MOBILE BODY DISCRIMINATION APPARATUS FOR RAPIDLY ACQUIRING RESPECTIVE DATA SETS TRANSMITTED THROUGH MODULATION OF REFLECTED RADIO WAVES BY TRANSPONDERS WHICH ARE WITHIN A COMMUNICATION REGION OF AN INTERROGATOR APPARATUS

• US 6,946,950 B1
• Filed: 07/12/2000
• Issued: 09/20/2005
• Est. Priority Date: 07/12/1999
• Status: Expired due to Term

• Current Assignee: Redwood Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ikeda, Shinkichi, Sangawa, Ushio, Ueno, Shinichiro, Fujita, Suguru, Maeda, Kenichi
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): BROWN, VERNAL U
• Application Number:
  US09/615,045
• Time in Patent Office: 1,896 Days
• Field of Search: 340/10.1, 340/10.34, 340/572.1, 340/10.2, 340/10.4, 340/5.65, 340/825.58, 455/107, 455/106, 455/101
• US Class Current: 340/10.1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• 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 7/10039 interrogator driven, i.e. synchronous
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device antennas per se H01Q
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/16235 the bump connector connecting to a via metallisation of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 2924/15192 Resurf arrangement of the internal vias
• CPC Class Codes: H01L 2924/19042 being an inductor
• CPC Class Codes: H01L 2924/19103 interposed between the semiconductor or solid-state device and the die mounting substrate, i.e. chip-on-passive
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding

Abstract

In a mobile body discrimination apparatus having an interrogator apparatus and a plurality of transponders each capable of transmitting information to the interrogator apparatus by modulation of radio waves that are reflected from a transponder antenna, which can be attached to respective articles, store data concerning the articles, and transmit the data to the interrogator apparatus in response to a command signal transmitted while the transponder traverses a communication region of an antenna of the interrogator apparatus, each transponder is configured to begin sending such response data after a randomly determined time interval following reception of the command signal, thereby reducing the probability of data conflict when plural transponders are within the communication region. In addition, radio waves from a second antenna of the interrogator apparatus are directed into that communication region in the intervals between transmissions of the command signal, thereby increasing the power level of radio waves that are reflected by a transponder antenna or used by a rectifier circuit to supply power for operating the transponder circuits.

Claims

1. A mobile body discrimination apparatus comprising a plurality of transponders and an interrogator apparatus, said interrogator apparatus comprising:

at least one interrogator antenna;

control means;

transmitting means controlled by said control means for driving said interrogator antenna to periodically transmit a transmission start command code conveyed by modulated radio waves, directed at each of said transponders which are currently within a communication region of said interrogator antenna, and for transmitting CW (continuous-wave) radio waves in intervals between transmissions of said transmission start command code;

interrogator receiving means coupled to said interrogator antenna, for obtaining requested signals from said transponders, conveyed by modulated reflected radio waves from said transponders which are within said communication region;

wherein

said at lest one interrogator antenna comprises a first antenna and a second antenna, and

said transmitting means comprises first transmitting means controlled by said control means for driving said first antenna to periodically transmit said transmission start command code conveyed by modulated radio waves and to transmit CW radio waves in intervals between said transmission of said transmission start command code, and second transmitting means for driving said second antenna to transmit said CW radio waves;

wherein said control means comprises means for periodically interrupting said transmission fo said CW radio waves by said second transmitting means and said second antenna, for the duration of each of respective time intervals in which said transmission start command code is transmitted by said fist transmitting means and first antenna; and

each of said transponders comprising;

a transponder antenna;

rectifier circuit means coupled to said transponder antenna, for converting a signal received by said transponder antenna to electrical power for operating circuits of said transponder;

transponder receiving means coupled to said transponder antenna, for obtaining said transmission start command code from said modulated radio waves transmitted by said interrogator apparatus;

memory means for storing data therein;

modulator means controllable for varying a reflection condition of said transponder antenna with respect to incident radio waves; and

response timing control means responsive to reception of said transmission start command code by said transponder receiving means for controlling said modulator means to vary said reflection condition of said transponder antenna according to response data comprising at least a part of said data of said memory means, to generate modulated reflected radio waves conveying said response data after a specific delay time has elapsed following reception of said transmission start command code;

wherein said response timing control means comprises means for setting a randomly determined value of said delay time, at each reception of said transmission start command code.

2. The mobile body discrimination apparatus according to claim 1, wherein said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communication regions overlap one another to comprise a common communication region.

3. The mobile body discrimination apparatus according to claim 1, wherein said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communication regions overlap one another, so that said plurality of transponders are for moving continuously or intermittently in a fixed direction along a fixed path comprising a series of positions, and are for being respectively located at a first position and a second position of said series of positions.

4. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 2, wherein said first and second antennas of said interrogator apparatus are spaced apart at respective fixed locations, the system comprising:

conveyer belt transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

5. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 2, the system comprising transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item, the system comprising:

a housing comprising a material for shielding electromagnetic waves and having a central aperture, wherein said transport means is for transferring such load items through said central aperture;

wherein said first antenna and second antenna are attached within said housing, at respective positions located on a periphery of said central aperture, and each oriented to comprise said common communication region within said central aperture.

6. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 2, wherein said first and second antennas of said interrogator apparatus are spaced apart at respective fixed locations, the system comprising:

a plurality of transport vehicles controllable for transporting respective pluralities of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

7. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 3, wherein said first and second antennas of said interrogator apparatus are spaced apart at respective fixed locations, the system comprising:

conveyer belt transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing first through said second communication region of said second antenna then through said first communication region of said first antenna, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

8. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 3, the system comprising transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing successively through said second communication region of said second antenna and then through said first communication region of said first antenna, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item, comprising:

a housing comprising material for shielding electromagnetic waves and having a central aperture, wherein means is for transferring such load items through said central aperture;

wherein said first antenna and second antenna are attached within said housing, at positions on a periphery of said central aperture, and each oriented to comprise said first communication region and second communication region within said central aperture.

9. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 3, with said first and second antennas of said interrogator apparatus are spaced apart at respective fixed locations, the system comprising:

a plurality of transport vehicles controllable for transporting respective pluralities of load items along a fixed path in a fixed direction for passing successively through said first communication region of said first antenna and then through said second communication region of said second antenna, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

10. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 2, wherein:

said interrogator apparatus is portable;

said system comprises supporting means for supporting a plurality of articles aligned along a common vertical plane, with each of said transponders being attached to a corresponding one of such articles and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding article; and

each of said transponders is for being oriented substantially facing said common vertical plane, thereby enabling said transponders to be successively scanned by said antennas of said interrogator apparatus oriented towards said transponders while said interrogator apparatus is for being moved in a direction parallel to said common vertical plane.

11. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 2, the system comprising:

supporting means for supporting a plurality of articles aligned along a common vertical plane, with each of said transponders being attached to a corresponding one of such articles and each of said transponders oriented substantially facing towards said common vertical plane, and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding article;

a movable supporting mechanism operable for moving said interrogator apparatus in directions parallel to said common vertical plane with said antennas of said interrogator apparatus oriented towards said common vertical plane, for thereby enabling said transponders to be successively scanned by said interrogator apparatus.

12. The mobile body discrimination system according to claim 11, comprising a computer system for automatically controlling said movement of said interrogator apparatus by said movable supporting mechanism.

13. The mobile body discrimination apparatus according to claim 1, wherein in said interrogator apparatus:

said at least interrogator one antenna comprises a first antenna and second antenna;

said transmitting means comprises first transmitting means controlled by said control means to periodically drive said first antenna to transmit modulated radio waves conveying a transmission start command code and to drive said first antenna to transmit spread spectrum radio waves which have been generated using a first pseudo-noise code sequence during intervals between transmitting said transmission start command code, and second transmitting means controlled by said control means to periodically drive said second antenna to transmit modulated radio waves conveying said transmission start command code, and to drive said second antenna to transmit spread spectrum radio waves which have been generated using a second pseudo-noise code sequence which is different from said first pseudo-noise code sequence, during intervals between transmitting said transmission start command code; and

said interrogator receiving means comprises first receiving means coupled to said first antenna, for obtaining said requested signals from said transponders, conveyed by modulated reflected spread spectrum radio waves which have been transmitted by said first antenna, and second receiving means coupled to said second antenna, for obtaining said requested signals from said transponders, conveyed by modulated reflected spread spectrum radio waves which have been transmitted by said second antenna.

14. The mobile body discrimination apparatus according to claim 13, wherein:

said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communications substantially entirely overlap one another to comprise a common communication region; and

said interrogator apparatus further comprises comparator and selector means for comparing a signal received via said first antenna and first receiving means of said interrogator apparatus, conveying a set of data from one of said transponders, with a signal received via said second antenna and said second receiving means of said interrogator apparatus, conveying said set of data from said transponder, to determine that one of said signals is stronger than the other, and for selecting a set of data expressed by said stronger one of said signals to be stored in said memory means.

15. The mobile body discrimination apparatus according to claim 13, wherein:

said plurality of transponders are for moving continuously or intermittently in a fixed direction along a fixed path, and said first antenna and said second antenna are located spaced apart from one another, with a first communication region of said first antenna and a second communication region of said second antenna positioned to partially overlap one another, and respectively located in relation to said fixed path such that said first communication region of said first antenna extends over a left-side portion of said path and said second communication region of said second antenna extends over a right-side portion of said path; and

said control means of said interrogator apparatus comprises means for storing in said memory means a set of data conveyed by a first signal which is transmitted by a first one of said transponders and is received via said first antenna and first receiving means of said interrogator apparatus, while also storing in said memory means of said interrogator apparatus a set of data conveyed by a second signal which is transmitted by a second one of said transponders and is received via said second antenna and second receiving means of said interrogator apparatus entirely or partially concurrently with said reception of said first signal from said first transponder.

16. The mobile body discrimination apparatus according to claim 13, wherein:

each of said transponders has stored in said memory means thereof a corresponding identification code, and said response timing control section is for controlling said modulator means of said transponder to transmit said identification code together with said response data, by said modulated reflected radio waves;

each of said transponders comprises means for detecting reception of a transmission halt command code by said transponder receiving means and for inhibiting further operation of said modulation means of said transponder for a predetermined time duration following reception of said transmission halt command code;

said plurality of transponders are for being moved continuously or intermittently in a fixed direction along a fixed path, and said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communications partially overlap one another, and are respectively located in relation to said fixed path such that all of said transponders first pass through said second communication region of said second antenna and then pass through said first communication region of said first antenna; and

said control means of said interrogator apparatus comprises means for detecting that said response data and identification code have been successfully acquired from a transponder by said first receiving means or said second receiving means of said interrogator apparatus, and, when said successful acquisition has been detected, for controlling at least one of said first transmitting means and second transmitting means of said interrogator apparatus to transmit said transmission halt command code together with the identification code of the one of said transponders from which said response data was successfully acquired.

17. The mobile body discrimination apparatus according to claim 13, wherein said plurality of transponders move continuously or intermittently in a fixed direction along a fixed path, and said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communications partially overlap one another, and are respectively located on said fixed path at a succeeding position and at a preceding position with respect to said fixed direction, further comprising:

detector means located adjacent to said fixed path at a position preceding said communication region of said second antenna, for detecting transfer of successive numbers of said transponders along said fixed path and for producing signals indicative of said numbers; and

operation control means located in said interrogator apparatus (300), responsive to said signals from said detector means for selectively enabling and inhibiting operation of at least a part of said second transmission means and second receiving means according to said numbers of said transponders.

18. The mobile body discrimination apparatus according to claim 17, further comprising a DC power supply, wherein said operation control means comprises power supply control means operable for selectively connecting and disconnecting the DC power supply for supplying power to least a part of said second transmission means and second receiving means.

19. The mobile body discrimination apparatus according to claim 13, wherein said first antenna and second antenna are respectively spaced apart and said first antenna comprises a first communication region and said second antenna comprises a second communication region, and said first and second communications are oriented such that respective communication regions of said first and second antennas partially overlap one another to comprise a common communication region, and wherein said interrogator apparatus comprises timing control means for alternately establishing, in successive time intervals, a first condition in which said first transmission means of said interrogator apparatus is in operation and said second transmission means is inoperative and a second condition in which said first transmission means is inoperative and said second transmission means is in operation.

20. The mobile body discrimination apparatus according to claim 13, wherein said first antenna comprises a polarizing antenna having a first type of polarization and said second antenna comprises a polarizing antenna having a second type of polarization.

21. The mobile body discrimination apparatus according to claim 20, wherein said antenna of each of said transponders is a polarizing antenna, and wherein in approximately half of said plurality of transponders said antenna has said first type of polarization and a remainder of said plurality of transponders has said second type of polarization.

22. The mobile body discrimination apparatus according to claim 20, further comprising timing control means for alternately establishing, in successive time intervals, a first condition in which said first transmission means is in operation and said second transmission means is inoperative and a second condition in which said first transmission means is inoperative and said second transmission means is in operation.

23. A mobile body discrimination apparatus according to claim 20, wherein each of said transponders comprises a first transmitting/receiving system comprising:

a first polarizing antenna comprising said first type of polarization;

first receiving means coupled to said first polarizing antenna, for obtaining said transmission start command code from said modulated radio waves transmitted by said interrogator apparatus;

first memory means for storing data;

first modulator means controllable for varying a reflection condition of said first polarizing antenna with respect to incident radio waves; and

first response timing control means responsive to reception of said transmission start command code by said first receiving means for controlling said modulator means to vary said reflection condition of said first polarizing antenna according to response data comprising at least a part of said data of said first memory means, to generate modulated reflected radio waves conveying said response data after a specific delay time has elapsed following reception of said transmission start command code;

and a second transmitting/receiving system comprising;

a second polarizing antenna comprising said second type of polarization;

second receiving means coupled to said second polarizing antenna, for obtaining said transmission start command code from said modulated radio waves transmitted by said interrogator apparatus;

second memory means for storing data therein;

second modulator means controllable for varying a reflection condition of said second polarizing antenna with respect to incident radio waves; and

second response timing control means responsive to reception of said transmission start command code by said second receiving means for controlling said second modulator means to vary said reflection condition of said second polarizing antenna according to response data constituted by at least a part of said data of said second memory means, to generate modulated reflected radio waves conveying said response data after a specific delay time has elapsed following reception of said transmission start command code.

24. A mobile body discrimination apparatus according to claim 23, wherein said first transmitting/receiving system comprises first rectifier circuit means coupled to said first polarizing antenna, for converting a signal received by said antenna to electrical power for operating at least a part of all circuits of said transponder, and said second transmitting/receiving system comprises second rectifier circuit means coupled to said second polarizing antenna, for converting a signal received by said second polarizing antenna to electrical power for operating at least a part of all circuits of said transponder.

25. A mobile body discrimination apparatus according to claim 20, wherein each of said transponders comprises a first polarizing antenna and a second polarizing antenna, and wherein said receiving means of said transponder is coupled to receive modulated radio signals from said first polarizing antenna and said modulator means of said transponder is coupled to said second polarizing antenna, for varying said reflection condition of said antenna with respect to incident radio waves.

26. A mobile body discrimination apparatus according to claim 25, comprising first rectifier circuit means coupled to said first polarizing antenna, for converting a signal received by said antenna to electrical power for operating at least a part of all circuits of said transponder, and second rectifier circuit means coupled to said second polarizing antenna, for converting a signal received by said second polarizing antenna to electrical power for operating at least a part of all circuits of said transponder.

27. A mobile body discrimination apparatus according to claim 20, wherein each of said transponders comprises:

a first polarizing antenna comprising said first direction of polarization and a second polarizing antenna comprising said second direction of polarization;

first rectifier circuit means coupled to said first polarizing antenna, for converting a signal received by said first polarizing antenna to electrical power for operating at least a part of all circuits of said transponder, and second rectifier circuit means coupled to said second polarizing antenna, for converting a signal received by said second polarizing antenna to electrical power for operating at least a part of all circuits of said transponder;

first receiving means coupled to said first polarizing antenna, for obtaining said transmission start command code and supplying said transmission start command code to said response timing control means;

second receiving means coupled to said second polarizing antenna, for obtaining said transmission start command code and supplying said transmission start command code to said response timing control means;

first modulator means controllable for varying a reflection condition of said first polarizing antenna, and second modulator means controllable for varying a reflection condition of said second polarizing antenna; and

power comparison circuit means for determining which of said first rectifier circuit means and said second rectifier circuit means is currently providing a higher level of supply power, and for enabling operation of one of said first modulator means and said second modulator means, which is coupled to the same one of said first polarizing antenna and second polarizing antenna as said determined one of said first and second rectifier circuit means providing the higher level of supply power, while inhibiting operation of the other one of said first modulator means and second modulator means.

28. A mobile body discrimination apparatus according to claim 20, wherein said first type of polarization is a right-handed direction of circular polarization and said second type of polarization is a left-handed direction of circular polarization.

29. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 19, with said first antenna and second antenna of said interrogator apparatus spaced apart at respective fixed locations, the system comprising:

conveyer belt transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

30. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 19, the system comprising transport means for transporting a plurality of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item, the system comprising:

a housing comprising a material for shielding electromagnetic waves and having a central aperture adapted to permit transfer of such load items by said transport means through said central aperture;

wherein said first antenna and second antenna of said interrogator apparatus are attached within said housing, at respective positions located on the periphery of said central aperture, respectively oriented to comprise said common communication region within said central aperture.

31. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and a plurality of transponders according to claim 19, with said first and second antenna of said interrogator apparatus spaced apart at respective fixed locations, the system comprising:

a plurality of transport vehicles controllable for transporting respective pluralities of load items along a fixed path in a fixed direction for passing through said common communication region of said first and second antennas, with each of said transponders being attached to a corresponding one of such load items and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding load item.

32. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 19, wherein said interrogator apparatus is, the system comprising supporting means for supporting a plurality of articles aligned along a common vertical plane, with each of said transponders being attached to a corresponding one of said articles and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding article;

wherein each of said transponders is for being oriented substantially facing said common vertical plane, thereby enabling said transponders to be successively scanned by said antennas of said interrogator apparatus oriented towards said transponders while said interrogator apparatus is for being moved in a direction parallel to said common vertical plane.

33. A mobile body discrimination system comprising in combination therewith said interrogator apparatus and said plurality of transponders according to claim 19, the system comprising:

supporting means for supporting a plurality of articles aligned along a common vertical plane, with each of said transponders being attached to a corresponding one of such articles and each of said transponders oriented substantially facing towards said common vertical plane, and with at least a part of said data stored in said memory means of said each transponder being data relating to a corresponding article; and

a movable supporting mechanism operable for moving said interrogator apparatus in directions parallel to said common vertical plane with said antennas of said interrogator apparatus oriented towards said common vertical plane, for thereby successively scanning said transponders by said interrogator apparatus.

34. A mobile body discrimination apparatus according to claim 1, wherein:

each of said transponders comprises modulator means comprising a plurality of absorber elements for applying respectively different degrees of absorption of said radio waves reflected by said antenna, response timing control means, selection control means for generating a selection control signal which specifies an arbitrarily determined pair of said absorber elements, and absorber element selector means controlled by said selection control signal to select a pair of said plurality of absorber elements each time that said response start command code is obtained by said receiving means, and for effecting said variation of said reflection condition of said antenna by selectively connecting the absorber elements constituting said selected pair of absorber elements to said antenna, to thereby perform amplitude modulation of said reflected radio waves with a modulation depth determined by said arbitrarily determined pair of absorber elements; and

said interrogator apparatus comprises data processing means for operating on an output signal produced from said receiving means of said interrogator apparatus for extracting, from said output signal, respective sets of data which have been transmitted by said transponders by modulation utilizing said arbitrarily determined pairs of absorber elements.

35. A mobile body discrimination apparatus according to claim 34, wherein said selected pair of absorber elements arbitrarily determined by said selection control means of said each transponder, and wherein said data processing means of said interrogator apparatus comprises means for separately extracting respective sets of data which are received concurrently by said receiving means of said interrogator apparatus and have been transmitted by a plurality of said transponders which select respectively different pairs of said plurality of absorber elements to transmit the corresponding data sets.

36. A mobile body discrimination apparatus according to claim 1, wherein:

said modulator means of each of said transponders comprises a first absorber element for applying a minimum amount of absorption of said incident radio waves, a second absorber element for applying an amount of absorption of said incident radio waves greater than said minimum amount, and a third absorber element for applying an amount of absorption of said incident radio waves greater than said amount applied by said second absorber element, selection control means for generating a selection control signal, and absorber element selector means controlled by said selection control signal for effecting either a first depth of amplitude modulation of reflected radio waves by selectively coupling said first and second absorber elements to said antenna of said transponder or a second depth of amplitude modulation of said reflected radio waves by selectively coupling said first and third absorber elements to said antenna of the transponder; and

said interrogator apparatus comprises data processing means for operating on an output signal produced from said receiving means of said interrogator apparatus for extracting, from said output signal, respective sets of data which have been transmitted by said transponders by modulation through selective coupling of said first and second absorber elements to said antenna of said transponder and sets of data which have been transmitted by modulation through selective coupling of said first and third absorber elements to said antenna of said transponder.

37. The mobile body discrimination system according to claim 36 wherein said selection by said absorber element selector means of amplitude modulation through selective coupling of said first and second absorber elements to said antenna of said transponder and amplitude modulation through selective coupling of said first and third absorber elements to said antenna of said transponder is arbitrarily determined at each occurrence of data transmission by said transponder.

38. The mobile body discrimination system according to claim 37, wherein each of said transponders further comprises random number generating means controlled to generate a random number in response to each detection of said response start command code by said response timing control means, and absorber element selection control means for operating on said absorber element selector means to determine that, in accordance with said random number, either said amplitude modulation is performed by selective coupling of said first and second absorber elements to said antenna of said transponder, or by selective coupling of said first and third absorber elements to said antenna.

39. The mobile body discrimination system according to claim 36, wherein said selection control means of each of said transponders comprises means for determining that, when said response start command code is first obtained by said receiving means of said transponder after said transponder has entered a communication region of said antenna of said interrogator apparatus, said amplitude modulation performed by selective coupling of said first and second absorber elements to said antenna of said transponder is applied, to transmit said response data by said modulated reflected radio waves, and that thereafter during at least a time duration for which said transponder remains within said communication region, said amplitude modulation performed by selective coupling of said first and third absorber elements to said antenna of said transponder is applied, to transmit said response data by said modulated reflected radio waves.

40. The mobile body discrimination apparatus according to claim 36, wherein:

said memory means of each of said transponders comprises a stored identification code, and said response timing control section is for controlling said modulator means of said transponder to transmit said identification code together with said response data, by said modulated reflected radio waves;

each of said transponders comprises means for detecting reception of a transmission halt command code by said receiving means of said transponder and for inhibiting further operation of said modulation means of said transponder for a predetermined time duration following reception of said transmission halt command code; and

said control means of said interrogator apparatus comprises means for detecting that said response data and identification code have been successfully acquired from a transponder by said receiving means and data processing means of said interrogator apparatus, and, when said successful acquisition has been detected, for controlling at said transmitting means of said interrogator apparatus to transmit said transmission halt command code together with the identification code of the one of said transponders from which said response data was successfully acquired.

41. The mobile body discrimination apparatus according to claim 36, wherein said first, second and third absorber elements apply respective degrees of absorption of 0 db, 10 db and 20 dB.

42. The mobile body discrimination apparatus according to claim 36, wherein:

said memory means of each of said transponders comprises a stored identification code, and said response timing control section is for controlling said modulator means of said transponder to transmit said identification code together with said response data, by said modulated reflected radio waves;

said selection control means of said transponder is for determining that said amplitude modulation by selective coupling of said first and third absorber elements to said antenna of said transponder is applied by said modulator means when said identification code is being transmitted and that said amplitude modulation by selective coupling of said first and second absorber elements to said antenna of said transponder is applied by said modulator means when said response data are being transmitted.

43. A mobile body discrimination apparatus according to claim 34, wherein:

said memory means of each of said transponders comprises a stored identification code, and said response timing control section is for controlling said modulator means of said transponder to transmit said identification code together with said response data, by said reflected phase-shifted radio waves;

each of said transponders comprises means for detecting reception of a transmission halt command code by said receiving means of said transponder and for inhibiting further operation of said modulation means of said transponder for a predetermined time duration following reception of said transmission halt command code; and

said control means of said interrogator apparatus comprises means for detecting that said response data and identification code have been successfully acquired from a transponder by said receiving means and data processing means of said interrogator apparatus, and, when said successful acquisition has been detected, for controlling said transmitting means of said interrogator apparatus to transmit said transmission halt command code together with the identification code of the one of said transponders from which said response data was successfully acquired.

44. A mobile body discrimination apparatus according to claim 43, wherein:

said plurality of absorber elements of said each transponder comprises at least a first absorber element for applying a minimum amount of absorption of said incident radio waves, a second absorber element for applying an amount of absorption of said incident radio waves greater than said minimum amount, and a third absorber element for applying an amount of absorption of said incident radio waves greater than said amount applied by said second absorber element;

said selection control means of said transponder is for generating said selection control signal such that said first absorber element and third absorber element are selected to be applied in said amplitude modulation of said reflected radio waves when said identification code is being transmitted, and that said first absorber element and second absorber element are selected to be applied in said amplitude modulation of said reflected radio waves when said response data set is being transmitted.

45. A mobile body discrimination apparatus according to claim 44, wherein

each of said transponders comprises means for processing said response data prior to transmission thereof, to generate data key information for use in extracting said response data from a demodulated received signal, and for combining said data key information with said identification code of said transponder to comprise a header which is transmitted immediately prior to said response data set, in response to each said reception of said response start command code by said transponder, and wherein said first absorber element and third absorber element are selected to be applied in said amplitude modulation of said reflected radio waves when said header is being transmitted;

and

said data processing section of said interrogator apparatus comprises means for operating on said output signal from said receiving means of said interrogator apparatus by applying said data key information of said header to correctly extract the contents of a corresponding response data set, when data conflict occurs within said output signal between said corresponding response data set and a response data set which is transmitted by another one of said transponders.

46. A mobile body discrimination apparatus according to claim 1, wherein:

said modulator means of each of said transponders comprises a plurality of phase shifter elements for applying respectively different degrees of phase shift to said radio waves which are reflected by said antenna, phase shifter selection control means, and phase shifter element selector means controlled by said phase shifter selection control means to select a specific pair of said phase shifter elements each time that said response start command code is obtained by said receiving means, and for effecting said variation of said reflection condition of said antenna of said transponder by selectively coupling respective ones of said selected pair of phase shifter elements to said antenna of said transponder; and

said interrogator apparatus comprises data processing means for operating on an output signal produced from said receiving means of said interrogator apparatus to extract data which have been transmitted by said transponders by modulation utilizing said selected pair of phase shifter elements.

47. The mobile body discrimination system according to claim 46 wherein said selection control means of each of said transponders comprises means for determining that, when said response start command code is first obtained by said receiving means of said transponder after said transponder has entered a communication region of said antenna of said interrogator apparatus, said phase modulation performed by selective coupling of said first and second phase shifter elements to said antenna of said transponder is applied, to transmit said response data by phase modulation of said reflected radio waves, and that thereafter during at least a time duration for which said transponder remains within said communication region, said phase modulation performed by selective coupling of said first and third phase shifter elements to said antenna of said transponder is applied, to transmit said response data by phase modulation of said reflected radio waves.

48. The mobile body discrimination apparatus according to claim 46, wherein:

said memory means of each of said transponders comprises a stored identification code, and said response timing control section is for controlling said modulator means of said transponder to transmit said identification code together with said response data, by said reflected phase-shifted radio waves;

each of said transponders comprises means for detecting reception of a transmission halt command code by said receiving means of said transponder and for inhibiting further operation of said modulation means of said transponder for a predetermined time duration following reception of said transmission halt command code; and

said control means of said interrogator apparatus comprises means for detecting that said response data and identification code have been successfully acquired from a transponder by said receiving means and data processing means of said interrogator apparatus, and, when said successful acquisition has been detected, for controlling said transmitting means of said interrogator apparatus to transmit said transmission halt command code together with the identification code of the one of said transponders from which said response data was successfully acquired.

49. The mobile body discrimination apparatus according to claim 46, wherein each of said transponders further comprises attenuator insertion control means and said modulator means of each of said transponders comprises attenuator means controlled by said attenuator insertion control means to selectively apply a fixed amount of attenuation to said reflected phase-shifted radio waves.

50. The mobile body discrimination system according to claim 49, wherein said attenuator insertion control means (826f) of each of said transponders comprises means for determining that, when said response start command code is first obtained by said receiving means of said transponder after said transponder has entered a communication region of said antenna of said interrogator apparatus, said attenuator is applied to effect attenuation of said phase-shifted reflected radio waves when data are transmitted by said transponder in response to said first reception of said response start command code, and that thereafter during at least a time duration for which said transponder remains within said communication region, no attenuation is applied by said attenuator to said phase-shifted reflected radio waves.

51. A mobile body discrimination apparatus according to claim 1, wherein said rectifier circuit means comprises a rectifier element, impedance matching means for transferring said signal received by said antenna to an input terminal of said rectifier element, and a low-pass filter for smoothing a rectified output voltage produced at an output terminal of said rectifier element;

and wherein said rectifier circuit means comprises an impedance adjustment element coupled to at least said input terminal of said rectifier element, said impedance adjustment element for optimizing a degree of rectification efficiency of said rectifier circuit means, by applying compensation for a deviation of an impedance parameter of said rectifier element from a nominal predetermined value of said parameter.

52. The mobile body discrimination apparatus according to claim 51, wherein said rectifier circuit means comprises means for supplying a fixed-amplitude test signal to said impedance matching means in place of a signal from said antenna, for thereby performing said adjustment of said impedance adjustment element by setting said impedance adjustment element in a condition whereby a predetermined minimum level of output power is available from said rectifier circuit means when said test signal is being supplied.

53. The mobile body discrimination apparatus according to claim 51, wherein said rectifier element is a single diode, said impedance parameter is a value of inter-terminal capacitance of said diode, and said impedance adjustment element is an adjustable capacitor which is connected in parallel with said input and output terminals of said diode.

54. The mobile body discrimination apparatus according to claim 53, wherein said diode is connected in series between said impedance matching means and said low-pass filter.

55. The mobile body discrimination apparatus according to claim 53, wherein said diode is connected in parallel between a junction point of said impedance matching means and low-pass filter and a ground potential of said rectifier circuit means.

56. The mobile body discrimination apparatus according to claim 53, wherein said diode is a component of an integrated circuit chip, wherein said integrated circuit chip is mounted in a flip-chip configuration on a substrate, and said adjustable capacitor is a first electrically conductive region on said substrate and a second electrically conductive region located adjacent to said first conductive region and is for being moved towards said first electrically conductive region by displacement of said integrated circuit chip towards said substrate.

57. The mobile body discrimination apparatus according to claim 56, wherein said first electrically conductive region is a conductive layer portion located on said substrate adjacent said integrated circuit chip, said second electrically conductive region is a conductive layer portion on an outer face of said integrated circuit chip, said face being oriented opposing said first electrically conductive region, and wherein said adjustment is performed by applying force between said integrated circuit chip and said substrate in a direction such as to displace said integrated circuit chip successively towards said substrate.

58. The mobile body discrimination apparatus according to claim 51, wherein said rectifier element is a diode, said impedance parameter is a value of internal series inductance of said diode, and said impedance adjustment element is an adjustable inductor which is connected in parallel with said input and output terminals of said diode, with respect to high-frequency signals, and wherein said adjustable inductor comprises a flat spiral coil adapted for selectively short-circuiting adjacent portions of aid coil for effecting said inductance adjustment.

59. The mobile body discrimination apparatus according to claim 58, wherein said diode is a component of an integrated circuit chip, wherein said integrated circuit chip is mounted in a flip-chip configuration on a substrate, and said adjustable inductor is a patterned electrically conductive layer on said substrate, comprising an elongated connecting lead having a curved shape such that a plurality of portions of said connecting lead are disposed adjacent to one another, and connection means attached to said integrated circuit chip and adapted to be brought into contact with respective pairs of said separate portions, to thereby reduce an inductance value of said adjustable inductor, as a result of displacement of said integrated circuit chip towards said substrate.

60. The mobile body discrimination apparatus according to claim 59, wherein:

said shaped connecting lead is located adjacent said integrated circuit chip on said substrate;

said connection means comprises a plurality of protrusions comprising an electrically conductive material each having respectively different heights, each protruding from a face of said integrated circuit chip towards said substrate and respectively positioned directly adjacent corresponding ones of said portions of the shaped connecting lead, and

said integrated circuit chip and said substrate are for receiving a force applied in a direction that displaces said integrated circuit chip successively towards said substrate thereby adjusting an inductance value of said adjustable inductor.

61. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card having a substrate with patterned connecting leads on a face thereof and an integrated circuit chip in bare chip condition, which comprises internal circuits of said transponder and has a plurality of connector elements, which are respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted on said face of said substrate;

wherein said IC card comprises;

an antenna connecting lead comprising a part of said patterned connecting leads, coupled through one of said connector elements to said internal circuits; and

first and second layers of electrically conductive material each located on one of opposite sides of said IC card, and having respective slot apertures therein, said slot apertures being located relative to specific portions of said antenna connecting lead to thereby comprise first and second slot antennas, with each of said slot antennas functioning independently of the other one thereof as said antenna of said transponder.

62. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card having a first substrate with patterned connecting leads on a first face thereof and an integrated circuit chip in bare chip condition, which comprises internal circuits of said transponder and has a plurality of connector elements, which are respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted on said first face of said first substrate, said IC card comprising:

an antenna connecting lead comprising part of said patterned connecting leads, having a first branch portion and a second branch portion which respectively extend from a junction thereof, each of said first and second branch portions having a length that is determined in accordance with a wavelength of said radio waves transmitted by said interrogator apparatus, and with said antenna connecting lead having a common portion which extends between said junction and one of said connector elements;

a second substrate having an aperture for receiving said integrated circuit chip and having a first face thereof fixedly attached to said first face of said first substrate;

a first layer of electrically conductive material formed over a second face of said first substrate, having a first slot aperture formed therein, with said first slot aperture located directly over a part of said first branch portion of said antenna connecting lead;

a second layer of electrically conductive material formed over a second face of said second substrate, having a second slot aperture formed therein, with said second slot aperture located directly above a part of said second branch portion of said antenna connecting lead; and

connection means coupled to one of said connector elements and to each of said first layer of electrically conductive material and second layer of electrically conductive material, for connecting each of said layers to a ground potential of said internal circuits of said transponder;

wherein said first slot aperture in conjunction with said first branch portion of the antenna connecting lead comprises a first slot antenna and said second slot aperture in conjunction with said second branch portion of the antenna connecting lead comprises a second slot antenna, whereby each of said first and second slot antennas implements the functions of said antenna of said transponder independently of the other one of said first and second slot antennas.

63. The transponder for a mobile body discrimination apparatus according to claim 62, further comprising a first layer of a dielectric material located over said first layer of electrically conductive material and a second layer of a dielectric material located over said second layer of electrically conductive material, with said first and second layers of dielectric material respectively covering said first and second slot apertures.

64. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card having a first substrate with patterned connecting leads located on a first face thereof and an integrated circuit chip in bare chip condition, which comprises internal circuits of said transponder and has a plurality of connector elements, which are respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted on said first face of said first substrate;

wherein said integrated circuit chip comprises a ground connecting layer of electrically conductive material connected to a ground potential of said internal circuits, located over at least a part of a face of said integrated circuit chip that is opposite to a face which supports said connector elements, and

said IC card comprises;

an antenna connecting lead formed as part of said patterned connecting leads, having a first branch portion and a second branch portion which respectively extend from a junction thereof, each of said first and second branch portions having a length that is determined in accordance with a wavelength of said radio waves transmitted by said interrogator apparatus, and with said antenna connecting lead having a common portion which extends between said junction and one of said connector elements;

a layer of electrically insulating sealing material formed upon said first face of said substrate surrounding said integrated circuit chip while leaving at least a part of said ground connecting layer uncovered by said layer of sealing material;

a first layer of electrically conductive material formed over a second face of said first substrate, having a first slot aperture therein, located to extend adjacent a part of said first branch portion of said antenna connecting lead;

a second layer of electrically conductive material located over an second face of said layer of electrically insulating sealing material and said ground connecting layer, having a second slot aperture therein, with said second slot aperture located to extend adjacent a part of said second branch portion of said antenna connecting lead; and

connection means coupled to one of said connector elements and to said first layer of electrically conductive material, for connecting said layer to said ground potential;

wherein said first slot aperture in conjunction with said first branch portion of the antenna connecting lead comprises a first slot antenna and said second slot aperture in conjunction with said second branch portion of the antenna connecting lead comprises a second slot antenna, whereby either one of said first and second slot antennas can implement the functions of said antenna of said transponder independently of the other one of said first and second slot antennas.

65. The transponder for a mobile body discrimination apparatus according to claim 60, further comprising a first layer of a dielectric material located adjacent said first layer of electrically conductive material and a second layer of a dielectric material located adjacent said second layer of electrically conductive material, with said first and second layers of dielectric material respectively covering said first and second slot apertures.

66. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card having a substrate with patterned connecting leads located on a first face thereof and an integrated circuit chip in bare chip condition, which comprises circuits of said transponder and has a plurality of connector elements, which are respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted on said upper face of said substrate;

wherein said IC card comprises;

an antenna chip comprises a block of dielectric material with planar first and second faces, mounted on said first face of said substrate, with a layer of electrically conductive material having a slot aperture therein and connected to a ground potential of internal circuits of said integrated circuit chip, located adjacent said first face of said block;

an antenna connecting lead, having a first portion located on said second face of said antenna chip and a second portion located on said first face of said substrate, coupled through one of said connector elements to said internal circuits; and

a layer of electrically conductive material located over a second face of said substrate and connected to said ground potential, having a slot aperture therein;

wherein said slot apertures are located in a relative to respective portions of said antenna connecting lead to thereby constitute respective slot antennas, and each of said slot antennas is configured to function independently of the other one thereof as said antenna of said transponder.

67. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card comprising a first substrate with patterned connecting leads located on a first face thereof and an integrated circuit chip in bare chip condition, comprising respective internal circuits of said transponder and has a plurality of connector elements, respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted on said first face of said first substrate;

wherein said IC card comprises;

an antenna chip comprising a block of dielectric material mounted on said first face of said substrate, said antenna chip being shaped with planar first and second faces and having a first layer of electrically conductive material located on said first face thereof and a plurality of connector elements attached to said second face thereof, said first layer of electrically conductive material having a first slot aperture therein, and patterned connecting leads located on said second face of said block to comprise a first branch portion and a second branch portion of an antenna connecting lead, with said first and second branch portions extending from a junction thereof which is coupled to a first one of said connector elements and said first branch portion positioned with a part thereof located adjacent said first slot aperture, each of said first and second branch portions having a length that is determined in accordance with a wavelength of said radio waves transmitted by said interrogator apparatus;

a common portion of said antenna connecting lead, located on said first face of said substrate to connect said first connector element of said antenna chip to one of said connector elements of said integrated circuit chip;

a second layer of electrically conductive material, located over a second face of said substrate, having a second slot aperture therein, with said second slot aperture positioned adjacent a part of said second branch portion of said antenna connecting lead;

first through-hole connection means located in said substrate, coupled to one of said connector elements and to said first layer of electrically conductive material, for connecting said layer to said ground potential; and

second through-hole connecting means located in said substrate, and third through-hole connecting means located in said block of dielectric material, to electrically interconnect said first layer of electrically conductive material of said antenna chip and said second layer of electrically conductive material of said substrate via one of said connector elements of said antenna chip;

wherein said first slot aperture in conjunction with said first branch portion of the antenna connecting lead constitutes a first slot antenna and said second slot aperture in conjunction with said second branch portion of the antenna connecting lead constitutes a second slot antenna, whereby either one of said first and second slot antennas can implement the functions of said antenna of said transponder independently of the other one of said first and second slot antennas.

68. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card comprising a substrate and an integrated circuit chip which comprise respective internal circuits of said transponder and has a plurality of connector elements, which are respectively coupled to said internal circuits, located thereon, said integrated circuit chip being mounted in bare chip form on a first face of said substrate;

wherein said IC card comprises;

first and second portions of a patterned layer of electrically conductive material located adjacent said first face of said substrate, said first portion connected to said internal circuits and shaped to comprise a co-planar antenna connecting lead of a slot antenna, and said second portion connected to a ground potential of said internal circuits and shaped with a cut-out portion which extends to an edge of said first face, to comprise said slot antenna in conjunction with said antenna connecting lead;

whereby said slot antenna has a directivity oriented parallel to said upper face of said substrate.

69. A mobile body discrimination apparatus according to claim 1, wherein said radio waves transmitted by said interrogator apparatus are in the microwave frequency range and wherein each of said transponders is structured as an IC (integrated circuit) card comprising a substrate and an integrated circuit chip which comprise respective internal circuits of said transponder and has a plurality of connector elements located thereon, with respective ones of said connector elements coupled to said internal circuits, with said integrated circuit chip being mounted in bare chip form on a first face of said substrate;

wherein said IC card comprises;

a first portion of a patterned layer of electrically conductive material that is located adjacent said first face of said substrate, said first portion being connected via at least one of said connector elements to a ground potential of said internal circuits and located with a shaped cut-out region, said shaped region extending to an outer edge of said first face; and

a second portion of said patterned layer of electrically conductive material, extending from said integrated circuit chip to a position adjacent said shaped region, shaped to function as a co-planar antenna connecting lead of a slot antenna, and connected at one end thereof via one of said connector elements to said internal circuits of said transponder;

said cut-out portion and said co-planar antenna connecting lead having respective shapes and dimensions determined in accordance with a wavelength of said microwave radio waves such as to constitute said slot antenna.