Multiple bar code decoding system and method

• US 5,262,625 A
• Filed: 11/15/1991
• Issued: 11/16/1993
• Est. Priority Date: 11/15/1991
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Mergenthaler, Barry M., Blanford, Denis M., Hilles, Wilbur I., Tom, Robert J.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): ALLEN, STEPHONE B
• Application Number:
  US07/793,934
• Time in Patent Office: 732 Days
• Field of Search: 235/462, 235/463, 235/467, 235/472, 235/473
• US Class Current: 235/462.07
• CPC Class Codes: G06K 7/0166 by means of clock-signals derived from the code marks, e.g. self-clocking code
• 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

There are disclosed a system and method for decoding data read from a plurality of different types of bar code labels which includes circuit means for detecting the occurrence of two equal continuous characters in the data generated by an optical scanner in reading a bar code label and a filter for each of the different bar code labels receiving simultaneously the two equal characters for decoding the character data and inserting locating bits in the data delimiting a valid character in the data.

Claims

1. A system for simultaneously decoding a plurality of different coded symbols each comprising a plurality of bars and spaces representing characters, comprising:

means for generating data representing bars and spaces of one of said symbols;

circuit means coupled to said generating means for applying first predetermined relationships to said data for generating signals representing continuous characters in response to receiving the data representing each consecutive bar and space whenever the relationships are satisfied;

means for storing the data;

a plurality of decoding means coupled to said circuit means for detecting valid and invalid characters in said signals; and

each of said decoding means including means for inserting data bits in the data stored in said storing means locating the start and ending of a valid character in said data.

2. The system of claim 1 in which said circuit means comprises a large scale integrated circuit chip.

3. The system of claim 1 in which said circuit means includes means for detecting the width of consecutive bars and spaces comprising a character and means for comparing the width of a predetermined number of bars and spaces to determine the occurrence of two equal width characters which comprise said signals.

4. The system of claim 3 in which said circuit means further includes storage means coupled to said storing means for storing the data representing a valid character including the start and ending data bits in response to the generation of said start and ending data bits.

5. The system of claim 4 in which each of said decoding means includes means for counting the number of valid characters in said data and logic means for generating a control signal when said counting means reaches a predetermined count, said decoding means outputting said control signal to said storage means enabling said storage means to store the data stored in said storing means.

6. The system of claim 1 in which said inserting means comprises means for counting the occurrence of a predetermined number of valid characters and logic means for generating control signals enabling said storing means to insert a start and stop bit in the data stored in the storing means indicating the location of valid coded character.

7. The system of claim 6 in which one of said decoding means includes a UPC decoder.

8. The system of claim 6 in which one of said decoding means includes a 128 decoder.

9. The system of claim 6 in which one of said decoding means includes a 2 of 5 and 3 of 9 decoder.

10. The system of claim 1 in which said decoding means comprises three filter circuits each decoding a different bar code.

11. The system of claim 10, in which said filter circuits include a plurality of adders.

12. The system of claim 10, in which said circuit means includes means for determining the number of intervals per character.

13. The system of claim 12, in which different bar codes include a different number of intervals per character.

14. The system of claim 10, in which said circuit means includes means for detecting the presence of two equal characters.

15. The system of claim 14, in which certain bar codes are identified by the presence of two equal characters.

16. A system for simultaneously decoding a plurality of different coded symbols each comprising a plurality of bars and spaces representing characters, comprising:

means for generating coded data representing bars and spaces of one of said symbols;

first storage means for storing the coded data generated by said generating means;

first logic means coupled to said generating means for detecting the occurrence of two equal characters in the coded data, said logic means generating a first control signal upon detecting the two equal characters;

a plurality of filter means each associated with a different coded symbol and coupled to said first logic means for detecting valid and invalid characters in the coded data stored in the first storage means in response to the generation of said control signal;

second logic means in each of said filter means coupled to said first storage means for inserting data bits in the coded data stored in said first storage means locating the start and ending of a valid character upon detecting a valid character in said coded data;

means in each of said filter means for counting the number of valid characters in said coded data;

third logic means in each of said filter means for generating a third control signal when said counting means reaches a predetermined count;

a second storage means coupled to said first storage means and said first logic means; and

said first logic means being coupled to said second and third logic means for outputting a fourth control signal to said second storage means in response to the generating of said start and ending data bits and said third control signal, said fourth control signal enabling the second storage means to store the coded data stored in said first storage means.

17. A method for decoding data representing a coded label consisting of a plurality of bars and spaces representing a numerical character in which character data is generated by scanning a bar code label which may represent one of a plurality of different types of bar code labels, comprising the steps of:

applying a first predetermined relationship to said character data representing a predetermined number of bars and spaces defining a number of numerical characters;

generating first control signals indicating the occurrence of said number of numerical characters;

transmitting said first control signals simultaneously to a plurality of filter circuits each

representing a different type of bar code label;

operating each of said filter circuits in response to receiving said first control signals to detect the occurrence of a valid numerical character associated with the type of bar code represented by the filter circuit; and

generating second control signals locating the position of the valid numerical character in the character data associated with the type of bar code represented by the filter circuit.

18. The method of claim 17, in which said filter circuits are operated in parallel.

19. The method of claim 17, in which the transmitting step includes the transmission of signals to one of said filter circuits if a predetermined number of intervals have been detected during scanning of a bar code label.

20. The method of claim 17, in which the transmitting step includes the transmission of signals to one of said filter circuits if the presence of two equal characters is detected during scanning of a bar code label.

21. The method of claim 17 which further includes the steps of:

storing the generated data in a first storage means;

transmitting the second control signals to said first storage means locating the position of the valid numerical character in the first storage means; and

storing the second control signals in said first storage means at a location locating the start and ending of a valid numerical character in said generated data.

22. The method of claim 21 which further includes the step of storing in said first storage means a third control signal with the second control signals indicating the type of bar code the valid numerical character is associated with.

23. The method of claim 17 in which said number of numerical characters is two.

24. The method of claim 22 which further includes the steps of:

storing the generated data stored in said first storage means in a second storage means;

counting the number of first signals generated until a predetermined count is reached;

generating a third control signal when said first predetermined count is reached; and

enabling said second storage means to store the generated data in response to the generation of said third control signal.

25. The method of claim 24 which further includes the steps of comparing the first predetermined count with a second predetermined count and generating said second control signals when the first and second predetermined counts are equal.