The story of the first touch screen begins not in the smartphone era, but in the cold war tension of the 1960s. Long before Apple or Samsung defined the technology, engineers were looking for ways to interact with complex machines using a more direct method than a keyboard or mouse. The initial goal was not consumer convenience but operational precision for military and aerospace applications, laying the groundwork for the intuitive interfaces we take for granted today.
The Origins: E.A. Johnson and 1965
While often overshadowed by later inventions, the first touch screen was developed in 1965 by E.A. Johnson. Working at the Royal Radar Establishment in Malvern, England, Johnson created a prototype that used a matrix of wires embedded across the screen's surface. His design relied on the human finger's capacitance to disrupt the electrical field, allowing the device to pinpoint the exact location of a touch. This invention was a significant theoretical leap, proving that a user could directly manipulate information on a display without a physical peripheral.
The Technology Behind the Innovation
Johnson's system was relatively simple by modern standards but revolutionary in its time. The screen was coated with a thin layer of copper, arranged in a grid pattern. When a finger touched the copper, it created a small, detectable change in capacitance at the intersection of the grid's X and Y coordinates. The controller would then calculate the precise location of the touch based on which wires registered the change, effectively allowing the machine to "see" where the user was pointing.
From Defense to Industry: The 1970s Evolution
Following Johnson's foundational work, the technology was quickly adopted for high-value industrial and military uses throughout the late 1960s and early 1970s. The focus shifted from simple detection to more robust and versatile systems. This era saw the development of resistive touchscreens, which used pressure to connect two layers, a technology that would eventually dominate the market for portable electronics decades later.
1971: The University of Illinois developed the "PLATO IV," an early computer terminal featuring a touch screen interface for student interaction.
1974: Samuel Hurst invented a new touch sensor that used a metallic-coated panel to detect touch via resistance, leading to a U.S. patent in 1977.
1977: HP introduced the HP-150, one of the first commercially available computers to integrate a resistive touch screen.
Defining the First Commercial Touch Screen
While E.A. Johnson holds the title for the first functional prototype, the distinction of the first widely recognized commercial touch screen often goes to the HP-150 released in 1977. This machine utilized a clever resistive technology where the screen physically gave way under finger pressure to make contact with a conductive layer beneath. Although limited by its mechanical structure and lack of modern clarity, the HP-150 proved that touch interfaces were viable for business environments, bridging the gap between laboratory curiosity and practical application.
The Path to Modern Implementation
The journey from the bulky HP-150 to the sleek screens of today is a testament to rapid innovation. The 1980s and 1990s saw touch screens in ATMs, medical devices, and early PDAs, but they were often expensive and fragile. The game changed in 2007 with the introduction of the iPhone, which utilized a capacitive multi-touch screen. This technology, similar in principle to Johnson's original design but exponentially more advanced, allowed for fluid gestures and transformed the touch screen from a tool into a direct extension of the user's hand.
