Two-dimensional code, reading and producing method and recording medium storing related software

• US 6,279,830 B1
• Filed: 08/26/1999
• Issued: 08/28/2001
• Est. Priority Date: 09/03/1998
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ishibashi, Toshiharu
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): LE, UYEN CHAU N
• Application Number:
  US09/383,991
• Time in Patent Office: 733 Days
• Field of Search: 235/494, 235/487, 235/462.01, 235/454, 235/456, 235/462.09, 235/462.1, 235/462.25, 235/460
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 2019/06262 with target- or other orientation-indicating feature
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1443 locating of the code in an image

Abstract

A two-dimensional code includes a plurality of cells arranged in a predetermined two-dimensional pattern. The code comprises an information recording region constituted by a plurality of blocks. Each block involves a recording mode designating code indicating a recording mode of the information recorded in each block. Partial decode processing is performed for decoding the recorded information in each block in accordance with the recording mode specified by the recording mode designating code. And, the information in the information recording region is read based on the partial decoding result of the plurality of blocks.

Claims

1. A two-dimensional code including a plurality of cells arranged in a predetermined two-dimensional pattern, said code comprising:

an information recording region for recording information;

a plurality of blocks constituting said information recording region; and

a recording mode designating code involved in each block, said recording mode designating code indicating a recording mode of the information recorded in each block,

wherein said recording mode designating code of each block is disposed in front of the information recorded in said block so that said recording mode designating code is decoded prior to said information in each block and said information is decoded according to the recording mode specified by said recording mode designating code.

2. The two-dimensional code in accordance with claim 1, wherein at least one of said plurality of blocks records error-correcting information applied to information recorded in another block.

3. The two-dimensional code in accordance with claim 2, wherein said plurality of blocks include a plurality of block pairs, each block pair consisting of a data block and an error-correcting block,

an error-correcting level is independently applied to each block pair, and

an error-correcting code is involved in each of said data block and said error-correcting block of said block pair, said error-correcting code indicating the error-correcting level of said block pair.

4. The two-dimensional code in accordance with claim 1, wherein an area code is involved in each block of said two-dimensional code for directly or indirectly indicating an existing area of each block in said two-dimensional code.

5. The two-dimensional code in accordance with claim 4, wherein said area code is disposed at the head of each block so that said area code is decoded prior to the information recorded in each block.

6. The two-dimensional code in accordance with claim 4, wherein said recording mode designating code and said area code are represented by a cell distribution pattern, said cell distribution pattern is decodable into a bit string which is not used for recording the information in said information recording region, and

said recording mode designating code and said area code are specified by decoding said bit string.

7. The two-dimensional code in accordance with claim 4, wherein

said recording mode designating code and said area code are located adjacent to each other so that said recording mode designating code and said area code are successively decoded.

8. The two-dimensional code in accordance with claim 1, wherein

a format code region represented by a cell pattern is provided to specify an existing area of each block.

9. The two-dimensional code in accordance with claim 1, wherein

a plurality of positioning symbols are provided at predetermined positions on said two-dimensional code to identify the position of said two-dimensional code.

10. The two-dimensional code in accordance with claim 1, wherein

at least one of said plurality of blocks contains specific information requiring a specialized reading apparatus in a decoding operation.

11. The two-dimensional code in accordance with claim 10, wherein

said specific information is recorded by using magnetic ink or special ink modifying a specific waveform so that said specific information is not optically recognized.

12. The two-dimensional code in accordance with claim 10, wherein said specific information is enciphered so that a deciphering operation is additionally required in a code reading operation.

13. A method for reading a two-dimensional code, said reading method comprising the steps of:

providing a two-dimensional code including a plurality of cells arranged in a predetermined two-dimensional pattern, said code comprising an information recording region for recording information, a plurality of blocks constituting said information recording region, and each block involving a recording mode designating code indicating a recording mode of the information recorded in each block,

wherein said recording mode designating code of each block is disposed in front of the information recorded in said block, so that said recording mode designating code is decoded prior to said information in each block and said information is decoded according to the recording mode specified by said recording mode designating code;

performing partial decode processing for each of said plurality of blocks to decode the recorded information in each block in accordance with the recording mode specified by said recording mode designating code; and

reading the information in said information recording region based on the partial decoding result of said plurality of blocks.

14. The two-dimensional code reading method in accordance with claim 13, wherein

entire decode processing is performed to decode all of the information in said information recording region, and

said partial decode processing is performed only when said entire decode processing has failed.

15. The two-dimensional code reading method in accordance with claim 13, wherein

said partial decode processing of said plurality of blocks is performed by determining a decoding order of said plurality of blocks.

16. The two-dimensional code reading method in accordance with claim 13, wherein

at least one of said plurality of blocks records error-correcting information applied to information recorded in another block, and

the information in said information recording region is read by performing an error-correcting operation based on a decoding result of two related blocks.

17. The two-dimensional code reading method in accordance with claim 13, wherein

said plurality of blocks include a plurality of block pairs, each block pair consisting of a data block and

an error-correcting block, an error-correcting level is independently applied to each block pair, an error-correcting code is involved in each of said data blocks and said error-correcting block of said block pair to indicate the error-correcting level of said block pair, and

said partial decode processing is performed by decoding the information in a designated block based on the error-correcting level specified by said error-correcting code.

18. The two-dimensional code reading method in accordance with claim 13, wherein

an area code is involved in each block of said two-dimensional code for directly or indirectly indicating an existing area of each block in said two-dimensional code, and

said reading method comprises the steps of:

detecting said area code from a picture image of said two-dimensional code, identifying the existing area of a designated block based on the detected area code, and

performing said partial decode processing of the designated block.

19. The two-dimensional code reading method in accordance with claim 18, wherein

said area code is disposed at the head of each block so that said area code is decoded prior to the information recorded in each block, and

said partial decode processing is applied to a block including said area code and a succeeding data region.

20. The two-dimensional code reading method in accordance with claim 18, wherein

said recording mode designating code and said area code are represented by a cell distribution pattern, said cell distribution pattern is decodable into a bit string which is not used for recording the information in said information recording region, and

said recording mode designating code and said area code are specified by decoding said bit string.

21. The two-dimensional code reading method in accordance with claim 18, wherein

said recording mode designating code and said area code are located adjacent to each other so that said recording mode designating code and said area code are successively identified in a decoding operation.

22. The two-dimensional code reading method in accordance with claim 13, wherein

said two-dimensional code includes a format code region represented by a cell pattern to specify an existing area of each block, and

said recording method comprises the steps of:

detecting said format code region from a picture image of said two-dimensional code to obtain a format of said two-dimensional code represented by said format code region,

identifying the existing area of a designated block based on the detected format of said two-dimensional code, and

performing said partial decode processing of the designated block.

23. The two-dimensional code reading method in accordance with claim 13, wherein

a plurality of positioning symbols are provided at predetermined positions on said two-dimensional code to identify the position of said two-dimensional code, and

said recording method comprises the steps of:

detecting said plurality of positioning symbols from a picture image of said two-dimensional code,

identifying an existing area of a designated block based on the position of said plurality of positioning symbols, and

performing said partial decode processing of the designated block.

24. A method for producing a two-dimensional code including a plurality of cells arranged in a predetermined two-dimensional pattern,

said two-dimensional code comprising:

an information recording region for recording information,

a plurality of blocks constituting said information recording region, and

each block involving a recording mode designating code indicating a recording mode of the information recorded in each block,

wherein said plurality of blocks include a plurality of block pairs, each block pair consisting of a data block and an error-correcting block, and

an error-correcting level is independently applied to each block pair, and said producing method comprising the steps of;

encoding all of the information based on a predetermined error-correcting level designated as an initial value,

additionally encoding the information of a block pair based on a designated error-correcting level when the designated error-correcting level of said block pair is different from said initial value,

performing an overflow judgment to check whether the coded information is accommodated in a corresponding block,

repeating the encoding operation when said coded information overflows the corresponding block, by using another format having a wider information recording region until the encoded information fits in the corresponding block.

25. The two-dimensional code producing method in accordance with claim 24, wherein an error-correcting code is involved in each of said data blocks and said error-correcting block of said block pair to indicate the error-correcting level of said block pair.

26. A recording medium storing a software program installable in a computer system to read a two-dimensional code including a plurality of cells arranged in a predetermined two-dimensional pattern, said code comprising an information recording region for recording information, a plurality of blocks constituting said information recording region, and each block involving a recording mode designating code indicating a recording mode of the information recorded in each block,

wherein said software program comprises the processing of:

performing partial decode processing for each of said plurality of blocks to decode the recorded information in each block in accordance with the recording mode specified by said recording mode designating code; and

reading the information in said information recording region based on the partial decoding result of said plurality of blocks.

27. The recording medium in accordance with claim 26, wherein

said software program comprises the processing of:

performing entire decode processing to decode all of the information in said information recording region, and

performing said partial decode processing only when said entire decode processing has failed.

28. The recording medium in accordance with claim 26, wherein

said partial decode processing of said plurality of blocks is performed by determining a decoding order of said plurality of blocks.

29. The recording medium in accordance with claim 26, wherein

at least one of said plurality of blocks records error-correcting information applied to information recorded in another block, and

said software program comprises the processing of reading the information in said information recording region by performing an error-correcting operation based on a decoding result of two related blocks.

30. The recording medium in accordance with claim 26, wherein

said plurality of blocks include a plurality of block pairs, each block pair consisting of a data block and an error-correcting block,

an error-correcting level is independently applied to each block pair, and

an error-correcting code is involved in each of said data block and said error-correcting block of said block pair, to indicate the error-correcting level of said block pair, and

said software program comprises the processing of performing said partial decode processing by decoding the information in a designated block based on the error-correcting level specified by said error-correcting code.

31. The recording medium in accordance with claim 26, wherein

said recording mode designating code of each block is disposed in front of the information recorded in said block, and

said software program comprises the processing of decoding said recording mode designating code prior to said information in each block and decoding said information according to the recording mode specified by said recording mode designating code.

32. The recording medium in accordance with claim 26, wherein

an area code is involved in each block of said two-dimensional code for directly or indirectly indicating an existing area of each block in said two-dimensional code, and

said software program comprises the processing of:

detecting said area code from a picture image of said two-dimensional code, identifying the existing area of a designated block based on the detected area code, and

performing said partial decode processing of the designated block.

33. The recording medium in accordance with claim 32, wherein

said area code is disposed at the head of each block so that said area code is decoded prior to the information recorded in each block, and said partial decode processing is applied to a block including said area code and a succeeding data region.

34. The recording medium in accordance with claim 32, wherein said recording mode designating code and said area code are represented by a cell distribution pattern, said cell distribution pattern is decodable into a bit string which is not used to record the information in said information recording region, and

said software program comprises the processing of specifying said recording mode designating code and said area code by decoding said bit string.

35. The recording medium in accordance with claim 32, wherein

said recording mode designating code and said area code are located adjacent to each other, and

said software program comprises the processing of successively identifying said recording mode designating code and said area code in a decoding operation.

36. The recording medium in accordance with claim 26, wherein said two-dimensional code includes a format code region represented by a cell pattern to specify an existing area of each block, and

said software program comprises the processing of:

detecting said format code region from a picture image of said two-dimensional code to obtain format of said two-dimensional code represented by said format code region,

identifying the existing area of a designated block based on the detected format of said two-dimensional code, and

performing said partial decode processing of the designated block.

37. The recording medium in accordance with claim 26, wherein

a plurality of positioning symbols are provided at predetermined positions on said two-dimensional code to identify the position of said two-dimensional code, and

said software program comprises the processing of:

detecting said plurality of positioning symbols from a picture image of said two-dimensional code,

identifying an existing area of a designated block based on the position of said plurality of positioning symbols,

and performing said partial decode processing of the designated block.

38. A recording medium storing a software program installable in a computer system to produce a two-dimensional code including a plurality of cells arranged in a predetermined two-dimensional pattern,

said two-dimensional code comprising:

an information recording region to record information,

a plurality of blocks constituting said information recording region, and

each block involving a recording mode designating code indicating a recording mode of the information recorded in each block,

wherein said plurality of blocks include a plurality of block pairs, each block pair consisting of a data block and an error-correcting block, and

an error-correcting level is independently applied to each block pair, and

said software program comprises the processing of;

encoding all of the information based on a predetermined error-correcting level designated as an initial value,

additionally encoding the information of a block pair based on a designated error-correcting level when the designated error-correcting level of said block pair is different from said initial value,

performing an overflow judgment to check whether the coded information is accommodated in a corresponding block,

repeating the encoding operation when said coded information overflows the corresponding block, by using another format having a wider information recording region until the encoded information fits the corresponding block.

39. The recording medium in accordance with claim 38, wherein an error-correcting code is involved in each of said data block and said error-correcting block of said block pair to indicate the error-correcting level of said block pair.