touch screen computers

[ketchupkid]

how do they work?! its like magic. im just curious because today i used the one in argos you can use to pay instead of going to the till and i just cant understand how it works. im not too technically minded so if someone could explain it in simple terms i would be eternally grateful x

[Postdog]

The old one's (years back) used to have sensors by the side of the screen forming a grid. depending on where you broke the grid on the x,y co-ordinates, they could tell where you were touching.

Didn't know about newer ones, so I found this on Wiki

http://en.wikipedia.org/wiki/Touch_screen

[tex8596]

postdog is more or less correct..the "gris is actually raised glass bumps in the screen. there very small, but you can feel them easy. SOme use light, but most use a statis electric field which is why when your hands are very dry, they don't work. There are presure screens which have millions of "switches" sandwiched between the display layers...they are more accurate but very expensive....you can buy a "touch adapter" for CRT or LCD/TFT screen (if fits over the screen) to allow touch usage (used mostly for disabled users)..they aren't bad, but fine usage is not possible (anyting less than a 75 pixel resolution) meaning you couldn't do anything more refined than the width of your finger...but for general button commands..there great...I have on on a windows media center machine..screw the remote or keyboard..just touch the screen to start movies!!!