Touch Screen Monitors

Displays with touch-screen technology let you input information or navigate applications by touching the surface of the display. The technology can be implemented through a variety of methods, including infrared sensors, pressure-sensitive resistors or electronic capacitors.

Touch screen monitors usually come in three varieties that enable it to recognize a person's touch. These are resistive, capacitive and surface acoustic wave. The resistive type works by having two panels with a thin space between them. When the user presses the screen, the two panels touch at that point, and the exact coordinates are then registered with the computer.

A capacitive system runs a small electrical charge throughout the touch screen. When the user touches the chosen area, some of the electrical charge is distributed to the finger, lessening the charge at that location. The coordinates are again recorded and sent to the computer. This type of touch screen produces a clearer picture because it transmits more light and doesn't require two panels.

Finally, the surface acoustic wave system is the best, and results in the clearest picture. Transducers are used to send electrical signals across the screen, and if a user touches the screen, they can determine where based on how the electrical signal is received from one transducer to the other.
Since the capacitive system must have a finger to absorb electricity, most non-living objects won't register as a touch. Resistive and surface acoustic wave systems on the other hand react to just about any form of pressure. Each has its different advantages as a result, and manufacturers will only find new ways to make use of them.