The beautiful technology of touchscreen.
Resistive: This is a kind of touch screen that consists mainly of two resistive layers that are separated by a gap in between them. There is conductive connections in both the layers where one layer has conductive connections on top and bottom portions while the other layer has conductive connection on right and left of it. When the touch screen is pressed then the two layers come in contact. The panels that are connected seems to act like voltage piders after the touch. The two conductors that are connected in sideways and top-bottom position send signals to the brain of the electronic device and asks it to do what the user intends to.
SAW (surface acoustic wave): In this technology of touch screen ultrasonic waves are passed over the touch screen panels continuously. When a user touches the screen then some of the ultrasonic waves that have been passing gets absorbed by the touch screen. This absorption cause the electronic device to send electric impulse to its processor and thus the desired objective is performed.
Capacitive: The capacitive touch screen consists of an insulator coated with a transparent conductor. As we all know that our body is also a good conductor of electricity so when we touch a capacitive touch screen then the electric field of the conductive layer gets distorted and thus impulses are sent to the control room of the device to get processed.
Surface capacitance: Unlike capacitive touch screen the surface capacitance touch screen is not fully coated with the transparent layer of conductor but rather only one of its side is coated with the transparent conductor layer. When the layer that is not coated is touched then the dynamic capacitor is formed and the sensors can detect the position of the touch.
Dispersible signal technology: This system is a very simple and old fashioned one and depends on the electricity that is produced when human body comes in contact with a glass. The impulse that is produced after the electricity is produced is passed along and complex calculations are made in the brain of the device to identify the location of the touch.
Infra-red: The infra-red system touch screen system consists of numerous infra-red rays emitter in the X and Y plane,The rays cross each other at several points. So when the screen is touched it becomes very easy for the detector to detect the exact location of the touch.
The innovations and ideas in the field of touch screen is simply amazing. It might be a simple advancement in technology but it certainly has made things look smart and fast.