Method for evaluating a succession of bar code symbols

Abstract

A method to detect, process, and evaluate the quality of a succession of spaced bar code symbols. The symbols are disposed on a continuous substrate, moving past a scanner unit arranged to scan each symbol of the succession, one after the other. The method of the invention continuously scans the substrate to detect the entry of a bar code symbol into the field of view of the scanner unit. The presence of the bar code symbol in the scanner's field of view being established by a first valid decode of the symbol. Next, the first decoded scan and a plurality of subsequent decodable and non-decodable scans of the bar code symbol are processed to determine and store at least one evaluation attribute. The scanning and processing of the bar code continues until a predetermined number of consecutive non-decodable scans are processed, thereby indicating the absence of the bar code symbol from the field of view of the scanner and that the symbol has moved past the scanner. A number of the scans processed and the evaluation attributes determined for each scan, may then be employed to determine a measure of quality indicative of overall quality of the bar code symbol. The process may then be repeated for each bar code in the succession of bar code symbols. Additional steps may be included with the present methods to count regions on the moving substrate wherein bar code symbols are known to be disposed.