Liquid crystal display glass-stack architecture

Six-layer build: polarizing film / glass substrate with indium tin oxide / twisted nematic liquid crystal / second glass substrate with ITO / polarizing film / reflective or backlit rear surface. Aside on indium tin oxide as a rare conductive-transparent material; "transparent aluminum is only on Star Trek."

Corning had this huge business in the 1970s in two products. One was light bulbs — just a little blown glass, incandescent light bulbs. The other was TV tubes. They were losing the TV tube business when plasma displays started coming around in the '80s, then LEDs and liquid crystal displays. A liquid crystal display is actually a composite of glass, and it's got a number of layers. This is right off Wikipedia. Layer one is not glass, it's actually a polarizing filter film — plastic — to polarize the light because this is going to be a liquid crystal display. Then you've got a glass substrate, which is layer two, which has indium tin oxide on it. Why indium tin oxide? It's conductive and transparent — a very interesting set of properties. Most things that are conductive will absorb electrons and therefore no light — they're impervious to light, like metals. You've never seen — only on Star Trek do we have transparent aluminum. There are no transparent metals, almost by definition. So they have glass here, then another layer, which is the liquid crystal — twisted nematic liquid crystal — then another glass substrate, number four. Two and four are glass substrates, five is another polarizing plastic filter, and six is a reflective back surface, or a light surface if you're doing a transmissive white backlit display.

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