Method for decoding bar-coded labels
AssigneeE. I. Du Pont de Nemours and Company
InventorsDavid C. Bullis, Alan G. Montross
Life of this patent
Estimating the term…
Abstract
A method for reading bar-coded labels by taking ratios of successive bars and spaces, then discriminating and categorizing the ratios of one of four possibilities. This output is combined and decoded into characters using a read-only-memory. The characters along with information on spacing between the characters is then passed to a microprocessor. The microprocessor decides which of the characters are valid and assembles a complete scans worth of information by making use of the data relating to the separation between characters. Handling the data in this fashion provides a means to assemble data from partial scans of the label into one complete scan.
Claims3
A method for decoding bar-coded labels comprising:
- computing separate ratios between adjacent bars and between adjacent spaces from an input data stream of bars and spaces;
- assigning a two-bit binary code to each computed ratio in order to classify it as a greater than, less than, equal to or erroneous relation;
- decoding the resultant string of binary bits of the classified ratios into corresponding tentative character identifications using associated bar count data;
- and assembling the tentative character identifications into a most likely to have occurred character set.
Dependencies are inferred from the claim text.