Virtual keyboard

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This article is about the type of computer program. For virtual keyboard that can be projected and touched on any surface, see Projection keyboard.
"OnBoard" Virtual Keyboard shipped with Ubuntu Linux
"OnBoard" Virtual Keyboard shipped with Ubuntu Linux

A virtual keyboard is a software and/or hardware component that allows a user to enter characters. A virtual keyboard can usually be operated with multiple input devices, which may include an actual keyboard, a computer mouse, a headmouse, and an eyemouse. On a desktop PC, the primary purpose of a virtual keyboard is to provide an alternative mechanism for disabled users that can not use a physical keyboard.

They can be further categorised by the following aspects:

  • physical keyboards with distinct keys comprising electronically changeable displays integrated in the keypads
  • virtual keyboards with touchscreen keyboard layouts or sensing areas[1]
  • optically projected keyboard layouts or similar arrangements of "keys" or sensing areas[2][3]
  • optically detected human hand and finger motions[4]
The On-screen Keyboard in Microsoft Windows.
The On-screen Keyboard in Microsoft Windows.

In stylus-operated personal data assistants, which lack a physical keyboard, it is also common for the user to input text by tapping a virtual keyboard built into the operating system of the PDA. Virtual keyboards are also used as features of emulation software for systems that have fewer buttons than a computer keyboard would have.

An optical virtual keyboard has been invented and patented by IBM engineers in 1992[4]. It optically detects and analyses human hand and finger motions and interprets them as operations on a physically non-existent input device like a surface having painted keys. In that way it allows to emulate unlimited types of manually operated input devices (mouse, keyboard, etc.). All mechanical input units can be replaced by such virtual devices, optimized for the current application and for the user's physiology maintaining speed, simplicity and unambiguity of manual data input.

[edit] References

  1. ^ EP patent application 546704 Thomas H. Speeter/AT&T: "Intelligent work surfaces" priority date 13.12.1991
  2. ^ DE patent application 19734511 B. Kämmerer, C, Maggioni, H. Röttger/SIEMENS AG: "Kommunikationseinrichtung" filing date 08.08.1997
  3. ^ WO patent 0003348 C. Maggioni, B. Kämmerer/SIEMENS AG: "Projection Device / Vorrichtung zur Projektion" priority date 10.07.1998
  4. ^ a b EP patent 0554492 Hans E. Korth: "Method and device for optical input of commands or data" filing date 07.02.1992

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