How TouchScreen Works??

These days TouchScreen cellphones are common among people,Touch screen technology has made the human life one step more advanced.These tech screens replaces the old dull buttons.A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area. The term generally refers to touching the display of the device with a finger or hand. Touchscreens can also sense other passive objects, such as a stylus. Touchscreen is common in devices such as all-in-one computers, tablet computers, and smartphones.


Touch screens are of Two types-

1. Capacitive Touch Screen
2. Resistive Touch Screen

In this issue we will explain the working of these touch screen technologies-


Capacitive Touch Screen-

This technology is costlier one,this is quite better than resistive tech.,Its response time is much less than resistive ones.
Lets have look on its working-
A capacitive touchscreen panel is one which consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO). As the human body is also an electrical conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field, measurable 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. Unlike a resistive touchscreen, one cannot use a capacitive touchscreen through most types type of electrically insulating material, such as gloves; one requires a special capacitive stylus, or a special-application glove with finger tips that generate static electricity. This disadvantage especially affects usability in consumer electronics, such as touch tablet PCs and capacitive smartphones.


Resistive Touch Screen-

This technology is quite cheaper.its only cons is its response time.You need to apply much pressure on the screen to operate it,Let's have a look on its working-
A resistive touchscreen panel is composed of several layers, the most important of which are two thin,electrically conductive layers separated by a narrow gap. When an object, such as a finger, presses down on a point on the panel's outer surface the two metallic layers become connected at that point: the panel then behaves as a pair of voltage dividers with connected outputs. This causes a change in the electrical current, which is registered as a touch event and sent to the controller for processing.In other words-A touch screen is a 2-
dimensional sensing device 
that is constructed of 2 sheets of material separated slightly by spacers.  A  common construction is a sheet of glass providing a stable bottom layer and a sheet of Polyethylene (PET) as a flexible top layer.The 2 sheets are coated with a resistivesubstance, usually a metal compound called Indium Tin Oxide (ITO).  The ITO is 
thinly and uniformly sputtered onto both the glass and the PET layer.  Tiny bumps called spacer dots are then added to the glass side, on top of the resistive ITO coating, to keep the PET film from sagging, causing an accidental or false touch.When the PET film is pressed down, the two resistive surfaces meet.  The position of this meeting (a touch) can be read by a touch screen controller circuit.For detailed look on capacitive touch screenClick Here


SHIVAM GAUTAM-
Founder-ShivamSoftwares & Company™