CODING PATTERN HAVING CELL TRANSLATIONS IDENTIFIABLE IN DIFFERENT ORIENTATIONS

• US 20090082972A1
• Filed: 07/24/2008
• Published: 03/26/2009
• Est. Priority Date: 09/21/2007
• Status: Abandoned Application

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul
• Application Number:
  US12/178,629
• Publication Number:
  US 20090082972A1
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: G06F 3/1206 resulting in increased flexibility in input data format or job format or job type
• CPC Class Codes: G06F 3/1265 Printing by reference, e.g. retrieving document/image data for a job from a source mentioned in the job
• CPC Class Codes: G06F 3/1284 Local printer device
• CPC Class Codes: G06K 19/06037 multi-dimensional coding

Abstract

A substrate having a coding pattern disposed on a surface thereof. The coding pattern comprises: a plurality of target elements defining a target grid; a plurality of data elements contained in each cell of the grid; and a plurality of tags. Each tag is defined by a plurality of contiguous cells and comprises respective tag data encoded by data elements. Each cell comprises a pair of registration symbols, each encoded by a respective set of the data elements. The set of data elements identifies a translation of the cell relative to a tag containing the cell. Further, each set of data elements maps to a first translation code symbol value when read in a first orientation, and maps to a second translation code symbol value when read in a second orientation. Thus, the translation of the cell relative to the tag is identifiable in either of the first or second orientations.

Claims

1. A substrate having a coding pattern disposed on a surface thereof, said coding pattern comprising:

a plurality of target elements defining a target grid, said target grid comprising a plurality of cells, wherein neighboring cells share target elements;

a plurality of data elements contained in each cell; and

a plurality of tags, each tag being defined by a plurality of contiguous cells, each tag comprising respective tag data encoded by data elements,

wherein each cell comprises at least one registration symbol encoded by a respective set of said data elements, said set of data elements identifying a translation of said cell relative to a tag containing said cell,

wherein each set of data elements maps to a first translation code symbol value when read in a first orientation, and maps to a second translation code symbol value when read in a second orientation which is different from said first orientation, such that said translation of said cell relative to said tag is identifiable in either of said first or second orientations.

2. The substrate of claim 1, wherein said second orientation is rotated 180 degrees from said first orientation.

3. The substrate of claim 1, wherein said set of data elements is represented by multi-pulse position modulation.

4. The substrate of claim 3, wherein said set of data elements consists of m macrodots, each of said macrodots occupying a respective position from a plurality of predetermined possible positions p within said cell, the respective positions of said macrodots representing one of a plurality of possible registration symbol values for said registration symbol.

5. The substrate of claim 4, wherein m is 2 or more and p>

m.

6. The substrate of claim 4, wherein m is 2 and p is 6 so as to provide 15 possible registration symbol values.

7. The substrate of claim 4, wherein a plurality of said registration symbol values are mapped to each translation code symbol value.

8. The substrate of claim 4, wherein said second orientation reverses each registration symbol value with respect to said first orientation.

9. The substrate of claim 8, wherein each tag contains an odd number of cells aligned in a row or column, and wherein a registration symbol contained in a central cell of said row or column is represented by a registration symbol value which maps to identical first and second translation code symbol values.

10. The substrate of claim 8, wherein each tag contains a plurality of cells aligned in a row or column, each row or column having a first cell at one end and a second cell at an opposite end, said first cell containing a first registration symbol represented by a first registration symbol value which maps to a first translation symbol code value in said first orientation, said second cell containing a second registration symbol represented by a second registration symbol value which maps to a second translation code symbol value in said first orientation, wherein said first translation code symbol value and said second translation code symbol value are interchanged in said second orientation.

11. The substrate of claim 1, wherein each registration symbol further identifies at least one of:

an orientation of a layout of said tag data with respect to said target grid;

a direction component of said orientation; and

a flag code.

12. The substrate of claim 1, wherein each cell comprises first and second registration symbols, said first registration symbol identifying a first orthogonal translation of said cell, said second registration symbol identifying a second orthogonal translation of said cell.

13. The substrate of claim 1, wherein each tag is square and comprises M² contiguous square cells, wherein M is an integer having a value of at least 2.

14. The substrate of claim 13, wherein M registration symbols in a row of M cells define a cyclic position code having minimum distance M, said code being defined by a first translation codeword.

15. The substrate of claim 13, wherein M registration symbols in a column of M cells define a cyclic position code having minimum distance M, said code being defined by a second translation codeword.

16. The substrate of claim 1, wherein each tag comprises N cells, and at least N registration symbols form a third translation codeword with minimum distance N, wherein N is an integer having a value of at least 4.

17. The substrate of claim 16, wherein any tag-sized portion of said coding pattern is guaranteed to contain at least N registration symbols, thereby capturing said third translation codeword.

18. The substrate of claim 1, wherein said tag data is encoded by one or more Reed-Solomon symbols.

19. The substrate of claim 18, wherein each cell defines a symbol group, each symbol group comprising a plurality of Reed-Solomon symbols encoded by a plurality of said data elements.

20. The substrate of claim 18, wherein said tag data is encoded as a local codeword comprised of a set of said Reed-Solomon symbols.