Patent ID: 6527193
Filing Date: 2003-03-04
Classification: G06K

Abstract:
A system for the tracking of metallic objects by the application and subsequent reading and comparison of information incorporated therein with stored data, the system comprising a device for applying information to the object along a prescribed pattern, storing devices and a device for reading the information from the marked object, the device applying the information contains elements adapted to perform local heat energy transfer along the prescribed pattern for producing markings by permanently changing the surface layer of the object to be marked to a prescribed depth, the information reading device contains an energizing device adapted to energize the surface layer of the marked object and a detecting unit for detecting a response signal derived from the marked object by said energizing and an unit for restoring information from deviations caused by local unevenness of said response signal, characterized in that said energizing device (902) is adapted to energize the surface layer of the marked object (103) at least up to the depth of the marking and said detecting unit (406) is adapted for detecting a response signal invoked in said marked object (103).