Return to Timeline of the History of Computers
E. A. Johnson (dates unavailable), Dr. Sam Hurst (1927–2010), Nimish Mehta (dates unavailable)
In 1955, the MIT Whirlwind project created a light pen that let a user indicate a point on a computer screen. But being able to point more naturally with your own finger? That was the invention of E. A. Johnson at the Royal Radar Establishment (RRE).
Johnson was a researcher working on the RRE’s air traffic control system. In 1965, he published an article in Electronic Letters titled “Touch Display—A Novel Input/Output Device for Computers” that described a touch-sensitive screen. Two years later, he expanded on the idea in an article in Ergonomics, showing how a touchscreen could be used to interact with graphs and pictures.
Johnson invented what is called today a capacitive touchscreen. It uses a layer in the screen to store an electric charge. When a user touches the screen, some of the charge is transferred to the user. This sends a signal to the device’s operating system where the touch occurred on the screen.
A few years later, Sam Hurst, a researcher at Oak Ridge National Laboratory in Tennessee, invented a similar kind of transparent, touch-sensitive film, but one based on changes in resistance that result when two transparent layers of material are pressed together. Unlike capacitive screens, touchscreens can be used with a stylus or a finger. They are generally cheaper but less accurate than capacitive screens. A third kind of screen relies on changes to ultrasonic waves sent over the surface of the touchscreen to measure where the screen is touched.
Early touchscreens could sense only one touch at a time. Nimish Mehta developed the first multitouch device at the University of Toronto in 1982. The technology continued to develop along with potential commercial applications, finally reaching the masses in the 2000s. During this period, it became a popular tool for design collaboration.
Today touchscreens are the primary way that people interact with smartphones and tablets, which in 2016 became the primary way that the world’s population accesses information on the World Wide Web.
SEE ALSO Trackball (1946), The Mouse (1967), PalmPilot (1997)
Touchscreens came to be used with many applications. Pictured here is an operator using a touchscreen on the shared computer-based education system PLATO (Programmed Logic Automated Teaching Operation).