June 10, 2022
We all use touchscreens every day, it’s just so common that we don’t really pay that much attention to them. Just think about it – you use it when you’re typing out a text message, when you’re getting cash from an ATM, and when you’re adjusting the temperature in the office.
By now you’ve probably noticed the differences between particular modules – the response time, the required pressure, and even the different textures under your fingers.
The reason why each type of touch panel responds so differently is the underlying technology.
When you’re working on a project, and you want to choose the type of touchscreen for it, you should decide based on what environment and what circumstances the display will be used.
The three main components of every touch screen are:
You can choose between two versions from our shop: the capacitive and resistive touch panel.
The resistive touch panel
Let’s start with resistive touch panels.
The history of resistive touch panels starts in the 1970s. For years, that was the most common touch input technology. But it wasn’t just the number of years the resistive touch panels had over capacitive ones – resistive technology is cheaper than capacitive.
As the name of the technology suggests – the resistance measurement is what detects the touch. The pressure on the screen translates directly to a change in the Ohm value.
A resistive touch panel has several layers:
The conductive layers of ITO or Indium Tin Oxide (see the image above) are separated by spacer dots – that prevents them from touching one another while the touch panel is not being used. When a finger touches the panel, that space disappears, the layers detect the resistance change, and the coordinates of the touch are calculated.
The main advantages of resistive touch panels are:
Resistive touch panel disadvantages:
The capacitive touch panel
Capacitive touch panel technology relies on the capacitance of the human body, and not on pressure like resistive technology. There are two types of capacitive touch panels – surface capacitive and projected.
Both work on detecting the change of capacitance on the screen.
Capacitive touch panels are more often used for big surfaces, as they need less accuracy.
Let’s see how they work.
As you probably know, a thin glass surface covers capacitive touch screens. Under this glass surface, covered with a protective layer, lies a thin layer of electrodes. The electrodes on the corner of the panel provide the voltage for the thin film layer. When the finger touches the screen a small electrical charge is transferred to the finger, and the electrical circuit is complete. This creates a voltage drop on that part of the screen, and the touch is detected.
So, next time you’re starting a project, and you don’t know which type of touch panel to choose, check out this article. Think of what kind of environment the device will be in. If you are planning to use it in a more rugged, industrial setting, a resistive touch panel will work better, since you can use it with both gloved hands and a stylus.
If on the other hand, you’re planning the device for a more sophisticated application, a capacitive touch panel is our recommendation. With capacitive touch panels, multi-touch is not a problem, you can scroll with ease, and have excellent sensitivity.