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From: mzenier@polari.UUCP (Mark Zenier)
Newsgroups: sci.electronics
Subject: Re: touch screen for crt display?
Message-ID: <4140@polari.UUCP>
Date: 19 May 91 05:58:07 GMT
References: <1656@fs1.ee.ubc.ca> <1991May18.025326.375@ddsw1.MCS.COM>
Organization: Seattle Online Public Unix (206) 328-4944
Lines: 28

In article <1991May18.025326.375@ddsw1.MCS.COM> whos@ddsw1.MCS.COM (Ben Feen) writes:
>In article <1656@fs1.ee.ubc.ca> jthornto@ee.ubc.ca (Johan Thornton) writes:
>>Does anyone know either >>- where to get >>- how to build
>>a clear touch screen to fit over a monitor.  It doesn't have to have
>>to have very high resolution--4 by 4 would be ok.

>Touch screens are not touch-operated, or at least the HP screens I've seen

Fluke made a crt display with a touch switch array over the screen.
It was all clear plastic film.  Either the wires were very small
or the x/y "wires" were thin films.

>The wires idea is cute, but there are two problems:

>1:  You'd have to prevent the "X" wires from shorting with the "Y" wires,
>but still have them close enough to touch two at once.

Little bumps in the film layers kept adjacent switch positions isolated.

>2:  Who wants wires on their screen?

There was another touch screen (Marconi?) that had fixed postions
with two parallel wire segments on the surface of the glass.  
The operator touched the two wires.  Since this was an air traffic 
control application, they must have relied on the conductivity of 
sweaty fingers.

Mark Zenier  markz@ssc.uucp  mzenier@polari.uucp