A Brief History of Touchscreen Technology: Part One

Touchscreens are so ubiquitous in today’s society that it’s hard to imagine life without them.

Yet, only a few decades ago, touchscreen technology was the stuff of sci-fi fantasy – as futuristically outlandish as flying cars and meals in pill form.

We may still be a few years off flying cars, but touchscreens have well and truly ensconced themselves in our lives.

But how did we get to this point? Let’s take a look back at the history of touchscreen technology.

The 1960s: the touchscreen is born

The first finger-controlled touchscreen is widely acknowledged to have been created by E.A. Johnson in 1965 at the Royal Radar Establishment in Malvern, UK.

In his article Touch Display – a Novel Input/Output Device for Computers, Johnson described a touchscreen mechanism employed by many modern smartphones – capacitive touch.

A capacitive touchscreen features an insulator, such as glass, coated with a transparent conductor like indium tin oxide. A human finger coming into contact with it acts as an electrical conductor.

Johnson’s original technology was only able to process one touch at a time. What we call ‘multi-touch’ technology was still some way off. Pressure sensitivity, too, was still the stuff of dreams – Johnson’s device either registered contact or it didn’t.

Johnson’s invention was adopted by air traffic controllers in the UK and remained in use until the late 1990s.

The 1970s: from capacitive to resistive

Capacitive touchscreens were soon eclipsed by resistive touchscreens. American inventor Dr G Samuel Hurst invented resistive touchscreens almost accidentally while studying atomic physics at the University of Kentucky. Whilst the university thought the technology was only applicable in a laboratory setting, Hurst had other ideas.

In 1970 Hurst began refining the technology, calling it ‘elographics’. Hurst and his team found that a touchscreen made an excellent interface for a computer monitor.

The screen simply required a conductive cover sheet to make contact with the sheet containing the X and Y axes. When pressure was placed on the cover sheet, electricity would flow between the X and Y wires. This was the foundation of resistive touchscreen technology, which responds to pressure instead of electrical conductivity.

By 1971, a variety of touch-capable machines had been developed, although none of them were pressure-sensitive. The University of Illinois’ PLATO IV terminal was one such device. It employed infrared technology rather than capacitive or resistive, and was the first touchscreen computer to be used in a classroom.

The 1980s: touch takes hold

The first human-controlled multi-touch device was invented at the University of Toronto in 1982 by Nimish Mehta. It featured a frosted glass panel in front of a camera, which detected action when it identified ‘black spots’ showing up onscreen.

Not long after, American computer artist Myron Krueger developed gestural interaction via an optical system that tracked hand movements using projectors and video cameras. His work was hugely influential, though not given the recognition it deserved.

Touchscreens became available commercially in the early 1980s. HP released the HP-150 in 1983, which featured a 9-inch Sony CRT monitor surrounded by infrared emitters and detectors which could sense the user’s finger touching the screen.

Multi-touch technology took a leap forward in 1984, when the first transparent multi-touch screen overlay was developed by Bob Boie of Bell Labs. The screen utilised a transparent capacitive array of touch sensors overlaid on a CRT, allowing users to manipulate graphical objects with their fingers.

This discovery was instrumental in the development of the multi-touch technology we rely on today in smartphones and tablets.

The history of touchscreen technology: to be continued…

Check back next week to discover the history of touchscreen technology from the 1990s onwards.