How do Touchscreens Work?

TOUCH TECHNOLOGIES Here are some technologies that are used in making touch screens: Resistive Capacitive Surface Acoustic Wave (SAW) Scanning Infrared Near Field Imaging

Resistive touch screen Made of a glass panel with a coating of uniform resistivity on which a voltage is applied.

A polyester cover sheet is tightly suspended over the top of the glass, separated from it by small, transparent insulating dots

The cover sheet has a hard, durable coating on the outer side and a conductive coating on the inner side.

With a light touch, the conductive coating makes electrical contact with the coating on the glass.

The voltages at the point ofcontact are the analog representation of the position touched.

The controller digitizes these voltages and transmits them to the computer for processing.