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Foxconn Manufacturing: How LCDs Work

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You probably use items containing an LCD (liquid crystal display) every day. They are all around us — in laptop computers, digital clocks and watches, microwave ovens, CD players and many other electronic devices. LCDs are common because they offer some real advantages over other display technologies. They are much lighter than old TVs and use less electricity.

But just what are these things called liquid crystals? The name “liquid crystal” sounds like a contradiction. We think of a crystal as a solid material like quartz, usually as hard as rock, and a liquid is obviously different. How could any material combine the two? The answer comes from a discovery in 1888 by Austrian Chemist, Frederich Reinitzer- a material which has various sub-states or phases based upon changing conditions- typically temperature- the material Reinitzer discovered is what we now call “liquid crystals”.

There is an entire science surrounding LCD technology, which will be covered in future articles, however, in a simpler sense, liquid crystals have two sub-states- the nematic, or more liquid state and smectic, the more solid state. Adding electricity allows the particles in these crystals to twist in different configurations.

These liquid crystals either polarize (block) or conduct (let through) red, green and blue light (colors) to combine into the various painted scenes that make a movie (or tv show, as it were).  

So, an LCD screen is a layer of liquid crystals in the middle, with a positive charge to one side and a negative to the other, a very thin polarizing film (usually a material known as tin indium), pieces of “filter” glass with microscopic pathways etched in them, a back light of some sort (depending on the size of the screen, but certainly (LED) light emitting diode in the larger screens to be built in Mt. Pleasant by Foxconn), and a glass screen to the front.

While this ever-changing technology will certainly be replaced by something different (just as it has replaced its Neanderthal counterpart, the CRT), it seems to represent the “State-of-the-art” technology in 2018 for home viewing technologies.

foxconn manufacturing plant to make SHArp lcd screens