LCD TV - The Latest In Viewing
Author: Roberto Sedycias

Liquid Crystal Display is all about flat panel television
technology. The technology of liquid crystal display has
penetrated our everyday life in everyday things like
wristwatches, mobile phones, calculators, computer monitors and
high definition television. The use is growing rapidly and sales
of LCD TV are expected to exceed 4 million in America alone.

There are some distinct advantages of LCD panels over other
kinds of display technologies. They are slimmer and hardly go
beyond 3.5`` in depth. These are lighter also and best of all
they draw less power - only about 60% of the power consumed by
plasma displays. LCD televisions do not spew electromagnetic
waves that are harmful.

There are drawbacks of course - viewing angle is restricted,
contrast ratio is limited and time of display response may cause
concern. The biggest frown of all is caused by the price.
Although it is falling but still it is considerably higher than
its plasma counterpart.

LCD displays comprises mainly of sheets of polarized glass
sheets - two in number. A liquid crystal solution is sandwiched
between these. These liquid crystals are very specific that
causes them to act as shutters that open or shut out entry of
light as the need arises depending upon flow of electric
current. This current passing through the liquid crystals is
regulated by voltage that is applied between the glass sheets
through the electrodes that are transparent. These form a
network having rows on one direction of the panel and columns on
the other side representing the pixels or picture elements.

What are these liquid crystals? Matter can be found in three
states - solid, liquid and gas. Nevertheless there are
substances that exist in a state that is neither liquid nor
solid at any one point of time. The behaviour of these molecules
is also peculiar. They keep to their orientation like those in a
solid and yet they shuffle around taking up various positions
like the molecules of a liquid. Thus these liquid crystals can
be termed neither solid nor liquid though they have more of an
affinity for the latter - that is the liquid state.

There are various types of liquid crystals with each having its
distinct properties. Those used in LCD panels are termed
nematic-phase liquid crystals. The molecules are arranged in a
particular fashion having distinctive pattern.

LCD display systems are of two types - passive and active
matrix. The former is more complicated, produces the best
pictures and consequently the price also goes up. During the
manufacturing stage bad-pixels pose a serious problem.
Innumerable controlling transistors are required on the glass
substrata to control each sub-pixel. A typical wide screen panel
will require 3.1 million transistors. Any one faulty transistor
cannot be replaced and are known as dead or stuck pixels. If one
is permanently off then a black spot will show and if it is on
then a white spot will show. If it crosses a certain number the
whole unit will have to be discarded.

It was during the early 2000`s that LCD flat panels took over
the television market from the typical CRT`s. The basis of the
technology is founded on the characteristics of polarized light.
The thin semi liquid crystal gel trapped between two slim
polarized sheets is divided into pixels.

There is hectic activity to overcome the technological
difficulties to make the set affordable. So the LCD TV has to be
made affordable to hit the headlines of success.


About The Author: This article can also be accessed in
portuguese language from the Article section of page
http://www.polomercantil.com.br/tv-lcd.php Roberto Sedycias
works as IT consultant for http://www.polomercantil.com.br