14 Jan
2005
14 Jan
'05
7:56 a.m.
On Fri, 14 Jan 2005, John Foust wrote:
Well, I have a particular project in mind for that but I agree
with you -- why stop there?
So...
what's the chance of doing this with a solid-state laser?
Say 9 of them? The idea of high-speed papertape (sic) thrills me.
I know I'm sick, but I don't want to stop.
Why stop at nine? Optical scanning of a tape via linear CCD
or video chip or reflected laser must be scads faster than
mechanical methods (from pins in holes, to helical scan mag tape). But why limit yourself to perpendicular rows? Sounds
like what
you want is a dense 2D barcode, like the UPS and USPS codes,
but somehow sequential, flowing, 2 1/2 D.
Well.. I simply hadn't considered anything else! But an N x M
array reading the tape, could do high density with redundancy and
correction, and make finding the edges of pits easy.
The hard part is picking the medium, I'd think.
You want something
that'll do a fast detectable change that'll keep over time,
burnable by a power-enough laser. They speak of mylar tape,
but my TTY stuff is so old I've never seen it. Will it detectably
deform if you heat it?
I was thinking more generically here, 'thin mylar tape' from other
industries, but whatever.
I've loved brainstorming about these sorts of
barcoding schemes.
It seems to me that it's a big missing hole in the convergence
that everyone's always talking about. There's few super-easy ways
to move a URL from print automagically into a computer, and RFID
seems almost clunky compared to burning microscopic bar codes all
over the surface of objects.
Well my crazy project could in fact use something higher density than
old style!