Touchscreens Type

Touchscreens enable users to interact with the visual display.There are three types of

touchscreen technology:

n Resistive—Two resistive material layers sit on top of a glass screen.When a finger,

n Capacitive—A charged material layer is overlaid on a glass screen.When a finger or

any conductive object touches the layer, some charge is drawn off, changing the

capacitance, which is measured to determine the location of the touch. Capacitive

touchscreens allow as much as 90 percent of the light through, although accuracy

can be less than resistive.

n Surface Acoustic Wave—This uses a more advanced method that sends and receives

ultrasonic waves.When a finger or any object touches the screen, the waves are absorbed.

The waves are measured to determine the location of the touch. It is the

most durable solution, but more suitable for large-scale screens such as automatic

bank tellers.

stylus, or any object applies pressure, the two layers touch together and the location

of the touch can be determined. Resistive touchscreens are cost-effective, but

only 75 percent of the light shows through, and until recently, multitouch was not

possible.