Patent ID: 6573523
Filing Date: 2003-06-03
Classification: G06K

Abstract:
A method for identifying a substrate having a surface, the surface of the substrate having indicia with an indicia length in a first direction and an indicia width in a second direction, and having edge features and substantially flat features, the method comprising:(a) radiating the indicia with incident radiation from a radiation source, the incident radiation having a radiation length substantially in the first direction and a radiation width substantially in the second direction, (b) generating relative motion between the substrate and the radiation source, thereby scanning the incident radiation over the indicia, (c) receiving reflected radiation having a first intensity level from the edge features of the indicia, (d) receiving reflected radiation having a second intensity level from the substantially flat features of the indicia, (e) detecting the reflected radiation to produce at least one output signal having a first amplitude level corresponding to the first intensity level and a second amplitude level corresponding to the second intensity level, (f) processing the at least one output signal based at least in part upon the first and second intensity levels to form at least one image portion of the indicia, (g) recognizing the indicia based at least in part upon the at least one image portion, and (h) identifying the substrate based at least in part upon the recognized indicia.