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.[1] 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.[2]

How a projection keyboard generally works:

A laser or beamer projects visible virtual keyboard onto level surface
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
detected co-ordinates determine actions or characters to be generated



An optical virtual keyboard[3] has been 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.