Bar codes and their associated reader/scanner systems are widely used in manufacturing, shipment and inventory control of various products and equipment, to assist in document control, article handling systems and security/access control systems. Bar code reading and scanning systems have been developed to scan and decode standard bar code formats and to generate digital representations to be used as inputs, typically to computer directed processing and control equipment.
Conventional bar code reading systems scan and read the printed bar code formats and decode the elements (i.e., the bars and spaces) represented by the printed bar code format. A typical printed bar code format includes multiple parallel bars of varying widths which are separated by a number of spaces of varying widths, prearranged to represent a string of digits in a known, encoded form. Conventional bar code reading systems scan the parallel bars along a transverse scan path which is substantially perpendicular to the parallel bars. The scan can be made in either direction, with the reading system being constrained, however, to read only encoded bar code formats which have been precisely printed as a bar code label. The preprinted label must contain a predetermined, standard bar code format pattern which is recognizable by the bar code reading system. Conventional bar codes conform with A.N.S.I., I.S.O., or A.F.N.O.R. national/international standards Examples of conventional preprinted, preencoded bar code formats which comply with such standards include UPC, CODE-A-BAR, Code 39, and Interleaved 2 of 5.