Monday, May 21, 2012

How Touch Screens Work....??

Capacitive Sensing Technology:

This is one of the most widely used techniques for touch screens. This technology is based on the capacitor coupling effects. It has been used in devices like MP3 players, computer monitors, mobile phone displays and so on. As this technology has advantages like detecting the correct position at a very small time, less cost in production, and also a very unique human—device interface, it is widely used. It also has properties like multiple touch sensing and also gesture based touch screens. The latest and most famous gadget to be released with this technology is the Apple i-Pod click wheel. This mechanism is more advantageous than the resistive sensing because it can transmit to a maximum of 90% of the light from the monitor. Thus a much better vision can be obtained from these screens.
Here also, a glass panel is arranged on top of which a layer that is able to store electrical charge is kept. When the monitor is touched by the user, the charge begins to move from the layer to our body. This decrease in the charge on the conductive layer is measured with the help of electronic circuits which are placed inside the monitor. As the electronic circuits are placed on each corner of the monitor the difference in charge attained at each corner is calculated by the computer and the exact position of the touch is obtained. This information is then passed on to the touch-screen driver software.