In computing, multi-touch refers to a touch sensing surface's (trackpad or touchscreen) ability to recognize the presence of two or more points of contact with the surface. This plural-point awareness is often used to implement advanced functionality such as pinch to zoom or activating predefined programs.

In an effort of disambiguation or marketing classification some companies further breakdown the various definitions of multi-touch. An example of this is 3M defining multi-touch as a touch-screen's ability to register three or more distinct positions.

History

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.

thumb|The prototypes of the x-y mutual capacitance multi-touch screens (left) developed at CERN

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 capacitative 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.

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 (Apple filed patents for in 2005-2007 and was awarded with in 2009-2010). Publication and demonstration using the term Multi-touch by Jefferson Y. Han in 2005 predates these, but Apple did give multi-touch wider exposure through its association with their new product and were the first to introduce multi-touch on a mobile device. Microsoft's table-top touch platform Microsoft Surface, 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.

Brands and manufacturers

Apple Inc. is the active holder of the trade mark "Multi-touch" and is the final stages of getting registration, and, correspondingly, lists "Multi-Touch" on their page of trademarks. Apple was also awarded a patent covering multi-touch on 20 January 2009.

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 common for laptop manufacturers include multi-touch trackpads on their laptops, and tablet computers respond to touch input rather than traditional stylus input.

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.

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.

Types

Multitouch Capacitive Technology

*Surface Capacitive Technology

*Projected Capacitive Touch (PST)

*In-cell: Capacitive

Touch Resistive Technology

*Analog Resistive

*Digital Resistive or In-Cell: Resistive

Multitouch Optical technologies

*Optical Imaging or Infrared technology

*Rear Diffused Illumination (DI)

*Infrared Grid Technology (opto-matrix) or Digital Waveguide Touch (DWT)™ or Infrared Optical Waveguide

*Frustrated Total Internal Reflection (FTIR) or Diffused Surface Illumination (DSI) / Dispersive Signal Touch (DST)

*Kinect

*In-Cell: Optical

Touch Wave Technologies

*Surface Acoustic Wave (SAW)

*Bending Wave Touch (BWT)

Force-Based Sensing or Near Field Imaging (NFI)

The 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. 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 and sent to the software, which then initiates a response to the gesture.

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.

Operating systems

Many recent operating systems support multi-touch, including Mac OS X, Windows 7 and Ubuntu (full support since version 10.10, partial support in 10.04), Apple's iOS, Nokia's Symbian ^3 OS on the flagship model Nokia N8 & the Nokia E7, Samsung's Bada, Google's Android, Palm's webOS, Microsoft's Windows Phone 7, BlackBerry OS 5.0 (on Storm models) and 6.0, Xandros.

Popular culture references

Pop culture has also portrayed potential uses of multi-touch technology in the future, including 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'' make use of multitouch surfaces and wall panels as an initiative to go digital. Another form of a multi-touch computer was seen in the motion picture, ''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. Multitouch 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 popular TV series ''The Simpsons'', when Lisa Simpson travels to the underwater headquarters of Mapple to visit Steve Mobs, the erstwhile pretender to the throne of Mapple is shown to be performing multiple multi-touch hand gestures on a large touch wall.

A device similar to the Surface was seen in the 1982 movie ''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 movie ''District 9'' features such similar technology.

Microsoft's Surface was also used in the movie "The Day the Earth Stood Still."

In the movie Minority Report, Tom Cruise uses a multi-touch interface to browse through information.

See also

List of multi-touch computers and monitors

Gesture recognition

Human-Computer Interaction

Pen computing

Multi-touch gestures

Natural User Interface

Sketch recognition

Surface Computing

Tenori-on

Touchpad

Touch user interface

References

External links

Video Demo Of FTIR using Touchscape Components

here is OmniGlobe Spherical Interactive (Multi touch) Display System

Multi-Touch Systems that I Have Known and Loved – An overview by researcher Bill Buxton of Microsoft Research, formerly at University of Toronto and Xerox PARC.

The Unknown History of Pen Computing contains a history of pen computing, including touch and gesture technology, from approximately 1917 to 1992.

Annotated bibliography of references to pen computing

Multi-touch Chordic Keyboard for iPhone and Android

Multi-touch in Windows 7

Multi-Touch Interaction Research @ NYU

Camera-based multi-touch for wall-sized displays

David Wessel Multitouch

The Virtual Autopsy Table

Video of Humanaquarium at makers faire using touchscape components

Jeff Han's Multi Touch Screen's chronology archive Debut from 7 Mar 2006 to present

MultiTouch Forever Group (MTFG) by SnickerDudle

Category:Touch user interfaces Category:User interface techniques

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Jefferson Y. Han is a research scientist for New York University's (NYU) Courant Institute of Mathematical Sciences, and one of the main developers of "multi-touch sensing," which unlike older touch-screen interfaces was able to recognize multiple points of contact.

Jeff Han also works on other projects in the fields of autonomous robot navigation, motion capture, real-time computer graphics, and human-computer interaction.

He presented his multi-touch sensing work in February 2006 at the TED (Technology Entertainment Design) Conference in Monterey, California. TED released the video online 6 months later and it spread quickly on YouTube.

Han has founded a company called Perceptive Pixel to develop his touch screen technology further, and he has already shipped touch screens to parts of the military. Han's technology has been featured most notably as the "Magic Wall" on CNN's Election Center coverage

Han graduated from The Dalton School in New York in 1993 and studied computer science and electrical engineering for three years at Cornell University before leaving to join a start-up company to commercialize the CU-SeeMe video-conferencing software that he helped develop while an undergraduate at Cornell.

Han was named to Time Magazine's 2008 listing of the ''100 Most Influential People in The World.''

References

External links

Jeff Han's Multitouch Demo (II) (2007Mar21)

Jeff Han: A year later (Wired Magazine)

Jeff Han demonstrating multi-touch interface on big screen

Jeff Han's 10 min Talk at TED Conference (2006) Monterey, CA

Jeff Han homepage at NYU

Specific Multi-Touch Sensing work - includes video

Transcript of a presentation delivered at ETech on 7 March 2006

Presentation over YouTube

Perceptive Pixel

TED Talks: Jeff Han demos his breakthrough touchscreen at TED in 2006

Category:Cornell University alumni Category:Dalton School alumni Category:Living people Category:Year of birth missing (living people)