Two-dimensional code reading apparatus
First Claim
1. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
- a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code;
a reference position determining device for determining a reference position where each cell constituting a pattern of a predetermined shape lies in said two-dimensional image detected by said two-dimensional image detecting device on the basis of a pattern of said pattern having said predetermined shape;
a cell size determining device for determining a size of a cell in said two-dimensional code from said pattern of said pattern said predetermined shape;
a cell position calculating device for calculating a position of each of cells from said reference position determined by said reference position determining device on the basis of said cell size determined by said cell size determining device;
a cell reading device for determining a type of a cell at a cell position calculated by said cell position calculating device;
an isolated cell distinguishing device for distinguishing whether or not a cell of which type has been determined is an isolated cell;
an actual position determining device for determining an actual position of the isolated cell on the basis of the two-dimensional image of the isolated cell, when said isolated cell distinguishing device distinguishes that the cell is the isolated cell;
a cell position correction value calculating device for calculating a correction value for correcting a calculated cell position from a difference between said calculated position and said actual position of said isolated cell; and
a cell position correcting device for correcting said cell position calculated by said cell position calculating device by using said correction value calculated by said cell position correction value calculating device.
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Accused Products
Abstract
A two-dimensional code reading apparatus uses the image of a reference pattern of a known shape in the two-dimensional code to compute areas, shapes and positions of cells in the image of the two-dimensional code and corrects these computed values using correction values obtained by identifying cells isolated from cells of the same type in at least one direction whenever they appear and extracting their actual boundary coordinates directly from the image data. As a result, even if there is distortion in the image of the two-dimensional a reading scope for each cell to be read is set to a suitable area and the reading position of each cell is determined accurately in correspondence with the distortion and the content of the two-dimensional code is thereby read correctly.
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Citations
55 Claims
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1. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
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a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code; a reference position determining device for determining a reference position where each cell constituting a pattern of a predetermined shape lies in said two-dimensional image detected by said two-dimensional image detecting device on the basis of a pattern of said pattern having said predetermined shape; a cell size determining device for determining a size of a cell in said two-dimensional code from said pattern of said pattern said predetermined shape; a cell position calculating device for calculating a position of each of cells from said reference position determined by said reference position determining device on the basis of said cell size determined by said cell size determining device; a cell reading device for determining a type of a cell at a cell position calculated by said cell position calculating device; an isolated cell distinguishing device for distinguishing whether or not a cell of which type has been determined is an isolated cell; an actual position determining device for determining an actual position of the isolated cell on the basis of the two-dimensional image of the isolated cell, when said isolated cell distinguishing device distinguishes that the cell is the isolated cell; a cell position correction value calculating device for calculating a correction value for correcting a calculated cell position from a difference between said calculated position and said actual position of said isolated cell; and a cell position correcting device for correcting said cell position calculated by said cell position calculating device by using said correction value calculated by said cell position correction value calculating device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
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a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code; a reference pattern detecting device for detecting a reference pattern of a predetermined shape existing in said two-dimensional image of said two-dimensional code detected by said two-dimensional image detecting device; a cell shape calculating device for obtaining an area of a cell of said two-dimensional code in said two-dimensional image on the basis of said reference pattern detected by said reference pattern detecting device; a reading control device for when a content of a cell is to be read from said two-dimensional image adjusting a size of a reading scope from which the content of the cell is to be read with respect to a cell area obtained by said cell shape calculating device according to a distance of the cell from said reference pattern; and a cell reading device for reading a content of a cell from said reading scope adjusted by said reading control device at a position of each cell of said two-dimensional image. - View Dependent Claims (31, 32, 33, 34, 35)
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36. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
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a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code; a reference pattern detecting device for detecting a reference pattern of a predetermined shape existing in said two-dimensional image detected by said two-dimensional image detecting device; a cell shape calculating device for obtaining an area of a cell of said two-dimensional code in said two-dimensional image on the basis of said reference pattern detected by said reference pattern detecting device; a cell grouping device for grouping cells of said two-dimensional code in said two-dimensional image with a position of said reference pattern detected by said reference pattern detecting device as a reference; a reading control device for when cells are to be read from said two-dimensional image adjusting for each group of cells formed by said cell grouping device a size of a reading scope from which a content of each of the cells in a group is to be read with respect to a cell area obtained by said cell shape calculating device; and a cell reading device for reading a content of the cell with said reading scope adjusted group by said reading control device at a position of each cell of said two-dimensional image. - View Dependent Claims (37, 38, 39, 40, 41)
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42. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
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a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code; a reference pattern detecting device for detecting a reference pattern of a predetermined shape existing in said two-dimensional image detected by said two-dimensional image detecting device; a cell shape calculating device for obtaining a shape of a cell of said two-dimensional code in said two-dimensional image on the basis of said reference pattern detected by said reference pattern detecting device; a reading control device for when a content of a cell is to be read from said two-dimensional image adjusting a shape of a reading scope from which the content of the cell is to be read with respect to a cell shape obtained by said cell shape calculating device according to a distance of the cell from said reference pattern; and a cell reading device for reading the content of the cell from said reading scope adjusted by said reading control device at a position of each cell of said two-dimensional image. - View Dependent Claims (43, 44, 45, 46, 47, 48)
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49. A two-dimensional code reading apparatus for reading a two-dimensional code wherein binary code data is expressed as a pattern of black and white cells in a two-dimensional matrix, comprising:
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a two-dimensional image detecting device for detecting a two-dimensional image of said two-dimensional code; a reference pattern detecting device for detecting a reference pattern of a predetermined shape existing in said two-dimensional image detected by said two-dimensional image detecting device; a cell shape calculating device for obtaining a shape of a cell of said two-dimensional code in said two-dimensional image on the basis of said reference pattern detected by said the reference pattern detecting device; a cell grouping device for grouping cells of said two-dimensional code in said two-dimensional image with a position of said reference pattern detected by said reference pattern detecting device as a reference; a reading control device for when contents of cells are to be read from said two-dimensional image adjusting for each group of cells formed by said cell grouping device a shape of a reading scope from which the content of each of the cells in a group is to be read with respect to a cell shape obtained by said cell shape calculating device; and a cell reading device for reading the content of the cell from said reading scope adjusted group by said reading control device at a position of each cell of said two-dimensional image. - View Dependent Claims (50, 51, 52, 53, 54, 55)
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Specification