Optically readable two-dimensional code and method and apparatus using the same

A two-dimensional code reading apparatus for optically reading a two-dimensional code including a plurality of binary-coded cells in a two-dimensional matrix pattern, said two-dimensional code including a symbol disposed in a vicinity of an apex of said two-dimensional matrix, said symbol having a specific pattern including concentric similar figures overlapped successively, said reading apparatus comprising:

• an image pickup device to take an image of said two-dimensional code to convert said image pixel by pixel into a resultant image signal in response to a light intensity of said image, and to successively output said resultant image signal;
• and
• a decoder unit to decode said resultant image signal into a binary-coded signal, said decoder unit comprising:
• binary-encoding means for binary encoding said resultant image signal in accordance with a level of said resultant image signal, and outputting said binary-coded signal successively;
• memory means for storing said binary-coded signal as image data in accordance with a position of a pixel where said image was taken;
• symbol detecting means for detecting said specific pattern corresponding to said symbol based on said binary-coded signal;
• apex detecting means for detecting coordinates of said symbol from said image data stored in said memory means based on said specific pattern detected by said symbol detecting means;
• matrix position determining means for finalizing a contour and an orientation of said two-dimensional matrix based on coordinates of said symbol detected by said apex detecting means, thereby identifying all coordinates of said plurality of binary-coded cells;
• and
• reading means for reading out said image data stored in said memory means in accordance with said finalized contour and said orientation of said two-dimensional matrix.

A two-dimensional code reading method for optically reading a two-dimensional code including binary-coded cells placed in a two-dimensional matrix pattern, comprising steps of:

• disposing a symbol in a vicinity of an apex of said two-dimensional matrix, said symbol having a specific pattern including concentric similar figures overlapped successively;
• taking an image of said two-dimensional code by an image pickup device, converting said image pixel by pixel into an image signal in response to a light intensity of said image, binary encoding said image signal in accordance with a level of said image signal, and storing a resultant binary-coded signal as image data in memory means in accordance with a position of a pixel where said image was taken;
• detecting said specific pattern corresponding to said symbol based on said resultant binary-coded signal in parallel with storage of said binary-coded signal in said memory means;
• detecting coordinates of said symbol from said image data stored in said memory means based on said detected specific pattern;
• finalizing a contour and an orientation of said two-dimensional matrix based on coordinates of said symbol, thereby identifying all coordinates of said binary-coded cells;
• and
• reading out said image data stored in said memory means in accordance with said finalized contour and said orientation of said two-dimensional matrix.

A two-dimensional code comprising:

• a plurality of cells, each of said plurality of cells representing a binary-coded datum;
• said plurality of cells forming a two-dimensional matrix pattern readable by a scanning operation along scanning lines;
• and
• timing cells arrayed in said two-dimensional matrix, said timing cells including light and dark cells arrayed alternately with an inclination of 1/1.

A two-dimensional code formed from a two-dimensional matrix having a plurality of binary-coded cells, said two-dimensional code comprising:

• total symbol cells representing an orientation of said two-dimensional matrix;
• said total symbol cells forming a two-dimensional matrix pattern and being readable by a scanning operation along scanning lines;
• and
• at least one data cell group, each of said at least one data cell group comprising a group of said plurality of binary-coded cells, each of said at least one data cell group representing only one character and being disposed in a two-dimensional n.times.m square region in said two-dimensional matrix, said two-dimensional n.times.m square region being defined by vertically stacked binary-coded cells and horizontally arrayed binary-coded cells, in which said n is a number of said vertically stacked binary-coded cells and said m is a number of said horizontally arrayed binary-coded cells.

A two-dimensional code comprising:

• a plurality of cells, each of said plurality of cells representing a binary-coded datum;
• said plurality of cells being placed on a two-dimensional matrix, said two-dimensional matrix having a square shape and being enclosed by straight peripheral lines so as to form a pattern readable by a scanning operation along any arbitrary scanning lines;
• at least two positioning symbols disposed at apex positions in said two-dimensional matrix, each of said at least two positioning symbols having a pattern capable of gaining an identical frequency component ratio irrespective of an orientation of said arbitrary scanning lines whenever said arbitrary scanning lines pass through a center of each of said at least two positioning symbols, said at least two positioning symbols being square in shape and having straight peripheral lines parallel to said straight peripheral lines of said two-dimensional matrix;
• and
• said plurality of cells being processed through a predetermined conversion processing into a characteristic pattern different from said pattern of said positioning symbols.

A two-dimensional code reading apparatus for optically reading a two-dimensional code including a plurality of binary-coded cells placed on a two-dimensional square matrix pattern, said two-dimensional code including an orientation symbol and timing cells, said orientation symbol being disposed in a peripheral region of said two-dimensional square matrix pattern and comprising three apexes of said two-dimensional square matrix pattern, said reading apparatus comprising:

• an image pickup device to take an image of said two-dimensional code, to convert said image pixel by pixel into an image signal in response to a light intensity of said image, and successively outputting said image signal;
• and
• a decoder unit for decoding said image signal into a plurality of binary-coded signals;
• wherein said decoder unit comprises:
• binary-encoding means for binary encoding said image signal in accordance with a level of said image signal, and outputting said plurality of binary-coded signals successively;
• memory means for storing said plurality of binary-coded signals as image data in accordance with a position of a pixel where the image was taken;
• symbol detecting means for detecting a specific pattern corresponding to said orientation symbol based on said plurality of binary-coded signals;
• apex and timing cell detecting means for detecting coordinates of said three apexes of said orientation symbol and coordinates of said timing cells from said image data stored in said memory means based on said specific pattern detected by said symbol detecting means;
• matrix position determining means for finalizing a contour and an orientation of said two-dimensional square matrix based on the coordinates of said orientation symbol detected by said apex and timing cell detecting means, and identifying all coordinates of said plurality of binary-coded cells placed on said two-dimensional square matrix pattern with reference to said coordinates of said timing cells;
• and
• reading means for reading out said image data stored in said memory means in accordance with the finalized contour and said orientation of said two-dimensional square matrix pattern.

A two-dimensional code reading apparatus for optically reading a two-dimensional code including a plurality of binary-coded cells placed on a two-dimensional square matrix pattern, said two-dimensional code including timing cells and total symbol cells, said total symbol cells representing an orientation symbol and being disposed in a peripheral region of said two-dimensional matrix pattern and comprising a plurality of separate apex cells, said reading apparatus comprising:

• an image pickup device to take an image of said two-dimensional code, to convert said image pixel by pixel into an image signal in response to a light intensity of said image, and successively outputting said image signal;
• and
• a decoder unit for decoding said resultant image signals into a plurality of binary-coded signals;
• wherein said decoder unit comprises:
• binary-encoding means for binary encoding said image signal in accordance with a level of said image signal, and outputting said plurality of binary-coded signals successively;
• memory means for storing said plurality of binary-coded signals as image data in accordance with a position of a pixel where the image was taken;
• symbol detecting means for detecting a specific pattern corresponding to said total symbol cells based on said plurality of binary-coded signals;
• apex and timing cell detecting means for detecting coordinates of said timing cells and coordinates of each of said plurality of separate apex cells comprised by said total symbol cells;
• matrix position determining means for finalizing a contour and an orientation of said two-dimensional square matrix pattern based on the coordinates of said plurality of said separate apex cells detected by said apex and timing cell detecting means, and identifying all coordinates of said plurality of binary-coded cells placed on said two-dimensional square matrix pattern with reference to said coordinates of said timing cells;
• and
• reading means for reading out said image data stored in said memory means in accordance with said finalized contour and said orientation of said two-dimensional square matrix pattern.

A two-dimensional code reading apparatus for optically reading a two-dimensional code including a plurality of white binary-coded cells and a plurality of black binary-coded cells in a two-dimensional matrix pattern, said plurality of white binary-coded cells and said plurality of black binary-coded cells comprising dummy cells in a data region so as to prevent one of said plurality of white binary-coded cells and said plurality of black binary-coded cells from being consecutively and extensively arrayed, said two-dimensional code comprising an orientation symbol disposed in a peripheral region of said two-dimensional matrix, said reading apparatus comprising:

• an image pickup device to take an image of said two-dimensional code, to convert said image pixel by pixel into an image signal in response to a light intensity of said image, and successively outputting said image signal;
• and
• an encoder unit for encoding said image signal into a plurality of binary-coded signals;
• wherein said encoder unit comprises:
• binary-encoding means for binary encoding said image signal in accordance with a level of said image signal, and outputting said plurality of binary-coded signals successively, said binary-encoding means comprising:
• a comparator means for comparing a white level and a black level of an input waveform representing said image signal with a follow-up waveform which approaches one of said white level and said black level of said input waveform when one of said plurality of white binary-coded cells and said plurality of black binary-coded cells are so consecutively and extensively arrayed;
• memory means for storing said binary-coded signals as image data in accordance with a position of a pixel where the image was taken;
• symbol detecting means for detecting a specific pattern corresponding to said orientation symbol based on said binary-coded signals;
• apex detecting means for detecting coordinates of said orientation symbol from said image data stored in said memory means based on said specific pattern detected by said symbol detecting means;
• matrix position determining means for finalizing a contour and an orientation of said two-dimensional matrix based on the coordinates of said symbol detected by said apex detecting means, thereby identifying all the coordinates of said plurality of binary-coded cells placed on said two-dimensional matrix;
• and
• reading means for reading out said image data stored in said memory means in accordance with said finalized contour and said orientation of said two-dimensional square matrix.

A two-dimensional code reading apparatus for optically reading a two-dimensional code including a plurality of white binary-coded cells and a plurality of black binary-coded cells placed on a two-dimensional matrix pattern, said two-dimensional code created by an operation of exclusive-ORing between a predetermined provisional two-dimensional code and a two-dimensional cell-feature-conversion code including a specific conversion pattern represented by light cells and dark cells so as to prevent said one of said plurality of white binary-encoded cells and said plurality of black binary-coded cells from being consecutively and extensively arrayed, said two-dimensional code comprising an orientation symbol disposed in a peripheral region of said two-dimensional matrix, said reading apparatus comprising:

• an image pickup device taking an image of said two-dimensional code, to convert said image pixel by pixel into an image signal in response to a light intensity of said image, and successively outputting said image signal;
• and
• an encoder unit encoding said image signal into a plurality of binary-coded signals;
• wherein said encoder unit comprises:
• binary-encoding means for binary encoding said image signal in accordance with a level of said image signal, and outputting said plurality of binary-coded signals successively, said binary-encoding means comprising a comparator means for comparing a white level and a black level of an input waveform representing said image signal with a follow-up waveform which approaches one of said white level and said black level of said input waveform when one of said plurality of white binary-coded cells and said plurality of black binary-coded cells is so consecutively and extensively arrayed;
• memory means for storing said plurality of binary-coded signals as image data in accordance with a position of a pixel where the image was taken;
• symbol detecting means for detecting a specific pattern corresponding to said orientation symbol based on said plurality of binary-coded signals;
• apex detecting means for detecting coordinates of said orientation symbol from said image data stored in said memory means based on said specific pattern detected by said symbol detecting means;
• matrix position determining means for finalizing a contour and an orientation of said two-dimensional matrix based on the coordinates of said orientation symbol detected by said apex detecting means, thereby identifying all coordinates of said plurality of binary-coded cells in said two-dimensional matrix;
• and
• reading means for reading out said image data stored in said memory means in accordance with the finalized contour and said orientation of said two-dimensional matrix, said reading means restoring information of said two-dimensional code by said operation of exclusive-ORing between said image data obtained from said image taken by said image pickup device and image data of said two-dimensional cell-feature-conversion code stored in said memory means.

A two-dimensional code formed as a two-dimensional matrix including a plurality of binary-coded cells, comprising:

• total symbol cells representing an orientation of said two-dimensional matrix, said total symbol cells on said two-dimensional matrix pattern to be readable by a scanning operation along scanning lines;
• a plurality of data cells, each of said plurality of data cells comprising a group of said plurality of binary-coded cells, each of said plurality of data cells representing only one character and disposed in a two-dimensional square region in said two-dimensional matrix;
• an error-correcting code to restore a predetermined data region when said predetermined data region is one of contaminated by a stain and otherwise damaged;
• and
• a code-reading-prohibition cell to prohibit a reading operation of said two-dimensional code when a code-reading-prohibition cell disposed within said two-dimensional code is a predetermined color.

A two-dimensional code formed as a two-dimensional matrix having a plurality of binary-coded cells, comprising:

• total symbol cells representing an orientation of said two-dimensional matrix, said total symbol cells being placed on said two-dimensional matrix pattern and readable by a scanning operation along scanning lines;
• and
• a plurality of data cells, each of said plurality of data cells comprising a group of said plurality of binary-coded cells being disposed in a two-dimensional region of said two-dimensional matrix, each of said plurality of data cells representing only one character;
• and
• dummy black lines having an optimal placement pattern to distinguish said total symbol cells from said plurality of data cells.

A two-dimensional code reading method for optically reading a two-dimensional code including a plurality of binary-coded cells placed on a two-dimensional square matrix pattern, said two-dimensional square matrix pattern comprising an orientation symbol and timing cells, said orientation symbol being disposed in a peripheral region of said two-dimensional square matrix pattern as a specific pattern and including three apexes of said two-dimensional square matrix pattern, comprising steps of:

• taking an image of said two-dimensional code by an image pickup device, then converting said image pixel by pixel into an image signal in response to a light intensity of said image, and binary encoding said image signal in accordance with a level of said image signal, then storing a plurality of binary-coded signals as image data in a memory in accordance with a position of a pixel where the image was taken;
• detecting said specific pattern corresponding to said orientation symbol based on said plurality of binary-coded signals;
• detecting coordinates of said three apexes of said orientation symbol and coordinates of said timing cells from said image data stored in said memory based on the detected specific pattern;
• finalizing a contour and an orientation of said two-dimensional matrix based on the coordinates of said orientation symbol, thereby identifying coordinates of said plurality of binary-coded cells placed on said two-dimensional matrix pattern;
• and
• reading out said image data stored in said memory in accordance with the finalized contour and said orientation of said two-dimensional square matrix pattern.

A two-dimensional code printing method for optically printing a two-dimensional code including a plurality of binary-coded cells placed on a two-dimensional matrix pattern, said two-dimensional matrix pattern comprising an orientation symbol disposed in a peripheral region of said two-dimensional matrix pattern as a specific pattern, comprising steps of:

• setting objective data in a work memory;
• binary encoding each of said objective data into one of "0" and "1";
• arranging said encoded objective data in a two-dimensional data pattern according to a predetermined rule;
• performing an operation of exclusive-ORing between said two-dimensional data pattern and each of a plurality of cell-feature-conversion matrix patterns prepared beforehand, to obtain placement patterns;
• selecting an optimum placement pattern from said placement patterns;
• placing said selected optimum placement pattern in said two-dimensional code;
• and
• printing said two-dimensional code by a printing device.

A two-dimensional code reading method for optically reading a two-dimensional code including a plurality of binary-coded cells placed on a two-dimensional matrix, said two-dimensional matrix comprising an orientation symbol disposed in a peripheral region of said two-dimensional matrix as a specific pattern, comprising steps of:

• taking an image of said two-dimensional code by an image pickup device;
• converting said image pixel by pixel into an image signal in response to a light intensity of said image;
• binary encoding said image signal in accordance with a level of said image signal, thereby successively producing a plurality of binary-coded signals;
• executing storing processing while performing detecting processing in parallel, wherein said storing processing successively stores said plurality of binary-coded signals into a memory as image data while said detecting processing detects said specific pattern corresponding to said orientation symbol based on said plurality of binary-coded signals;
• finalizing a contour and an orientation of said two-dimensional matrix based on coordinates of said plurality of binary-coded cells on said two-dimensional matrix;
• and
• reading out said image data stored in said memory in accordance with said finalized contour and said orientation of said two-dimensional matrix.

A two-dimensional code reading method for optically reading a two-dimensional code including a plurality of binary-coded cells on a two-dimensional square matrix pattern, said two-dimensional square matrix pattern comprising an orientation symbol and timing cells, said orientation symbol comprising a plurality of apex cells of said two-dimensional square matrix pattern, said two-dimensional code reading method comprising steps of:

• taking an image of said two-dimensional code by an image pickup device, then converting said image pixel by pixel into an image signal in response to a light intensity of said image, and binary encoding said image signal in accordance with a level of said image signal, then storing a plurality of binary-coded signals as image data in a memory in accordance with a position of a pixel where the image was taken;
• detecting a specific pattern corresponding to said orientation symbol based on said plurality of binary-coded signals;
• detecting coordinates of each one of said plurality of apex cells comprised by said orientation symbol, and coordinates of said timing cells from said image data stored in said memory based on said detection of said specific pattern;
• finalizing a contour and an orientation of said two-dimensional matrix based on said detected specific pattern and said coordinates of said plurality of apex cells, and identifying coordinates of said plurality of binary-coded cells placed on said two-dimensional square matrix pattern with reference to said coordinates of said timing cells;
• and
• reading out said image data stored in said memory in accordance with said finalized contour and said orientation of said two-dimensional square matrix pattern.

A two-dimensional code comprising:

• a plurality of cells, each of said plurality of cells representing a binary-coded datum, said plurality of cells on a two-dimensional matrix pattern readable by a scanning operation along scanning lines;
• at least two positioning symbols disposed at predetermined positions in said two-dimensional matrix pattern, each of said at least two positioning symbols having a pattern capable of gaining an identical frequency component ratio irrespective of an orientation of said scanning lines when said scanning lines pass through a center of each of said at least two positioning symbols;
• and
• a series of timing cells including light and dark cells alternately arrayed with an inclination of 1/1 in said two-dimensional matrix pattern.

A two-dimensional code comprising:

• a plurality of cells, each of said plurality of cells representing a binary-coded datum, said plurality of cells on a two-dimensional matrix pattern readable by a scanning operation along scanning lines;
• at least two positioning symbols disposed at predetermined positions in said two-dimensional matrix pattern, each of said at least two positioning symbols having a pattern capable of gaining an identical frequency component ratio irrespective of an orientation of said scanning lines when said scanning lines pass through a center of each of said at least two positioning symbols;
• and
• an apex detecting cell disposed on an apex of said two-dimensional matrix pattern where said at least two positioning symbols are not disposed.

A two-dimensional code formed from a two-dimensional matrix having a plurality of binary-coded cells, said two-dimensional code comprising:

• a plurality of symbol cells representing an orientation of said two-dimensional matrix;
• said plurality of symbol cells forming a two-dimensional matrix pattern and being readable by a scanning operation along any arbitrary scanning lines, said pattern being capable of gaining an identical frequency component ratio irrespective of an orientation of said arbitrary scanning lines whenever said arbitrary scanning lines pass through a center of said pattern;
• and
• at least one data cell group comprising a group of said plurality of binary-coded cells, each of said at least one data cell group representing only one character and being disposed in a two-dimensional square region in said two-dimensional matrix, said two-dimensional square region being defined by vertically stacked binary-coded cells and horizontally arrayed binary-coded cells.