Virtual input device operation method for computer system, cellular telephone, involves sensing penetration of stylus into optical beam plane to detect relative position of stylus in the plane

摘要

An optical system (20) emits an optical fan-shaped beam such that the plane (30) of the beam is parallel to and spaced from the planar work surface (40) of a virtual input device (50). Penetration of stylus into the beam plane (30) is sensed to determine the relative position of stylus in the plane. An independent claim is also included for virtual input system.