What is an LCD TV?
In an LCD TV or "transmissive" display, a light source shines
through a panel of liquid crystals in order to display an image.
A white diffusion panel behind the LCD redirects and scatters
the light evenly to provide a more uniform image than most
competing technologies.
The LCD face consists of two transparent layers which polarize a
liquid crystal layer sandwiched in between. The front layer of
glass is etched with a grid pattern on the inside surface to
form a template for the liquid crystals. Liquid crystals are rod
shaped molecules that bend light in response to an electric
current; the crystals align so that no light can pass through.
Each crystal acts like a camera's shutter, either blocking light
or allowing it to pass through. A pattern of transparent or dark
crystals forms the image. This same technology has been around
for awhile, even in such unsophisticated items as digital
watches.
LCD TVs use an "active matrix" LCD; the most advanced type of
LCD. The active matrix design is based on TFT, or thin film
transistors. These are tiny switching transistors and capacitors
that are arranged in a matrix on a glass substrate, they switch
the LCD pixels on and off. In a color TV's LCD, each color pixel
is created by three sub-pixels with red, green, and blue color
filters.
One of the biggest challenges for LCD TV manufacturers has been
speeding up the pixel response time, (how fast an individual
pixel's color can change without blurring) so that fast moving
images don't exhibit motion lag or "ghosting". This is
especially critical for larger-screen LCD TVs, or for LCD TVs on
which much of the viewing will be HDTV, or DVD movies.
An important difference between LCD technology and Plasma is
that an LCD screen doesn't have a coating of phosphor dots; LCD
TVs color is created through the use of filters. This keeps
image burn-in from being a problem--- which is good news
in-particular for people who might use a video gaming system or
PC on their TV. Another benefit of owning an LCD TV is the
energy efficiency of this technology. LCD TVs typically consume
60% lees power than comparably sized tube-type, direct-view TVs.
In most ways that really matter there isn't much difference
between LCD TVs and Plasma TVs. Both of these highly popular
types of flat panel TVs are thin enough to be placed virtually
anywhere, and both produce images that are startlingly clear,
sharp, and bright. The most notable difference is screen size.
The majority of LCD TVs have a screen size measuring 30 inches
and smaller. Plasma TVs are, for the most part, uninhibited by
measurement restrictions.
Basically, LCD and Plasma TVs are different approaches to the
same result because the both create superior images using
radically different technology.