Decoding bar code symbols by determining the best alignment of partial scans

Claim 1

A method for processing a bar code symbol composed of an ordered sequence of characters, each character including a plurality of individual elements of different light reflectivity, comprising the steps of; (a) scanning said symbol along a first scanning path and storing a representation of said elements from the scan to form a first sequence of elements; (b) scanning said symbol along another path different from the preceding scanning path and storing a representation of elements from such scan to form a second sequence of elements; (c) comparing elements of the second sequence to elements of the first sequence for different alignments of the first and second sequences; (d) calculating a score for each comparison, the score representing the degree to which elements from the second sequence match elements from the first sequence at an alignment; (e) identifying a best match and a next-best match based upon the scores; (f) determining the difference between the scores for best match and the next-best match; (g) in the event that the difference in scores exceeds a predetermined amount, combining the first sequence and the second sequence at the alignment that produces the best match.

Claim 2

A method for processing a bar code symbol composed of an ordered sequence of characters, each character including a plurality of individual elements of different light reflectivity, comprising the steps of; (a) scanning said symbol along a first scanning path and storing a representation of said elements from the scan to form a first sequence of elements; (b) scanning said symbol along another path different from the preceding scanning path and storing a representation of elements from such scan to form a second sequence of elements; (c) comparing elements of the second sequence to elements of the first sequence for different alignments of the first and second sequences; (d) calculating a score for each comparison, the score representing the degree to which elements from the second sequence match elements from the first sequence at an alignment; (e) identifying a best match and a next-best match based upon the scores; (f) determining the difference between the scores for best match and the next-best match; (g) in the event that the difference in scores exceeds a predetermined amount, combining the first sequence and the second sequence at the alignment that produces the best match.

Claim 7

A method for reading indicia having elements of different light reflectivity by a scanner comprising the steps of: (a) scanning a target containing a bar code symbol and detecting at least a portion of light of variable intensity reflected off the target with a sensor and generating a first electrical signal having portions representative of elements of the symbol; (b) detecting at least another portion of light of variable intensity reflected off the target with a sensor and generating an additional electrical signal having portions representative of elements of the symbol; (c) comparing portions of the additional signal to portions of the first signal for different alignments of the first and additional signals; (d) calculating a score for each comparison, the score representing the degree to which portions of the additional signal match portions of the first signal at an alignment; (e) identifying a best match and a next-best match based upon the scores; (f) determining the difference between the score for the best match and the next-batch match; (g) in the event that the difference exceeds a predetermined amount, combining the first signal and the additional signal at the alignment that produced the best match.

Claim 8

A method for reading indicia having elements of different light reflectivity by a scanner comprising the steps of: (a) scanning a target containing a bar code symbol and detecting at least a portion of light of variable intensity reflected off the target with a sensor and generating a first electrical signal having portions representative of elements of the symbol; (b) detecting at least another portion of light of variable intensity reflected off the target with a sensor and generating an additional electrical signal having portions representative of elements of the symbol; (c) comparing portions of the additional signal to portions of the first signal for different alignments of the first and additional signals; (d) calculating a score for each comparison, the score representing the degree to which portions of the additional signal match portions of the first signal at an alignment; (e) identifying a best match and a next-best match based upon the scores; (f) determining the difference between the score for the best match and the next-batch match; (g) in the event that the difference exceeds a predetermined amount, combining the first signal and the additional signal at the alignment that produced the best match.

Claim 14

A method for processing a symbol composed of an ordered sequence of characters, each character including a plurality of individual elements of different light reflectivity with a set of predetermined patterns of elements representing valid characters, while all other patterns represent invalid characters, comprising the steps of: (a) scanning said symbol along a first scanning path and storing a representation of said elements from the scan to form a first sequence of elements; (b) scanning said symbol along another scanning path different from the preceding scanning path and storing a representation of elements from such scan to form a subsequent sequence; (c) comparing elements of the second sequence to elements of the first sequence for different alignments of the first and second sequences; (d) calculating a score for each comparison, the score representing the degree to which elements from the second sequence match elements from the first sequence at an alignment; (e) identifying a best match and next-best match based on the scores; (f) determining the difference between the scores for the best match and the next-best match; (g) in the event that the difference in score exceeds a predetermined amount, combining the first sequence and the subsequent sequence at the alignment that produced the best match.

Claim 15

A method for processing a symbol composed of an ordered sequence of characters, each character including a plurality of individual elements of different light reflectivity with a set of predetermined patterns of elements representing valid characters, while all other patterns represent invalid characters, comprising the steps of: (a) scanning said symbol along a first scanning path and storing a representation of said elements from the scan to form a first sequence of elements; (b) scanning said symbol along another scanning path different from the preceding scanning path and storing a representation of elements from such scan to form a subsequent sequence; (c) comparing elements of the second sequence to elements of the first sequence for different alignments of the first and second sequences; (d) calculating a score for each comparison, the score representing the degree to which elements from the second sequence match elements from the first sequence at an alignment; (e) identifying a best match and next-best match based on the scores; (f) determining the difference between the scores for the best match and the next-best match; (g) in the event that the difference in score exceeds a predetermined amount, combining the first sequence and the subsequent sequence at the alignment that produced the best match.

Claim 17

A method of processing a bar code symbol containing distortion, said symbol including a sequence of characters, each character including a plurality of individual elements of different light reflectivity, with a set of predetermined patterns of elements representing legitimate characters, while all other patterns represent illegitimate characters, comprising the steps of: (a) storing a first representation of elements of said bar code symbol derived from scanning through said bar code symbol; (b) storing a second representation of elements of said bar code symbol derived from scanning through only a portion of said bar code symbol; (c) comparing elements of the second representation to elements of the first representation for different alignments of the first and second representations; (d) calculating a score for each comparison, the score representing the degree to which elements from the second representation match elements from the first representation at an alignment; (e) identifying a best match and a next-best match based on the scores; (f) determining the difference between the scores for the best match and the next-best match; and (g) in the event that the difference exceeds a predetermined amount, combining the first representation and the second representation at the alignment that produced the best match.

Claim 18

A method of processing a bar code symbol containing distortion, said symbol including a sequence of characters, each character including a plurality of individual elements of different light reflectivity, with a set of predetermined patterns of elements representing legitimate characters, while all other patterns represent illegitimate characters, comprising the steps of: (a) storing a first representation of elements of said bar code symbol derived from scanning through said bar code symbol; (b) storing a second representation of elements of said bar code symbol derived from scanning through only a portion of said bar code symbol; (c) comparing elements of the second representation to elements of the first representation for different alignments of the first and second representations; (d) calculating a score for each comparison, the score representing the degree to which elements from the second representation match elements from the first representation at an alignment; (e) identifying a best match and a next-best match based on the scores; (f) determining the difference between the scores for the best match and the next-best match; and (g) in the event that the difference exceeds a predetermined amount, combining the first representation and the second representation at the alignment that produced the best match.