LCD - How does it work?

LCD stands for Liquid Crystal Display, it is the technology used to display images on our TV screens. This technology allows for modern day LCD televisions to be much thinner and lighter than their CRT predecessors. It is based upon the fact that liquid crystals in their natural state are twisted and that when introduced to an electric current their shape changes. Thousands of these liquid crystals and sandwiched between two panes of polarised glass, with a light source shining behind the panes. The light passes through the first pane, along the layers of liquid crystals and passes out the other side. If a current is added to the crystals they untwist and as a result block the light from passing through, thus making it darker than the other areas.

LCD TV’s have much brighter screen displays with a high contrast, this means they can work effectively in any kind of room lighting and as they have a much higher native resolution than plasma TV’s of similar size they are ideal for HD output. However unlike their rivals LCD TV’s aren’t readily available in larger sizes and those that are available are extremely expensive. LCD display sizes are limited by problems faced during the manufacturing process. In order to increase screen sizes manufacturers must add more pixels and transistors, increasing the chance of including a bad transistor in the display. Up to 40% of panels that come off the production line are rejected, the level of rejection relates directly to the price of LCD TV’s. The sales of good displays must cover the costs for manufacturing both the good displays and the rejected ones. Hence why big screen LCD’s can cost up to double the price of similar sized plasma TV’s, until the manufacturing process is improved big screen LCD TV’s will continue to be expensive.

There is a wide variety of smaller LCD televisions on the market, most of which have the standard 4:3 aspect ratio and simple stereo sound. Those that have 16:9 aspect ratios will simply stretch or zoom the image in order to fill the screen and preserve the integrity of the picture. Due to the difficulties in production quality LCD’s over 40” are a rarity, those that are on the market offer exceptional quality but prices are known to be astronomical.

Versatility is another key to LCD televisions, they are extremely light and energy efficient. Larger models tend to consume a lot more power than the smaller models; however this is still 30% lower than plasma rivals. They can be displayed on a pedestal stand (normally supplied) or even wall/ceiling mounted. The high resolution also means that LCD TV’s can work exceptionally well as a computer monitor. Many LCD TV’s come with an integrated digital tuner providing further enhanced picture and sound.

Whilst Plasma TV’s are more readily available in larger sizes and offer better value for money, LCD’s provide a better picture quality. The readily available smaller models offer good value for money and there are plenty to choose from. Larger models will continue to be expensive whilst production is so complex, but as more and more television steers towards High-Definition, LCD Technology will come to the fore.