Projection keyboard is, in essence, an electronic device that can project onto a flat surface a keyboard layout which users can type on and input data into computer with. It does what a common physical keyboard can do, but has a much smaller size. 

For decades, scientists have been working on giving computers three-dimensional interface for human beings to interact with them more naturally. This wish is illuminated through the lens of a lot of science fiction  films, like The Minority Report. We’ve been expecting that the projected interface might change people’s ways of interaction with technologies greatly. Projection Keyboard, though far from perfect, might be a step toward that direction.