In computing, multi-touch is technology that enables a surface (a touchpad or touchscreen) to recognize the presence of more than one point of contact with the surface at the same time. The origins of multitouch began at CERN, MIT, University of Toronto, Carnegie Mellon University and Bell Labs in the 1970s. CERN started using multi-touch screens as early as 1976 for the controls of the Super Proton Synchrotron. Capacitive multi-touch displays were popularized by Apple's iPhone in 2007. Multi-touch may be used to implement additional functionality, such as pinch to zoom or to activate certain subroutines attached to predefined gestures using gesture recognition.
Several uses of the term multi-touch resulted from the quick developments in this field, with several companies using the term to market older technology called gesture-enhanced single-touch or several other terms by other companies and researchers. Several other similar or related terms attempt to differentiate between whether a device can exactly determine or only approximate the location of different points of contact to further differentiate between the various technological capabilities, but they are often used as synonyms in marketing.
Multi-touch is commonly implemented using capacitive sensing technology in mobile devices and smart devices. A capacitive touchscreen typically consists of a capacitive touch sensor, application-specific integrated circuit (ASIC) controller and digital signal processor (DSP) fabricated from CMOS (complementary metal–oxide–semiconductor) technology. A more recent alternative approach is optical touch technology, based on image sensor technology.
Definition In computing, multi-touch is technology that enables a touchpad or touchscreen to recognize more than one or more than two points of contact with the surface. Apple popularized the term "multi-touch" in 2007 with which it implemented additional functionality, such as pinch to zoom or to activate certain subroutines attached to predefined gestures.
The two different uses of the term resulted from the quick developments in this field, with several companies using the term to market older technology called gesture-enhanced single-touch or several other terms by other companies and researchers. Several other similar or related terms attempt to differentiate between whether a device can exactly determine or only approximate the location of different points of contact to further differentiate between the various technological capabilities, but they are often used as synonyms in marketing.
History 1960–2000 The use of touchscreen technology predates both 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.Buxton, Bill. "Multitouch Overview" IBM began building the first touch screens in the late 1960s. In 1972, Control Data released the PLATO IV computer, an infrared terminal used for educational purposes, which employed single-touch points in a 16×16 array user interface. These 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.
Exceptions to these were a "cross-wire" multi-touch reconfigurable touchscreen keyboard/display developed at the Massachusetts Institute of Technology in the early 1970s and the 16 button capacitive multi-touch screen developed at CERN in 1972 for the controls of the Super Proton Synchrotron that were under construction.
In 1976 a new x-y capacitive screen, based on the capacitance touch screens developed in 1972 by Danish electronics engineer Bent Stumpe, was developed at CERN. This technology, allowing an exact location of the different touch points, 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. In the final device, a simple lacquer coating prevented the fingers from actually touching the capacitors. In the same year, MIT described a keyboard with variable graphics capable of multi-touch detection.
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.Mehta, Nimish (1982), A Flexible Machine Interface, M.A.Sc. Thesis, Department of Electrical Engineering, University of Toronto supervised by Professor K.C. Smith. 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 it 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.Krueger, Myron, W., Gionfriddo, Thomas., &Hinrichsen, Katrin (1985). VIDEOPLACE - An Artificial Reality, Proceedings of the ACM Conference on Human Factors in Computing Systems (CHI’85), 35–40.
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.Dannenberg, R.B., McAvinney, P. and Thomas, M.T. Carnegie-Mellon University Studio Report. In Proceedings of the International Computer Music Conference (Paris, France, October 19–23, 1984). ICMI. pp. 281-286.McAvinney, P. The Sensor Frame - A Gesture-Based Device for the Manipulation of Graphic Objects. Carnegie Mellon University, 1986. 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. In October 1985, Steve Jobs signed a non-disclosure agreement to tour CMU's Sensor Frame multi-touch lab. In 1990, Sears et al. published 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.Sears, A., Plaisant, C., Shneiderman, B. (June 1990) A new era for high-precision touchscreens. Advances in Human-Computer Interaction, vol. 3, Hartson, R. & Hix, D. Eds., Ablex (1992) 1-33 HCIL-90-01, CS-TR-2487, CAR-TR-506.
In 1991, Pierre Wellner advanced the topic publishing about his multi-touch "Digital Desk", which supported multi-finger and pinching motions.Wellner, Pierre. 1991. The Digital Desk. Pierre Wellner's papers via DBLP Various companies expanded upon these inventions in the beginning of the twenty-first century.
2000–present Between 1999 and 2005, the company Fingerworks developed various multi-touch technologies, including Touchstream keyboards and the iGesture Pad. in the early 2000s Alan Hedge, professor of human factors and ergonomics at Cornell University published several studies about this technology.Westerman, W., Elias J.G. and A.Hedge (2001) Multi-touch: a new tactile 2-d gesture interface for human-computer interaction Proceedings of the Human Factors and Ergonomics Society 45th Annual Meeting, Vol. 1, 632-636.Shanis, J. and Hedge, A. (2003) Comparison of mouse, touchpad and multitouch input technologies. Proceedings of the Human Factors and Ergonomics Society 47th Annual Meeting, Oct. 13–17, Denver, CO, 746-750.Thom-Santelli, J. and Hedge, A. (2005) Effects of a multitouch keyboard on wrist posture, typing performance and comfort. Proceedings of the Human Factors and Ergonomics Society 49th Annual Meeting, Orlando, Sept. 26-30, HFES, Santa Monica, 646-650. In 2005, Apple acquired Fingerworks and its multi-touch technology.
In 2001, Microsoft's table-top touch platform, Microsoft PixelSense (formerly Surface) started development, which interacts with both the user's touch and their electronic devices and became commercial on May 29, 2007. Similarly, in 2001, Mitsubishi Electric Research Laboratories (MERL) began development of a multi-touch, multi-user system called DiamondTouch.
In 2004, French start-up JazzMutant developed the Lemur Input Device, a music controller that became in 2005 the first commercial product to feature a proprietary transparent multi-touch screen, allowing direct, ten-finger manipulation on the display.
In January 2007, multi-touch technology became mainstream with the iPhone, and in its iPhone announcement Apple even stated it "invented multi touch". Nonetheless, both the function and the term predate the announcement or patent requests, except for the area of 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).
Nonetheless, the U.S. Patent and Trademark office declared that the "pinch-to-zoom" functionality was predicted by U.S. Patent # 7,844,915 relating to gestures on touch screens, filed by Bran Ferren and Daniel Hillis in 2005, as was inertial scrolling, thus invalidated a key claims of Apple's patent.
In 2008, the Diamondtouch became a commercial product and is 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. In 2007, NORTD labs open source system offered its CUBIT (multi-touch).
In 2009, Android 2.0 has added support for multi-touch. Also, in 2009, Windows 7 and Windows Mobile 6.5 has added support for multi-touch.
Small-scale touch devices rapidly became commonplace in 2008. The number of touch screen telephones was expected to increase from 200,000 shipped in 2006 to 21 million in 2012.Wong, May. 2008. Touch-screen phones poised for growth https://www.usatoday.com/tech/products/2007-06-21-1895245927_x.htm. Retrieved April 2008.
In May 2015, Apple was granted a patent for a "fusion keyboard", which turns individual physical keys into multi-touch buttons.
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