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How Do Touchscreens Work?

Kundan Pandey Aug 25, 2020
Touchscreen phones have become the choice of today's generation. Knowing their working process is extremely interesting.
Touchscreens have become the most popular interface between computers and their users. Owing to the comfort they provide, they are used in a variety of applications, like computers, mobile phones, and video games.
In essence, a touchscreen is an input device, and for it to function effectively, a display is required. Just a touchscreen is of no use unless it is installed with peripherals like a PC monitor and the required software. The main parts that constitute these are:
  • Touch Sensor
  • Controller
  • Software Driver
  • Computer/Laptop/Other Devices
Touchscreens are similar to monitors, wherein they have a bezel or an overlay on the screen. They, in the first step, act as a computer monitor. When the screen is touched, the sensitive layers on the screen are designed to convert the touch into a signal, as the layers transfer electrical signals between each other.
The signal usually is identified by various sensors that are installed. The touch driver on the screens identify your touch, similar to the cursor of a desktop mouse.

Working of Touchscreens

In essence, the touch drivers are like the computer mouse. Generally, left click mouse button functions are performed by touching the screen. The only disadvantage is you can't use the touchscreen to right click, as done by a conventional mouse. If you're playing games or using any software, then it won't identify if your using a mouse or just your fingers.

Resistive Touchscreens

Considered to be the most innovative touchscreen technology, resistive technology can be called a transparent keyboard. There are two layers under the touchscreen, the upper layer of polyester and the lower one made of glass.
When you touch the screen, the polyester is touched and it completes the circuit, thereby sending corresponding signals. The integrated chip in such screens help in figuring out the specific area on the screen or buttons you touch.

Capacitive Technology

These touchscreens are made of many layers of glass and it acts like a capacitor, creating electric fields between glass plates and conducting the signal. When the fingers are brought close to the screen, the electric field varies depending on the touching position on the screen.

Ultrasonic Sound Beam

In these type of touchscreens, ultrasonic sounds are used instead of light. The ultrasound frequency is generated from the edges of the screen and when we touch the screen, the sound is interrupted and the signal is established.

Near Field Imaging (NFI)

In military and other places where it is difficult to intercept signals, NFI employs the principle of electromagnetic interference. NFI responds to the change in the electrical field of glass plates. When we bring the fingers close to the object, the electric field changes and so it registers our touch.
For example, electromagnetic waves of a radio are affected when we place our hands or body in front of a radio. Similarly, in this technology, the closer your hand is, the larger the effect will be.
With innovative technologies making their way into the electronic market, it won't be surprising that in future, the mouse will become non-existent.