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What Is An LCD TV
By Mitch Medford
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% less 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.
Article written by Mitch Medford.
About the Author
Mitch Medford
southern california home theater
california home theater
email: bivan_dense@yahoo.com
Article Source: http://www.simplysearch4it.com/article/47642.html
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