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Re: [ARSCLIST] Ampex & Sticky Shed Syndrome
At 10:15 AM 12/20/2004 -0500, James Lindner wrote:
They received the patent on August 17, 1993. They have plenty of time. As
for Richards comment suggesting prior art - I believe that one would have to
argue that the paper you suggested was in fact a public disclosure and that
more then one year had lapsed from the time of that disclosure and the
patent application. But they may have made a preliminary filing in which
case they would probably be OK. Also I don't believe there is any rule in
terms of disclosing ALL The research in any given field in a patent
application - indeed I believe that one is required to disclose what other
patents the invention may rely on.
Hi, Jim,
The prior art that I'm suggesting was published in the IEEE Transactions on
Magnetics, Vol MAG-18, No. 5, September 1982.
Patent 5,236,790 was filed on Mar. 31, 1989
George's comments were very interesting in that the Ampex patent would be
an improvement on the process where I suggest that changing the temperature
to shorten the processing time should be obvious to someone skilled in the
art from the Bertram/Cuddihy paper from 1982.
But now on to today's patent: Richardson's 6,797,072 for removal of
back-coating.
It makes some assumptions that we need to revisit as we've been told that
they are categorically wrong:
Nearly every tape that has Backcoating has "Sticky Shed" problems
to a varying degree. Thus, Applicant has concluded that the
Backcoating is the bad actor in this situation. While Backcoating
may have helped with some mechanical issues in the
1960s, it left behind a chemical time bomb which is destroy-
ing tapes today and will do more destruction in the future
until and unless a process is used to solve the "Sticky Shed"
problem.
...
In the worst case situations, the
sticking Backcoating would rip the Oxide off the base of the
tape, thus completely destroying all the magnetic data on the
tape.
Well, this is very interesting. This doesn't explain the tape from the
1960s and 1970s without backcoating that is losing its oxide at Cal State
Fullerton (CSF) due to high humidity storage. I certainly think the Bertram
paper addresses the issues.
Now, I can see how Richardson in US Patent 6,797,072 can make the above
claims as most of the tapes which suffer from sticky-shed are tapes that
are backcoated, CSF notwithstanding. I think the common thread here is that
there are now two binder systems--perhaps both using the same chemical
components--that are deteriorating. But my observations is that while the
backcoating may have degradations and is suffering from sticky shed,
usually the oxide is as well.
A very interesting read.
Also, Marie O'Connell discolsed her use of an isopropyl drip for playing
tapes to this list on 12 May 2003 which predates the filing of this patent
by four months. While it's not the same, I think the isopropyl drip while
hinted at in the Richardson patent is a separate invention and, I think,
clearly Marie's.
Cheers,
Richard