[optacon-l] consider another braille display technology proposal on its way: was Orbit Research Group & TBG announce project for low cost braille display.
- From: "C. Pond" <cpond@xxxxxxxxx>
- To: "optacon list" <optacon-l@xxxxxxxxxxxxx>, "Philip Hall" <p.hall.eml1@xxxxxxxxx>
- Date: Wed, 13 Aug 2014 01:40:01 -0400
I'd like for the Thousandth Time for Someone to be pleased to linked me up
with the R&D group, which I have tried to do off and off for hears with no
success. A braille display project concept which I have been gradually
chipping away at on my own here (so far no company, and I here release my
design ideas) and I freely share is as follows, albeit on another list might
be in a technical sense more suitable.
In very general terms so not to clutter up an optacon-dedicated list: a
thin, long, neodymium rectangle magnet of about 2-inches by 3/8-inch wide or
narrowerer is made with eight holes per group and four groups, with four
groups of eight holes which correspond to the dimensions of the braille
cell. The width of the rectangle magnet is just about the size of a braille
line. So eight cells of 32 dots per base magnet, which yields a magnet of
about 2-inches in length, about a quarter inch for each cell and their
spacing. This rectangle magnet is magnetized through its thickness with
north nominally on the top. Small rod magnets acting as dots (and they can
be fabricated to make the actual shape of the dot with its slightly
elongated, rounded tip, no need for an extra layer) slide through these
holes (numbering 32) in the base rectangle magnet. The rod magnet will flip
from one stable state to another as a force influences it to flip and "slip"
into one direction or another. This bistable property of concentric magnets
process in its basic form was shown to me by Matt Deakin, a visiting
student from Oxford. He had a nice, chunky ring magnet magnetized through
its thickness, with a rod magnet magnetized through its length fitted
loosely inside, but it served the purpose to show a very basic bistable
arrangement. Good. We never worked on braille technology whatsoever; not a
speck. we were essentially playing at that point and putting the limited
FEMM simulator through its paces, since it is not a three-dimensional finite
elements simulator. These simulators are very graphic, so a headache for a
blind person to use.
So then, a set of magnetic coils, one for each magnet dot sits below the
base rectangle carying magnet, "pulls" or pushes (attracts of repells(these
movable rod dot magnet as determined and controlled by a generated bit code.
The coils are pulsed only momentarily, and the vast majority their driving
waveform is "off". so electronic time they are off, not on. Therefore,
although some chunky in-rush current (chunky by electronics standards,
nothing like with a washing machine)is used to get the rod magnet dots
moving and to accelerate, most of the time the coils are simply off, so
therefore they do not become overheated. Overheating is not a problem. If
it were, a few Peltier diodes and a few other creative transfer and
regenerative electronic techniques would take care of that. Nevertheless,
heat simply is not an issue.
I am now trying to reduce the stroke of the moving rod dot magnets from at
least 2 cm to perhaps 2 or 3 mm, which I know will successfully be done.
It is not essential for the cell to work, but it drastically reduces the
cell's height, and it reduces the power it uses to move the dot magnets
lined up like faithful braille soldiers in their holes within their
rectangle base magnet, which already is small enough. The key here is that
when the rod magnets settle and are latched by their intrinsic concentric
arrangement of rod magnets ina rectangle block, no power is required to
keep them there until pulses from the appropriate coils come along and
"move" the dots to their different desired states, either up or down.
Latching means no sustained power to keep dots up or down, and so less power
is used, the coils stay cool, no damage to the cell results from
overheating, and the magnet dots stay where you want them.
Although it costs initially hundreds of dollars to have custom magnets done,
each one after the initial mold is essentially pennies. I do have a very
small amount of my own money which will be dedicated to this development,
whether or not we see the vaporware promised by Orbit. That is unless they
capitalize on my ideas and run with them. So be it; I have been open source
as much as possible. Let there be no mis-understanding about this. Let
ther be no more accusations from a company in Ottawa here and his mis-guided
director who had no hand in the design and ongoing development of this
braille display technology in the first place whatsoever as my failing
health permits.
This device is quite different from an optacon display (even if one can be
built uding a very refined magnetic actuator) in many ways. Just for one
thin, because it need not vibrate and even more so because it need not
resonate, it makes design and implementation easier. The magnetcs latch by
nature of their properties when arranged concentrically as with this
rectangle base magnet matrix and its 32 passenger rod magnets which act as
the braille dots. Whereas an optacon display must vibrate within a range
from between 230Hz and 270Hz,--and resonating would be even better--a
braille display needs to latch and the dots remain stanery as the reader
wishes. Even the neuro/psycosensory modalities are vastly different for
optacon displays and for braille displays users. There canbe be no
confusion between the two on any level whatsoever.
In addition to reducing the stroke movement of the rod dot magnets (which is
completely doable), there are at least three more easily doable technical
considerations:
1. Should the actuating coils be wire wound, or in this case will layered
planar PCB coils work. I know little enough about PCB layered coils if such
a thing even exists. Wire wound coils have been proven to work fine as long
as they can be easily produced. They are small. A machinist is helping me
design and to build a coil winding machine which winds tiny coils. I could
resort to my biomedical friends, but for now we'll hold of on that option.
Contrary to an accusatory someone here in Ottawa, air core solenoids, or
open frame solenoids, are Far less efficient than solenoids with the
suitable ferromagnetic metallic former around which the coil is wound. To
disagree would be throwing out a hundred years of very practically proven
solenoid technology. Hence, the need for refining the pulsing/actuating
coils. This design works very differently from the older display of which
Dave wrote on the list.
2. I have been looking at interesting elastomemory shape foils to cover and
completely seal the bank of four braille cells, in this case a set of four
cells per block. This elastic foil serves to address at least five purposes
which have been longstanding longstanding weaknesses:
A. The elestomemory foil completely seals the braille cells from their
worst enemies: finger acid,dust and polin, dead skin a la finger, bug stuff,
moisture, children's delightfully curious peanutbutter and honey laden
hands, spilled drinks all of which simply and permanently ruin a
bimorph-based braille display. You should see some of the crazy stuff
pulled out of displays! <smile>
B. The fine, elastic nature of the foil actually is integral to the shape
of the braille dots themselves which we feel; for, it conforms like a nice
elastic sheep to each individual dot with out obscuring their shape, unlike
the silk covering over the old Braille-Link dots. It does not merely cover
them; its thin film size becomes a part of the dots' shape which we feel.
Raising dots does not distort the fine elastofilm as when the blanket is
distorted when we play with our cats with our fist hidden beneath the
mysterious blanket, and lowering dots does not creat a loose slidable layer.
The foil siimply conforms to its shape. There is a number of such elastic
foils on the market, so testing them ad putting them through their paces
regardless of their stated specs is a time -comsuning project in and of
itself.
C. The elastomemory foil provides a safe, nonconductive barrier to protect
the poor hapless photon-independent user as she sallies forth with her
inexpensive braille dispaly to slay the dragon of illiteracy. As she does
this, she notes that the size of the dragon is somewhere between a budgie an
and ostrich. The foils has no electrical connection except to a safe
ground.
D. It provides a smooth, not-binding or in a sense sticky reading surface
compared to the long-standing and very useful kind of thermoform paper which
we used extensively at WRM School about 30 years ago. I used to rub a
finger in my hair, dabbed with nice bacteria-laden hair grease, so I could
better slide along the thermoform plastic sheets and read until that
fingerful of grease ran out, and I went back for another lubricating fill.
<smile> Well one has to admit along with an apologies to the girls here, my
solution worked, and it was completely home grown, fresh and organic, and
completely replenishable and environmentally friendly,. So there. haha
E. The foil surface can easily be cleaned and maintained by the user. As
one wipes off a flat surface stove (stoves which I do not like) one can
easily clean the surface of the display, that is, the fine foil surface.
These comcepts for an inexpensive braille display for any number of cells
and banks of cells have been proven to work on my bench. As yet, I do not
have a prototype display working. I just haven't been able to get to it
until this week, and I am essentially working alone since my shared office
was removed in mid-2011.
3. I have done the hardware just to test if the concept of a suitable
driving algorithm will "hold back" dots adjacent actuators to ones which are
magnetically activated. If adjacent actuators are to be activiated, then
their inadvertent activation by adjacent magnetic acturators does not
interfear with the driving signal of the adjacent, activated actuator. The
coils are still mostly off given their requirements and their driving
waveform. So, magnetic cross-talk and induction to ajacent coils need not
be an issue.
Since a braille cell does not vibrate save for a cursor at times, vibration
from one cell to another is not an issue.
With the proper nunber of these specially shaped magnets produced, and the
electronics costing little, I do believe that such a design for a single
line--or double line if it is of any use--is completely doable. My health
is going out, and O am I no longer able to do what I used to take for
granted. Therefore, perhaps something can be done to forward this design.
The magnets are more robust than bimorphs; they can easily be obtained
and/or manufactured with the right specs; they are easily assembled, in fact
the process can be automated; the electronic layer of coils and driver
electronics below the base rectangle magnet matrix can be mass produced and
the whole thing can be modular. The driving scheme I have come up with is
different from the "standard" braille displays on the market today. Six of
one, half a dozen of the other, basically.
Does anyone have any feeback and comments?
If you can, do forward this to the appropriate people.
the guys and gals at Smith-Kettlewell might have been interested at one
time, but the ones I knew are no longer there. I wonder if Dr. Bill Gerrey
is even still living?
Thanks you in advance for any patience shown,
Charles in Ottawa
From: David
Sent: Tuesday, August 12, 2014 10:36 PM
To: optacon-l@xxxxxxxxxxxxx
Subject: [optacon-l] Re: Orbit Research Group & TBG announce project for low
cost braille display.
Yep, and do you think I ever did that, just to have the fun of mocking
the Braille cells? Smile. Besides, the plastic film over time got pretty
lousy, and if you pressed too hard with your fingertips while reading,
the pins could actually leave markings in the film. This all made it
quite an interesting guesswork to read the display reliably, after a few
years.
David
to view the list archives, go to:
www.freelists.org/archives/optacon-l
To unsubscribe at any time, just send a message to:
optacon-l-request@xxxxxxxxxxxxx with the word "unsubscribe" (without the
quotes) in the message subject.
Tell your friends about the list. They can subscribe by sending a message to:
optacon-l-request@xxxxxxxxxxxxx with the word "subscribe" (without the quotes)
in the message subject.
Other related posts:
- » [optacon-l] consider another braille display technology proposal on its way: was Orbit Research Group & TBG announce project for low cost braille display. - C. Pond
