Process for reading electronic labels by identification of their code by block of bits

• US 20030132834A1
• Filed: 09/04/2002
• Published: 07/17/2003
• Est. Priority Date: 09/05/2001
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Robert, Gerard
• Granted Patent: US 7,075,452 B2
• Time in Patent Office: Days
• US Class Current: 340/10.3
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10049 binary tree

Abstract

The invention concerns a method for reading a set of electronic labels, each comprising a distinct identification code of N bits and situated in the electromagnetic field of an interrogator device, characterised in that it comprises the following steps:

a) for each given code of N bits, defining an elementary analysis block comprising m bits, where m is a sub-unit of N,

b) analysing the code of each label by scrolling through this code, block of m bits by block of m bits,

c) and, for a given label, generating a serial number representing the number of labels identified before this label in such a way that the interrogator knows at any moment the number of labels present in the electromagnetic field,

d) establishing a cross reference table between the serial numbers generated and the values of the identification codes of each label.

Claims

1. Method for reading a set of electronic labels, each comprising a distinct identification code of N bits and situated in the electromagnetic field of an interrogator device, characterised in that it comprises the following steps:

(a) for each given code of N bits, defining an elementary analysis block comprising m bits, where m is a sub-unit of N greater than 1,

(b) analysing the code of each label by scrolling through this code block of m bits by block of m bits,

(c) assigning a same serial number to all of the labels with the same partially identified code on the row being analysed, the number of serial numbers assigned representing the number of groups of labels with the same partially identified code,

(d) establishing a cross reference table between each serial number and the value of the partially identified code.

2. Method according to claim 1, characterised in that the serial numbers assigned are consecutive to each other.

3. Method according to claim 2, characterised in that the serial numbers of the labels are updated as the detection of the bits of the identification codes progresses.

4. Method according to any of claims 1 to 3, characterised in that it consists in verifying, after all of the labels present in the electromagnetic field have been identified, the identification codes detected by a call of already identified labels.

5. Method according to claim 4, characterised in that the call of already identified labels is carried out by means of serial numbers.

6. Method according to any of claims 1 to 5, characterised in that the identification of a label is carried out according to a sequential mode in which the codes of the blocks of m successive bits of labels are analysed label by label by scrolling through a search tree from a row of block of bits up to the last row of block of bits for each code.

7. Method according to claim 6, characterised in that the identification of a label is carried out according to a systematic mode in which, after identification of a label, the analysis of the tree is taken up again at the first block of m bits.

8. Method according to claim 6, characterised in that the identification of a label is carried out according to a deep mode in which, after identification of a label, the analysis of the tree is carried out from the highest row k where at least two values of m bits have been detected.

9. Method according to any of claims 1 to 5, characterised in that the identification of a label is carried out according to a parallel mode in which the blocks of m bits of the same row are analysed for all the labels.

10. Method according to claim 9, characterised in that in parallel mode, the analysis of a row k+1 from a row k is carried out by consecutively interrogating each serial number.

11. Method according to claim 9, characterised in that in parallel mode, the analysis of a row k+1 from a row k is carried out in two phases, i.e. a first phase in which all of the labels of all of the serial numbers indicate the value of their (k+1)^th block and a second phase in which the (k+1)^th block is analysed serial number by serial number if all of the labels do not have the same block at row k+1.

12. System for reading a set of labels (42) by an interrogator device (40), the labels (42) and the interrogator device (40) each comprising signal emitter—

receptor means (44) linked via modulation/demodulation means (46, 47) to sequencing means (48), characterised in that the interrogator device (40) moreover comprises means for analysing each label (42) block of m bits by block of m bits, and calculating, for each label (42), a serial number representing the number of groups of labels with the same partially identified code in such a way that said interrogator (40) knows at any moment the number of groups of labels present in the electromagnetic field, and a first memory (49) intended to memorise a cross reference table between the serial numbers and the partially identified codes, a first row counter (58) indicating the number of the group of bits being analysed and a second counter (52) indicating the number of labels either totally identified or partially identified, and in that each label (42) also comprises means for calculating the serial numbers, and a first counter (68) to count the rows of blocks of bits currently being analysed and a first memory (74) to memorise said serial numbers and to store the identification code of the label.

13. System according to claim 12, characterised in that said means for analysing each label consist in algorithms capable of operating according to two modes:

a sequential mode, in which the codes of blocks of m successive bits of labels are analysed label by label by scrolling through a search tree from a row of block of bits up to the last row of block of bits for each code,

or a parallel mode, in which the block of m bits of the same row are analysed for all of the labels before analysing the blocks of the following row.

14. System according to claim 12, characterised in that the interrogator device operates in sequential mode, each label moreover comprising a second counter (60) of totally identified labels.

15. System according to claim 12, characterised in that the interrogator device operating in deep sequential mode comprises, moreover, a second memory (50) intended to memorise the multiple branch nodes of the analysis tree in the sequential mode and in that each label comprises, moreover, a second memory (64) to memorise the number of the node at which the label has not been selected and a second counter (60) of totally identified labels.

16. System according to claim 12, characterised in that the interrogator device, operating in parallel mode, moreover comprises:

a third serial number counter (54), indicating the number of groups of labels identified in the analysis row k+1,

a fourth serial number counter (56), indicating the number of serial numbers processed in the row being analysed for the parallel mode

and wherein each label (42) comprises;

a second memory (72) intended to memorise the number of groups with an identical partially identified code at the analysis row k

a second serial number counter (62) intended to indicate the serial number currently being analysed in the parallel mode

a third memory (70) intended to memorise the serial number assigned to a label during the processing of a row k in the parallel mode.