touch screen with ir and bs2?

markmcleod50

I'm a sculpture grad looking to create a huge, possibly 10 feet by 6 feet transparent touch screen without mortaging the house. I was thinking of somehow using multiple x y ir detectors and running those to the basic stamp. I want to have "objects" projected on to the screen and when the viewer touches their finger/hand to the screen it will change, just like an atm or wedding registry machine, only bigger. Real touch screens use transparent pressure sensitive conductors so if anyone knows about this that would be helpful too. I have very little electrical knowledge, so any suggestions, please dumb it down. Any ideas on how I might do this the easiest and cheapest way? thanks! mark

Jon Williams

10' x 6'? -- zoiks, that's going to take a lot of sensors. What kind of resolution are you looking for? If you want to sense a single finger width, I think you're going to need somewhere on the order of 576 IR detectors! (estimating about 3 per inch along one x and one y side).

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Jon Williams
Applications Engineer, Parallax
Dallas Office

allanlane5

Hmm, a scanning laser and a whole bunch of IR receiving diodes?

There are several ways of doing this. One is to have an 'X' axis emitter, and a 'Y' axis emitter. Then you put a whole lot of recievers in holes along the frame. When the 'X' emitter is on, check the 'shadow' of the person's finger against the receivers. Of course, the 10' distance makes this a problem, for anything except MAYBE a laser-emitter.

I suppose the 'shadow' cast by a laser would have as little scatter as the laser itself, so that might be ok. Still, a finger is a hard thing to sense.

markmcleod50

when you say x emitter what exactly are you talking about? has anyone heard of using a basic stamp with another program say flash or being able to take the inputs, the touch from a finger to point to certain chapters as on a dvd? would an ir emitter and detector work across 10'? thanks for all the help.