Process for inspecting and automatically classifying objects presenting configurations with dimensional tolerances and variable rejecting criteria depending on placement, apparatus and circuits therefor

摘要

1. A process for inspecting and automatically sorting objects showing patterns with dimensional tolerances and reject criteria varying in accordance with the location of said patterns, of the type including the comparison of the image of a reference object with the image of an object to be inspected, the latter being liable to show geometrical defects with respect to the reference object, characterized in that it includes the following steps : - Elaborating binary electronic images IREF and IEXA from the reference object and the object to be inspected, - Defining a structuring element B for each image point (pixel), the size of said structuring element being able to vary for each pixel in function of predetermined data and adjusting IREF to the maximum and minimum dimensional tolerances by expanding and eroding said image by means of structuring element B, which provides (IREF )max and (IREF )min , - Forming images of the "spreading" and "lack" type defects by respectively carrying out the following logical operations : [(IREF )max OR IEXA ] EXCL. OR (IREF )max and [(IREF )min OR IEXA ] EXCL. OR IEXA , - Measuring the size of the defects on the defect images and comparing said defects with respect to reject criteria which define, for each pixel, the dimensions of the defects which can be accepted according to predetermined data, and - Sorting and selecting objects without any defect or showing defects allowed by the reject criteria.