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US 5,479,515 AGranted
One-dimensional bar code symbology and method of using same
AssigneeWelch Allyn, Inc.
InventorAndrew Longacre, Jr.
Life of this patent
Estimating the term…
Abstract
A linear bar code symbology combines delta distance start and stop patterns, a space efficient, bit oriented data character structure, and Reed-Solomon redundancy for error detection and correction. A method of writing the bar code structures onto a character medium and reading the resulting symbols under adverse conditions is presented.
Claims18
A bar code structure containing encoded information therein comprising:
- a start pattern, a stop pattern and a predetermined number of code words therebetween, said start pattern, said stop pattern and said code words being arranged in a single row, said code words comprising:
- a plurality of elements having identical width dimensions, each element being selected from the group of a bar and a first space;
- said code words being separated from one another by a said element, and including at least one data word and at least one check word that is calculated from said data word by Reed-Solomon encoding.
A method for decoding a bar code symbol having a structure comprising:
- a start pattern, a stop pattern and a predetermined number of code words therebetween, said start pattern, said stop pattern and said code words being arranged in a single row, said code words comprising:
- a plurality of elements having identical width dimensions, each element being selected from the group of a bar and a first space;
- said code words being separated from one another by a said element, and including at least one data word and at least one check word;
- the method comprising the steps of:
- determining a first value of each of said code words;
- and performing a Reed-Solomon decoding of said first values.
3 more elements
A bar code structure containing encoded information therein comprising:
- a start pattern, a stop pattern and a fourteen code words therebetween, said start pattern, said stop pattern and said code words being arranged in a single row;
- said code words each comprising eight elements having identical width dimensions, each element being selected from the group of bar and a first space, said code words further comprising seven data words and seven check words that are calculated from said data words by systematic Reed-Solomon encoding using a 2.sup.8 Galois Field;
- said code words each being bracketed by a said bar and a said first space;
- said start pattern and said stop pattern each comprising:
- a group comprising three second spaces in alternation with two said bars;
- and
- a third space having a width dimension that exceeds a width dimension of said group.
4 more elements
Dependencies are inferred from the claim text.