Screen

Touch screen working | How Touch Screen Works | Working of smart phone | How touch works in smart phone | Gorilla Touch working | capacitative touch 

An image which showing how touch screen sense touch

An effort of human mind . But this is all happening with technology. We land in an era where everything that can be possibly thought, can also be practically put into . And that too quite reasonably..!! Just move the hand or walk your fingers over a thing and it works. Now you are at Electro Physics . You will get complete knowledge about this technology.

What is touch screen

It is a type of electronic visual display screen which sense pressure . This type of screen designed such that it can sense the zone of pressure and to perform specific task. Now a days these screens are deployed everywhere for better user interface. Screens can be LCD and LED.

There are three types of touch screens we are going to discuss.

1. Resistive Touch :- Resistive touch screen consist mainly two layers one is top flexible layer of Polyethylene and a fixed bottom layer of glass .These layers are coated with a conducting compound-  Indium Tin Oxide.When the monitor is operational, current flows between the two layers. When a user touch the screen, the flexible screen presses down and touches the bottom layer. That leads to a change in current, which detected and the coordinates where touch is made calculated by the controllrer and parsed into readable signals for the operating system to react accordingly. 

Internal View of resistive touch screen

2. Capacitative touch :-  Capacitative touch also called Gorilla touch are different from the resistive touch and Unlike resistive touch screens, a capacitive screens do not work on pressure of your finger to change the flowing current. Instead, they work on the charge ,as a human body comprised of lot of charges (negative and positive) .A Capacitive touch screen is constructed from materials like copper or indium tin oxide because these materials are capable to store electrical charges in an grid of fine and tiny wires, and each of them is smaller than a human hair.

There are two types of capacitive touch screens – one is surface and other is projective. 

1. Surface capacitive screen uses sensors at the corners and a thin uniformly distributed film across the surface (as shown above) 

2. Projective capacitive uses a grid of rows and columns with a dedicated chip for sensing the touch area. In both instances, When a human finger touch the touch screen a small charge exchange between the body and the screen results in completion of circuit , you will amazed if you take a metal glass in your hand and touch the screen your  screen will respond , creating a voltage drop on that point of the screen and that voltage drop sense by the controllers to find out the touch area. That why if a user who wear gloves in his hand not able to perform action on the touch screen. If you want you can touch your screen with current carrying wire you will amazed that it will work.

                                

              As shown in the figure grids as X and Y coordinates 

Like us on facebook  :-  Click here