Multi-touch - History of Multi-touch

History of Multi-touch

The use of touchscreen technology to control electronic devices pre-dates multi-touch technology and the personal computer. Early synthesizer and electronic instrument builders like Hugh Le Caine and Bob Moog experimented with using touch-sensitive capacitance sensors to control the sounds made by their instruments. IBM began building the first touch screens in the late 1960s, and, in 1972, Control Data released the PLATO IV computer, a terminal used for educational purposes that employed single-touch points in a 16x16 array as its user interface.

One of the early implementations of mutual capacitance touchscreen technology was developed at CERN in 1977 based on their capacitance touch screens developed in 1972 by Danish electronics engineer Bent Stumpe. This technology was used to develop a new type of human machine interface (HMI) for the control room of the Super Proton Synchrotron particle accelerator.

In a handwritten note dated 11 March 1972, Stumpe presented his proposed solution – a capacitive touch screen with a fixed number of programmable buttons presented on a display. The screen was to consist of a set of capacitors etched into a film of copper on a sheet of glass, each capacitor being constructed so that a nearby flat conductor, such as the surface of a finger, would increase the capacity by a significant amount. The capacitors were to consist of fine lines etched in copper on a sheet of glass – fine enough (80 μm) and sufficiently far apart (80 μm) to be invisible (CERN Courier April 1974 p117). In the final device, a simple lacquer coating prevented the fingers from actually touching the capacitors.

Multi-touch technology began in 1982, when the University of Toronto's Input Research Group developed the first human-input multi-touch system. The system used a frosted-glass panel with a camera placed behind the glass. When a finger or several fingers pressed on the glass, the camera would detect the action as one or more black spots on an otherwise white background, allowing it to be registered as an input. Since the size of a dot was dependent on pressure (how hard the person was pressing on the glass), the system was somewhat pressure-sensitive as well.

In 1983, Bell Labs at Murray Hill published a comprehensive discussion of touch-screen based interfaces. In 1984, Bell Labs engineered a touch screen that could change images with more than one hand. In 1985, the University of Toronto group including Bill Buxton developed a multi-touch tablet that used capacitance rather than bulky camera-based optical sensing systems.

Sears et al. (1990) gave a review of academic research on single and multi-touch touchscreen human–computer interaction of the time, describing single touch gestures such as rotating knobs, swiping the screen to activate a switch (or a U-shaped gesture for a toggle switch), and touchscreen keyboards (including a study that showed that users could type at 25 wpm for a touchscreen keyboard compared with 58 wpm for a standard keyboard, with multi-touch hypothesized to improve data entry rate); multitouch gestures such as selecting a range of a line, connecting objects, and a "tap-click" gesture to select while maintaining location with another finger are also described.

A breakthrough occurred in 1991, when Pierre Wellner published a paper on his multi-touch "Digital Desk", which supported multi-finger and pinching motions.

Various companies expanded upon these inventions in the beginning of the twenty-first century. The company Fingerworks developed various multi-touch technologies between 1999 and 2005, including Touchstream keyboards and the iGesture Pad. Several studies of this technology were published in the early 2000s by Alan Hedge, professor of human factors and ergonomics at Cornell University. Apple acquired Fingerworks and its multi-touch technology in 2005. Mainstream exposure to multi-touch technology occurred in 2007 when the iPhone gained popularity, with Apple stating they 'invented multi touch' as part of the iPhone announcement, however both the function and the term predate the announcement or patent requests, except for such area of application as capacitive mobile screens, which did not exist before Fingerworks/Apple's technology (Fingerworks filed patents in 2001-2005, subsequent multitouch refinements were patented by Apple). Microsoft's table-top touch platform Microsoft PixelSense, which started development in 2001, interacts with both the users touch and their electronic devices. Similarly, in 2001, Mitsubishi Electric Research Laboratories (MERL) began development of a multi-touch, multi-user system called DiamondTouch, also based on capacitance but able to differentiate between multiple simultaneous users (or rather, the chairs in which each user is seated or the floorpad the user is standing on); the Diamondtouch became a commercial product in 2008.

Small-scale touch devices are rapidly becoming commonplace, with the number of touch screen telephones expected to increase from 200,000 shipped in 2006 to 21 million in 2012.

Some of the first devices to support multi-touch were:

• Mitsubishi DiamondTouch (2001)
• Apple iPhone (January 9, 2007)
• Microsoft PixelSense (formerly Surface) (May 29, 2007)
• NORTD labs Open Source system CUBIT (multi-touch) (2007)
• ELAN eFinger