- Author John Steward
- Published December 10, 2013
5 crucial moments in the history of TV
Your TV is what you watch Homeland on. What you use to play Gran Turismo. But have you thought about how it came about? Just how do you invent telly?
Your TV is what you watch Homeland on. What you use to play Gran Turismo. But have you thought about how it came about? Just how on earth do you invent the telly? By almost killing yourself, it seems…
Making a television is easy, really. All you have to do is convert light to electricity, find a way of transmitting that signal, then come up with a way to convert the current back to light again. There could be some sort of cathode ray gizmo involved, too. Maybe an electron beam. Perhaps some ionised gas… Or organic pixels that emit their own light. OK, maybe not that easy…
But to get to where we are now, slumped on our sofas with pizza all over our shirts while we gawp at America’s Awesomest Explosions: Part 2, history’s scientists have had to go through a lot. Here are our favourite moments in the history of your goggle-box.
A cable guy invents the photo-electric cell
Great Yarmouth in Norfolk might not be obvious as the place that the development of TV started, particularly when you consider that the man who started it all didn’t actually mean to start anything. Willoughby Smith was a telegraph engineer working with iron and copper cables. In 1873 he developed a method of testing cables as they were being laid on the sea bed. That would be impressive even now (go on, you come up with a way of doing it) – but back then it was truly groundbreaking. Smith settled on selenium as the material he’d use to check the cabling, but while it was fine in the lab, when it came to actually using it in the sea the results were inconsistent.
He discovered selenium is more electrically conductive in strong light. That makes it useless for telegraph-circuit testing, but pretty good if you want to invent the photo-electric cell. Photo-electric cells convert light – such as the orange glow radiating from Geordie Shore characters – into electric signals. And those electric signals, transmitted and decoded, can be converted back into light. Et voilà! Endless re-runs of Friends.
John Logie Baird almost kills himself
In 1884 Paul Nipkow patented a mechanical system for dissecting an image into small parts and transmitting it in bits. It was a rotating disc with a spiral of holes around the edge: the light from the object being scanned by the disc falls onto a selenium photo-cell (cheers, Willoughby Smith!) and gets converted into an electrical signal. This varies the voltage of the light source in the receiver and then passes through another, synchronised disc to show the image on the screen. Brilliant… except he never actually built it.
Enter John Logie Baird in 1924. By the mid-20s, Baird had experienced his fair share of failure. His pneumatic shoes were doomed, his efforts to produce artificial diamonds by exploding a carbon rod embedded in concrete not only shorted out half of Glasgow but worse, failed to create any diamonds, and his efforts marketing a home-brew haemorrhoid cream that made sitting difficult for days. Luckily for us, he turned his attention to television. This was his stroke of genius: he realised that because the photo-electric cells available at the time weren’t very sensitive, lots of light is the way to do it. After deducing that creating lots of light requires an enthusiastic amount of electricity, he was evicted from his Hastings lab after nearly almost killing himself with a 1000-volt shock.
After moving to 22 Frith Street, Soho, Baird used Nipkow’s disc idea to encode images. But to get enough light to the photo-cells, the disc needed to be big. Huge. Baird took things to typically exuberant extremes: one of his test machines was 8ft across with 8in lenses, spinning at up to 750rpm. More than once, lenses popped out, shot across the room and shattered against the wall at more than 200mph. This unbalanced the wheel, which would leap unpredictably around the lab before tearing itself apart. “I had some exciting moments,” Baird said later.
But the spinning death-disc proved the concept. In March 1925 Baird went to Selfridges to drum-up publicity and funding. Using a smaller, less lethal machine, he demonstrated the transmission of a moving silhouette.
By October he’d transmitted an image of a ventriloquist dummy’s head (called Stooky Bill) at 5 frames per second in his lab. This was the first-ever broadcast of a greyscale image with tonal variation between black and white. He followed this up immediately by doing the same with an image of the terrified William Taynton – an office-worker from downstairs – and determined 30 lines as the minimum needed to display a recognisable face.
Baird then flourished, making advancements in fibre-optic tech, night-vision and radio direction-finding. Shame about those pneumatic shoes, though.
CRT sets bring CERN to your living room
By the late 1960s, pretty much everyone in the country had something to point their furniture at: the cathode-ray tube TV set. These don’t need whirling harbingers of doom to produce a picture: instead they use an electron gun to focus and accelerate electrons towards a phosphor-coated screen. The electrons hit the radiation-sensitive phosphor atoms, which excite them and make them glow. This is the light you see as the picture.
Let’s just take a moment to consider a few key phrases here. “Electron gun”. “Focus and accelerate”. “Radiation-sensitive”. That’s right: your old telly was a freakin’ particle accelerator.
OK, so it’s not the type of atom-smasher that creates mini black-holes and could hold the key to life, the universe and why One Direction is still relevant. But the fact that your CRT set was capable of “painting” 576 lines of light and shade, 50 times per second – and used electromagnets to actually bend the beams of pure energy side to side and up and down to produce the complete picture – is almost as impressive than the moon-landings many people bought their TVs to watch.
Flatscreens make particle-smashing TVs obsolete
It’s saying something that electron rays were old-hat even in the 1990s. Put one of those in a holster and add a DeLorean (or something) and you’d be some kind of cyber-space-hero. You can’t do that with the bits inside a flatscreen TV.
But what you can do is miniaturise. You can’t get a CRT telly in your pocket, for example – and even if you could you’d need the mother of all extension cords. But in 1983 Casio released the first mass-produced portable TV with an LCD (liquid-crystal display) screen. Its contrast was poor, it only displayed black and white and the screen was just 2.6in diagonally. And it set the scene…
By the beginning of 2008, LCD sets started to outsell CRT televisions, and now dominate the market. It’s relatively simple technology, too: two polarising panels with a liquid-crystal solution between, and a backlight behind. Pass current through the liquid crystals and they move, blocking out light. And that’s it. Each pixel has colour filters that give you the final image. Vary the current in the right way across the liquid-crystal layer and you have a picture. No wonder it’s so successful – it’s pretty easy to build, doesn’t require much power and can be made super-flat.
But the tech has a frenemy: plasma. Now that’s more like it. Atoms and electrons and smashing and ionised gas and energy release in the form of Jeremy Kyle’s face. Plasma emerged on the consumer market in 1997 and offered initially deeper blacks and greater contrast than LCD, since its pixels generate their own light. But it’s more expensive, bulkier and has greater power needs than LCD tech, and has been overtaken in sales in recent years.
OLED is changing everything
Organic light-emitting diodes. Organic light-emitting diodes. Wait… what? My new OLED telly is… alive? Will it become self-aware and force me to watch nothing but Road Wars? Not that that would be a bad thing.
No, it isn’t alive. The ‘O’ merely signifies the presence of a carbon-based compound. In a nutshell, it involves electrocuting bits of cellophane and manipulating quantum things… but we won’t go into the tech here. It’s all very complicated, and besides, Jamie Condliffe has already written an excellent thing about it here. Read it. It’s good.
What we will say, though, is that it’s amazing. Amazing. Watch an OLED TV in full flight and you’ll be wowed by the depth of colours and contrast on offer. And the thinness of the TVs – that’s something else.
OLED, to us, is as momentous as John Logie Baird diving for cover as his proto-television destroyed itself in a maelstrom of plywood and glass. It’s as important as Willoughby Smith corrugating his forehead as he tried to work out why he couldn’t test cables properly in the sun. It’s the future – and you can buy it on the high-street.
John Steward is assistant production editor of What Hi-Fi? Sound and Vision