Simplified bar code decoding with dynamically loadable data character sets

• US 5,455,414 A
• Filed: 09/15/1994
• Issued: 10/03/1995
• Est. Priority Date: 09/15/1994
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Metanetics Corporation
• Inventors: Wang, Ynjiun P.
• Primary Examiner(s): PITTS, HAROLD I
• Application Number:
  US08/306,690
• Time in Patent Office: 383 Days
• Field of Search: 235/462, 235/463
• US Class Current: 235/462.1
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 2D bar codes

Abstract

The reading and decoding of two-dimensional bar codes in a bar code reader are simplified and field loading of different data character sets is enabled. Decoding of bar/space patterns of a bar code is simplified by deriving T-sequence data representative of the bar/space pattern and then processing a majority of the T-sequences directly into decoded values representative of the bar/space pattern. Dynamic loading of new data character sets fully or partially superseding a factory installed default character set correlation listing is enabled by use of loadable correlation listings keyed to foreign language characters, symbols, words or phrases relevant to particular applications. The loadable correlation listings can be encoded into a two-dimensional bar code and loaded via a reading of the bar code by the bar code reader.

Claims

1. A method of decoding a 2-D bar code in a bar code reader, comprising the steps of:

(a) loading into said bar code reader, prior to step (b), a loadable correlation listing correlating decoded values of bar/space patterns to corresponding data characters;

(b) selecting, prior to step (h), between said loadable correlation listing and a default correlation listing available in said bar code reader;

(c) reading a plurality of bar/space patterns of said 2-D bar code and deriving corresponding sequence data;

(d) processing said sequence data corresponding to a bar/space pattern to provide a numerical value representative thereof;

(e) utilizing said step (d) numerical value as the decoded value of said bar/space pattern, if said numerical value does not exceed a predetermined number;

(f) converting said step (d) numerical value to a corresponding number, if said numerical value exceeds said predetermined number, and utilizing said corresponding number as the decoded value of said bar/space pattern;

(g) repeating steps (d), (e) and (f) for other bar/space patterns of said 2-D bar code to provide decoded values thereof;

(h) utilizing the correlation listing selected in step (b) to correlate each of a plurality of said decoded values as provided in steps (e), (f) and (g) to a corresponding data character; and

(i) providing a decoded bar code signal representative of the corresponding data characters from step (h).

2. A method of decoding a 2-D bar code as in claim 1, wherein step (a) comprises loading said loadable correlation listing by reading a 2-D bar code containing said loadable correlation listing in encoded form.

3. A method of decoding a 2-D bar code as in claim 1, wherein step (a) comprises loading a plurality of said loadable correlation listings and step (b) comprises selecting between said loadable correlation listings and said default correlation listing.

4. A method of decoding a 2-D bar code as in claim 1, wherein step (c) comprises deriving T-sequences corresponding to said bar/space patterns.

5. A method of decoding a 2-D bar code as in claim 1, wherein said 2-D bar code is a 16 module wide bar code, including 4 bars and 4 spaces each up to 5 modules wide, and said predetermined number in steps (e) and (f) is 1023.

6. A method of decoding a 2-D bar code as in claim 1, wherein said bar code comprises data bar/space patterns representative of data characters and instruction bar/space patterns representative of information relating to said data bar/space patterns, and steps (h) and (i) are performed only with respect to a plurality of decoded values provided from said data bar/space patterns.

7. A method of decoding a 2-D bar code as in claim 6, additionally including the following step between steps (g) and (h):

(x) utilizing decoded values of said instruction bar/space patterns to provide information used to control the processing of said data bar/space patterns in said bar code reader.

8. A method of decoding a 2-D bar code in a bar code reader, comprising the steps of:

(a) loading into said bar code reader, prior to step (f), a loadable correlation listing correlating decoded values of bar/space patterns to corresponding data characters;

(b) reading a plurality of bar/space patterns of said 2-D bar code and deriving corresponding sequence data;

(c) processing said sequence data corresponding to a bar/space pattern to provide a numerical value representative thereof;

(d) utilizing said step (c) numerical value to provide a decoded value for said bar/space pattern;

(e) repeating steps (c) and (d) for other bar/space patterns of said bar code to provide decoded values thereof; and

(f) utilizing said correlation listing to correlate each of a plurality of said decoded values as provided in steps (d) and (e) to a corresponding data character.

9. A method as in claim 8, wherein step (f) comprises:

(f) selectively utilizing one of said loadable correlation listing and a default correlation listing available in said bar code reader, to correlate each of a plurality of said decoded values as provided in steps (d) and (e) to a corresponding data character.

10. A method of decoding a 2-D bar code as in claim 8, wherein step (a) comprises loading said loadable correlation listing by reading a 2-D bar code containing said loadable correlation listing in encoded form.

11. A method of decoding a 2-D bar code as in claim 8, wherein step (b) comprises deriving T-sequences corresponding to said bar/space patterns.

12. A method of decoding a 2-D bar code as in claim 8, wherein said 2-D bar code is a 16 module wide bar code, including 4 bars and 4 spaces each up to 5 modules wide.

13. A method of decoding a 2-D bar code as in claim 8, wherein said bar code comprises data bar/space patterns representative of data characters and instruction bar/space patterns representative of information relating to said data bar/space patterns, and step (f) is performed only with respect to a plurality of decoded values provided from said data bar/space patterns.

14. A method of decoding a 2-D bar code as in claim 13, additionally including the following step between steps (e) and (f):

(x) utilizing decoded values of said instruction bar/space patterns to provide information used to control the processing of said data bar/space patterns in said bar code reader.

15. A method of decoding a 2-D bar code in a bar code reader comprising the steps of:

(a) reading a plurality of bar/space patterns of a bar code and deriving corresponding sequence data;

(b) processing said sequence data corresponding to a bar/space pattern to provide a numerical value representative thereof;

(c) utilizing said step (b) numerical value as the decoded value of said bar/space pattern, if said numerical value does not exceed a predetermined number;

(d) converting said step (b) numerical value to a corresponding number, if said numerical value exceeds said predetermined number, and utilizing said corresponding number as the decoded value of said bar/space pattern; and

(e) repeating steps (b), (c) and (d) for other bar/space patterns of said bar code to provide decoded values thereof.

16. A method of decoding a 2-D bar code as in claim 15, additionally comprising the following steps:

(f) utilizing a correlation listing available in said bar code reader to correlate each of said decoded values as provided in steps (c), (d) and (e) to a corresponding data character; and

(g) providing a decoded bar code signal representative of the corresponding data characters from step (f).

17. A method of decoding a 2-D bar code as in claim 15, wherein step (a) comprises deriving T-sequences corresponding to said bar/space patterns.

18. A method of decoding a 2-D bar code as in claim 15, wherein said 2-D bar code is a 16 module wide bar code, including 4 bars and 4 spaces each up to 5 modules wide, and said predetermined number in steps (c) and (d) is 1023.

19. A method of decoding a 2-D bar code as in claim 16, wherein said bar code comprises data bar/space patterns representative of data characters and instruction bar/space patterns representative of information relating to said data bar/space patterns, and steps (f) and (g) are performed only with respect to a plurality of decoded values provided from said data bar/space patterns.

20. A method of decoding a 2-D bar code as in claim 19, additionally including the following step between steps (e) and (f):

(x) utilizing decoded values of said instruction bar/space patterns to provide information used to control the processing of said data bar/space patterns in said bar code reader.

21. A method of decoding a 2-D bar code in a bar code reader comprising the steps of:

(a) loading into said bar code reader, prior to step (g), a loadable correlation listing correlating decoded values of bar/space patterns to corresponding data characters;

(b) reading a plurality of bar/space patterns of said 2-D bar code and deriving corresponding sequence data;

(c) processing said sequence data corresponding to a bar/space pattern to provide a numerical value representative thereof;

(d) utilizing said step (c) numerical value as the decoded value of said bar/space pattern, if said numerical value does not exceed a predetermined number;

(e) converting said step (c) numerical value to a corresponding number, if said numerical value exceeds said predetermined number, and utilizing said corresponding number as the decoded value of said bar/space pattern;

(f) repeating steps (c), (d) and (e) for other bar/space patterns of said bar code to provide decoded values thereof; and

(g) utilizing said correlation listing to correlate each of said decoded values as provided in steps (d), (e) and (f) to a corresponding data character.

22. A method of decoding a 2-D bar code as in claim 21, wherein step (a) comprises loading said loadable correlation listing by reading a 2-D bar code containing said loadable correlation listing in encoded form.

23. A method of decoding a 2-D bar code as in claim 21, wherein step (b) comprises deriving T-sequences corresponding to said bar/space patterns.

24. A method of decoding a 2-D bar code as in claim 21, wherein said 2-D bar code is a 16 module wide bar code, including 4 bars and 4 spaces each up to 5 modules wide, and said predetermined number in steps (d) and (e) is 1023.

25. A method of decoding a 2-D bar code as in claim 21, wherein said bar code comprises data bar/space patterns representative of data characters and instruction bar/space patterns representative of information relating to said data bar/space patterns and step (g) is performed only with respect to a plurality of decoded values provided from said data bar/space patterns.

26. A method of decoding a 2-D bar code as in claim 25 additionally including the following step between steps (f) and (g):

(x) utilizing decoded values of said instruction bar/space patterns to provide information used to control the processing of said data bar/space patterns in said bar code reader.