areas do not fade, and colours
remain almost identical regardless of where the
viewer is positioned.
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