And by 1974 the first devices containing this compound were on sale, such as calculators and digital watches. The molecule is known as 4-Cyano-4’-pentylbiphenyl, or 5CB for short. Removing the power allowed the stack to reform and the pixel to flip back to white. The charge meant that an electric field could be applied to a pixel, pulling on the charged molecule to break up the structure of the liquid crystals and turn the pixel dark. Within a year, Gray’s research team had developed a liquid crystal that was stable, easy to manufacture and, most importantly, included a positive charge at one end. And that moment of brilliance won him the contract. He couldn’t answer – but a young George Gray, a chemistry lecturer from the University of Hull, could. ![]() When it came to the meeting on liquid crystals, the expert was asked why the light was reflecting off his sample bottle of liquid crystals and casting such a curious pattern on the wall. A government working group, led by the physicist Professor Cyril Hilsum, met with experts in their respective fields to decide which technologies should receive funding. This convinced him that the UK needed to develop a colour flat-screen panel. In his role at the Ministry of Technology, Stonehouse soon learnt that the UK was paying the Americans more for the rights to use their colour cathode ray tube technology (in those big bulky televisions and monitors) in displays used by the military than it was spending on developing the supersonic airliner, Concorde. The parallel slats of the gate only allow the waves travelling up and down to propagate, while the waves from all the children shaking their ropes in other directions are restricted – that’s what polarisation does with light.Īnd, this is where we return to Stonehouse – because back in 1967 he got the ball rolling to crack that problem. If we return to our rope analogy, imagine the ropes are fed through a slatted gate. As well as in LCDs, you find them in some sunglasses, for example. Polarising filters bring order to emanating light waves by only allowing waves with a particular orientation to pass. Some will wave their ropes up and down and some side to side, and some at angles in between. By analogy, imagine a group of schoolchildren all waving skipping ropes. The light emanating from a bulb, LED or the Sun is known as unpolarised, in the sense that it consists of waves travelling outwards in a variety of orientations. Each pixel within an LCD is comprised of a light source, usually a light-emitting diode (LED), and a thin layer of liquid crystals sandwiched between two filters that scientists describe as polarising. ![]() The long and thin molecules pack against one another in an ordered rectangular arrangement of rows.Ĭrucially, these liquid crystal structures can interact with light in interesting ways, and this is key to how they work within flat-screen displays. They flow like a liquid, while the molecules within them maintain some order relative to each other, like in a crystal. ![]() Liquid crystals are a state of matter that sits between liquids and solids. Unfortunately for Stonehouse, his amazing foresight has since been overshadowed by his attempt (in 1974) to fake his own death to avoid punishment for multiple counts of fraud and forgery.īut before we get back to the colourful characters involved, let’s take a look at the science of LCDs. The story begins back in 1967 when John Stonehouse, a Labour MP and minster for technology under Prime Minister Harold Wilson, established a group to develop a technology that had only just made its debut on Star Trek – a full colour flat-screen display.
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