Multi-touch

In computing, multi-touch is a special technology that lets a surface, like a touchpad or touchscreen, feel more than one finger touching it at the same time. This idea started a long time ago in the 1970s at places like CERN, MIT, University of Toronto, Carnegie Mellon University, and Bell Labs.

Later, many people learned about multi-touch because of Apple’s popular iPhone in 2007. With multi-touch, you can do things like pinch to zoom or use special movements on the screen, thanks to something called gesture recognition.

Today, most mobile devices and smart devices use a type of technology called capacitive sensing to make multi-touch work. This means the screen can sense tiny changes when your fingers touch it. Some newer screens even use optical touch technology, which looks at images to know where your fingers are. Multi-touch makes using devices easier and more fun!

Definition

In computing, multi-touch is a special technology that lets a touchpad or touchscreen feel more than one finger at the same time. This helps you do things like pinch to zoom or start actions by moving your fingers in special ways, called predefined gestures.

The word "multi-touch" became well-known in 2007 thanks to Apple. Before that, some companies used different names for similar technology, which made things confusing. Even today, there are many words people use to describe these abilities, but they often mean the same thing.

History

1960–2000

Touchscreen technology existed before multi-touch and personal computers. Early music makers like Hugh Le Caine and Robert Moog tested touch-sensitive sensors to control sounds. IBM made the first touch screens in the late 1960s. In 1972, Control Data made the PLATO IV computer, which could only register one touch at a time.

Some early exceptions were a special touchscreen keyboard made at the Massachusetts Institute of Technology in the early 1970s and a 16-button screen made at CERN in 1972 for controlling the Super Proton Synchrotron.

In 1976, a new type of screen was made at CERN using ideas from Danish engineer Bent Stumpe. This screen could find exact touch points and was used to control the Super Proton Synchrotron.

In the early 1980s, researchers at the University of Toronto studied multi-touch software. A 1982 system used a glass panel and a camera to detect touches.

By 1984, both Bell Labs and Carnegie Mellon University had multi-touch prototypes. In 1985, a famous "pinch-to-zoom" action was shown on CMU’s system. In 1991, Pierre Wellner created a "Digital Desk" that supported multi-finger actions.

2000–present

Between 1999 and 2005, Fingerworks developed many multi-touch technologies. In 2005, Apple bought Fingerworks and its technology.

In 2004, a French company made the Lemur Input Device, the first product with a clear multi-touch screen for music control.

In January 2007, multi-touch became popular with the iPhone. In 2001, Microsoft began work on Microsoft PixelSense, a table-top touch system that launched in 2007. Also in 2001, Mitsubishi Electric Research Labs started work on DiamondTouch, a system that could tell apart different users.

Small touch devices became common in 2008. By 2015, Apple got a patent for a "fusion keyboard" that could turn keys into multi-touch buttons.

Applications

Apple has made many products with multi-touch technology, like the iPhone and iPad. They own several patents for how multi-touch works, but some people argue about these patents. Apple tried to make "Multi-touch" a special brand name in the United States, but it was not allowed because the term is too general.

Now, many laptops have multi-touch touchpads, and most tablet computers use touch instead of a stylus. This technology works with many modern operating systems. Some companies are also making large multi-touch tables or walls for places like museums and government offices to show information and displays.

Implementations

Multi-touch technology can be used in many ways, depending on the size and type of screen. Popular uses include mobile devices, tablets, touchtables, and touch walls. Touchtables and touch walls show an image through acrylic or glass and light it up with LEDs.

Touch surfaces can feel pressure if they have a special coating. Handheld devices use a panel with an electrical charge. When a finger touches the screen, it changes the electrical field, and this change is recognized as a computer event. The software can then respond to this.

In recent years, many companies have made products using multi-touch. Hobbyists have also shared ways to make DIY touchscreens.

Capacitive

Capacitive technologies include:

• Surface Capacitive Technology or Near Field Imaging (NFI)
• Projected Capacitive Touch (PCT)
  • Mutual capacitance
  • Self-capacitance
• In-cell Capacitive

Resistive

Resistive technologies include:

• Analog Resistive
• Digital Resistive or In-Cell Resistive

Optical

Optical touch technology uses image sensor technology. When a finger or object touches the surface, it scatters light, and sensors or cameras catch this reflection. The data is sent to software to decide how to respond to the touch.

Optical technologies include:

• 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)
• Diffused Surface Illumination (DSI)
• Laser Light Plane (LLP)
• In-Cell Optical

Wave

Acoustic and radio-frequency wave-based technologies include:

• Surface Acoustic Wave (SAW)
• Bending Wave Touch (BWT)
  • Dispersive Signal Touch (DST)
  • Acoustic Pulse Recognition (APR)
• Force-Sensing Touch Technology

Multi-touch gestures

Main article: Pointing device gesture

Multi-touch gestures let devices understand special movements you make with your fingers. This helps you control the device and its software more easily. Many devices, such as smartphones, tablet computers, laptops, and desktop computers, use these gestures to let users do things in new and easy ways.

Popular culture

Before 2007, movies and TV shows imagined how multi-touch technology might look in the future. In the 1982 Disney movie Tron, a character used a big desk-like device to talk to a computer. The 2002 film Minority Report showed a character using hand movements on a screen.

After 2007, multi-touch screens appeared in more shows and movies. The 2008 James Bond film Quantum of Solace had characters using touch screens. The same year, The Day the Earth Stood Still used a similar screen. The TV show NCIS: Los Angeles, which started in 2009, also used touch walls and screens. Even The Simpsons had an episode where a character used hand movements on a big touch wall. The 2009 film District 9 also showed a spaceship controlled with touch technology.

10/GUI

10/GUI is a new way to use computers that was made in 2009 by R. Clayton Miller. It mixes multi-touch input with a new kind of windowing manager.

This design keeps the touch area separate from the screen. This helps reduce tiredness and stops hands from covering the screen. Instead of windows everywhere, the Con10uum windowing manager uses a straight-line layout. Multi-touch makes it easy to move and organize windows. On the right side of the screen, there is a menu for general options. On the left side, there are menus for specific applications.

An open source preview of the Con10uum windowing manager was shared with the public in November 2009.