

The laser unprinter - colluphid42
http://www.extremetech.com/extreme/122415-the-laser-unprinter

======
dangrossman
I don't get the environmentalist angle. The paper industry is a net carbon
sink; much more carbon is captured in growing the forests of fast-growth trees
they plant and cut down than in manufacturing paper or lumber products from
it. Every sheet of paper you buy is that much carbon in your hand that would
otherwise be in the atmosphere, and will now stay out of the atmosphere as
long as it's not burned.

The Intergovernmental Panel on Climate Change identified exactly this as the
most effective man-made carbon sequestration method we have.
[http://www.ipcc.ch/pdf/assessment-
report/ar4/wg3/ar4-wg3-cha...](http://www.ipcc.ch/pdf/assessment-
report/ar4/wg3/ar4-wg3-chapter9.pdf)

So, paper is cheap and producing it is a net positive for the environment.
What about the coal-burning power plants generating electricity to shoot
lasers at the paper so we can reuse it again? Is the electricity cost to blast
off the toner going to be less than the cost of a sheet of paper?

~~~
mhb
_The paper industry is a net carbon sink_

How is that? Neglecting processing-related effects, isn't this zero-sum since
they're planting trees and then turning them into paper which eventually
decomposes and releases the carbon? A reduction in paper use would leave the
existing trees standing.

~~~
krupan
The trees that the paper companies plant would remain standing? I think you
missed part of the argument.

------
iwwr
Reused paper tends to be crumpled and warped, especially if you try to feed it
through a (laser) printer multiple times. It's more trouble than it's worth,
unless they make printers that can handle less-than-perfect paper.

~~~
wpietri
If you'll just use a sheet of paper once, then there's only so much it makes
sense to pay for it. But what if you'll be reusing it 20 times? Perhaps
there's an opportunity there. Kind of like how paper plates are generally
flimsy, but normal plates are very durable.

~~~
peeters
True. But there are other trivialities that need to be considered. The first
thing I do when I've got 5+ pages is either hole punch or staple them. The
second thing I do is scribble on it or highlight things. If I wasn't going to
do that, I probably wouldn't have printed it out in the first place (unless it
was for record-keeping, in which case the paper will probably never be reused
anyway).

If this becomes popular there will be a new industry around non-destructive
paper management (more than our current choice of paper clips and
highlighters).

But I think the critical factor for success is if the technology development
outpaces paper-thin, writable LED displays or even tablets (which have
progressed a LOT in the last few years). If you can give your "paper" a WiFi
connection is anybody really going to invest in traditional (but reusable)
paper?

------
Tim-Boss
So I guess everyone has given up on the paper-free office ideal now?

It seems like only yesterday I had to sit through a two hour meeting to
convince us that printing things is a needless expense now we're all supposed
to be using laptops and iPads! Wait a second....it was only yesterday!

~~~
nknight
Might I suggest a job search? I'm not some paper fanatic, I rarely print
anything out and I'm physically incapable[1] of making substantial use of a
pen or pencil, but any company spending two hours on the subject is one I
don't think I want to work for.

It was bad enough the day I sat through a 10 minute speech by a CEO on proper
urinal usage...

[1] <http://en.wikipedia.org/wiki/Dysgraphia#Motor>

------
cs702
I can't help but wonder if the same ultra-short pulses of laser light can be
used to vaporize dark pen ink, giving users the ability to erase or alter
things like signatures.

~~~
aiscott
I used to work in a integrated circuit debugging lab. We had a pulse laser
that we would use to ablate the layer of glass on top of the metallization so
we could probe the die.

While goofing around I discovered that I could vaporize the ink of dollar
bills. The largest area per pulse was pretty small, 25 microns if I remember
right. Maybe 100. So it wasn't very practical, but it worked.

I don't remember if I tried it with pen ink. It might work okay for ball-point
as that mostly lays ink on top of the paper. You'd still have the impression
in the paper from the pen though.

Ink that didn't soak in but lay on top of the paper would probably stand a
good chance of working. Maybe gel ink?

~~~
cs702
Thank you. That's what I thought: any dark ink that just lays on top of (i.e.,
isn't absorbed by) the paper could probably be vaporized in similar fashion by
a pulse laser.

Anyway, when I wrote that, I had an inkling that someone in HN would know
probably something about the subject matter, but I never expected anyone to
have real-world experience using pulse lasers to vaporize ink from a piece of
paper, let alone dollar bills!

Awesome.

This is why I _love_ HN.

------
FelixP
What about the fumes and such from the ablation of the toner? Seems like it
could be a serious health hazard.

------
Ecio78
Toshiba is releasing a technology for removing the printer up to 5 times from
printed paper, but it uses a special toner

[http://www.youtube.com/watch?v=r--
y9VvSTyg&feature=playe...](http://www.youtube.com/watch?v=r--
y9VvSTyg&feature=player_embedded)

------
mhb
So it's the new eInk but with a refresh rate of a few minutes...

------
dhughes
Will you have to unjam the paper first before unprinting?

~~~
krupan
Very likely. I used to work in the HP printer division, and used paper was the
bane of the existence of the mechanical engineers that designed our paper
handling systems.

------
maeon3
Paper is going the way of the stone tablet with chiseled etchings, it is too
heavy and slow, let the paper tech die peacefully next to the stone chisel
tech. Don't revive paper tech just as we are getting into cool stuff, getting
to the root of why paper exists, to exchange ideas between brains.

------
Rinum
What else would a laser unprinter be used for besides sensitive documents?
Paper is cheap, wouldn't it be easier to just use a new piece of paper and
recycle the old one.

