More frame designs, this time some lower cost options, images can be found
here: https://tactact.wordpress.com/2015/06/01/frame-design-5/
These frames consist of one part, typically made of plastic, with actuators
mounted directly below the finger plate. This way they can be relatively low
cost and low profile. Compact coils are used like with the previously shown
high-res display, and they aren't necessarily limited to low power operation
despite being mounted in plastic, as explained below.
The first example (tctct2-frame-open-mini.png) accomodates a 10x16 array of 160
pins in roughly the same finger plate area as the standard Optacon display.
With a horizontal pitch of 1.5mm and a vertical pitch of 1.8mm, this layout is
not really appropriate for Optacon-like reading use (vertical resolution is
relatively low) but it may be an attractive alternative for the 'mobile'
version proposed before. Smaller versions with lower vertical resolution (e.g.
10x10, 100 pins, just covering a fingertip) may be more suitable for low cost
and low power applications.
Disadvantages of this first design are resolution and power limitations, and
high precision manufacturing requirements due to the actuator packing density.
Also, interconnect cost will be high because of the curved actuator array
without a common node available, requiring two connections per actuator.
The next design (tctct2-frame-open-mini-wide.png) improves resolution by
increasing width rather than height, intended for use with more than one finger
at a time. The example in the image has the same pin pitch as before but has a
less curved finger plate and is rotated 90 degrees. With 28x14 pins at
1.8x1.5mm it provides for 392 pins on a 48.6x19.5mm active area, usually enough
for 3 fingertips.
This arrangement has several advantages besides an obvious higher overall
resolution. Pin pitch is smaller in vertical direction now (like Optacon
displays), and even though the density is lower than an Optacon display it
covers a larger total area, all of which consists of the most sensitive part of
fingertips. Because of this I expect this display to perform quite well at
lower power and frequencies. Like the previous design, it still requires a high
precision plastic part and interconnect cost will be high.
Cost (including precision and interconnect requirements) can be brought down by
moving to a flat lower density display as shown in the third image
(tctct2-frame-open-mini-flat.png). This example has a 24x10 array of 240 pins
on a 46x18mm active area display similar to the previous one. The lower density
allows for somewhat higher efficiency coils, mounted on a lower precision, more
heat resistant plastic frame, which allows driving at high power. Also, with
actuators mounted in a flat plane coil contacts can be made to fit a printed
circuit board below to simplify assembly.
This last frame design is quite a departure from the Optacon standard layout
but seems promising: it is relatively high resolution yet low cost, suitable
for high and low power modes, and has a simple low profile construction.
I am calculating costs for the various designs, will post on that soon!
Signatures for reference:
tctct2-frame-open-mini.png:
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJVbMxBAAoJEFRnUmrjvQPl7H8H/2fe6V79GtGgQLqivL3Z1FoX
lBSwuP6qiB78pmXcjdH5X0M8u20eUOYCEOarkvIEkKrSXtMr3p3SKoENytbUa82I
z8Or9/EACkMF9fITSm1FzK1O1N9yj8F+5SNc0S/Y6CrJPp/XBH4HlPaF9l0NrEYk
QDN8F53y1FxfSQ15gv1QSi3GYh4K+YRwQrlTKWhm9uoi1dIv6Wrg7t+70vjkxlUp
igDhrWLjd7vSArLpZK2xuMvvzASalq9PkQPhiloADSGvjHMSxPQMC8bqY85AADrN
qpAYizSJAchlfkMnW6KHyl9ZMVyAkF+ZlhfW++CWkMDtROcrxNkvfyWnMLUMDpI=
=pm2S
-----END PGP SIGNATURE-----
tctct2-frame-open-mini-wide.png:
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJVbMyBAAoJEFRnUmrjvQPlsxMH/14lzBJwEECvPX/b+MYi1Zpw
ueNS1CSi5KM7dyp/KF9UBiqgwQhZOb+MSTRrB0rwu+uJ6U8bvvLyHScLdhY4O3J+
gWOZ54RxtL5QomU3iNIHxXhSRhQqen7/Pmh9DoNBJUAYqI+QMtMX0kzw+76PevbY
EznetKoq52GBo9euHvFgCNCAsCsWI1clEml12BpYGBOak13GS34F1N1R2BSIx9MU
RWC1G3x17aadY2UK3Rxfy56gKjMrWq8INau2klqIr/hcgqc3pEa3S2LKv8W2VsdE
LM8pVI5faudbx/MD9YrHQsOZxW4gEXn6umLSPA94gs90Z/EI1kzDyWih25abm3k=
=SMwR
-----END PGP SIGNATURE-----
tctct2-frame-open-mini-flat.png:
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJVbMv6AAoJEFRnUmrjvQPlMSMH/jKYToLRiHyUq0y33E6nzTCn
iO8EyZ8oXjFHooghsTkbe00t0dPtDvmdwLQlbF+VyG+7+NfGAIy70K2F9AWsYc30
M5/Te/dbUCKhsYn9DpwGYODJHYR31gS6WyNw1Zgkg9d17UCzBlgeoodmte+g/1Zz
AYxC0jy/7Kr8P4RRw2n7EnUnbH1aI1PX6o0kpdARzMe1UjF/LJB7zoBQgO24s37M
9L38Y4ZUtXfkjIT0M+AOdJF83nBhMFMEDEf7w0joSZRBQ1uPIDo6CwZRox4gOK9F
bmuekh6/s2V6MyPWuWRKX06TT9kD6liX1Hx5UN8jRiS61H1ECe32zQyFRTvSpLs=
=Llbp
-----END PGP SIGNATURE-----
tctct2-frame-open-mini.pdf:
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJVbMwhAAoJEFRnUmrjvQPlSUMIAI8jELLhyQDbdBzHterCf9/f
ShYhDwipoF0rg1rvvyncFxN3qfPsAEqU8X51Rc/yBdUpSufoob9eiws0nw4qHfNo
0PpydJOK10+/qqm7laNdeLAGXaVIiYVSWVtGY6yMeWN77MMp5clTO2CYheKt0PmL
2jAbtyZcENLaI/UMTHA0MD28NXNkySg/abtTGDdSx7ANACmjQSxhPZSE8x55GqUC
iZwASsM1pfXFUwy8A3Jhxq1c97ZVf1XQ0ADPgp4+vHGHX+Qq1w+Iity3CZXTcBLh
E+RK+izr9pG/Or5kHoqVCREg5fStqfMmug6vlHtazmamvmOAbxxnQu97phRFt64=
=6MZp
-----END PGP SIGNATURE-----
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.
