How Does a Touchscreen Work
Almost everyone around you does have a smartphone. Although you can call it, it is no longer the most used function of this mobile. You use it to the app, snap chat, photograph, use the internet, and so on. To control all different applications, you just have to place your finger on the screen or swipe the screen. Useful!
In the early days of mobile phones, you could only call and send text messages with a mobile phone. To type a text, you had to use the number keys. If you pressed the key for the number 2 once you typed an ‘a’, twice it became a ‘b’ and after three times a ‘c’. Very clumsy. Later, there were also mobile phones with a separate keyboard, but of course, that took up a lot of space.
Smartphone with touchscreen
The great progress in all kinds of techniques made it possible to develop a new type of phone with a touchscreen: the smartphone. This phone offered all kinds of new possibilities. The keyboard became a projected keyboard that you could tap with your finger. The touch of icons was enough to start an application on your smartphone. For many generations of smartphones further, the touchscreens have also developed more and more.
Types of touchscreens
There are several types of touchscreens. The touchscreen that is in a smartphone or tablet is a resistive touchscreen or a capacitive touchscreen. A resistive touchscreen uses the difference in resistance at different positions of small wires that are on your screen. A capacitive display uses the principle that your finger can conduct current and cause charge to leak. We will take a closer look at both types of touchscreens.
With a resistive touchscreen, there are two wafer-thin transparent layers on top of the color screen with a thin layer of air in between. In one layer there are vertical threads and in the other layer horizontal threads. Together these threads form a grid. You can imagine that if you give the horizontal and vertical threads a number and letter, you can indicate exactly the location of each grid node, just like with a city map.
When you press the screen with your finger, the two layers come together with threads. To prevent multiple points from touching each other when pressing the grid, small spacers (insulating balls, see figure 3) have been placed between all grid points.