How LCD TVs Work

Before we go into comparing LCD TVs to plasma TVs, you need to know how each one works first so you can get a better understanding of them. This way the comparisons will make better sense.

 

·        LCD Technology: To understand how LCD TVs work, you need to know how the LCD works.  

o       Liquid crystals: Liquid crystals are neither solid nor liquid. Why? Because the molecules in solid matter stay in one place while molecules in liquids matter wonder from place to place. Liquid crystals don’t do either way. However, as matter, they are more liquid than a solid. Liquid crystals are very sensitive to temperature, being that they can turn into a real liquid at the slightest rise in temperature.

o       Nematic Liquid Crystals: There are many types of liquid crystal substances. The nematic liquid crystal is the heart of the LCD. This is what makes it work. One particular nematic liquid crystal is the twisted nematic. They way the whole process works is that an electric current is applied to the crystal. This makes the crystal untwist. Now depending on how much voltage is applied will determine the amount of untwist involved. Liquid crystals are very predictable. They always work when current is applied. This is why they are used to control light.

o       External light source: Unfortunately liquid crystals do not emit light. They only reflect it. This means there has to be an external light source. In order for LCDs to work, small electrodes charge the liquid crystals so as to make them untwist. When the liquid crystal untwisting, it block light. In most displays, there are little fluorescent tubes built-in either above, beside, or behind the LCD. This way the LCD gets the light it needs to display the image.

·        How LCD TVs work: Unlike CRT TVs, LCD TVs are slimmer and a better viewing area. The LCD TVs works like this: two sheets of polarized transparent material, one that holds liquid crystals are brought together. Electric current passes through each crystal, corresponding to the signal received, so as to allow the right amount of light to go through to create the image. Because the crystals do not produce light, there is no radiation like in CRTs. Fluorescent tubes are used to illuminate the image. This kind of system has the advantage because it uses less power to operate.