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 Robert 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.

Early touchscreens only registered one point of touch at a time. On-screen keyboards (a well-known feature today) were thus awkward to use, because key-rollover and holding down a shift key while typing another were not possible. An exception was a multi-touch reconfigurable touchscreen keyboard/display developed at the Massachusetts Institute of Technology in the early 1970s.

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 capacitance 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. In 1976, MIT described a keyboard with variable graphics capable of multi-touch detection, for what is very likely to be the very first multitouch screen.

In the early 1980s, The University of Toronto's Input Research Group were among the earliest to explore the software side of multi-touch input systems. A 1982 system at the University of Toronto 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. Of note, this system was input only and not able to display graphics.

In 1983, Bell Labs at Murray Hill published a comprehensive discussion of touch-screen based interfaces, though makes no mention of multiple fingers. In the same year, the video-based Video Place/Video Desk system of Myron Krueger was influential in development of multi-touch gestures such as pinch-to-zoom, though this system had no touch interaction itself. By 1984, both Bell Labs and Carnegie Mellon University had working multi-touch-screen prototypes – both input and graphics – that could respond interactively in response to multiple finger inputs. The Bell Labs system was based on capacitive coupling of fingers, whereas the CMU system was optical. In 1985, the canonical multitouch pinch-to-zoom gesture was demonstrated, with coordinated graphics, on CMU's system.

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 words per minute for a touchscreen keyboard compared with 58 words per minute for a standard keyboard, with multi-touch hypothesized to improve data entry rate); multi-touch 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.

An advance 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 multi-touch refinements were patented by Apple).

Microsoft's table-top touch platform, Microsoft PixelSense, which started development in 2001, interacts with both the user's 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 on which the user is standing); the Diamondtouch became a commercial product in 2008.

In May 2015, Apple was granted a patent for a "fusion keyboard", which turns individual physical keys into multi-touch buttons.

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:

Brands and manufacturers

Apple has retailed and distributed numerous products using multi-touch technology, most prominently including its iPhone smartphone and iPad tablet. Additionally, Apple also holds several patents related to the implementation of multi-touch in user interfaces, however the legitimacy of some patents has been disputed. Apple additionally attempted to register "Multi-touch" as a trademark in the United States—however its request was denied by the United States Patent and Trademark Office because it considered the term generic.

Multi-touch sensing and processing occurs via an ASIC sensor that is attached to the touch surface. Usually, separate companies make the ASIC and screen that combine into a touch screen; conversely, a trackpad's surface and ASIC are usually manufactured by the same company. There have been large companies in recent years that have expanded into the growing multi-touch industry, with systems designed for everything from the casual user to multinational organizations.

It is now common for laptop manufacturers to include multi-touch trackpads on their laptops, and tablet computers respond to touch input rather than traditional stylus input and it is supported by many recent operating systems.

A few companies are focusing on large-scale surface computing rather than personal electronics, either large multi-touch tables or wall surfaces. These systems are generally used by government organizations, museums, and companies as a means of information or exhibit display. Large scale multi-touch surfaces are manufactured by Finnish company MultiTaction on their 55" MT Cells (55" screens) who also have office locations in London, California and Singapore. MultiTaction also build unique collaboration software especially designed for multi-touch screens such as MT Canvus and MT Showcase.

Implementations

Multi-touch has been implemented in several different ways, depending on the size and type of interface. The most popular form are mobile devices, tablets, touchtables and walls. Both touchtables and touch walls project an image through acrylic or glass, and then back-light the image with LEDs.

Touch surfaces can also be made pressure-sensitive by the addition of a pressure-sensitive coating that flexes differently depending on how firmly it is pressed, altering the reflection.

Handheld technologies use a panel that carries an electrical charge. When a finger touches the screen, the touch disrupts the panel's electrical field. The disruption is registered as an computer event (gesture) and may be sent to the software, which may then initiates a response to the gesture event.

In the past few years, several companies have released products that use multi-touch. In an attempt to make the expensive technology more accessible, hobbyists have also published methods of constructing DIY touchscreens.

Capacitive

Capacitive technologies include:

Resistive

Resistive technologies include:

Optical

Optical touch technology functions when a finger or an object touches the surface, causing the light to scatter, the reflection is caught with sensors or cameras that send the data to software which dictates response to the touch, depending on the type of reflection measured.

Optical technologies include:

Wave

Acoustic and radio-frequency wave-based technologies include:

Multi-touch gestures

Multi-touch touchscreen gestures enable predefined motions to interact with the device and software. An increasing number of devices like smartphones, tablets, laptops or desktop computers have functions that are triggered by multi-touch gestures.

Multi-touch software

Many vendors have developed multi-touch software products that allow people to drag, resize, and rotate photos, videos and electronic documents (e.g. unedged arena, nuiSense business, snowflake, omnitapps).

Multi-touch software often has common features that enable non-technical people to quickly configure multi-touch presentations. This software may be useful in museums, kiosks, education, storefront windows, fairs and showrooms. It can be also used for collaboration purposes.

Popular culture

Years before it was a viable consumer product, popular culture portrayed potential uses of multi-touch technology in the future, including in several installments of the Star Trek franchise.

The television series CSI: Miami introduced both surface and wall multi-touch displays in its sixth season. Another television series, NCIS: Los Angeles, makes use of multi-touch surfaces and wall panels as an initiative to go digital. Another form of a multi-touch computer was seen in the film The Island, where the professor, played by Sean Bean, has a multi-touch desktop to organize files, based on an early version of Microsoft Surface^[3] (not be confused with the tablet computers which now bear that name). Multi-touch technology can also be seen in the James Bond film Quantum of Solace, where MI6 uses a touch interface to browse information about the criminal Dominic Greene. In an episode of the television series The Simpsons, Lisa Simpson travels to the underwater headquarters of Mapple to visit Steve Mobbs, who is shown to be performing multiple multi-touch hand gestures on a large touch wall.

A device similar to the Microsoft Surface was seen in the 1982 Disney sci-fi film Tron. It took up an executive's entire desk and was used to communicate with the Master Control computer.

The interface used to control the alien ship in the 2009 film District 9 features such similar technology.

Microsoft's Surface was also used in the 2008 film The Day the Earth Stood Still.

In the 2002 film Minority Report, Tom Cruise uses a set of gloves that resemble a multi-touch interface to browse through information.