Machine readable 2D symbology printable on demand

• US 8,011,596 B2
• Filed: 02/13/2008
• Issued: 09/06/2011
• Est. Priority Date: 02/13/2008
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Longacre, Andrew Jr.
• Primary Examiner(s): Hess; Daniel A
• Application Number:
  US12/069,911
• Publication Number:
  US 20090200386A1
• Time in Patent Office: 1,301 Days
• Field of Search: 235/454, 235/494
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding

Abstract

An optically readable two dimensional symbology employed to encode a string of characters belonging to a source string alphabet. The two dimensional symbol can comprise an ordered plurality of printable elements. The printable elements can be arranged in a rectangular array. The printable elements can be positioned on a grid diagonal to the longitudinal axis of the rectangular array, and sequenced according to a pre-defined pattern. Each character of the character string can be encoded into a sequence of printable elements using an encoding scheme comprising at least one code set. A code set can include a plurality of bit sequences. Each bit sequence can correspond to a group of one or more characters of the source string alphabet. Each bit sequence can comprise one or more binary digits. The first binary digit can be encoded by a printable element printed in a printable element position, and a second binary digit can be encoded by a vacant printable element position.

Claims

1. An optically readable two dimensional symbol employed to encode a character string each character belonging to a source string alphabet, the two dimensional symbol comprising an ordered plurality of printable elements arranged in a rectangular array having a longitudinal axis, the rectangular array comprising a plurality of columns, each of the plurality of columns being substantially orthogonal to the longitudinal axis, the rectangular array further comprising a plurality of rows, each of the plurality of rows being substantially parallel to the longitudinal axis;

wherein the printable elements are positioned in a checker board-like manner on a grid, the grid being diagonal to the longitudinal axis, wherein intersections between rows of the plurality of rows and columns of the plurality of columns define both printable element positions and spaces between printable element positions;

wherein two neighboring corner positions of the optically readable two dimensional symbol are printable element positions, and two positions opposite to the two neighboring corner positions are space positions; and

wherein each character of the character string is encoded into a sequence of printable elements using an encoding scheme comprising at least one code set, said at least one code set including a plurality of bit sequences, each bit sequence corresponding to a group of at least one character of the source string alphabet, each bit sequence comprising one or more binary digits, each binary digit selected from the group consisting of;

a first binary digit encoded by a printable element printed in a printable element position and a second binary digit encoded by a vacant printable element position.

2. The optically readable two dimensional symbol of claim 1, wherein each printable element of the plurality of printable elements has a form factor of a circular dot.

3. The optically readable two dimensional symbol of claim 1, wherein the rectangular array has a first array dimension and a second array dimension, and wherein a sum of the first array dimension and the second array dimension is an odd number.

4. The optically readable two dimensional symbol of claim 1, wherein the printable elements are sequenced in a pre-defined direction along one of:

successive rows of the rectangular array, successive columns of the rectangular array.

5. The optically readable two dimensional symbol of claim 1, wherein the rectangular array has a first array dimension having an even value and a second array dimension;

and wherein the printable elements are sequenced along the first array dimension starting from one of;

a leftmost corner element, a bottommost corner element.

6. The optically readable two dimensional symbol of claim 1, wherein the printable elements belonging to one of:

adjacent rows, adjacent columns, are sequenced in opposite directions.

7. The optically readable two dimensional symbol of claim 1, wherein the printable elements are sequenced following a spiraling pattern.

8. The optically readable two dimensional symbol of claim 1, wherein the source string alphabet is selected from the group consisting of:

ASCII, UNICODE, EBCDIC.

9. The optically readable two dimensional symbol of claim 1, wherein the source string alphabet includes at least one functional character.

10. The optically readable two dimensional symbol of claim 1, wherein the character string has a character string size;

and wherein the rectangular array has a first array dimension having a pre-defined value and a second array dimension, the second array dimension depending on the character string size.

11. The optically readable two dimensional symbol of claim 1, wherein the rectangular array has a first array dimension and a second array dimension, an aspect ratio of the first array dimension to the second array dimension being a pre-defined value.

12. The optically readable two dimensional symbol of claim 1, wherein a first plurality of the printable elements encode characters of the character string and a second plurality of the printable elements encode at least one error correction character.

13. The optically readable two dimensional symbol of claim 1, wherein a first plurality of the printable elements encode characters of the character string and a second plurality of the printable elements encode one or more Reed-Solomon error correction characters.

14. The optically readable two dimensional symbol of claim 1, wherein a first plurality of the printable elements encode the characters of the character string and a second plurality of the printable elements encode at least one dummy codeword.

15. The optically readable two dimensional symbol of claim 1, wherein alternating rows of the plurality of rows have unequal numbers of printable element positions.

16. A method of converting a character string into an optically readable two dimensional symbol, each character belonging to a source string alphabet, the two dimensional symbol comprising an ordered plurality of printable elements, the method comprising the steps of:

selecting an encoding scheme comprising at least one code set, said at least one code set including a plurality of bit sequences, each bit sequence corresponding to a group of at least one character of the source string alphabet, each bit sequence comprising a pre-defined number of binary digits, each binary digit selected from the group consisting of;

a first binary digit and a second binary digit;

generating a sequence of code words, the sequence of code words representing the character string according to the encoding scheme;

generating a sequence of printable elements by encoding each first binary digit in the sequence of code words by a printable element printed in a printable element position and by encoding each second binary digit in the sequence of code words by a vacant printable element position;

arranging the sequence of printable elements in a rectangular array having a longitudinal axis, the rectangular array comprising a plurality of columns, each of the plurality of columns being substantially orthogonal to the longitudinal axis, the rectangular array further comprising a plurality of rows, each of the plurality of rows being substantially parallel to the longitudinal axis, the printable elements being positioned on a grid in a checker board-like manner, the grid being diagonal to the longitudinal axis, each printable element occupying a printable element position defined by an intersection of a printable element row and a printable element column, each printable element position being spaced from neighboring printable element positions, the printable elements being sequenced according to a pre-defined pattern

wherein two neighboring corner positions of the rectangular array are printable element positions, and two positions opposite to the two neighboring corner positions are space positions.

17. The method of claim 16, wherein the rectangular array has a first array dimension and a second array dimension, sum of the first array dimension and the second array dimension is an odd number.

18. The method of claim 16, wherein the printable elements are sequenced in a pre-defined direction along one of:

successive rows of the rectangular array, successive columns of the rectangular array.

19. The method of claim 16, wherein the rectangular array has a first array dimension having an even value and a second array dimension;

and wherein the printable elements are sequenced along the first array dimension starting from one of;

the leftmost corner element, the bottommost corner element.

20. The method of claim 16, wherein the printable elements belonging to one of:

adjacent rows, adjacent columns, are sequenced in opposite directions.

21. The method of claim 16, wherein the printable elements are sequenced following a spiraling pattern.

22. The method of claim 16, wherein the source string alphabet is selected from the group consisting of:

ASCII, UNICODE, EBCDIC.

23. The method of claim 16, wherein the source string alphabet includes at least one functional character.

24. The method of claim 16, wherein the character string has a character string size;

and wherein the rectangular array has a first array dimension having a pre-defined value and a second array dimension, the second array dimension depending on the character string size.

25. The method of claim 16, wherein the rectangular array has a first array dimension and a second array dimension, an aspect ratio of the first array dimension to the second array dimension being a pre-defined value.

26. The method of claim 16, wherein a first plurality of the printable elements encode characters of the character string and a second plurality of the printable elements encode at least one error correction character.

27. The method of claim 16, wherein a first plurality of the printable elements encode characters of the character string and a second plurality of the printable elements encode one or more Reed-Solomon error correction characters.

28. The method of claim 16, wherein a first plurality of the printable elements encode characters of the character string and a second plurality of the printable elements encode at least one dummy codeword.

29. An optically readable two dimensional symbol employed to encode a character string each character belonging to a source string alphabet, the two dimensional symbol comprising an ordered plurality of printable elements arranged in a rectangular array having a longitudinal axis, the rectangular array comprising a plurality of columns, each of the plurality of columns being substantially orthogonal to the longitudinal axis, the rectangular array further comprising a plurality of rows, each of the plurality of rows being substantially parallel to the longitudinal axis, wherein intersections between rows of the plurality of rows and columns of the plurality of columns define both printable element positions and spaces between printable element positions;

wherein the printable elements are positioned on a grid, the grid being diagonal to the longitudinal axis, each printable element occupying a printable element position defined by an intersection of a printable element row and a printable element column, each printable element position being spaced from neighboring printable element positions;

wherein the plurality of printable elements is sequenced according to a pre-defined pattern; and

wherein each character of the character string is encoded into a sequence of printable elements using an encoding scheme comprising at least one code set, said at least one code set including a plurality of bit sequences, each bit sequence corresponding to a group of at least one character of the source string alphabet, each bit sequence comprising one or more binary digits, each binary digit selected from the group consisting of;

a first binary digit encoded by a printable element printed in a printable element position and a second binary digit encoded by a vacant printable element position; and

wherein the printable elements are sequenced following a spiraling pattern.

30. A method of converting a character string into an optically readable two dimensional symbol, each character belonging to a source string alphabet, the two dimensional symbol comprising an ordered plurality of printable elements, the method comprising the steps of:

selecting an encoding scheme comprising at least one code set, said at least one code set including a plurality of bit sequences, each bit sequence corresponding to a group of at least one character of the source string alphabet, each bit sequence comprising a pre-defined number of binary digits, each binary digit selected from the group consisting of;

a first binary digit and a second binary digit;

generating a sequence of code words, the sequence of code words representing the character string according to the encoding scheme;

generating a sequence of printable elements by encoding each first binary digit in the sequence of code words by a printable element printed in a printable element position and by encoding each second binary digit in the sequence of code words by a vacant printable element position;

arranging the sequence of printable elements in a rectangular array having a longitudinal axis, the rectangular array comprising a plurality of columns, each of the plurality of columns being substantially orthogonal to the longitudinal axis, the rectangular array further comprising a plurality of rows, each of the plurality of rows being substantially parallel to the longitudinal axis, wherein intersections between rows of the plurality of rows and columns of the plurality of columns define both printable element positions and spaces between printable element positions, the printable elements being positioned on a grid, the grid being diagonal to the longitudinal axis, each printable element occupying a printable element position defined by an intersection of a printable element row and a printable element column, each printable element position being spaced from neighboring printable element positions; and

wherein the printable elements are sequenced following a spiraling pattern.