Touch screens are becoming more and more prevalent today, especially with the advent of Apple’s iPod touch. What the iPod touch and the iPhone have done is to bring the touch screen technology to the masses and make them comfortable using it. Not all touch screens on the market offer the multi touch functionality that Apple features in its devices. The majority of them function in same manner that they would if they were being used with a mouse. This is an explanation of a basic touch screen system.
To function accurately a touch screen needs three components:

1. A touch sensor – this is placed over the viewable that the user operates. Although many technologies are used in the sensor mechanism, they all are variations of one method. The sensor is has a minute electrical current running through it which is disrupted when a finger is placed on it. This difference in the voltage is then processed to locate the point of contact on the screen.

2. The controller – This hardware converts signals from the touch sensor into data. With touch screen built-in monitors, the controller would be an internal device. However, if you purchase a touch screen kit, the controller would be located externally as a small device. All controllers connect to the PC via COM or USB ports.

3. The software driver – This software sits on the OS and takes in signals from the controller. It then emulates a mouse and sends the data to the OS, which proceeds to act as if a mouse is being used.