Pressure as in Touchwindows and infra red (Touchit, Microvitec) are the common
types in school
Resistive, surface Acoustic wave and Capacitive are the most frequently found
in commercial and industrial settings.
Resistive touch technology:
Resistive touch technology consists of a glass or acrylic panel that is coated
with thin metallic electrically condictive and resistive layers. The metallic
layers are separated by invisible separator dots. A final scratch-resistant
coating is placed over all the layers for durability. When operating, an
electrical current moves through the metallic layers. When pressure is applied
to the screen the metallic layers are pressed together, causing
a change in the electrical current and a touch event to be registered at the
location touched. Because it is touch pressure that causes the touch event, the
user can be using any type of stylus, be it finger, gloved hand, credit card,
etc. The durability, affordability, and versatility of Resistive technology
makes it useful in a wide variety of applications. It is recommended for POS,
restaurants, informational kiosks, and more.
Advantages/Disadvantages
High touch resolution
Works with any stylus
Not affected by dirt, dust, water, or light
80 % clarity
Resistive layers can be damaged by a sharp object
Surface Acoustic Wave:
Surface Acoustic Wave technology is based on sending acoustic waves across a
clear glass panel. When a finger touches the screen, the waves are interrupted,
causing a touch event to be detected at that point. Because the panel
is all glass there are no layers that can be worn, giving this technology a
high durability factor and also high clarity.
This technology is recommended for public kiosks, or other high traffic indoor
environments, not for POS or restaurant use.
Advantages/Disadvantages
High touch resolution
High clarity
No-drift operaton, so doesn't need recalibration often
Must be touched by finger, gloved hand, or soft-tip stylus. Something hard like
a pen won't work
Not completely sealable, can be affected by large amounts of grease, water, or
dirt on the touchscreen
Capacitive:
works by locating change in capacitance on surface of screen
Advantages/Disadvantages
High touch resolution
High Clarity
Completely sealable
Must be touched by finger- will not work with any non-conductive input
Can be affected by electricity
May need re-calibration often
Mass multimedia (An American firm) do different touchscreen they don't seem to
be wildly expensive (http://www.touchscreens.com/index.html)
I saw in the HCCS Global catalogue (computer peripherals) a Magic Touch
pressure/touch touchscreen for 209 ukpds for a 17"
I rang them up but they weren't prepared to let me have one on spec to try
(sale or return).
Perhaps someone with more economic clout could try.
Isn't a touchscreen survey a job NCET could usefully do ?
I'm convinced of its potential as an access method for our pupils but as with
so much in education I think we've been made more trouble for ourselves by
going for a cheap solution. More and more I feel we should go straight for
industrial solutions, SEN in general needs the highest spec multimedia machines
with the highest quality software and peripherals.
and yes I know .....
I'm convinced (well almost) that touchscreen technology offers a really useful
input device for our pupils.
--
Richard Walter
email: richard.walter@argonet.co.uk
Web site: http://www.rmplc.co.uk/eduweb/sites/meldreth/
From: Angela Fryer <angela@citas.demon.co.uk>
On Mon 13 Oct 97 (21:07:13), Richard wrote:
> I have been asked by a colleague to find out if anyone has used the
> Touch IT touchscreen from SEMERC and if so how they have found it.
> Thank
Can I widen this to ask if anyone has used a particular make of touchscreen
that has proved successful.
I'm sure there are a number of commercial touchscreens that would probably be
initially more expensive but might be better than the ones common to education.
To start:
We mainly use touchwindows (membrane type) from Lindis. The main difficulty
being that they are always falling off the monitors however hard I try to stick
them on. Accurracy is o.k. mouse emulation is good (click/double click/drag).
They do require some pointing pressure to use (which with some of our pupils is
a difficulty). I have found they make quite a good kind of concept keyboard
turned upside down (and reversed in software).
We have also had a hybrid touchscreen (beam type) which when it worked was
excellent. It only fitted on a microvitec square monitor on an A3000 and set
itself up nicely with full mouse emulation. It did alter the run files of
programs which I don't like as a concept.
We have one TouchIT on a BBC which I haven't had much success with.
We have also got several microvitecs on BBC which I tend to move around as they
fade in and out of working.
Perhaps some of the built in ones (like on the chameleon) would be worth
looking at.
I'm sure I there was also one that was a touch sensitive plastic sheet that
stuck over the monitor but I can't remember who made it.
Does anyone know of any industrial suppliers ?
--
Richard Walter
email: richard.walter@argonet.co.uk
Web site: http://www.rmplc.co.uk/eduweb/sites/meldreth/
From: AnnMcD1@aol.com
To: richard.walter@argonet.co.uk
Date: Wed 15 Oct 97 (21:31:48)
Subject: Re: SENIT: Touchscreens
I have used it a little but was worried because the foam at the side ( that
fills the gap between screen and monitor ) was only fixed on with a sort of
double sided tape. This came off very easily and a child could easily stick
its fingers into the 'works'. If a child COULD do this they invariably WILL
do it!
Can't really comment on the operation of the Touch IT but I have suggested to
parents who were thinking of buying for BBC program use that they, at least,
tape it firmly to the monitor and thereby cover the potential gap.
From: jmunro@djsn.u-net.com (Jamie Munro)
To: richard.walter@argonet.co.uk
Date: Thu 16 Oct 97 (11:19:39 +0000)
Subject: Re: SENIT: Re: Touchscreens
Dear Richard
The leading industrial manufacturer I believe is MicroTouch Inc., they
produce touch screens for information booths and that type of thing. I
used one about 7 years ago on an Apple Macintosh and they were very good.
However, at that time, adding one to a monitor would double the price of
the monitor (and that was back when an Apple monitor was about =A3400!).
Fitting it wasn't easy either, the UK office did offer a fitting service
but rather bravely I decided to fit it myself. It took two of us two days
to do it and it involved cutting away parts of the internal chassis of the
monitor to fit the electronics inside. On the first attempt the screen
cracked as I tightened up the casing when we finished fitting it.
NOTE: We were both qualified technicians and I wouldn't recommend anyone who doesn't know what they are doing going in a monitor as it has a potentially lethal charge inside EVEN WHEN TURNED OFF AND UNPLUGGED!
To be fair, 7 years is a very, very long time in the computer industry and
I'm sure that prices will have come down and fitting will be easier.
MicroTouch used to have a UK office but I've lost the details. You can
find the US office on the web though.
(To declare my commercial interest we provide the Edmark TouchWindow for PC
and Mac).
Jamie Munro
------------------------------
Jamie Munro - UK Manager
Don Johnston Special Needs Ltd.
18 Clarendon Court, Calver Road,
Winwick Quay, Warrington WA2 8QP
01925 241642 (Fax 01925 241745)
------------------------------
From: Jennifer Taylor <jen@rushbed.demon.co.uk>
To: richard.walter@argonet.co.uk
Date: Fri 17 Oct 97 (09:48:49 +0100)
Subject: SENIT: Touchscreens
There is a completely different sort of touch screen that I've only seen
at exhibitions on PCs, but it looks wonderful. Its a platform that any
monitor stands on which calculates the screen position from the tilt it
dectects. These seem to stand up to pretty heavy exhibition use and I
think, three or four years ago were about two and a half times the price
of what we wre using,
Jen
***********************
Jennifer Taylor
Rushbed Cottage
Crawshawbooth
Rossendale BB4 8LX
phone/fax 01706 26659
jen@rushbed.demon.co.uk
***********************