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The Laser Unprinter
MrSeb writes "You've heard of laser printers — and now a team of researchers from the University of Cambridge in England has created a laser unprinter that can remove ink without damaging the paper. Despite both methods using lasers, their (un)printing approaches are fundamentally very different. In a laser printer, a laser is used to give individual 'pixels' on a piece of paper a positive charge (a separate heat source is used to fuse toner). In the laser unprinter, picosecond pulses of green laser light are used to vaporize the toner, or ablate in scientific terms. The primary goal of unprinting is to cut down on the carbon footprint of the paper and printing industries. Manufacturing paper is incredibly messy business, with a huge carbon footprint. Recycling paper is a good step in the right direction, but it still pales in comparison to unprinting. In a worst-case scenario, The University of Cambridge unprinting method has half the carbon emissions of recycling; best-case, unprinting is almost 20 times as efficient."
I wonder what protections the banks will have to put in place to prevent fraud.
And make sure you have a copy of any contracts you sign. Who knows what shenanigans someone can get up to by modifying the original.
[Fuck Beta]
o0t!
...is avoiding paper in the first place, and instead using digital methods to distribute information.
Unless they also developed a way to make paper that can not be unprinted without damage, I imagine that unprinting a signed contract that is just a little too fair and replacing everything but the signature with something more to your liking will be far more efficient than regular forgery.
I would bet that if you compared the carbon foot print of "Laser the sh*t out of it" with "Stuff it in a vat and let the microbes have a party", the current technology would win... it doesn't need much (if any) electricity.
If you care about which particular microbes party, and that they party the way you want, I'm curious how you accomplish this without the electricity usually required to create and maintain the required controlled environment. I suspect you're vastly underestimating the effort required to do this, as well as vastly overestimating the power requirements of your typical laser.
"Convictions are more dangerous enemies of truth than lies."
So, how unhealthy would the vaporized toner be? I really don't know. Somebody care to enlighten me?
wait for this to be built into printers. It detected text, zaps it, then prints.
The real issue is wrinkled papers.
The Kruger Dunning explains most post on
the current technology would win... it doesn't need much (if any) electricity
Electricity isn't the major factor - total energy is what matters.
Collecting tonnes of paper and transporting it to recycling centres, pulping, cleaning, processing, re-bleaching (we don't like blue-brown paper, we want white paper) and then transporting the finished paper back to where it is used. Calculate the energy in that.
At work we almost exclusively use reams of recycled paper. Print something on it and then sometime later (occasionally minutes later) it goes into a recycling bin. That bin is emptied once a week and the paper will travel 20 miles to a local depot. Where it is recycled and turned into new paper I don't know - but what I do know is that the reams of recycled paper we buy will come from at least 400 miles away (and will have travelled that via a circuitous route involving suppliers, buyers and distribution warehouses). Taking the same bit of paper and running it through a unprinter for 20 seconds and then reuse. Energy wise I don't think there will be any contest, but the numbers would have to be crunched to prove it.
What about the environmental impact of vaporizing toner? Isn't that some kind of air pollution?
I am not really here right now.
Cyan, Magenta, Yellow and blacK, actually.
If you're going to be pedantic, you have to be right too.
The standard laser printer does not put a charge on paper, it puts a charge on a transfer roller that then transfers the toner to the paper. That toner is then melted onto the paper.
Kodak (and others), used to make dye sublimation printers, where a sheet of plastic with dye on it was whacked with a laser to sublimate the dye directly onto the paper. This had the advantage of being something more than the typical "yes/no" "is there toner there" question, and thus resulted in much better color reproductions. No dithering was required. The major downside, besides cost of supplies, was that you were left with a negative image on the dye sheet, just like the old plastic film typewriters had.
This system sounds like an incredibly wasteful and complicated process. You have to scan the paper to determine where there is toner and sublimate only those spots. If you miss by just that much, you'll char the paper and miss toner. If you put in a sheet of inkjet-printed paper, you'll burn the paper anyway.
Making/recycling paper isn't that hard. This is silly.
Unprint $1 bills, print $100's
Professor, I totally had my paper finished but I accidentally unprinted it!
picosecond pulses of green laser light are used to vaporize the toner, or ablate in scientific terms
So all that toner gets vaporized and is now floating around in the air of your office? What could go wrong?
Ceci n'est pas un sig.
one major flawed assumption: that the "unprinted' paper will be used in printers instead of recycled paper. As a professional laser printer repair tech, I can tell you right now that won't happen. Even paper that has just been run through the printer once and left on a neat pile is significantly more likely to cause printer jams than fresh paper that's never been used. Any "savings" (whether carbon footprint, money, or otherwise) over using recyled paper will be quickly consumed by the extra repair trips.
There is no -1 Disagree mod. Slashdot.org/faq defines mod options. USE IT.
Does that include the carbon footprint of building and maintaining the laser unprinters?
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Spouse in the forest sciences here,
A minor point, but the huge carbon footprint of paper manufacturing is (at least in Scandinavia) deceptive. While paper factories do burn large amounts of wood to boil the fibres into pulp, the emitted carbon is a part of the natural cycle: it gets picked up again by the trees in the mandatory-by-law reforesting step. As long as the forest is kept at a constant size, the net carbon emission is pretty much zero.
(The sulphite and nitrogen emissions are another story, however.)
"Unprint" violates the phonotactic constraints of Latin. Unpossible! Clearly, the antonym of "print" should be "imprint". (Wait. Oh noooooo...)
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
Why was a laser "eraser" not a perfectly adequate word for it ?
-- Julien Pierre http://www.madbrain.com/blog
THIS! Aerosolizing carbon black sounds like a really, really bad idea since it's a known carcinogen (HP got sued by workers in toner plants over exposure). Not to mention I can only imagine the paper jams from trying to use randomly handled paper (brand new reams cause enough problems).
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Laser printers don't use lasers to charge paper, they use them to selectively discharge an image transfer drum, which is then covered in toner and pressed against a piece of paper. The toner and paper are on opposite ends of the triboelectric series and spontaneously develop opposite charges when brought into contact with each other.
As for the toxicity of the toner vapor, the composition is of course proprietary, but black toner historically has comprised mainly oxides of selenium. In small quantities it's probably harmless, but long-term exposure is almost certainly bad for you.
Actually, I wrote my thesis on life experience.