Projection keyboard

A projection keyboard is a virtual keyboard that can be projected and touched on any surface. The keyboard watches finger movements and translates them into keystrokes in the device. Most systems can also function as a virtual mouse or even as a virtual piano.A proposed system called the P-ISM will combine the technology with a small video projector to create a portable computer the size of a fountain pen.

How a projection keyboard generally works:

1. A laser or beamer projects visible virtual keyboard onto level surface
2. A sensor or camera in the projector picks up finger movements
3. detected co-ordinates determine actions or characters to be generated

Some devices use a second (invisible infrared) beam:

1. An invisible infrared beam is projected above the virtual keyboard
2. Finger makes keystroke on virtual keyboard. This breaks infrared beam and infrared light is reflected back to projector
3. Reflected infrared beam passes through infrared filter to camera
4. Camera photographs angle of incoming infrared light
5. Sensor chip determines where infrared beam was broken
6. detected coordinates determine actions or characters to be generated

An optical virtual keyboard was invented and patented by IBM engineers in 1992. 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 or projected 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.

In 2002, the start-up company Canesta developed a projection keyboard using their proprietary "electronic perception technology". The company subsequently licensed the technology to Celluon of Korea.

How Laser Keyboard Works


The laser keyboards use laser and infra-red technology to create the virtual keyboard and to project the hologram of a keyboard on a flat surface.

The projection is realized in four main steps and via three modules: projection module, sensor module and illumination module. The main devices and technologies used to project the hologram are a diffractive optical element, red laser diode, CMOS camera and sensor chip and an infrared (IR) laser diode.

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