How Touchscreen Works ??

A touchscreen is an electronic visual display that the user 
can control through simple or multi-touch gestures by touching the screen with one or more fingers. Some touchscreens can also detect objects such as a stylus or ordinary or specially coated gloves.

Touchscreens are common in devices such as game consoles, all-in-one computers, tablet computers, and smartphones. They also play a prominent role in the design of digital appliances such as personal digital assistants (PDAs), satellite navigation devices, mobile phones, and video games.

Working of Touch Screen Are very Interesting. Here's How they Work:

There are three basic systems of Touch Screen:

1. Resistive System
2. Capacitive System
3. Surface Wave acoustic

The RESISTIVE SYSTEM consists of a normal glass panel that is
 covered with a conductive and a resistive metallic layer.
 These two layers are held apart by spacers, and a 
scratch-resistant layer is placed on top of the whole setup.
 An electrical current runs through the two layers while the
 monitor is operational. When a user touches the screen, the
 two layers make contact in that exact spot. The change in
 the electrical field is noted and the coordinates of the point
 of contact are calculated by the computer. Once the coordinates 
are known, a special driver translates the touch into
 something that the operating system can understand.

Working Of Resistive Touch Screen !!!

In the CAPACITIVE SYSTEM, a layer that stores electrical charge 
is placed on the glass panel of the monitor. When a user touche
s the monitor with his or her finger, some of the charge is 
transferred to the user, so the charge on the capacitive layer
 decreases. This decrease is 
measured in circuits located at each corner of the monitor. The 
computer calculates, from the relative differences in charge at
 each corner, exactly where the touch event took place and then
 relays that information to the touch-screen driver software.
 One advantage that the capacitive system has over the resistive
 system is that it transmits almost 90 percent of the light from 
the monitor, whereas the resistive system only transmits about 
75 percent. This gives the capacitive system a much clearer
 picture than the resistive system

Working Of Capacitive Touch Screen !!!

The SURFACE WAVE ACOUSTIC SYSTEM works with help of wave energy.
 This enables a touch to transform into another form of energy and deliver the command which in response perform the desired action. A Pair of
 transducers is placed on glass plate sides. In the Glass Plates 
there are reflectors. On touching the screen wave produced and
 which transforms into energy for fulfilling the command. It tells where on the screen touch is detected.

Working Of Wave Acoustic Touch Screen !!!