<P> 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 . 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 . </P> <P> In 1991, Pierre Wellner advanced the topic publishing about 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 . </P> <P> 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 . In 2005, Apple acquired Fingerworks and its multi-touch technology . In January 2007, multi-touch technology became mainstream with the iPhone, and in its iPhone announcement Apple even stated it "invented multi touch", however 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). </P> <P> 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 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). </P>

Who invented the first multitouch device what are the basics of how it works