Method and apparatus for reading bar codes
First Claim
1. A method for reading a bar code having at least one code block of bars and spaces between the bars having respective widths and representing a plurality of characters and partitions of respective, different types flanked beside the block, comprising:
- scanning a surface of the bar code with different scan lines;
measuring the widths of the bars and the widths of the spaces between the bars in each scan line;
storing a plurality of rows of data in a storage unit, each row of data having a plurality of bar width and space width data obtained by scanning the bar code with each scan line;
extracting partition indicative data, each having a series of bar width and space width data and each corresponding to a partition and an adjacent character to the partition in the bar code, from the row of data stored in the storage unit;
appending a first flag to the partition indicative data, which represents a scanning sequence indicating which is scanned first, from among the partition and the adjacent character;
appending a second flag to the partitioning indicative data, which determines the type of the partition;
determining whether the partition is a first type or a second type based on the bar configuration of the partition; and
determining the type and the direction of each scan line scanned when obtaining each partition indicative data based on respective states of the first flag and the second flag and thus the determined type of the partition.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and an apparatus for reading a bar code are in which a plurality of types of bar codes which may coexist can be demodulated with higher accuracy and higher speed. A bar code data detector 31 extracts the features of a guard bar and a center bar. This information is searched for by a search section 39a and the features and the bar code types read are identified. The bar code data are demodulated in a bar code demodulator 32 by a method corresponding to the result of identification of the features and the bar code types.
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Citations
32 Claims
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1. A method for reading a bar code having at least one code block of bars and spaces between the bars having respective widths and representing a plurality of characters and partitions of respective, different types flanked beside the block, comprising:
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scanning a surface of the bar code with different scan lines; measuring the widths of the bars and the widths of the spaces between the bars in each scan line; storing a plurality of rows of data in a storage unit, each row of data having a plurality of bar width and space width data obtained by scanning the bar code with each scan line; extracting partition indicative data, each having a series of bar width and space width data and each corresponding to a partition and an adjacent character to the partition in the bar code, from the row of data stored in the storage unit; appending a first flag to the partition indicative data, which represents a scanning sequence indicating which is scanned first, from among the partition and the adjacent character; appending a second flag to the partitioning indicative data, which determines the type of the partition; determining whether the partition is a first type or a second type based on the bar configuration of the partition; and determining the type and the direction of each scan line scanned when obtaining each partition indicative data based on respective states of the first flag and the second flag and thus the determined type of the partition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for reading a bar code having a least one code block of bars and spaces between the bars having respective widths and representing a plurality of characters and partitions of respective, different types flanked beside the block, comprising:
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scanning a surface of the bar code with different scan lines; reading a plurality of different scan data obtained by scanning along the different scan lines; storing the plurality of different scan data in a storage unit; extracting partially scanned data obtained by scanning along separate scan lines that pass through a partition and a part of a block adjacent to the partition in the bar code from the plurality of scan data stored in the storage unit; reproducing a plurality of partially decoded data form the partially scanned data; extracting a pair of decoded data from the partially decoded data, each thereof having a number of character digits overlapped with each other and having different respective partitions; calculating the number of character digits overlapped with between the pair of extracted decoded data; and reading the bar code by synthesizing the pair of decoded data when the calculated number is equal to or more than a determined value in response to a type of the bar code. - View Dependent Claims (15, 16, 19, 20, 21)
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17. An apparatus for reading a bar code having at least one code block of bars and spaces between the bars having respective widths and representing a plurality of characters and partitions of respective, different types flanked beside the block, comprising:
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an optical source producing a light illuminating the bar code; a scanning mechanism applying the light from the optical source to a surface of the bar code along a plurality of scanning lines; an optical receiver receiving the light reflected from the surface of the bar code illuminated by the light applied thereto and producing a corresponding output; a counter measuring bar widths and space widths alternatively appearing in each scan line in response to the output of the optical receiver; a storage unit storing each row of data having a plurality of bar width and space width data obtained from the bar width counter by scanning the bar code each time with each scan line; an extracting unit extracting partition indicative data each having a series of bar width and space width data from each stored row of data corresponding to a partition and an adjacent character to the partition in the bar code; a flag appending unit appending a first flag to the partition indicative data which represents a scanning sequence indicating which is scanned first from among the partition and the adjacent character, and for appending a second flag to the partition indicative data which determines the type of the partition; and a scanning line type determining unit determining the type and direction of each scan line scanned when obtaining each partition indicative data based on respective states of the first flag and the second flag and the determined first type or second type of the partition, based on the bar configuration of the partition. - View Dependent Claims (18, 22, 23, 24, 25, 26, 27, 28, 29)
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30. An apparatus for reading a bar code having at least one code block of bars and spaces between the bars having respective widths and representing a plurality of characters and partitions of respective, different types flanked beside the block, comprising:
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a scanned data reader reading a plurality of scanned data obtained by scanning a surface of the bar code with different scanning lines; a storage unit storing the plurality of scanned data; a first extracting unit extracting partially scanned data, obtained by scanning along separate scanning lines that pass through a partition and a part of a block adjacent to the partition in the bar code, from the plurality of scanned data stored in the storage unit; a reproducing unit reproducing a plurality of partially decoded data from the partially scanned data; a second extracting unit extracting a pair of partially decoded data, each having a number of character digits mutually overlapped and having respective different partitions; a calculator calculating the number of character digits overlapped between the pair of extracted partially decoded data; and a synthesizing unit synthesizing the pair of decoded data when the calculated number of overlapped character digits is equal to or more than a determined value. - View Dependent Claims (31, 32)
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Specification