For every problem there is a solution that is simple, clean, and wrong.
Henry Louis Mencken
The concept of the finger-driven touchscreen interface was put into words in 1965, by the British engineer Eric Arthur Johnson. He worked at the Royal Radar Establishment in Malvern, England, and was interested in developing a touchscreen for air traffic control, as the UK National Air Defense was in need of a solution that would accelerate response time, minimize workloads, and allow for more accurate decision making for air traffic control operators.
In August 1965 Eric Johnson filed his first patent application, which was amended in 1966, and the complete specification was published on 26 November 1969 (see GB patent No. 1172222). In 1969 Johnson received also a US patent for his invention (see US patent Nr. 3482241).
In October 1965 Johnson described his ideas for a capacitive Touch Sensitive Electronic Data Display in a short 2-page article (Touch Display—A novel input/output device for computers. Electronics Letters, 1(8), 219-220). In 1967, he published another more comprehensive paper on the topic (Touch Displays: A Programmed Man-Machine Interface. Ergonomics, 10(2), 271-277), explaining how the technology worked through diagrams and photographs of a prototype. He also foresaw that the design could work as a keyboard for entering characters.
The touchscreen of Johnson was a device that used wires, sensitive to fingers’ touches, on the face of a cathode-ray tube (CRT) on which the computer could write information. His design consisted of a glass-coated insulator with a transparent conductor made of indium tin oxide. Thin copper wires placed across a computer’s CRT allowed the circuits to sense when they were being touched. Interestingly, although Johnson published the idea in the middle 1960s, it wasn’t made a reality or used by British air traffic controllers until the 1990s.
The next step was made in early 1972, by a Danish engineer working in CERN, Bent Stumpe (born 1938). He was asked by Frank Beck, who was in charge of the central control hub in the Super Proton Synchrotron, SPS, control room, to build the hardware for an intelligent system that, in just three console units, would replace all those conventional buttons, switches, etc.
In March 1972, after a few days, Stumpe presented a hand-written proposal to build a touch screen with a fixed number of programmable buttons. It also uses a tracker ball as a computer-controlled pointing device—something like a mouse—and a programmable knob.
“We had very little time to design the new system and demonstrate that both the hardware and the software could really work”, recollected Bent Stumpe. “Thanks to Chick Nichols from the CERN EP workshop, it was possible to evaporate a very thin layer of copper on a flexible and transparent Mylar sheet. This allowed us to produce the very first prototype of a capacitive touch screen.”
The first touchscreens, developed by Bent Stumpe, were installed in CERN in 1973 and remained in operation until 2008.