A virtual keyboard is made of infrared laser light. As a result the keyboard can be projected onto any flat surface. A separate infrared sensor tracks the keys as they are tapped. A virtual keyboard is created using both visible and invisible light. The visible light is used to project the keyboard on to a surface, and invisible infrared light is used to track the keystrokes.
How a virtual keyboard works:
1. A Laser projects a visible virtual keyboard onto a level surface.
2. Invisible infrared beam is projected above virtual keyboard.
3. The finger makes keystroke of the virtual keyboard. This breaks the infrared beam and infrared light is reflected back to the projector.
4. Reflected infrared beam passes through an infrared filter for the camera.
5. The camera photographs angle of incoming infrared light.
6. The sensor chip determines where the infrared beam was broken and translates it into co-ordinates and characters are created on screen