Patent ID: 7573463

Claim:
An apparatus comprising an optical input device controlled by a moving object near a window and an optical keyboard, wherein the optical input device comprises at least two optical sensor units comprising at least two diode lasers for supplying at least two measuring beams and converting means for converting measuring beam radiation reflected by the object into an electric signal, which converting means are constituted by the combination of a laser cavity and measuring means for measuring changes in operation of the laser cavity, which are due to interference of reflected measuring beam radiation re-entering the laser cavity and the optical wave in this cavity and which are representative of the movement of the object, wherein at least two paths of the at least two measuring beams from the at least two diode lasers to the window extend through at least two light guides of the optical keyboard, said at least two paths including mirrors and passing through the window, wherein each key of the optical keyboard along said at least two paths is associated with only a single path of said at least two paths.