Touchscreen

A touchscreen (or touch screen) is a type of display that can detect touch input from a user to do a specific task. It consists of both an input device (a touch panel) and an output device (a visual display). The touch panel is typically layered on the top of the electronic visual display of a device. Touchscreens are commonly found in smartphones, tablets, laptops, and other electronic devices. The display is often an LCD, AMOLED or OLED display.

A person can give input or control the information processing system through simple or multi-touch gestures by touching the screen with a special stylus or one or more fingers. Some touchscreens use ordinary or specially coated gloves to work, while others may only work using a special stylus or pen. The user can use the touchscreen to react to what is displayed and, if the software allows, to control how it is displayed; for example, zooming to increase the text size.

A touchscreen allows users to interact directly with on-screen content, rather than using indirect input devices such as a mouse or touchpad. Touchscreens are commonly found on smartphones, tablets, kiosks, and many modern laptops, where they allow tapping, swiping, and pinching to perform actions on the screen.

Touchscreens are common in devices such as smartphones, handheld game consoles, and personal computers. They are common in point-of-sale (POS) systems, automated teller machines (ATMs), electronic voting machines, and automobile infotainment systems and controls. They can also be attached to computers or, as terminals, to networks. They play a prominent role in the design of digital appliances such as personal digital assistants (PDAs) and some e-readers.

History

One early version of the modern touchscreen used a special tool called a stylus.

1946: Direct light pen

In 1946, a company named Philco created a special tool for television broadcasts. This tool, when placed on a screen, could draw arrows or circles on live TV shows.

1960s

1962: Optical

In 1962, AT&T made a touchscreen that could work without light from the screen. It used lights shining across the screen, and when a tool interrupted the light, sensors could tell where the touch happened.

1963: Indirect light pen

In 1963, Robert E. Graham made a system where users could draw on one surface, and the drawing would show up on a computer screen. This made it easier to draw and store pictures.

1965: Finger driven touchscreen

In 1965, Eric Johnson in England made the first touchscreen that could be used with a finger. He used a special type of screen that could sense touch.

Mid-60s: Ultrasonic Curtain

Around the same time, a team in Germany made a pointing device using sound waves for air traffic control. Later, this idea was used in a touch screen for a computer terminal.

1968: ATC

In 1968, Frank Beck and Bent Stumpe, working at CERN, made a clear touchscreen for air traffic control systems.

1970s

1972

Researchers at the University of Illinois made a touchscreen for a computer terminal. It used lights and sensors to detect touches on the screen.

1973: Multi-Touch Capacitance

Beck and Stumpe made a touchscreen that could sense multiple touches, but they decided not to use this feature at the time.

1977: Resistive

In 1977, a company called Elographics started working on a touchscreen that could be used with fingers. This was shown at a world's fair in 1982.

1980s

1982: Multi-touch Camera

In 1982, researchers in Toronto made a touchscreen that could detect many touches at once using a camera behind the screen.

1983: HP-150

In 1983, the HP-150 was one of the first computers to use a touchscreen. It had lights around the screen to detect touches.

1983: Multi-touch force sensing touchscreen

Bob Boie at AT&T Bell Labs made a touchscreen that could sense how hard something was touching the screen.

Up to 1984: Capacitance

Researchers kept improving touchscreens that could sense fingers directly or through a thin plastic layer.

1984: Touchpad

In 1984, Fujitsu made a touchpad for a computer to help enter complicated characters.

1986: Graphic Touchpad

In 1986, Sega made a touchpad for a computer that could be used for drawing.

Early 80s: Evaluation for Aircraft

In the early 1980s, people tested touchscreens for airplanes to help pilots control the plane more easily.

Early 80s: Evaluation for Cars

Also in the early 1980s, General Motors tested touchscreens in cars to control things like the stereo or air conditioner.

1985: Graphic Tablet

In 1985, Sega made a device for a video game console that could be used for drawing.

1985: Multi-Touch Tablet

Researchers in Toronto made a tablet that could sense many touches using special sensors.

1985: Used for Point-of-sale

In 1985, a company showed a touchscreen computer that could be used in stores for checking out items.

1987: Capacitance Touch Keys

In 1987, Casio made a small computer with a touchscreen that had many touch areas.

1988: Select on "Lift-Off"

In 1988, researchers found a way to make touchscreens more accurate. Users could move their finger before lifting it off to choose exactly what they wanted.

1988 World Expo

In 1988, during an event in Brisbane, Australia, many touchscreens were used to give visitors information about the event.

1990s

1990: Single and multi-touch gestures

Researchers studied how people could use touchscreens for actions like sliding and tapping.

1990: Touchscreen slider and toggle switches

Researchers made a slider on a touchscreen, which was later used in mobile phones.

1991: Inertial control

In 1991, a prototype handheld computer used a touchscreen that could scroll by moving the finger quickly.

1993: First touchscreen phone

In 1993, IBM made the first phone with a touchscreen.

2000s and beyond

2004: Mobile multi-touch capacitance patent

In 2004, Apple got a patent for touchscreens that could sense many touches at once.

2004: Video games with touchscreens

Touchscreens started being used in video games with the release of the Nintendo DS in 2004.

2007: Mobile phone with capacitive touchscreen

In 2007, LG made a mobile phone with a touchscreen that could sense touches very well. After that, many phones started using touchscreens.

2015: Force-sensing touchscreens

In 2015, the Apple Watch was released with a touchscreen that could sense how hard you were pressing.

Technologies

There are different ways to make a touchscreen work, each with its own way of feeling a touch.

Resistive

A resistive touchscreen has several thin layers. The most important ones are two special layers that can feel electricity, placed very close together with a tiny gap. When you press on the screen, these layers touch and tell the screen where you pressed. This kind of touchscreen is cheap and can work even with gloves or other things that press the screen. But it needs a firm press and can show glare.

Surface acoustic wave

Surface acoustic wave touchscreens use special waves that move over the screen. When you touch it, some of the waves get blocked, and the screen can figure out where you touched. This type can be affected by dirt or other things on the screen.

Capacitive touchscreen

A capacitive touchscreen has a special coating, like glass, that can feel changes when you touch it. Your finger changes the screen’s electrical field, and the screen can tell where you touched. Some of these screens can feel your finger even if you’re not quite touching the screen, like through a thin glove.

Infrared grid

An infrared touchscreen uses special lights around the edges of the screen. When you touch the screen, it blocks some of the light, and the screen can tell where you touched. This type works with many things, like fingers or pens, and is often used outside where other types might not work well.

Infrared acrylic projection

Some touchscreens use a special clear sheet and lights around the edges. When you touch the sheet, it changes how the lights behave, and the screen can tell where you touched.

Optical imaging

Optical touchscreens use special cameras around the screen. When you touch the screen, it blocks some lights, and the screen can figure out where you touched. This type is good for big screens and can work in many ways.

Dispersive signal technology

This type of touchscreen feels a touch by sensing special changes when the screen is pressed. It can work with any object, like a gloved finger, and isn’t bothered by dirt or scratches.

Acoustic pulse recognition

This touchscreen uses sound to feel a touch. When you press the screen, it makes a special sound that the screen can hear, and it tells where you touched. This type can work well even if the screen gets scratched or dusty.

Development

Multi-touch screens let users use more than one finger at the same time, making tasks easier. These screens can even let several people use the device together.

As touchscreens became more common, their cost went down. Now many products, like airplanes, cars, game machines, and phones, use them because they work well. New ideas, like combining tablet screens with drawing tools, are making touchscreens even better. Some new technology can tell if you are using your fingertip, knuckle, or fingernail, which can help with different tasks on the screen.

Ergonomics and usage

For touchscreens to work well, users need to be able to choose what they want on the screen without picking something close by by mistake. The way these screens are made should think about how people use them, how they think, and how their bodies work.

Guidelines for making touchscreen designs were created in the 2000s, based on older systems that used infrared grids. These rules matter less now because most modern devices use capacitive or resistive touch technology.

It is important how accurate people are when they pick something on the screen with their finger or a pen. People are most accurate in the middle of the screen, less so on the sides, and least accurate at the top and bottom edges. This happens because of how our eyes and fingers work together. When special tools like screen magnifiers are used, people can move their finger very precisely.

Touchscreens are often used with haptic response systems. For example, when you tap a button on a touchscreen, it might vibrate. This helps make using the screen better because it gives a feeling of touch, making it easier and faster to use.

Touchscreen technology is now used in many places where people serve customers. For example, some restaurants like Taco Bell, Panera Bread, and McDonald's let people order food by touching a screen instead of talking to a cashier. Some restaurants even have screens built into the tables so people can order from there.

Long use of touchscreens without resting your arm can cause tired arms, sometimes called "gorilla arm." This can be fixed by letting users rest their hand or arm on the screen or around it. This is important in places like ATMs and data kiosks, where people only use the screen for short times.

Touchscreens can sometimes show fingerprints, which can be reduced by using special coatings or screen protectors.

Capacitive touchscreens usually do not work well with gloves because of the material and thickness. Some devices can be set to work better with gloves, but this can cause mistakes. Thin gloves, like medical ones, can sometimes be used with touchscreens.