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Crystal clear: behind the LCD screen

Crystal clear: behind the LCD screen
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We are surrounded by screens for much of our daily life; televisions, computers, mobile phones, tablets, the GPS in the car and so on. And around 90 per cent of these screens draw on the same technology, LCD or Liquid Crystal Display.

The man behind this technology is Swiss inventor Martin Schadt.

Sales of LCD television screens are thought to overtaken the older cathode ray technology in 2007 and in 2012 40 million sets were sold.

Inventor Martin Schadt said: “They are flat, they are low weight and they have very low rate operating voltage, very low power consumption. You can view them from any direction today; they have a very good color quality. Looking around here in this shop, we have portable radios, so all portable application they couldn’t be possible without this technology, because they would consume too much power to display the information which they have to display.”

We went to meet Martin Schadt in the Swiss town of Liestal, not far from Basel.

The 75-year-old continues to work on his invention, improving the optical quality of the display and trying to open up new fields and newapplications for the liquid crystals.

Unsurprisingly he has plenty of LCD screens at home.

To see how they work, we need to get up close and personal with the screen itself. The image is composed of thousands of little dots, which continually change colour and brightness. Each one is a liuid crystal and is made up of hydrocrabon molecules which change orientation under an electrical field. So the liquid crystals generate an optical signal – which we can see now.

Martin Schadt said: “Let’s start with these two optical filters, which are identical and they are an integral part of every Liquid Crystal display. These filters have the property that they pass only light which oscillates in one direction. That means that if I place these two filters behind each other in parallel, then the light can pass, they are bright. If I rotate one of these filters by 90 degrees, then light cannot pass and the display appears – so to say – black. And a liquid crystal display does this manual rotation electrically.”

These filters represent a little dot. In this way the brightness of each dot can be graduated from dark to light and the colours can be adjusted with the appropriate filters. In this way the optical signal on each of the thousands of dots is created.

This is the first LCD screen ever created. Martin Schadt built it in 1971. It’s a simple black and white screen used for watches and calculators.

Here the liquid crystals are tested to see how they perform in high temperatures as LCD screens have to be able to resist extremes of heat and cold.

Martin Schadt has been nominated for Lifetime Achievement category in the European Inventor Awards, organised by the European Patent Office, which will be held in Amsterdam on May 28.

Martin Schadt said: “For me inventing is something of a lifestyle, let’s say. You are curious, you want to find new ways, and you want to discover new aspects of which other people don’t think. And this is very exciting and it never ends!”

euronews’ Claudio Rocco asked: “You have invented a technology that is used today by millions of people in the entire world. How do you feel about that?”

“This is very useful for a lot of people; it enables you to communicate with machines, with cars, with airplanes and so on. And this is very exciting, I think,” said Martin Schadt.

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