Technologies
There are a variety of touchscreen technologies with different methods of sensing touch.The Main Categories are as following
Resitive :
This was technology was used in early times. This Was Reall Push Hard Technology.A resistive touchscreen panel contains several thin layers, the most important of which are two transparent electrically resistive with a thin gap between layers facing each other. The top layer ( which is touched) has a coating on the underside surface; just beneath it's a similar resistive layer on top of its underlying layer. One layer has conductive connections on its sides, the other has along top and bottom. A voltage is applied to one of the layer of touchscreen panel, and is sensed by the other. When any object, such as a fingertip or touchpen etc. , presses down onto the outer surface, the two layers touch to become connected at that point. The panel then behaves as a pair of voltage dividers, one axis at a time. By rapidly switching between each layer, the position of pressure on the screen can be determined.
Capacitance :
This is the technology we are using now a days.
A capacitive touchscreen panel consists of an insulator ( that does not allow current to flow through ), such as glass, coated with a transparent conductor ( that allows the current to flow through ), such as indium tin oxide(ITO). As the human body is also an conduct electricity, when human touches the surface of the screen results in a distortion of the screen's electrostatic field,which is then measured 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. By which the processor understand the surface where the screen was touched.Written By
Bhai Loog
External Links : WikiPedia
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