CODING PATTERN COMPRISING MULTI-PPM DATA SYMBOLS WITH MINIMAL CLUSTERING OF MACRODOTS

• US 20110180612A1
• Filed: 01/27/2010
• Published: 07/28/2011
• Est. Priority Date: 01/27/2010
• Status: Abandoned Application

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Napper, Jonathon Leigh, Lapstun, Paul
• Application Number:
  US12/694,265
• Publication Number:
  US 20110180612A1
• Time in Patent Office: Days
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

A substrate having a coding pattern disposed thereon or therein. The coding pattern comprises a plurality of macrodots encoding contiguous data symbols. Each data symbol is represented by d macrodots, each of the d macrodots occupying a respective position from a plurality of predetermined possible positions p. The respective positions of the d macrodots represent one of possible symbol values, and a predetermined number of unused symbol values are selected to minimize clustering of macrodots between adjacent data symbols.

Claims

1. A substrate having a coding pattern disposed thereon or therein, said coding pattern comprising a plurality of macrodots encoding contiguous data symbols, wherein:

each data symbol is represented by d macrodots, each of said d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of said d macrodots representing one of i possible symbol values; and

a predetermined number of unused symbol values are selected to minimize clustering of macrodots between adjacent data symbols.

2. The substrate of claim 1, wherein each data symbol is a j-bit symbol and (ĩ

^j) unused symbol values are selected to minimize clustering of macrodots between adjacent data symbols.

3. The substrate of claim 1, wherein said unused symbol values represent symbol values having d macrodots clustered together in a predetermined region of said data symbol.

4. The substrate of claim 3, wherein said predetermined region of said data symbol is selected from at least one of:

an edge region; and

a corner region.

5. The substrate of claim 1, wherein said unused symbol values are treated as erasures.

6. The substrate of claim 1, wherein p≧

2 m.

7. The substrate of claim 1, wherein d is an integer value of 2, 3, 4, 5 or 6.

8. The substrate of claim 1, wherein p is an integer value of 4, 5, 6, 7, 8, 9, 10, 11 or 12.

9. The substrate of claim 1, wherein p=7 and the data symbol is substantially L-shaped having corner regions, a convex edge and a concave edge.

10. The substrate of claim 9, wherein d=3 which provides 35 possible symbol values for a 5-bit data symbol, and wherein 3 unused symbol values represent symbol values having macrodot triplets clustered together in the corner regions of said data symbol.

11. The substrate of claim 9, wherein d=2 which provides 21 possible symbol values for a 4-bit data symbol, and wherein 5 unused symbol values represent symbol values having macrodot doublets clustered together along the convex edge of said data symbol.

12. The substrate of claim 1, wherein the value of d is selected to modify at least one of:

an overall visibility of the coding pattern; and

a data capacity of the coding pattern.

13. The substrate of claim 1, wherein said coding pattern further comprises a plurality of target elements defining a target grid, said targets elements being distinguishable from said macrodots.

14. The substrate of claim 13, wherein said coding pattern comprises a plurality of symbol groups, each symbol group comprising at least one target element and a plurality of said data symbols.

15. The substrate of claim 14, wherein said coding pattern comprises a plurality of tags, each tag comprising a plurality of symbol groups and a plurality of target elements.

16. The substrate of claim 15, wherein each tag comprises at least one Reed-Solomon codeword comprised of a plurality of said data symbols.

17. The substrate of claim 16, wherein said data symbols comprise Reed-Solomon data symbols and Reed-Solomon redundancy symbols.

18. The substrate of claim 16, wherein each tag comprises at least one local codeword identifying a location of a respective tag.

19. The substrate of claim 16, wherein each tag comprises one or more common codewords, each common codeword being common to a plurality of contiguous tags.

20. The substrate of claim 1, wherein said plurality of macrodots further encode registration symbols identifying one or more of:

an integer value of d;

a translation of a symbol group relative to a tag containing said symbol group, each symbol group containing a plurality of said data symbols;

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

a flag.