CODING PATTERN COMPRISING MULTI-PPM DATA SYMBOLS IN A FORMAT IDENTIFIED BY REGISTRATION SYMBOLS

• US 20110180611A1
• 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:
  US12/694,264
• Publication Number:
  US 20110180611A1
• Time in Patent Office: Days
• US Class Current: 235/494
• CPC Class Codes: G06F 3/0321 by optically sensing the absolute position with respect to a regularly patterned surface forming a passive digitiser, e.g. pen optically detecting position indicative tags printed on a paper sheet constructional details of pen-shaped pointing devices G06F3/03545, G06F3/03542, G06F3/037
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

A substrate having a coding pattern disposed thereon or therein. The coding pattern comprises a plurality of macrodots encoding data symbols and registration 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 a plurality of possible symbol values. Each registration symbol, or a set of the registration symbols, identifies an integer value of d, with the condition that p>d.

Claims

1. A substrate having a coding pattern disposed thereon or therein, said coding pattern comprising a plurality of macrodots encoding data symbols and registration 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 a plurality of possible symbol values;

each registration symbol, or a set of said registration symbols, identifies an integer value of d; and

p>

d.

2. The substrate of claim 1, wherein p≧

2d.

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

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

5. The substrate of claim 1, wherein each data symbol provides i possible symbol values, and wherein a predetermined number of unused symbol values are treated as erasures.

6. The substrate of claim 1, wherein each data symbol provides i possible symbol values for a j-bit symbol, and wherein (ĩ

2^j) unused symbol values are treated as erasures.

7. The substrate of claim 6, wherein d=3 and p=7 which provides 35 possible symbol values for a 5-bit data symbol, and wherein 3 unused symbol values are treated as erasures.

8. The substrate of claim 6, wherein d=2 and p=7 which provides 21 possible symbol values for a 4-bit data symbol, and wherein 5 unused symbol values are treated as erasures.

9. The substrate of claim 5, wherein said unused symbol values are selected to minimize clustering of macrodots between adjacent data symbols.

10. The substrate of claim 9, wherein said unused symbol values represent symbol values having d macrodots clustered together in a predetermined region of said data symbol.

11. The substrate of claim 10, wherein said predetermined region of said data symbol is selected from at least one of:

a convex edge region;

a concave edge region; and

a corner region.

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, at least one registration symbol 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, a plurality of registration symbols and a plurality of target elements.

16. The substrate of claim 15, wherein each symbol group comprises at least one set of registration symbols, said set identifying the integer value of d.

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

18. The substrate of claim 17, wherein each tag comprises at least one local codeword identifying a location of a respective tag.

19. The substrate of claim 17, 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 registration symbols further identify one or more of:

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.