Patent ID: 6452150
Filing Date: 2002-09-17
Classification: G06T

Abstract:
Apparatus for on-line monitoring of objects such as cassettes and similar devices used for handling semiconductor wafers to determine whether the objects remain within relevant dimensional tolerances during wafer processing, the apparatus comprising:a first digital camera for photographing an object at suitable distance to provide digital images to be used to determine whether relevant dimensions of the object are within tolerance limits, the object and the camera being moved relative to each other to position them for taking pictures of one or more faces of the object; a computer coupled to the camera for storing images of the object taken by the camera and for analyzing the images to determine whether relevant dimensions of the object are still within tolerance limits; and at least one additional camera identical to the first, the cameras photographing respective parts of a whole object, the individual camera pictures being assembled by the computer into a composite digital image having greater resolution than obtainable with a single camera alone.