Patent ID: 7355727

Claim:
A method for checking the position of a mechanical part along at least one checking direction by means of an apparatus including a device for generating a light beam along a trajectory transverse to said at least one checking direction, a sensor for detecting the interruption of the light beam, and devices for causing relative displacements between the mechanical part and the light beam along said at least one checking direction and along an inspection direction transverse to the at least one checking direction, the method comprising: identifying a first linear interval and a second linear interval related to relative positions between the mechanical part and the light beam along the at least one checking direction and the inspection direction, respectively, said first linear interval and said second linear interval defining a checking area of the mechanical part; controlling a sequence of checking displacements between the mechanical part and the light beam, including: controlling displacements for bringing the light beam to inspection positions along the first linear interval; and controlling linear inspection movements at said inspection positions along said inspection direction; detecting the interruption or the non-interruption of the light beam in the course of said linear inspection movements along the inspection direction, and consequently selecting a subsequent of said inspection positions along the first linear interval at which subsequent linear inspection movements are controlled; stopping the sequence of checking displacements at a final inspection position of the light beam along the first linear interval, wherein said final inspection position lies at a distance less than a preset value from a previous inspection position, and wherein in the course of linear inspection movements at said final inspection position and said previous inspection position in the first linear interval, there have been detected the interruption and the non-interruption of the light beam, respectively, or vice versa; and identifying the position of the mechanical part along the at least one checking direction on the basis of said final inspection position.