Touch screen

Updated: 06/30/2019 by Computer Hope
Touch screen

A touch screen is a display device that allows the user to interact with a computer by using their finger or stylus. They can be a useful alternative to a mouse or keyboard for navigating a GUI (graphical user interface). Touch screens are used on a variety of devices, such as computer and laptop displays, smartphones, tablets, cash registers, and information kiosks. Some touch screens use a grid of infrared beams to sense the presence of a finger instead of utilizing touch-sensitive input.

Touch screen history

The idea of a touch screen was first described and published by E.A. Johnson in 1965. In the early 1970s, the first touch screen was developed by CERN engineers Frank Beck and Bent Stumpe. The physical product was first created and utilized in 1973. The first resistive touch screen was developed by George Samuel Hurst in 1975 but wasn't produced and used until 1982.

How do you use the touch screen?

Note

Not all touch screens have the same functions, but the actions below are the most common.

Tap - A single touch or tap on the screen with a finger opens an app or select an object. When compared to a traditional computer, a tap is the same as clicking with a mouse.

Double-tap - A double-tap can have different functions depending on where it is utilized. For example, in a browser, double-tapping the screen zooms the view, centered at the tap location. Double-tapping in a text editor can be used to select a word or section of words.

Touch and hold - Pressing and holding your finger to a touch screen selects or highlight an object. For example, you could touch and hold an icon, and then drag it somewhere else on the screen. See our long press page for further information on this term.

Drag - If you press and hold your finger on an object (such as an app shortcut) on the screen, you can move your finger to "pull" the object to a different location. The same action, used with text, allows you to highlight text. Lift your finger when you are done moving or highlighting.

Swipe - Swiping your finger across the screen can be used to scroll in a certain direction or change pages. For example, pressing your finger at the bottom of the screen and quickly moving it up (swiping) scrolls the screen down. See our swipe page for further information and related links.

Pinch - Placing two fingers on the screen in different spots and then pinching them together zooms in. Pinching your fingers together and then moving them away from each other, zooms out on the screen. See our pinch-to-zoom page for further information on this term.

Why is a touch screen an input device?

Any computer device (including a touch screen) that takes input from the person operating the device is considered an input device. When you touch your finger on a touch screen to interact with an icon, text, or another object that is considered input because you're telling the computer what you'd like for it to do. Your finger is very similar to a computer mouse on a desktop computer, which is also another type of input device.

Note

Technically speaking, a touch screen is an input/output device. Not only is it capable of accepting input, but it also displays the output from the computer.

How is a touch screen different than a mouse?

A computer mouse and touch screen have many similarities. Many of them are mentioned in the how do you use the touch screen section above.

One of the most significant differences between a mouse and a touch screen is the ability to hover. Almost all touch screens can only detect input when your finger is in direct contact with the screen. However, a computer mouse uses a cursor that allows the user to view information by moving the pointer over an object, but not clicking on it. For example, this link to Computer Hope shows the text "Visit the Computer Hope Page" when hovered over using a computer mouse. However, a user with a touch screen cannot see this text because if they place their finger on the link, it opens the link.

Note

Some web pages and apps may simulate the hover feature by making the first tap do the hover feature and the second tap open the link or app. Also, some Apple devices use Force Touch, which can offer features similar to hovering.

Where are touch screens used?

Today, the touch screen is one of the most popular types of input devices. Below are some places and examples of where touch screens may be used.

Examples of touchscreens: smartphones, a tablet computer, and a point of sale device.

Why are touch screens used?

Below are some of the reasons a manufacturer may decide to use a touch screen in their products instead of another input method, such as buttons.

  1. Touch screens are intuitive and usually simpler to use.
  2. Having one touch screen instead of dozens of buttons can make a device smaller.
  3. Can be cheaper to design and manufacture a device with one screen instead of on with a screen and buttons.

Touch screen technologies

Not all touch screens are the same. Different technologies can be utilized to allow a user to interact with a screen. Some technologies may work with only your finger and other technologies may allow other tools, like a stylus. Below is a brief description of each of these technologies.

Capacitive

A capacitive touch screen is coated with a special material that stores an electrical charge that is monitored by circuits at each corner of the screen. When you touch a capacitive touch screen, a small amount of the electrical charge is drawn from the point of contact to indicate where you touched the screen.

To use a capacitive screen, you must use your bare finger or a specially designed capacitive stylus. Most users experience this type of screen technology when attempting to use a smartphone touch screen while wearing gloves and being unable to do anything.

Tip

There are specially designed gloves that allow one or more fingers to interact with a capacitive screen.

Resistive

A resistive touch screen is coated with a metallic electrically conductive and resistive layer that detects the pressure of your finger or another object. This technology is often a more affordable solution when compared to capacitive, but can be damaged by sharp objects touching the screen.

Surface acoustic wave

A SAW (surface acoustic wave) or surface wave touch screen sends ultrasonic waves and detects when the screen is touched by registering changes in the waves. This technology is more advanced than the other two, but does not work with hard materials that do not absorb the pulse and can be affected by outside elements.

Infrared

Infrared touch screens utilize a matrix of infrared beams that are transmitted by LEDs with a phototransistor receiving end. When a finger or other object is near the display, the infrared beam is blocked, and that interruption gives the device input to where your finger or another object is positioned.

Do touch screens have a keyboard?

To input letters and numbers, touch screens utilize a virtual keyboard that allows the user to tap the virtual keys with their finger. Also, devices like smartphones and tablets have voice recognition that can be used to input information into the device.

Is it "touch screen," "touchscreen," or "touch-screen"?

In all forms of writing, when used as a phrase touch screen should be written as two words. If the word is used as an adjective, hyphenate the word. Never use "touchscreen" as one word, unless you're writing instructions where "touchscreen" is used.

Tip

The Associated Press Stylebook, Oxford Dictionary of Computing, and Microsoft Computer Dictionary recommend and use touch screen as two words.

App, Force touch, Hardware terms, Input device, Pointing device, Swipe, Video terms