The touch screen is an electronic visual display that is able to detect the presence and location of any touch within the display area. The term itself usually refers to touching the screen with your finger or hand. The touch screen is able to detect the touches of other passive objects as well, such as the stylus. The reason why the touch screen is so popular is because it lets the users directly interact with what is displayed on the screen, without the need of using a mouse or a trackpad.
Not only that you do not need a trackpad but you do not need anything at all, you don't have to hold anything in your hand, which is a huge advantage and it makes the touch screen devices faster and more "handy" when they are used. A touch screen can be attached to a computer or network as a terminal. The touch screen also plays an important role in the design of digital appliances such as the PDA, the satellite navigation system and the video games. In terms of touch screen technologies, there are many from which you can choose such as the resistive touch screen.
The resistive touch screen is composed of several layers. The most important layers are two thin layers divided just by a narrow gap which are electrical conductive . When you touch the screen with your finger, these two layers get connected in that spot, and make the entire panel act like a pair of voltage dividers with connected outputs. The touch produces changes in the electric current and registers the action as a touch event. After that, the information is sent for processing.
Surface acoustic wave touch screen technology refers to a type of touch screen that uses ultra sound. When the screen is touched, a part of the ultra sound wave is absorbed, and when the device senses changes in the ultra waves, it registers it as a touch event and it sends it to the controller for processing. The bad part about this kind of touch screens is that it is easy influenced by outside elements, and any type of contamination on the screen's surface make it hard to use.
The capacitive touch screen is a single panel made from an insulator such as glass, and a conductor such as ITO. ( "ITO" stands for Indium Tin Oxide). Because the human body is also an electrical conductor, touching the screen leads to changes in the panel' s electrostatic field. Different technologies may be used to help these changes be registered as touch events.