Capacitive And Resistive Touch Systems

A touch screen is an electronic visual display that can detect the presence and location of a touch within the display area.


Resistive Touch Screen
A Resistive Touch Screen panel comprises several layers, the most important of which are two thin, transparent electrically-resistive layers separated by a thin space.

These layers face each other, with a thin gap between. One resistive layer is a coating on the underside of the top surface of the screen. Just beneath it is a similar resistive layer on top of its substrate. One layer has conductive connections along its sides, the other along top and bottom.




Capacitive Touch Screen
A capacitive touch screen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO). As the human body is also an electrical conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field, measurable as a change in capacitance. Different technologies may be used to determine the location of the touch.The location is then sent to the controller for processing. Unlike a resistive touch screen, one cannot use a capacitive touch screen through most types of electrically insulating material, such as gloves; one requires a special capacitive stylus, or a special-application glove with an embroidered patch of conductive thread passing through it and contacting the user's fingertip. This disadvantage especially affects usability in consumer electronics, such as touch tablet PCs and capacitive smart phones in cold weather.