A projection keyboard, also known as a virtual keyboard, is a projection that looks and works like a keyboard; when touched, the system will pick up finger movements and will accurately register them as keystrokes. All projection keyboard units are made to be wireless, giving them greater operating lengths than wired keyboards. There are two systems in use for registering keystrokes with projection keyboards; one uses a camera sensor to capture finger movements, while the other uses an infrared sensor to detect finger movement. Along with keystrokes, most of these systems also provide virtual mouse and piano projections. The most popular use of these keyboards is with mobile devices, but desktops also can use them.
The projection keyboard is a wireless device that typically uses Bluetooth® technology to link the keyboard sensor and the computer or mobile device. This allows projection keyboards to have a much longer operating distance than wired keyboards. Bluetooth® technology also has been integrated with computers for years, so the computer should have no trouble picking up the keystrokes.
There are two versions of the projection keyboard, though both produce the same result. The most common version projects the keyboard via a laser and, when the user pushes a virtual key, a camera records the finger movements. From this image, the camera uses the coordinates to pick the correct key and enters it into the computer or device. The second type projects a keyboard and projects an infrared beam over it. When a key is hit, a sensor detects where the infrared light was broken by finger movement and records the appropriate keystroke.
Most projection keyboard units are able to project two other devices: a mouse and piano. The virtual piano works pretty much the same way as the virtual keyboard. When someone pushes a piano key, the system detects the movements and responds by making the appropriate sound. With the virtual mouse, the user moves the mouse with his or her hand, and it will respond by moving the mouse pointer around the computer screen.
Projection keyboard units are used most commonly with mobile devices and are considered a replacement for the fold-up keyboard and the mobile keyboard. Mobile devices that have digital keyboards, or those on the device’s screen, can use this system if the user finds it difficult to type on the device's small digital keyboard. While primarily used with mobile devices, this keyboard also can integrate with desktops to replace wired keyboards.