How Does A TOUCHSCREEN Phone Work?

There are three different types of touchscreen phone technologies available: resistive, capacitive, and infrared. 

INFRARED(heat sensitive and optical)
 HTC Diamond and LG Viewty.
 Apple iPhone, and the HTC Desire. 
 Samsung SGH-E900 and Samsung U600
The conductive and a resistive metallic layers are separated by spacers, when the top layer pushed into the lower, electrical current changes and location of impact is calculated.
The current is broadcast from the corners of the screens, touch of finger transfer the current and with the help of corners change in current is calculated to find the location.
The Infrared System is much like capacitive screens, it is resistant towards dust, moisture and scratches
A layer of flexible material(polyester film) over a layer of glass
Stylus, Bare fingers or gloved fingers
Bare fingers only
Optical: Stylus, Bare fingers or gloved fingers
Heat-Sensitive: Warm, Bare fingers
Poor Visibility
Good Visibility
Good Visibility, strong ambient light impacts productivity and precision.
Fair Durability
Screens are very susceptible to scratches and other minor damages. Need to replace over time.
Good Durability
Screens break upon major impact only.
Good Durability
Screens break upon major impact only.
Resistive System transmits almost 75 percent of the light from the monitor.
Capacitive System transmits almost 90 percent of the light from the monitor, helps in clearer picture.
Infrared System transmits almost 92 percent of the light from the monitor, helps in clearer picture
The average lifespan of resistive touchscreens are about 35 million clicks. 
Capacitive touchscreens boast an extremely long life of about 225 million clicks.
It has an average lifespan of about seven years.

The touchscreen phone technology, resistive system is composed of a normal glass panel, covered with a conductive and a resistive metallic layer. These two layers are separated by spacers, and a scratch-resistant layer is placed on top of the whole setup.
An electric current run straight through these two layers, and monitor instrument is used for continuous observation and keeping record.
When a user touches the screen, coordinates of the point of contact between a conductive and a resistive metallic layer is calculated by computer based on the change in the electric field.
Now the coordinates are translate by an interface drivers that operating system can understand to make decision.

The touchscreen phone technology, Capacitive System has a layer on top of the monitor that stores electric charge, when a user touches the layer with the fingers some of the charge 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 and the relative difference in charge is calculated to find exact touch event location. Information is then received and passed to the touchscreen driver software which translates it to operating system understandable to make the decision.

The touchscreen phone technology, Infrared System is much like capacitive screens, it is resistant towards dust, moisture and scratches and is best of all others in terms of durability but most expensive too. 

Infrared touchscreens phone technology consist of two types: optical and heat-sensitive.

The optical uses infrared beams, invisible to the naked eye and worked using a number of sensors, arranged above and around the screen, forming a grid of invisible beams. If an object such as a finger or stylus touches the display, it interrupts the rays in a certain area, thus determining the point of touch.

Heat-sensitive type infrared touchscreens are more commonly used among the two, the best example for this particular type of touchscreen is the Samsung SGH-E900 and Samsung U600, which can only be interacted with heat emitting objects.


Hi there, You've done an incredible job. I will definitely digg it and personally recommend to my friends. I am confident they'll be benefited from this website.
Feel free to visit my blog ... iphone parts replacement

thanks a lot for such wonderful words for us, we will keep sharing such articles...

Thank you for your great posting.

This is great. May I use in my 8th grade science class? It helps them get motivated in electricity and how things work.

Mr H

The post shared here in purpose of knowledge share, It is great to listen you wanna share with the science students.

Does this mean that the heat-sensitive screen can, over time, become sensitive and dysfunctional with various environmental changes in temperature?

Post a Comment