HARDWARE

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.
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]
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


Projection keyboards connectivity
Projection keyboards connect to the devices they are used for either through Bluetooth or USB.
The Bluetooth projection keyboard is a wireless virtual keyboard, a pocket-size device that projects a full-size keyboard through infrared technology onto any flat surface.
Bluetooth dongle technology enables the projection keyboard for point to multi-point friendly connectivity with other Bluetooth devices, such as PCs, PDAs and mobile phone. Bluetooth is an open specification for wireless data transmission which operates on the globally available 2.4GHz radio frequency.
The way the Bluetooth projection keyboard is connected to a device varies depending on the specific laptop, phone or computer that the user intends to use it for. All the connectivity instructions normally come with the product and they basically consist in turning on the Bluetooth connection on one's device and then turning on the keyboard.
The USB projection keyboard works like a regular USB keyboard. The connection between the virtual keyboard and the device is made through a USB port, which is available on every computer, laptop and other devices that are compatible with the projection keyboard. Connection instructions come as well with the product and with the manufacturer's specifications but it mainly consists in Plug and Play the devices