Celluon magic cube
At the bottom of the box beams of a good light are emitted just above the surface of the desk. As your fingers tap that surface they cut through this beam, which is reflected up to a camera in the middle of the box. The camera looking like the reflection and works out from its position that key when you have “Pressed”, news from the Sydney Morning Herald. Though the Magic Cube is clever so it is essentially just a very portable replacement for a real keyboard.