How does a touch screen work?

Tim

At the local supermarket, they have some automated checkout counters, and they use touch screens for part of the process. I'm wondering how the screen knows where you touched it. I don't see any external things on the screen that might explain it.

TheSmJ

There are two grids of thin wires over the screen. When you press on the screen, these wires get touched together. By looking to see which wires touched, the computer "knows" where you pressed the monitor. By compairing this with whats on teh screen, it can see if there is a button at this position or not. If so, it presses the button, just as if you were to click it with a mouse.

BlackHawk

http://apprais.tripod.com/TIPS/30%20TouchScreens.htm

croc_

well I am no expert, but It prolly has a heat sensor grid behind the plastic front covering that senses where you press your finger, or a pressure sensitive grid.

edit: i am slow.

edcentric

One of the systems uses a single grid of coducting lines (not physical wires) and senses location by capacitance discharge.
some of the older systems actually used an IR system to detect where your finger was.

keto

I tried it with a cashier at my supermarket once, 2 polite and well dressed gentlemen took me away in a nice shiny sedan with no inside back doorhandles.

DogSoldier

There are emaciated hamsters on the inside of the monitor, they've been trained to reach for fingers as it was the trainers hands that fed them. When they touch the inside of the screen , there is a row of tiny buttons encased in a thin rubber membrane. It is these buttons that send the signal to the cpu.

gtghm

DogSoldier had this to say
There are emaciated hamsters on the inside of the monitor, they've been trained to reach for fingers as it was the trainers hands that fed them. When they touch the inside of the screen , there is a row of tiny buttons encased in a thin rubber membrane. It is these buttons that send the signal to the cpu.

ROFLMAO