a blog from CenturyLink

How do touchscreens work?

by | Sep 19, 2022


Many of the devices we use today have touchscreen technology. From our phones to tablet and computers to smart home devices, we use touchscreens every day. In fact, touchscreen technology improves input accuracy and input speed by twenty percent. This means touchscreen users make twenty percent fewer mistakes and can perform touch commands twenty percent more quickly than traditional devices that don’t have a touchscreen.

Even though we are swiping and tapping touchscreens all day, do we really know that much about them? Touchscreen technology effects our daily life, but what exactly is it? And how does it work?

What are touchscreens?

Woman using touchscreen

Touchscreens are display devices that allow you to interact with a computer using your finger or a stylus. They can be a useful alternative to a mouse or keyboard for navigating on tablets, computers, smart phones, cash registers, and kiosks. Your finger acts as the cursor of a mouse to select icons and perform actions on the screen.

In 2007, Apple was the first company to successfully launch a touchscreen smartphone. Since then, touchscreen technology has continued to become more popular and improve. Now, we have multitouch screens, where multiple motions can be made with one or two fingers. In the future, we will likely have multiuser screens so many people can interact on the same screen at one time.

How do touchscreens work?

Some touchscreens use infrared beams to sense your finger, while others use touch-sensitive input based on the pressure of your finger. While there are several different types of touchscreens, the three main types are infrared, capacitive, and resistive.

Infrared touchscreens

Woman using a touchscreen to order a coffee

So how does infrared touchscreen technology work? The screen detects interruptions of infrared beams emitted by LEDs embedded in the frame around the screen. Infrared LEDs line the display’s edges, one vertical and one horizontal, while the other two edges are lined with light sensors. When an opaque object (like your finger or a stylus) touches the screen, it blots out the beams. The LEDs detect this and send the signal to the processor, which responds with the relevant action.

These types of touchscreens are popular because they’re cheaper to manufacture, support multi-touch and 4K resolution, and are scratch-resistant thanks to a glass overlay. You can also write on the screen with any object, including fingers, gloves, or a stylus—as long as it is not transparent.

Capacitive touchscreens

When two conductive objects touch each other, they share their respective electrical charge. This is the principle that capacitive touchscreens use to detect touch commands. These touchscreens generate an electrostatic field. When you touch the screen, your finger will draw some of its electricity, which lowers the electrostatic field. The screen identifies this electrical reduction as a command.

Capacitive touchscreens are popular due to their ability to respond more quickly to commands than other touchscreens. You can gently place your finger on the screen to perform a command, rather than pressing or tapping with more force. Since they don’t contain moving parts to detect commands, they’re exposed to less stress during use. This is why capacitive touchscreens typically last longer and are more durable than other types of touchscreens.

Resistive touchscreens

Resistive touch screens are made of layers that are resistive to touch. A glass or hard plastic layer is blanketed by a metallic layer that conducts charge. The layers are separated by spacers in the screen so when your finger presses the plastic, the two layers make contact, signaling the software to respond.

Because of the thick layers, resistive screens aren’t as bright and their interface appears darker than capacitive screens. They tend to be more durable and affordable than capacitive screens, thanks to that hard plastic outer layer. So you’ll see resistive screens used in self-service technology, such as ATM machines, self-checkout, and point-of-sale (POS) terminals.

How to use a touchscreen

Woman in a mask using a touchscreen

It’s important to remember that not all touchscreens have the same abilities. However, most touchscreens have the following functions:

Tap: A touch or tap on the screen with a finger opens a file or makes a selection. A tap is the same as clicking with a mouse on a traditional computer.

Double-tap: A double-tap has different functions depending on where it’s performed. Double-tapping the screen functions as a zoom. And double tapping in a text editor selects a word or section of text.

Touch and hold: Pressing and holding your finger to a touch screen selects or highlights an object. You can touch and hold an icon to drag it around the screen.

Drag: By pressing and holding your finger on a movable object, you can pull the object to a different location. This same action lets you highlight text.

Swipe: Swiping your finger across the screen allows you to scroll in a certain direction or change pages. Pressing your finger at the bottom of the screen and swiping will scroll the screen down.

Pinch: Placing two fingers on the screen in different spots and pinching them together zooms in. Pinching your fingers together and moving them away from each other zooms out.

The future of touchscreens

As technology continues to develop and expand, we can look forward to new and improved touchscreens for our devices. Proche predicts the future of touchscreen technology includes OLED displays in foldable devices, improved virtual reality screens, increased multitouch technology, and self-capacitance touchscreens.

How often do you use touchscreens in your life? Leave us a comment below with your thoughts. Do you know how to clean a screen the right way?  Learn more with guides from CenturyLink.

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<a href="https://discover.centurylink.com/author/emilyr" target="_self">Emily Richey</a>

Emily Richey


Emily Richey is the Content Manager for the CenturyLink and Quantum Fiber blogs. A recent graduate of Pace University NYC, she's an avid reader and writer. She spends most of her free time in bookstores and cafes, seeking the perfect cup of coffee.