==================BEGIN FORWARDED MESSAGE==================
>From: "Steve Pattison" <pattist@ozemail.com.au>
>Date: Fri, 10 Mar 2000 17:34:38 +1100
>Subject: Fwd: Re: Another braille display method
>Message-Id: <200003101029.VAA05723@fepa.mail.ozemail.net>
>To: gui-talk@NFBnet.org (Multiple recipients of NFBnet GUI-TALK Mailing List)
To: access-l@icomm.ca
>From: John Roberts john.roberts@nist.gov
Hello Martin,
I've been meaning to send out an announcement that we have recently
updated
the web page for the NIST Braille Reader project at
<http://www.itl.nist.gov/div895/isis/projects/Braille/>.
This technology (based on one rotating wheel to carry the Braille text)
was discussed on this list last year, particularly in October and
December,
and we received many helpful comments, which we have used to guide the
course of development. I believe our work was described in Deane
Blazie's
speech, though it was attributed to NASA/Langley. We are presently
working
on a second-generation prototype, which is described in more detail on
the
web page, but in brief has the following new features:
- The Braille text is set on the rim of a rotating wheel (unlike our
first
prototype, which placed the Braille on the face of a disc) at one point
in
the rotation of the wheel, using three actuators for 6-dot Braille, or
four actuators for 8-dot Braille. The text remains intact as it rotates
through an extended reading area, thus allowing the use of multiple
fingers
for reading.
- A Stop/Start mode allows users who so wish to display text a segment
at
a time, with rotation of the wheel stopped while they read. This also
provides immediate utility to users who have just obtained a display,
while
they are in the process of learning to read in continuous rotation
mode.
- The chief benefit of this technology is low cost, which should now be
even
lower. The "Passive Pin Displacement System" associates the Braille
dots with
very simple pins, shaped (for example) like a carpenter's nail, but
with
a rounded tip in the proper size and shape to make a Braille dot when
extended from the reading surface. Passive (unpowered, unmoving)
structures
such as ramps and slots utilize the energy of rotation of the wheel to
raise or lower the pins to a default position (from which they can be
shifted by the actuators), and across the reading area passive
structures
hold the pins in the positions that were set by the actuators. We hope
that this will get the cost for the moving parts and drive electronics
(not including packaging, control electronics, design, etc.)
down to a few cents per pin/dot.
- The technology can probably be extended to linear text displays (the
line
of text is written from one end to the other using three or four
actuators,
remains static during reading, then is erased and rewritten). This
approach
is likely to be more complicated and expensive than a wheel display,
but
much cheaper than current methods for producing line displays - so much
less that it could make page displays (e.g. one write head per line)
practical.
This new technology has been incorporated into our patent application,
and
we (John Roberts, Oliver Slattery, and David Kardos) have started on
some
preliminary test devices for the second generation prototype - so far,
the
approach appears to be workable. We hope that sometime this year we
will
have a new prototype that works well enough for testing by Braille
users.
As always, we're looking for opportunities for collaboration, and for
manufacturers interested in building commercial displays using this
design.
Regards,
John Roberts
NIST
john.roberts@nist.gov
From: Martin McCormick martin@dc.cis.okstate.edu
>
> I think the idea of the rotating wheels would work, but the
>problem would still be that of cost and mechanical complexity. The
>way one presently turns something to the exact position is with a
>stepper motor. These things are used in printers, plotters, and CNC
>or Computer Numerically Controlled shop machines. They look like a
>little electric motor and that is what they are except that they turn
>some predictable fraction of their full rotation each time the coils
>are excited in a certain sequence. They may divide a rotation in to
>200 steps or 50 steps or whatever.
>
> The problem is that they are expensive if one wanted to use
>lots of them such as one for each cell. They also draw enough current
>that if many of them were run at the same time, they would suck a
>battery dry in no time flat or would need a power supply so big that
>it could crank the engine of a truck when it wasn't running the
>Braille display.
>
> When they aren't actually turning, steppers must be energized
>or the shaft will turn freely like a cart wheel. If that was a
>Braille wheel, a person's fingers would move it if the power was off
>to the stepper. One could have a mechanical break to stop the wheels,
>but that's one more electromagnet to draw current and one more
>mechanism to maintain.
>
> I want to be clear about one thing. I don't have an agenda
>such as a secret plan to sell my version of a Braille display or
>printer. I wish I had a plan, secret or otherwise, but I don't right
>now.
>
> An affordable Braille display that would revolutionize
>computer Braille technology needs to have the following
>characteristics or it is doomed to be expensive like all the others.
>
> The individual dots have to make themselves, so to speak.
>They should be the result of electrical or possibly fluid or hydraulic
>potential that makes dots or bumps everywhere a row and column
>intersect and the row and column are energized.
>
> It almost goes without saying that the materials should be
>commonly available, cheap, and safe for people to use.
>
> We already have very good electronic Braille displays so the
>fun is to come up with a good and cheap electronic Braille display
>that gives its operator a proper sensory experience. If you remember
>the Blazy speech, Mr. Blazy talked about the need to run one's fingers
>over the dots just like what happens when reading Braille embossed on
>the page.
>
> The refresh rate of the Braille must be much faster than we
>can read so that one doesn't get in to a race with the display.
>
> I thought it was kind of amusing that somebody actually tried
>electrical shock stimulation directly to the fingers. Anybody who has
>ever worked with electronics has been at least mildly shocked and one
>can sure feel the nip of a mild shock, but it is not like touching a
>Braille dot and more like getting bitten by a mosquito. I think I'll
>pass on reading War and Pease via shock Braille.
>
> The idea of heat is interesting except that human skin doesn't
>have anywhere close to enough heat nerve endings to make fine
>distinctions like we do with touch. We're kind of stuck with raised
>dots or possibly vibrating dots.
>
> Keep the good ideas coming and remember that they have to be
>good cheap ideas.
>
>Martin McCormick
Regards Steve,
mailto:pattist@ozemail.com.au
-- This mailing list is sponsored by the National Federation of the Blind, NFB. For more information about the NfB, please call (410) 659-9314, point your internet browser to http://www.nfb.org or Telnet to nfbnet.org.===================END FORWARDED MESSAGE===================
Steve Jacobson E-mail: sojacobson@mmm.com National Federation of the Blind
The Opinions expressed do not necessarily reflect those of the 3M Company
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