A method of manufacturing a platform includes the steps of providing an interconnecting line adhering first and second regions of a mold, disposing an optical fiber with its end surface facing the mold, sealing the optical fiber and the interconnecting line with a molding material, and removing the interconnecting line and the molding material together with the optical fiber from the mold. Solving Means Not only on a real screen but also on a virtual screen set around the real screen, coordinates of a virtual pointer are generated and stored. The uncompensated drive train provides for the direct coupling of a rotor to a drive motor.