The LCD
screen can be seen in use in almost every electronic gadget
known to man. Watches, laptops and PC's, readouts on guages of all
descriptions and of course, televisions.
Their thin and lightweight form have allowed once bulky technology to
be slimmed down and generally downsized to a fraction of it's former
size.
LCD
stands for Liquid
Crystal Display but this is somewhat of a misnomer. The
crystals are not actually liquid but their molecules behave more like
liquid than a solid when exposed to temperature changes. They lie
somewhere between liquid and solid. This 'best of both
worlds' capability means that liquid crystals can take
advantage of the movement of liquid but can also be made to remain in
place like a solid when required. Warmer temperatures make the crystals
act more like a liquid but when they cool down, they take on the
properties closer to a solid.
An LCD
television screen is made up of liquid crystals sandwiched
between two layers of clear glass. Behind those glass panels is a bank
of coloured lights which are allowed to shine through the crystals at
different points on the screen and at different intensities. To achieve
this, a small electrical charge is passed through the liquid crystals
to change the temperature. This change in temperature stretches the
coil-like molecules in the liquid crystal and allows light to pass
through the gaps. Picture a tightly coiled spring which you stretch
apart from both ends. You see gaps appear between the circles of wire.
This process of passing currents through the crystals at split-second
speeds, compressing or stretching the coiled molecules rapidly, works
so fast that the individual flashes of light passing through them
cannot be distinguished by the human eye, and so the brain interprets
the whole mass of flashing lights as a single picture.
