The Secret Life of Machines (1988) s03e05 Episode Script
The Photocopier
"Goodbye, seeya Monday.
" "Goodbyeee!" "Good bye dear.
" [Jazzy music: 'The Russians Are Coming' - Val Bennett.]
[Jazzy music: 'The Russians Are Coming' - Val Bennett.]
[photocopier noises.]
Tim: The photocopier has become an indispensable part of any modern office.
Every bit of paper that goes in and out of an office gets copied, usually more than once.
The machines themselves remain rather mysterious black boxes.
And have an infuriating habit of going wrong just when you want to copy something in a hurry.
In this programme, Rex and I are going to try and, er, demystify these ingenious, but often infuriating, machines.
Before the photocopier was invented, there were many different methods of copying documents available.
But they were all slow and inconvenient.
[Ding!.]
Thermal machines from the '50s involved a complicated sequence of intermediate stages, and only produced the final copies on special chemical paper.
The most common way of making multiple copies was the duplicator.
But the original had to be specially typed on a wax stencil.
The typing perforated the wax, allowing the ink through onto the copies.
The Victorians invented the copybook.
The page was damp, so it absorbed some of the ink from the original, when pressed against it.
[squeaking screw.]
Copybooks were still used for legal documents until the 1950s.
But even before the copybook, a chemical process had been invented for copying engineering drawings.
A mixture of these two chemicals is first, er, spread on a bit of paper And then the drawing to be copied is put on top.
And this is now exposed to a very bright light.
Arc lights were often used, early electric arc lights like this.
[buzzing of arc.]
Well anyway, this actually takes rather a long time, so I've done one already, that I've prepared earlier.
A bit like a cookery programme(!) Erm Here it is.
Well it doesn't, er, look very promising, but if I now spread another chemical on it, the image should start to appear.
And then just have to wash the chemicals all off now.
And a dye, Prussian blue, is left impregnated in paper, on the bits which have been exposed to the light.
Well the process has actually been obsolete for over 50 years now, but the word 'blueprint' has become stuck in the language.
Wet chemical systems were also developed for the office.
[music.]
[music.]
Voiceover: Two minutes is the time needed to deliver the print.
And she'll get not a negative, with all blacks and whites reversed, but a direct copy of the original.
That's positive.
No trays to bother about either, she just brushes on the developer, then watches while the picture appears.
[music.]
Fixed in much the same way, the copy is now squeezed dry.
It's just too bad the outfit doesn't include properly watermarked paper for copying bank notes! [music.]
The idea that revolutionised copying, came from an unassuming American patent lawyer called Chester Carlson.
Chester: Well, in the course of my patent work I frequently had need for, er, copies of patent specifications and drawings, and there was no really convenient way of, er, getting them at that time.
Tim: Carlson started experimenting with a copying process based on the ancient, but unpredictable, science of static electricity.
[music.]
Greek: Oooh Zeus, the lamp is dustios! Boys! Boys: What is it Master? Greek: Polish well the lamps! [squeaking of polishing.]
Boy: Rub harder Ajax! Tim: The ancient Greeks first noticed static electricity when they observed that lamps made of amber attracted dust after being rubbed.
Greek: Preposterous! The lamp is dustiosterous! Boys: But but sir, we Greek: Get outside while I administer the usual! [whip cracks.]
[whimpering of boys.]
[sheep baaaa-ing.]
Tim: Our word for electricity comes from the Greek for amber, electron.
The Greeks also had trouble with their spinning wheels, because the bearings were made of amber.
[Baaa-aaa-aaaa.]
[Crackle ZZZZT!.]
[photocopier noise.]
Modern plastics, like nylon carpets and synthetic shoe soles, work much better than amber.
I'm now charging myself up, and er, it's called static electricity, because the electricity is literally static, it's trapped inside me.
And I'll stay charged up until I discharge myself, by holding my finger near something that's earthed.
I might be able to make a tiny spark and give myself an electric shock, on this No, nothing.
Erm, static electricity experiments, er, only really work when the air's very dry.
And in any case they seem to be incredibly unpredictable, I hope these work better.
Erm If I charge up this bit of plastic I should be able to make some bits of tin foil dance around Oh yes! That's not working too badly.
Erm, static electricity can also make, er, dust fly up and stick to things.
Pour some dust on there Yes! It's this effect of attracting small particles that's used in the photocopier.
Carlson did his early experiments in his kitchen, in fact we found the only place we could reliably repeat them was in Rex's kitchen.
Cos he's got under-floor central hearing and so it's extremely dry.
Tim: Is this going to work alright? Rex: I think so.
Tim: Carlson started by casting blocks of sulphur, after reading that sulphur lost it's electrostatic charge when it was, um, exposed to bright light.
Erm, yeah it does look good.
It's not easy casting these plates of sulphur, and it makes an awful smell as well.
Tim: Erm, well we've got to leave that one to cool, haven't we? So err Rex: Yes.
So perhaps we'd better try it with one of the other ones? What Carlson did was to charge the plates up, by rubbing them Rex: Don't rub too hard.
Tim: Alright then, er, so now we have to put some sort of an image on top of it.
That's it Now we'll expose it Okay.
The sulphur is now losing it's electrostatic charge as it's exposed to the light.
So it's now only the areas under the black letters, protected from the light, that are still charged.
If a fine powder is now dusted over the surface, Carlson used lycopodium, it would be attracted only to the charged parts, revealing the image.
Tim: There's an 'A' Rex: It's coming out quite good.
Tim: Although our result isn't very impressive, Carlson himself didn't do much better.
No one was very impressed at the time, October the 22nd 1938.
But he somehow managed to persuade a research institute to try and develop his idea.
The Battelle institute replaced Carlson's sulphur with plates made by vacuum depositing thin layers of selenium.
In the late '40s in conjunction with a small company called Haloid, the first electrostatic copiers appeared.
Including one model called the 1385.
This is one of the few surviving 1385s in Britain, and er, it's a magnificent contraption.
Erm, it's all entirely manually operated, and it takes several minutes to make a copy.
It doesn't look anything like Carlson's equipment, but it actually goes through exactly the same stages.
Er, this is the plate, and the first stage is to charge it up.
So it goes in this slot here, simply have to press the button.
Battelle had replaced Carlson's sulphur with a thin glassy layer of selenium.
That's so sensitive to light that I can only show how it works in a darkroom.
Instead of rubbing it to charge it, Battelle used a very very fine high voltage wire that's inside this casing.
He simply moved it slowly across the plate.
This gives it a very even charge and, er, this is what's happening inside the slot in the 1385.
The next stage is to expose it, so take it over to this camera here.
Erm, slips in the back, This is the image I'm going to expose.
[click.]
[ticking noise.]
It's basically just an old fashioned plate camera, this.
That's it, put the slide back in And the next stage is developing it.
And that happens in, in here.
Er, put the plate in here.
Pull the slide out again, [clunking and clanking.]
This reminds me of some sort of magician's cabinet.
Inside, a mixture of sand and toner powder, the equivalent of Carlson's Lycopodium, runs over the plate.
It's only attracted to the parts of the plate that are still charged, that's the dark parts of the image.
And we should now be left with an image on the plate.
Yes! Having a lot of trouble getting it as good as that.
The copy paper is then put over the plate so the image can be transferred.
The corona wire now charges the paper, transferring the toner powder onto it.
Finally, the toner powder on the copy has to be heated to fix it Probably about done now, er? Yes.
That's fixed.
And that's the final copy.
Well, this process is obviously rather impractical for an office, but it found one specialist use for printers, for making short run printing plates.
That's why I'm in a printer's now.
Erm, I'm going to.
.
away and try and print it.
Tim: Here's the plate.
Printer: Thank you.
The 1385 already embodied the same technology as today's copiers, but it still wasn't the machine of Carlson's dreams.
Chester: The idea of developing an office copier which had never been done before.
and I thought of a machine that could be sat on a desk in an office, to which one could bring an original to be copied, and put it in the machine and push a button and get a copy out.
Tim: His dream finally came true in 1959.
The Haloid company had changed it's name to Xerox and introduced the model 914.
Jones: I can't type.
I don't take dictation.
I won't sharpen pencils.
I can't file.
My boss calls me indispensable! Boss: Miss Jones? Jones: Just a minute! Boss: Will you make a copy of this? Jones: Naturally! I push the button on the Xerox 914.
I make perfect copies of whatever my boss needs, by just turning a knob and pushing a button.
Anything he can see, I can copy in black and white.
On ordinary paper.
And am I fast! I can make 7 copies a minute! By the way, I never need wet chemicals.
My 914 is a dry machine.
Powder dry.
Sometimes my boss asks me, which is the original.
And sometimes, I don't know! Here, Mr.
Smith.
I'm going to lunch with Mother.
[squeaking.]
Man: Easy there, Easy there [knock knock.]
Woman: Hello? Man: Here's your Xerox 914 Ma'am.
Woman: Oh Great! "Just push-uh" "Push" "Oh no!" Man: I reckon Boss, it'll have to go through the window.
[motor.]
Tim: Although large and cumbersome, the machine revolutionised office copying.
[CRASH!.]
Woman: Oh I just love pressing the button! Ohh! Copy after copy! They keep coming! Tim: The key to automating the process was to change the exposure stage.
In the 1385 the camera lit the whole of the original and exposed it through the lens on to the selenium plate.
In automatic machines, the selenium plate is wrapped, is wrapped round into a drum.
The light is then enclosed in a box, so that it only lights a thin strip of the original at a time.
So now, erm, if you slowly move the original over the light, or the light over the original, while the drum rotates It's exposed a bit at a time.
It can then all become a continuous process: While one bit of the drum is being charged up, another is being exposed.
another is being developed with toner powder, and yet another is transferring its toner to the copy.
The advantage of the drum, is that all the stages of the process can be arranged around it.
[motor noise.]
The charging stage is a fine wire, a fine corona wire just like in the original manual machines.
[more noises.]
I think this machine's a bit on its last legs.
Erm, the exposing stage is just like my model: The original goes on the top here, and then the bright light moves across it, and the image is exposed via a couple of mirrors through the lens and onto the drum.
Then the developing stage is in here, it's a bit difficult to get at, so I've got another developer unit here.
The toner is actually mixed with iron powder, and it sticks to this magnetic roller.
As this rotates, this spreads the toner powder onto the drum.
The copy paper comes along the bottom of the machine.
Comes in through, through this end Along here, and there's another, corona wire in the bottom here, that attracts the toner from the drum onto the copy.
Of course when it first gets transferred onto the copy, it's still just a powder.
But the toner's mixed with a plastic, [roar of blowtorch.]
That, er, melts at quite a low temperature when its heated up a bit.
In the, in the copier there are a pair of heated rollers.
You can see the element, it switches on every now and then.
And the copy goes between the two of them.
This is what you have to wait for to warm up when you first switch the machine on.
in the back, there's a mass of machinery, gears and cogs and things Both to pull the light across the original and to pull the copy paper through the machine.
But despite all this complexity, copiers have progressively got cheaper and cheaper and smaller and smaller.
[fast paced singing in Japanese.]
[voiceover in Japanese.]
The Japanese also made colour copying popular.
The machine is extremely complicated, but the basic idea's really quite simple.
At the back there are 4 magnetic rollers with different coloured toner on.
This is the magenta.
Cyan blue.
Yellow.
And the black.
The same colours as in colour printing.
And the bit of paper just goes through the machine 4 times, once for each colour.
You should be able to see the different colours appearing on the drum one after an other by looking in here.
First it's exposed through a magenta filter and deposits the magenta toner.
Then the blue.
Then the yellow.
And err finally the black.
Before it, er, comes out the slot at the end of the machine.
In photographic reproduction, the toner powder is much finer than in an ordinary copier, enabling subtle gradations in each colour.
The fixing stage melts the four layers of toner powder together, creating the final true colours.
Despite their sophistication, modern copiers still have their drawbacks.
For a start the static electricity creates a certain amount of ozone, which isn't very good for people.
Large copiers are now fitted with carbon filters.
And the static can have the effect of attracting dust inside the machine.
This coats the rollers and the corona wires and the optics, producing worse and worse copies.
Er, this one's jammed up again [clanking.]
Not a very brilliant copy.
The static also attracts the toner powder, which is terribly messy stuff, deliberately designed to melt and congeal on everything it touches.
This is basically what makes copiers still so heavily dependent on regular maintenance and servicing.
Small copiers are now often made with disposable cartridges, erm, these not only contain the toner, they contain everything including the drum.
And the idea is that when the toner runs out, it all gets replaced before it has a chance to get dirty.
Then there are problems with the paper.
Paper tends to shrink as it dries out, just like wood, And often inside the machine it distorts and jams up.
And even without shrinkage, it's impossible to design a paper-handling system that's totally reliable.
The best that manufacturers can do is to make the machines quite easy to rescue the mess.
With all these problems, it's really a miracle that copiers work at all.
It's partly because of their temperamental qualities that copiers are so often the focal point of the office.
Brian: Whoops.
Boss: I've got a million and one things to write today! Oh! It's up to it's tricks again! Polly! Can you sort this out for me? I need 50 copies.
Polly: Oh I hate this machine, it's always going wrong! Brian! Get Lost! Brian: evil laughter I see that Jones's promotion isn't on the cards.
Terry: What's up Poll? [beeping.]
Polly: I can't get it to work Terry! What's wrong? [beeping.]
Terry: Oh.
It needs paper? Oh no, the paper's jammed.
Oh, I think it needs toner! Polly: It needs an expert.
[engineer whistles.]
Brenda: Oh, not again! Terry: Oh dear.
Boss: What Is the holdup? If you want a job done properly, do it yourself! [fingers tapping desk.]
Terry: Uh, when's it gonna be fixed? Engineer: Oh, needs new corona wires.
Tomorrow if you're lucky.
Terry: Oh, dear.
Polly: They won't let us use this one.
Terry: This one's broken as well.
Polly: There's a big queue here! Brenda: It's only 50 copies, there's no need to be so rude.
Tim: The unreliability of copiers leads to many of them being thrown out in disgust.
Which is great for me and Rex, because we both find the parts very useful.
The general has bearings, microswitches, and a solenoid taken out of an old copier.
Almost everything I make has some bit of an old copier inside.
[click.]
[clank.]
Rex recently used the high voltage supply from a copier in an enormous static electricity machine.
Rex: This weird looking contraption behind me is a Van der Graaf generator.
I built it to explain the principles of electrostatics.
[snap.]
[snap.]
[snap.]
[snap.]
Static electricity has got some spectacular effects.
Tim: 10 years ago, there were a lot of predictions about the paperless office.
Computer memories were going to completely replace piles of paper.
And there'd never be any need to print anything out or copy anything.
This doesn't seem to have happened though.
More and more copiers get sold every year, and more and more paper gets used making copies.
It isn't very ecologically sound, although at least some paper, like this, is now recycled.
However, I find copiers much the most useful of all office machines, and I'd be very sad to be without one.
Whoops! [Jazzy music: 'Take 5' - Dave Brubeck.]
[bulldozer engine noise.]
[Jazzy music: 'Take 5' - Dave Brubeck.]
" "Goodbyeee!" "Good bye dear.
" [Jazzy music: 'The Russians Are Coming' - Val Bennett.]
[Jazzy music: 'The Russians Are Coming' - Val Bennett.]
[photocopier noises.]
Tim: The photocopier has become an indispensable part of any modern office.
Every bit of paper that goes in and out of an office gets copied, usually more than once.
The machines themselves remain rather mysterious black boxes.
And have an infuriating habit of going wrong just when you want to copy something in a hurry.
In this programme, Rex and I are going to try and, er, demystify these ingenious, but often infuriating, machines.
Before the photocopier was invented, there were many different methods of copying documents available.
But they were all slow and inconvenient.
[Ding!.]
Thermal machines from the '50s involved a complicated sequence of intermediate stages, and only produced the final copies on special chemical paper.
The most common way of making multiple copies was the duplicator.
But the original had to be specially typed on a wax stencil.
The typing perforated the wax, allowing the ink through onto the copies.
The Victorians invented the copybook.
The page was damp, so it absorbed some of the ink from the original, when pressed against it.
[squeaking screw.]
Copybooks were still used for legal documents until the 1950s.
But even before the copybook, a chemical process had been invented for copying engineering drawings.
A mixture of these two chemicals is first, er, spread on a bit of paper And then the drawing to be copied is put on top.
And this is now exposed to a very bright light.
Arc lights were often used, early electric arc lights like this.
[buzzing of arc.]
Well anyway, this actually takes rather a long time, so I've done one already, that I've prepared earlier.
A bit like a cookery programme(!) Erm Here it is.
Well it doesn't, er, look very promising, but if I now spread another chemical on it, the image should start to appear.
And then just have to wash the chemicals all off now.
And a dye, Prussian blue, is left impregnated in paper, on the bits which have been exposed to the light.
Well the process has actually been obsolete for over 50 years now, but the word 'blueprint' has become stuck in the language.
Wet chemical systems were also developed for the office.
[music.]
[music.]
Voiceover: Two minutes is the time needed to deliver the print.
And she'll get not a negative, with all blacks and whites reversed, but a direct copy of the original.
That's positive.
No trays to bother about either, she just brushes on the developer, then watches while the picture appears.
[music.]
Fixed in much the same way, the copy is now squeezed dry.
It's just too bad the outfit doesn't include properly watermarked paper for copying bank notes! [music.]
The idea that revolutionised copying, came from an unassuming American patent lawyer called Chester Carlson.
Chester: Well, in the course of my patent work I frequently had need for, er, copies of patent specifications and drawings, and there was no really convenient way of, er, getting them at that time.
Tim: Carlson started experimenting with a copying process based on the ancient, but unpredictable, science of static electricity.
[music.]
Greek: Oooh Zeus, the lamp is dustios! Boys! Boys: What is it Master? Greek: Polish well the lamps! [squeaking of polishing.]
Boy: Rub harder Ajax! Tim: The ancient Greeks first noticed static electricity when they observed that lamps made of amber attracted dust after being rubbed.
Greek: Preposterous! The lamp is dustiosterous! Boys: But but sir, we Greek: Get outside while I administer the usual! [whip cracks.]
[whimpering of boys.]
[sheep baaaa-ing.]
Tim: Our word for electricity comes from the Greek for amber, electron.
The Greeks also had trouble with their spinning wheels, because the bearings were made of amber.
[Baaa-aaa-aaaa.]
[Crackle ZZZZT!.]
[photocopier noise.]
Modern plastics, like nylon carpets and synthetic shoe soles, work much better than amber.
I'm now charging myself up, and er, it's called static electricity, because the electricity is literally static, it's trapped inside me.
And I'll stay charged up until I discharge myself, by holding my finger near something that's earthed.
I might be able to make a tiny spark and give myself an electric shock, on this No, nothing.
Erm, static electricity experiments, er, only really work when the air's very dry.
And in any case they seem to be incredibly unpredictable, I hope these work better.
Erm If I charge up this bit of plastic I should be able to make some bits of tin foil dance around Oh yes! That's not working too badly.
Erm, static electricity can also make, er, dust fly up and stick to things.
Pour some dust on there Yes! It's this effect of attracting small particles that's used in the photocopier.
Carlson did his early experiments in his kitchen, in fact we found the only place we could reliably repeat them was in Rex's kitchen.
Cos he's got under-floor central hearing and so it's extremely dry.
Tim: Is this going to work alright? Rex: I think so.
Tim: Carlson started by casting blocks of sulphur, after reading that sulphur lost it's electrostatic charge when it was, um, exposed to bright light.
Erm, yeah it does look good.
It's not easy casting these plates of sulphur, and it makes an awful smell as well.
Tim: Erm, well we've got to leave that one to cool, haven't we? So err Rex: Yes.
So perhaps we'd better try it with one of the other ones? What Carlson did was to charge the plates up, by rubbing them Rex: Don't rub too hard.
Tim: Alright then, er, so now we have to put some sort of an image on top of it.
That's it Now we'll expose it Okay.
The sulphur is now losing it's electrostatic charge as it's exposed to the light.
So it's now only the areas under the black letters, protected from the light, that are still charged.
If a fine powder is now dusted over the surface, Carlson used lycopodium, it would be attracted only to the charged parts, revealing the image.
Tim: There's an 'A' Rex: It's coming out quite good.
Tim: Although our result isn't very impressive, Carlson himself didn't do much better.
No one was very impressed at the time, October the 22nd 1938.
But he somehow managed to persuade a research institute to try and develop his idea.
The Battelle institute replaced Carlson's sulphur with plates made by vacuum depositing thin layers of selenium.
In the late '40s in conjunction with a small company called Haloid, the first electrostatic copiers appeared.
Including one model called the 1385.
This is one of the few surviving 1385s in Britain, and er, it's a magnificent contraption.
Erm, it's all entirely manually operated, and it takes several minutes to make a copy.
It doesn't look anything like Carlson's equipment, but it actually goes through exactly the same stages.
Er, this is the plate, and the first stage is to charge it up.
So it goes in this slot here, simply have to press the button.
Battelle had replaced Carlson's sulphur with a thin glassy layer of selenium.
That's so sensitive to light that I can only show how it works in a darkroom.
Instead of rubbing it to charge it, Battelle used a very very fine high voltage wire that's inside this casing.
He simply moved it slowly across the plate.
This gives it a very even charge and, er, this is what's happening inside the slot in the 1385.
The next stage is to expose it, so take it over to this camera here.
Erm, slips in the back, This is the image I'm going to expose.
[click.]
[ticking noise.]
It's basically just an old fashioned plate camera, this.
That's it, put the slide back in And the next stage is developing it.
And that happens in, in here.
Er, put the plate in here.
Pull the slide out again, [clunking and clanking.]
This reminds me of some sort of magician's cabinet.
Inside, a mixture of sand and toner powder, the equivalent of Carlson's Lycopodium, runs over the plate.
It's only attracted to the parts of the plate that are still charged, that's the dark parts of the image.
And we should now be left with an image on the plate.
Yes! Having a lot of trouble getting it as good as that.
The copy paper is then put over the plate so the image can be transferred.
The corona wire now charges the paper, transferring the toner powder onto it.
Finally, the toner powder on the copy has to be heated to fix it Probably about done now, er? Yes.
That's fixed.
And that's the final copy.
Well, this process is obviously rather impractical for an office, but it found one specialist use for printers, for making short run printing plates.
That's why I'm in a printer's now.
Erm, I'm going to.
.
away and try and print it.
Tim: Here's the plate.
Printer: Thank you.
The 1385 already embodied the same technology as today's copiers, but it still wasn't the machine of Carlson's dreams.
Chester: The idea of developing an office copier which had never been done before.
and I thought of a machine that could be sat on a desk in an office, to which one could bring an original to be copied, and put it in the machine and push a button and get a copy out.
Tim: His dream finally came true in 1959.
The Haloid company had changed it's name to Xerox and introduced the model 914.
Jones: I can't type.
I don't take dictation.
I won't sharpen pencils.
I can't file.
My boss calls me indispensable! Boss: Miss Jones? Jones: Just a minute! Boss: Will you make a copy of this? Jones: Naturally! I push the button on the Xerox 914.
I make perfect copies of whatever my boss needs, by just turning a knob and pushing a button.
Anything he can see, I can copy in black and white.
On ordinary paper.
And am I fast! I can make 7 copies a minute! By the way, I never need wet chemicals.
My 914 is a dry machine.
Powder dry.
Sometimes my boss asks me, which is the original.
And sometimes, I don't know! Here, Mr.
Smith.
I'm going to lunch with Mother.
[squeaking.]
Man: Easy there, Easy there [knock knock.]
Woman: Hello? Man: Here's your Xerox 914 Ma'am.
Woman: Oh Great! "Just push-uh" "Push" "Oh no!" Man: I reckon Boss, it'll have to go through the window.
[motor.]
Tim: Although large and cumbersome, the machine revolutionised office copying.
[CRASH!.]
Woman: Oh I just love pressing the button! Ohh! Copy after copy! They keep coming! Tim: The key to automating the process was to change the exposure stage.
In the 1385 the camera lit the whole of the original and exposed it through the lens on to the selenium plate.
In automatic machines, the selenium plate is wrapped, is wrapped round into a drum.
The light is then enclosed in a box, so that it only lights a thin strip of the original at a time.
So now, erm, if you slowly move the original over the light, or the light over the original, while the drum rotates It's exposed a bit at a time.
It can then all become a continuous process: While one bit of the drum is being charged up, another is being exposed.
another is being developed with toner powder, and yet another is transferring its toner to the copy.
The advantage of the drum, is that all the stages of the process can be arranged around it.
[motor noise.]
The charging stage is a fine wire, a fine corona wire just like in the original manual machines.
[more noises.]
I think this machine's a bit on its last legs.
Erm, the exposing stage is just like my model: The original goes on the top here, and then the bright light moves across it, and the image is exposed via a couple of mirrors through the lens and onto the drum.
Then the developing stage is in here, it's a bit difficult to get at, so I've got another developer unit here.
The toner is actually mixed with iron powder, and it sticks to this magnetic roller.
As this rotates, this spreads the toner powder onto the drum.
The copy paper comes along the bottom of the machine.
Comes in through, through this end Along here, and there's another, corona wire in the bottom here, that attracts the toner from the drum onto the copy.
Of course when it first gets transferred onto the copy, it's still just a powder.
But the toner's mixed with a plastic, [roar of blowtorch.]
That, er, melts at quite a low temperature when its heated up a bit.
In the, in the copier there are a pair of heated rollers.
You can see the element, it switches on every now and then.
And the copy goes between the two of them.
This is what you have to wait for to warm up when you first switch the machine on.
in the back, there's a mass of machinery, gears and cogs and things Both to pull the light across the original and to pull the copy paper through the machine.
But despite all this complexity, copiers have progressively got cheaper and cheaper and smaller and smaller.
[fast paced singing in Japanese.]
[voiceover in Japanese.]
The Japanese also made colour copying popular.
The machine is extremely complicated, but the basic idea's really quite simple.
At the back there are 4 magnetic rollers with different coloured toner on.
This is the magenta.
Cyan blue.
Yellow.
And the black.
The same colours as in colour printing.
And the bit of paper just goes through the machine 4 times, once for each colour.
You should be able to see the different colours appearing on the drum one after an other by looking in here.
First it's exposed through a magenta filter and deposits the magenta toner.
Then the blue.
Then the yellow.
And err finally the black.
Before it, er, comes out the slot at the end of the machine.
In photographic reproduction, the toner powder is much finer than in an ordinary copier, enabling subtle gradations in each colour.
The fixing stage melts the four layers of toner powder together, creating the final true colours.
Despite their sophistication, modern copiers still have their drawbacks.
For a start the static electricity creates a certain amount of ozone, which isn't very good for people.
Large copiers are now fitted with carbon filters.
And the static can have the effect of attracting dust inside the machine.
This coats the rollers and the corona wires and the optics, producing worse and worse copies.
Er, this one's jammed up again [clanking.]
Not a very brilliant copy.
The static also attracts the toner powder, which is terribly messy stuff, deliberately designed to melt and congeal on everything it touches.
This is basically what makes copiers still so heavily dependent on regular maintenance and servicing.
Small copiers are now often made with disposable cartridges, erm, these not only contain the toner, they contain everything including the drum.
And the idea is that when the toner runs out, it all gets replaced before it has a chance to get dirty.
Then there are problems with the paper.
Paper tends to shrink as it dries out, just like wood, And often inside the machine it distorts and jams up.
And even without shrinkage, it's impossible to design a paper-handling system that's totally reliable.
The best that manufacturers can do is to make the machines quite easy to rescue the mess.
With all these problems, it's really a miracle that copiers work at all.
It's partly because of their temperamental qualities that copiers are so often the focal point of the office.
Brian: Whoops.
Boss: I've got a million and one things to write today! Oh! It's up to it's tricks again! Polly! Can you sort this out for me? I need 50 copies.
Polly: Oh I hate this machine, it's always going wrong! Brian! Get Lost! Brian: evil laughter I see that Jones's promotion isn't on the cards.
Terry: What's up Poll? [beeping.]
Polly: I can't get it to work Terry! What's wrong? [beeping.]
Terry: Oh.
It needs paper? Oh no, the paper's jammed.
Oh, I think it needs toner! Polly: It needs an expert.
[engineer whistles.]
Brenda: Oh, not again! Terry: Oh dear.
Boss: What Is the holdup? If you want a job done properly, do it yourself! [fingers tapping desk.]
Terry: Uh, when's it gonna be fixed? Engineer: Oh, needs new corona wires.
Tomorrow if you're lucky.
Terry: Oh, dear.
Polly: They won't let us use this one.
Terry: This one's broken as well.
Polly: There's a big queue here! Brenda: It's only 50 copies, there's no need to be so rude.
Tim: The unreliability of copiers leads to many of them being thrown out in disgust.
Which is great for me and Rex, because we both find the parts very useful.
The general has bearings, microswitches, and a solenoid taken out of an old copier.
Almost everything I make has some bit of an old copier inside.
[click.]
[clank.]
Rex recently used the high voltage supply from a copier in an enormous static electricity machine.
Rex: This weird looking contraption behind me is a Van der Graaf generator.
I built it to explain the principles of electrostatics.
[snap.]
[snap.]
[snap.]
[snap.]
Static electricity has got some spectacular effects.
Tim: 10 years ago, there were a lot of predictions about the paperless office.
Computer memories were going to completely replace piles of paper.
And there'd never be any need to print anything out or copy anything.
This doesn't seem to have happened though.
More and more copiers get sold every year, and more and more paper gets used making copies.
It isn't very ecologically sound, although at least some paper, like this, is now recycled.
However, I find copiers much the most useful of all office machines, and I'd be very sad to be without one.
Whoops! [Jazzy music: 'Take 5' - Dave Brubeck.]
[bulldozer engine noise.]
[Jazzy music: 'Take 5' - Dave Brubeck.]