Topic 7

7.1 - Touchscreens

Touch screens work by using the natural electricity properties embedded in humans. Touch screens such as iPod touches use a layero f capacitors under a protective covering. When your skin touches one of these surfaces, the amount of charge it holds changes.

The iPod's can use one of two methods to register the electrical changes, the first being circuitary mointoring of changes in an array of electrodes, and the second, a layer of driving lines carries current, and a separate line detects changes in electrical charge.

When the charge is changed (ie you touch the screen) - The iPod records the change and mathematically pinpoints where your fingers are on the screen.

The iPod touch's processor keeps track of where you put your fingers and where they move once you've placed them on the screen. You can slide your fingers from place to place, or you can make pinching or spreading motions to zoom in and out. The iPod touch matches what your fingers are doing with what's happening on the screen:

* The iPod touch determines the shape, size and location of your finger -- or fingers -- on the screen.
* The device uses gesture software in its memory to classify your touch. It takes into account whether your fingers move and what your iPod is doing at the time.
* The processor sends instructions to the iPod touch's display, software and hardware based on the data your fingers create.

The touchscreen would be great over any other device when you are travelling in a car and trying to use a GPS. you do not want to be searching for the right buttons, or anything, you want GPS to be as hands free as possible. by being able to pinch the screen and slide fingers around it could make navigation much simpler!