Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
  • G06K7/10316—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers
  • G06K7/10346—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers the antenna being of the far field type, e.g. HF types or dipoles
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
  • G06K19/0723—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
  • G06K7/10019—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
  • G06K7/10029—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
  • G06K7/10019—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
  • G06K7/10079—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
  • G06K7/10316—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers
  • G06K7/10336—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers the antenna being of the near field type, inductive coil

Definitions

• the present invention relates to a method of identifying a plurality of passive transponders located in a detection space of a reader having several antennas with their emission-reception fields not confused spatially or temporally.
• the invention relates to a method making it possible to identify and draw up the list of a set of transponders associated with various objects placed in a defined space, with the aim of establishing the inventory of these objects.
• the method relates to the management of the entry or the exit of batches of clothes respectively associated with transponders. These clothes are brought in bulk in bags and placed in a cylinder defining a reader detection space. This application is represented in FIG.
• FIG. 1 which shows a reader 2 comprising three antennas X, Y and Z having different orientations with their emission-reception fields not confused spatially.
• the antenna Z is arranged around a cylinder 1 for receiving the objects to be identified. These objects form a set or a batch 4, each of them being associated with a transponder 6.
• FIG 2 is shown schematically the method of identifying the plurality of transponders according to the known prior art.
• An anti-collision protocol is provided for each antenna one after the other.
• the method begins an anti-collision protocol by activating the antenna Z, which makes it possible to establish the list Z of a subset of the plurality of objects to be identified.
• Conventionally, in such an anti-collision protocol when a transponder is identified, it is put in a "silent" mode so that it no longer sends a response signal during successive interrogations after its detection.
• the identification method activates another antenna Y having a different orientation.
• An anti-collision protocol is also implemented with this antenna Y, making it possible to establish a list Y forming a subset of the plurality of transponders.
• certain transponders are identified by the antenna Z and also by the antenna Y.
• a subset of list X is formed of transponders already identified by the other antennas.
• the plurality of transponders is referenced ID1 to IDn.
• the process of fully identifying the plurality of transponders takes a relatively long time, which is in particular due to the fact that certain transponders can pick up the field of emission of at least two antennas and communicate with them.
• This situation results from the fact that the transponders used in this kind of application keep the "silent" mode as long as they are powered.
• the transponders are automatically reinitialized and lose their respective state.
• Such a power cut occurs during the identification process when passing from one antenna to another. Indeed, during a certain period, the first antenna is deactivated and a switching takes place for the benefit of the second antenna. During this antenna switching operation and the activation of the new selected antenna, the passive transponders are no longer supplied.
• transponders already identified by one antenna can again be identified by another antenna.
• the redundancy in the detection of transponders therefore increases the duration of the identification process, as well as the final sorting step necessary to establish a complete list of identified transponders, avoiding duplicates or even triplets.
• the object of the present invention is to overcome the major drawback mentioned above by proposing an effective identification method with a reduced detection time.
• the identification method according to the invention is characterized in that there is provided in each transponder a memory arranged so as to store its information without power supply only for a certain period, and in that it is planned to store in this memory information relating to the identification of the transponder considered, in particular the activation of the "silence" mode, at least at the end of the implementation of the anti-collision protocol associated with a first antenna, this information being kept by the transponders identified by this first antenna at least during a time interval comprising the switching period from this first antenna to said second antenna during which there is absence of supply field for the passive transponders.
• the memory does not require the use of a process specific to non-volatile memories for the manufacture of the transponder.
• the memory is an analog memory formed by a capacitor associated with a switch allowing its charging and with means for detecting the voltage level of this capacitor arranged to supply binary information to the logic circuit of the transponder. .
• FIG. 3 schematically represents the arrangement of a transponder for the implementation of the identification method according to the invention
• - Figure 4 shows an alternative embodiment of an analog memory of the transponder of Figure 3
• FIG. 5 schematically describes a preferred embodiment of the identification method according to the invention
• FIG. 6 shows a list of the plurality of transponders and the sub-assemblies detected by three antennas X, Y and Z according to a variant of the process.
• FIG. 1 already described schematically represents an installation for implementing the identification method according to the invention
• FIG. 2 already described, represents a method of identifying a plurality of transponders according to the prior art
• FIG. 3 schematically represents the arrangement of a transponder for the implementation of the identification method according to the invention
• - Figure 4 shows an alternative embodiment of an analog memory of
• the transponder 6 according to the invention comprises an antenna 12 connected to an analog part 14.
• the electronic circuit 10 of the transponder also includes a logic circuit 16 and a memory 18.
• the analog part comprises a converter AC / DC 20 connected to both ends of the antenna coil. At the output of the converter 20, a rectified voltage + V is obtained. This voltage signal is supplied to regulation means 22 which produce the voltage V DD used to supply the various parts of the electronic circuit 10.
• a clock signal is obtained by the clock circuit 24 which extracts from the carrier of the received signal a time base.
• a demodulator 26 used for decoding the data received is also provided.
• the transponder 6 is also arranged to supply at least one response signal using an encoder 30 and a modulator 32, the output of which is connected to the antenna 12.
• each transponder preferably an analog memory 34 supplied directly by the voltage + V at the output of the converter 20.
• the arrangement of this analog memory is shown in FIG. 4. It comprises a capacity C having one earth terminal and the other connected to an electrical track 38 along which is arranged an actuatable switch 40 by the logic circuit 16.
• the switch 40 is connected to the potential + V so that the capacitor C can be charged to the maximum when the switch 40 is on, that is to say closed.
• the analog memory 34 also comprises means 42 for detecting the level of the voltage of the capacitor V. These detection means 42 are formed by a comparator at an input of which a reference voltage is supplied. At the output, the analog memory provides a binary read signal depending on whether the voltage of the capacitor is above or below the reference voltage.
• the capacity is integrated into the electronic circuit of the transponder formed entirely of an integrated circuit.
• the information of high voltage that is to say above the reference voltage, of the 'order of the second in the absence of power from the reader field.
• the write signal supplied by the logic circuit therefore makes it possible to actuate the switch 40 to charge the capacitor C when the passive transponder is supplied by the external field.
• the analog memory therefore forms a "semi-volatile" memory, the duration of conservation of the information in this memory in the absence of a power field depending in particular on its dimensions. To increase this duration, it is provided in another variant to arrange the capacity in the form of a discrete element connected to the electronic circuit 10 of the transponder. This more expensive and less compact solution than the integrated solution makes it possible to store the information in the analog memory 34 of the order of a minute to in particular ten minutes. This variant makes it possible to implement a particular mode of implementation of the method according to the invention, as will be explained below.
• FIG. 5 a preferred embodiment of the identification method according to the invention will be described below.
• This anti-collision protocol provides for putting in a "silent” mode any transponder detected by a given antenna during the anti-collision protocol associated with this antenna.
• a command is sent by the reader to the transponders having been identified by the antenna Z instructing these transponders to put in the analog memory 34 the information concerning their state, namely whether they have been identified and put in "silent" mode.
• the logic circuit 16 of the transponder therefore sends a write signal to memory 34 while the transponders are still supplied by the field of antenna Z, so that the identified transponders put in "silent" mode charge their capacity C which has then a high voltage.
• the subset of transponders forming the list Z will keep the information because they have been identified by the antenna Z at least for a certain period of time after the deactivation of the antenna Z.
• the analog memory 34 is arranged so that this time interval includes at least the switching period from the antenna Z to the next antenna Y.
• the transponders again receive a supply field and the analog memory automatically supplies, in a first preferred variant, to the logic circuit 16 the binary information relating to the voltage of the capacitor C. If the capacity C has been loaded at the end of the anti-collision protocol associated with the antenna Z, the logic circuit receives the information that the transponder in question has already been identified during the previous protocol. Thus, the logic circuit again puts the transponder 6 in the "silence" mode so that this transponder will not respond to the interrogation signals from the reader during the anti-collision protocol associated with the antenna Y. Therefore , as shown in FIG.
• the subset of identified transponders forming the list Y is completely distinct from the subset forming the list Z.
• the anti-collision protocol associated with the antenna Y is more faster than in the case of the prior art.
• a final sorting step to rule out possible duplicates becomes superfluous or at the very least quick if implemented for reasons of reliability of the identification process.
• the identification method described using FIG. 5 relates to a system in which the transponders have an integrated analog memory so as to retain binary information during a time interval little longer than the switching period between the successive activation. two antennas by the reader.
• the reader sends a control signal so that the identified transponders retain this information. Then, the reader switches between the antenna Y and the antenna X to perform a third anti-collision protocol associated with the antenna X. Thanks to the method of the invention, the list X of the subset of transponders identified by antenna X does not overlap with the subset of list Y. However, in this variant of the process, list X can present a certain overlap with the list Z, as represented in FIG. 5. This stems from the fact that certain transponders activated by the antenna Z are no longer activated by the antenna Y.
• the information relating to the state of the "semi-volatile" memory is communicated to the logic circuit upon interrogation of the latter.
• Other variants can be envisaged by those skilled in the art.
• the regulating circuit 22 is associated with a supply initialization circuit (POR) acting on the logic circuit 16.
• POR supply initialization circuit
• This POR circuit initializes the logic circuit 16 when the supply voltage drops below a given threshold.
• a flip-flop 52 is provided which is connected to the logic circuit but arranged so as not to be initialized by the POR circuit during a power cut.
• this POR circuit actuates a switch arranged between the supply V D and a power supply terminal of the flip-flop when the supply voltage of the transponder drops below said given threshold.
• This terminal is connected to a capacity 54 for supplying the scale.
• the capacity 54 and the scale are arranged in parallel and together form a unit independent, electrically isolated from the rest of the electronic circuit of the transponder during a power cut, that is to say when the latter becomes lower than said threshold.
• the flip-flop receives at its input a signal 56 concerning the identification state of the transponder and provides in reading a logic signal given by the state of the flip-flop corresponding to this state of identification. This reading is automatic when the logic circuit is put into operation or upon interrogation of the latter.
• the write signal can act automatically and directly on the flip-flop when the transponder identification state changes, that is to say just after its identification. In this variant, it is therefore no longer necessary to send, at the end of the identification protocol relating to a given antenna, a write signal of the identification state of the transponder.
• the flip-flop 52 keeps its logic state for a certain limited period, as a function of the capacity 54 selected and of the implementation thereof. Indeed, the leakage currents inherent in the electronic circuits generate a decrease in the electric charge and the voltage of the capacitor 54. It will be noted that these leakage currents can be of variable magnitudes. It is therefore possible to define their importance in the design of the electronic circuit of the transponder.
• the present invention also applies in the case of several antennas having the same orientation, but activated successively, in particular when a multiplexing of these antennas is provided.
• the transmit-receive fields of the antennas are temporally not confused.
• they can also be spatially not confused, especially when a certain distance separates them.

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• 2002
  • 2002-10-02 EP EP02079135A patent/EP1406208A1/de not_active Withdrawn
• 2003
  • 2003-09-26 US US10/530,201 patent/US20060164212A1/en not_active Abandoned
  • 2003-09-26 AU AU2003271650A patent/AU2003271650A1/en not_active Abandoned
  • 2003-09-26 EP EP03753467A patent/EP1554689A1/de not_active Withdrawn
  • 2003-09-26 WO PCT/EP2003/010743 patent/WO2004032041A1/fr not_active Ceased

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