US3755803A - Electronic surveillance system - Google Patents
Electronic surveillance system Download PDFInfo
- Publication number
- US3755803A US3755803A US00024319A US3755803DA US3755803A US 3755803 A US3755803 A US 3755803A US 00024319 A US00024319 A US 00024319A US 3755803D A US3755803D A US 3755803DA US 3755803 A US3755803 A US 3755803A
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- US
- United States
- Prior art keywords
- energy
- label
- signals
- resonator
- receiver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
- G08B13/2422—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using acoustic or microwave tags
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR 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
- G06K19/0672—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 resonating marks
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR 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
- G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR 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
- G06K7/02—Methods or arrangements for sensing record carriers, e.g. for reading patterns by pneumatic or hydraulic means, e.g. sensing punched holes with compressed air; by sonic means ; by ultrasonic means
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR 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
- G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes
- G06K7/082—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors
- G06K7/083—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive
- G06K7/086—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive sensing passive circuit, e.g. resonant circuit transponders
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR 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
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2465—Aspects related to the EAS system, e.g. system components other than tags
- G08B13/2468—Antenna in system and the related signal processing
- G08B13/2471—Antenna signal processing by receiver or emitter
Definitions
- the label is constructed to produce the 3,63l,442 l2/l97l FCUBI'OH 343/6.8 reply signal in a form of energy different from that of 31500373 3/l970 Mmasy 340/280 x the original transmitted signal. It is preferred that the gzgagg' first form of energy is accoustic energy and the second 3:52l:280 7/1970 Janco et all. .3. 343/6.8 energy is electmmagnefic energy 3,399,405 8/1968 Daniel, Jr. 343/6.8 X 14 Claims, 6 Drawing Figures TRANS/M7752 ANTi/V/VA 05mm g LABEL MAa/wmm.
- the facilities offered by the present invention provide for the open or secret interrogation by radio and- /or acoustic waves of information from prepared passive labels by a remote sensing apparatus.
- the intended application of the invention is in the prevention of theft of merchandise from shops or warehouses, of books in libraries or of appropriate items in factories or other places, by tagging such items with a label and locating a receiver covering each exit so that the unauthorised passage of such tagged items through each exit will be detected.
- the basic principle of operation of any interrogating system for passive labels is as follows. Energy in some form is transmitted to the label by a transmitter and transmitting antenna unit. This energy is then processed in some way by the label, and the resulting energy retransmitted by the label as a reply" signal. This reply energy is then detected, suitably processed and information extracted therefrom by a sensitive receiver and receiving antenna unit. It is basic to all interrogation systems that the very small reply energy from the label be distinguished from the very much larger transmitter or interrogation energy. This distinction can be obtained by various methods; the present invention utilises a method which achieves the desired result by incorporating means in the label capable of changing the type of the energy, so that the reply energy is of a different type from the interrogate energy. For example in the system described below, the interrogate energy is in the form of acoustic energy while the reply energy is in the form of magnetic field energy.
- the labels are passive, with indefinitely long storage life, can be read non destructively, are durable under various environmental and handling conditions, are small and have low manufacturing cost.
- the labels can have any orientation relative to and considerable distance from the-sensing apparatus, can be in motion, and can be separated from the sensor by optically opaque barriers.
- the signal is distinguishable from background clutter signals accidentally produced by the environment of the label being interrogated.
- a distinction from clutter signals and the encoding of the information is made by choosing a combination of the type of interrogate energy and type of reply energy such that apart from the label, objects found in nature do not possess the necessary combination of characten istics to enable them to receive the type of interrogation energy, to convert this energy to the correct type of reply energy, and then re-radiate this reply energy in the correct way.
- FIG. I is a block diagram showing the basic components of the system
- FIG. 2 is an isometric view of a label card for use with the system
- FIGS. 3 and 4 are views in plan and elevation of the label card showing further details
- FIG. 5 shows one electrode configuration for the resonator incorporated in the label.
- FIG. 6 is a block diagram of a pulsed system.
- the system to be described is intended for detecting the presence only of a label at a distance of l metre, as might be required for example in a theft-detection system.
- the general principleof the system is to provide in the label card a means of receiving energy in acoustic fonn, converting it to electromagnetic energy, and reradiating it as electromagnetic energy or more precisely in this case as magnetic energy. Since the transmitted energy is in acoustic form, and the reply from the label is in a different energy form, namely magnetic, it is thus possible to separate the small label reply from the large transmitted interrogate signal.
- the basic components of the system are shown in the block diagram in FIG. 1.
- the system consists of a.
- a suitable electrical-to-acoustic energy transducer and acoustic antennae unit 2 (For example a barium titanate piezoelectric resonator coupled to the atmosphere by an acoustic horn) which is driven by the power oscillator l and radiates acoustic energy through the air illuminating the volume through-out which it is desired to detect the label,
- a magnetic coil pair 4 connected to a sensitive receiver 5 which detects the reply magnetic field produced by the label when illuminated by the acoustic field.
- FIG. 2 The construction of a suitable passive label is shown in the isometric drawing FIG. 2.
- the label consists of an inner plastic card 6 approximately 2 by 1 inches in size which serves as a protection and supporting substrate for the inner sensitive elements.
- Cardboard covers 7 and 8 sufficiently thin so as to be essentially transparent to I00 kc/s acoustic radiation, are glued to each side of the plastic card. Further details of the label are shown in FIGS. 3 and 4. In FIG. 3 the plastic card 6 and sensitive element 5 are shown with the cardboard covers 7 and 8 removed.
- the acoustic energy is detected by its action in causing resonant vibration of a I00 kc/s flexural-mode resonator 9.
- the resonator 9 shall be taken as being made of quartz, however any other material having suitable mechanical properties, low acoustic damping, and high piezoelectric coefficients could be used.
- the flexural vibration mode is used to lower the acoustic impedance level of the resonator and hence to provide a better acoustic impedance match to the air.
- Approximate dimensions of the resonator 9 are 1.5 cm long by 0.75 cm wide by 0.010 inch thick.
- the resonator 9 is set into a cut-out in the plastic card 6, between but not in contact with the cardboard covers 7 and 8. In order to cause minimum damping by its support, it is held at the flexural-mode vibrational nodal-points by four dimples projecting from the sides of the cut-out in the plastic card.
- Suitable electrodes are plated onto the resonator 9, one possible electrode configuration being shown in FIG. 5, such that the acoustic vibrational energy in the resonator is converted to electrical energy available between the electrodes 10 and 11 through the piezoelectric properties of the quartz.
- This electrical energy or more precisely the piezoelectric displacement current between electrodes 10 and 11, produces a current through a 10 turn, one square inch area coil 12 connected between electrodes and 11.
- Coil 12 is conveniently produced on the surface of the plastic card 6 by well-known printed circuitboard techniques. The magnetic field produced by this current flow through coil 12 is then detected by the Helmohltz coil pair 4 and receiver 5, thus enabling the presence of the label to be detected as required.
- Magnetic propogation loss between the reactive power available at the resonator 9 output electrodes 10 and 11 to the real power magnetically induced in the receiving coil-pair 4 75db.
- the overall transmission path loss is thus l29db.
- the noise bandwidth of the receiver is 1000 c/s. Narrower bandwidths are not practical due to the acoustic Doppler shift associated with a person carrying the label through the field.
- the consequent input noise level of the receiver allowing for a receiver noise figure of 3db is 17ldbW. With a transmitted power of.+ 20 dbW, the input signal level at the receiver is l09dbW.
- the signal-to-noise ratio at the receiver is thus 62db and the system is not receiver noise limited.
- the frequency of operation of the system can be decreased or increased. Decreasing the frequency improves the system signal to noise ratio, however the size of the label is also increased. Increasing the frequency reduces the system signal to noise ratio and decreases the size of the labels.
- the attenuation of acoustic waves through the air also increases with frequency and this has the important advantage of increasing the discrimination of the system against spurious signals from labels outside the desired detection volume since these signals suffer attenuation due to the longer acoustic propogation path. For example at an operating frequency of 200 KHZ acoustic attenuation in air is 8 db/m. Consequently signals from extraneous labels will be attenuated by 8 db per metre of their distance from the detection volume.
- the system can also be operated in reverse in the sense that magnetic field energy can be transmitted to the label by the coil-pair 4, converted to and re-radiated as acoustic energy by the label, and this acoustic energy received by the acoustic transducer-antenna 2.
- This alternative system can have advantages in installations where the atmospheric magnetic field noise energy is higher than the atmospheric acoustic noise energy. Atmospheric acoustic noise energy is normally low at 100 KHZ and increasingly so at higher frequencies due to the acoustic attenuation of the air at these frequencies.
- suitable values are a transmitter pulse length of 6 m/sec, a pulse repetition period of 300 m/sec, with the receiver synchronously gated on for a 3 m/sec period following 3 m/sec after the commencement of each transmitter pulse.
- FIG. 6 One particular embodiment of such a pulse system is shown in FIG. 6. The principal components are:
- a 37 db, l00kc/s gated power amphifier 14 which when gated on by pulse generator 15 delivers W average power, 5 kW peak power to antenna unit 21. Amplifier 14 is gated on for a 6 msec pulse period with a pulse repetition period of 300 in see by pulse generator 15.
- a magnetic coil pair 24 connected to a sensitive receiver 18 which detects the reply magnetic field produced by the label when illuminated by the acoustic field.
- the bandwidth of receiver 18 is l000c/s.
- a gate 19 following receiver 18 which is gated open by pulse generator 17 for a 3 m sec period following 3 in see after the commencement of each transmitter pulse.
- a final amplifier and detector unit 20 of bandwidth l000c/s which operates an appropriate alarm equipment if the detector output exceeds a certain threshold level during the on-gated period.
- An as table multivibrator pulse generator 15 which provides a 6 in sec pulse having a 300 in sec pulse repetition rate to gated amplifier 14 plus a trigger pulse to delay generator 16 synchronised with the leading edge of the gating pulse to 14.
- a monostable multivibrator pulse generator 16 which is triggered by the trigger pulse from 15 and hence provides a second trigger pulse to pulse generator l7 delayed 3 m see after the trigger pulse from l5.
- a monostable pulse generator 17 which is triggered by the delayed trigger pulse from 16 and whence provides a 3 m sec duration on-gating pulse to receiver gate 19.
- the particular embodiment herein described has used in the label a resonator of piezoelectric material which converted received acoustic energy to electrical energy by menas of the piezoelectric effect. It is also possible to use a resonator of magnetostrictive material which converts received acoustic energy to electrical energy by means of the magnetostructive effect. In the latter case the fluctuating magnetic moment induced in the magnetostrictive material would be detected directly by a receiver coil-pair 4 and no transmitting coil 12 would be necessary on the label.
- An electronic surveillance system comprising transmitter means for transmitting signals having a first form of energy, a passive label for attachment to an article to be placed under surveillance, signal answering means mounted on said label for receiving the signals from said transmitting means and producing signals having a second form of energy and corresponding to the received signals, receiver means responsive to the signals transmitted by said signal answering means for receiving and processing the signals of the second form of energy, control means for defining a surveillance volume, said control means including modulator means coupled to said transmitter means and rendering said receiver means unresponsive to signals from said answering means when the phase of the signals from said answering means relative to the phase of signals from said transmitter means exceeds a given value.
- said modulator means constrains said transmitter means to produce a series of regular pulses and gate said receiver means synchronously so as to switch on said receiver means at a predetermined time after the commencement of each transmitter pulse and for a predetermined period.
- said answering means includes second receiver means on said label for receiving the signals of the first form of energy, transducer means on said label coupled to said receiver means for responding to the signals on said second receiver means for forming signals of the second form of energy, and second transmitter means on said label responsive to said transducer means for transmitting the signals of the second form of energy.
- said answering means includes an electroacoustic resonator on said label.
- said answering means includes an antenna connected to said resonator.
- said label includes a plastic card having a cutout
- said answering means including a piezoelectric resonator adapted to vibrate in a flexural mode, said resonator including electrodes attached to the surface of said piezoelectric resonator, and an antenna formed on the surface of the card connected to said electrodes.
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Theoretical Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Artificial Intelligence (AREA)
- Automation & Control Theory (AREA)
- Computer Security & Cryptography (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
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- Burglar Alarm Systems (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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AU5296869 | 1969-04-02 |
Publications (1)
Publication Number | Publication Date |
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US3755803A true US3755803A (en) | 1973-08-28 |
Family
ID=3739076
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US00024319A Expired - Lifetime US3755803A (en) | 1969-04-02 | 1970-03-31 | Electronic surveillance system |
Country Status (11)
Country | Link |
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US (1) | US3755803A (de) |
BE (1) | BE748054A (de) |
BR (1) | BR7017852D0 (de) |
CH (1) | CH516853A (de) |
DE (1) | DE2015295C2 (de) |
FR (1) | FR2038184A1 (de) |
GB (1) | GB1292380A (de) |
IL (1) | IL34185A0 (de) |
LU (1) | LU60653A1 (de) |
NL (1) | NL7004748A (de) |
SE (1) | SE394042B (de) |
Cited By (57)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3849633A (en) * | 1972-01-04 | 1974-11-19 | Westinghouse Electric Corp | Object identifying apparatus |
US3914829A (en) * | 1973-06-01 | 1975-10-28 | Eaton Corp | Releasably attachable clip |
US4000488A (en) * | 1974-04-19 | 1976-12-28 | Bernard Ephraim | Label alarm system |
JPS534410A (en) * | 1976-07-02 | 1978-01-17 | Masakiyo Negishi | Device for transmitting information wave using resonator |
USRE29610E (en) * | 1973-04-13 | 1978-04-11 | Knogo Corporation | Field strength uniformity control system |
US4134538A (en) * | 1976-03-18 | 1979-01-16 | La Societe Metalimphy | Process and apparatus for identification of objects |
US4223830A (en) * | 1978-08-18 | 1980-09-23 | Walton Charles A | Identification system |
US4236068A (en) * | 1979-03-29 | 1980-11-25 | Walton Charles A | Personal identification and signaling system |
US4342904A (en) * | 1980-10-27 | 1982-08-03 | Minnesota Mining And Manufacturing Company | Lightweight ferromagnetic marker for the detection of objects having markers secured thereto |
DE3438052A1 (de) * | 1984-10-09 | 1986-04-24 | X-Cyte, Inc., Mountain View, Calif. | System zum abfragen eines passiven, phasenkodierte informationen aufweisenden transponders |
DE3438051A1 (de) * | 1984-10-09 | 1986-04-24 | X-Cyte, Inc., Mountain View, Calif. | Akustische reflektoren aufweisender, passiver transponder auf akustische oberflaechenwellen |
US4600829A (en) * | 1984-04-02 | 1986-07-15 | Walton Charles A | Electronic proximity identification and recognition system with isolated two-way coupling |
WO1986004171A1 (en) * | 1985-01-11 | 1986-07-17 | Indala Corporation | Identification system |
US4604623A (en) * | 1983-06-30 | 1986-08-05 | X-Cyte Inc. | Surface acoustic wave passive transponder having non-reflective transducers and pads |
US4605929A (en) * | 1983-06-30 | 1986-08-12 | X-Cyte Inc. | Surface acoustic wave passive transponder having optimally-sized transducers |
US4620191A (en) * | 1983-06-30 | 1986-10-28 | Halvor Skeie | Surface acoustic wave passive transponder having parallel acoustic wave paths |
US4625207A (en) * | 1983-06-30 | 1986-11-25 | X-Cyte Inc. | Surface acoustic wave passive transponder having amplitude and phase-modifying surface pads |
US4625208A (en) * | 1983-06-30 | 1986-11-25 | X-Cyte Inc. | Surface acoustic wave passive transponder having acoustic wave reflectors |
US4725841A (en) * | 1983-06-30 | 1988-02-16 | X-Cyte, Inc. | System for interrogating a passive transponder carrying phase-encoded information |
US4798175A (en) * | 1986-10-09 | 1989-01-17 | Alfa-Laval Agri, Inc. | Electronic identification system |
WO1989009984A1 (en) * | 1988-04-08 | 1989-10-19 | Scientific Generics Limited | Antipilferage tags and their use |
EP0340015A2 (de) * | 1988-04-29 | 1989-11-02 | Esselte Meto International GmbH | Sicherungsetikett und Diebstahlschutzsystem |
US5012224A (en) * | 1989-12-05 | 1991-04-30 | Sensormatic Electronics Corporation | Audible tag for magnetic electronic article surveillance systems |
US5021767A (en) * | 1987-10-12 | 1991-06-04 | N.V. Nederlandsche Apparatenfabriek Nedap | Method and an apparatus for electronically identifying articles moving along a surface |
EP0431343A2 (de) * | 1989-12-05 | 1991-06-12 | Sensormatic Electronics Corporation | Härtbares Etikett für magnetische elektronische Artikel-Überwachungssysteme |
EP0615285A2 (de) * | 1993-03-11 | 1994-09-14 | Btg International Limited | Montierung einer elektronischen Schaltung auf einem Substrat |
US5367289A (en) * | 1991-11-27 | 1994-11-22 | Sensormatic Electronics Corporation | Alarm tag for an electronic article surveillance system |
FR2727549A1 (fr) * | 1994-11-29 | 1996-05-31 | Verardi Giorgio Adriano | Procede de securisation globale et inconditionnelle dans la surveillance d'articles (eas) sur un lieu predetermine par maillage de pseudo-satellites et unites d'acquisition |
US5523749A (en) * | 1991-04-03 | 1996-06-04 | Integrated Silicon Design Pty. Ltd. | Identification system for simultaneously interrogated labels |
US5552778A (en) * | 1994-11-23 | 1996-09-03 | International Business Machines Corporation | Multibit bimorph magnetic tags using acoustic or magnetic interrogation for identification of an object coupled thereto |
US5767773A (en) * | 1994-07-29 | 1998-06-16 | Kubota Corporation | Theft preventive apparatus and radio wave receiving signaling device |
US5844484A (en) * | 1993-08-31 | 1998-12-01 | Kubota Corporation | Theft preventive apparatus having alarm output |
US5883575A (en) * | 1997-08-12 | 1999-03-16 | Hewlett-Packard Company | RF-tags utilizing thin film bulk wave acoustic resonators |
US5959532A (en) * | 1994-07-29 | 1999-09-28 | Kubota Corporation | Theft preventive apparatus and radio wave receiving signaling device |
US5986382A (en) * | 1997-08-18 | 1999-11-16 | X-Cyte, Inc. | Surface acoustic wave transponder configuration |
US6060815A (en) * | 1997-08-18 | 2000-05-09 | X-Cyte, Inc. | Frequency mixing passive transponder |
US6107910A (en) * | 1996-11-29 | 2000-08-22 | X-Cyte, Inc. | Dual mode transmitter/receiver and decoder for RF transponder tags |
US6114971A (en) * | 1997-08-18 | 2000-09-05 | X-Cyte, Inc. | Frequency hopping spread spectrum passive acoustic wave identification device |
US6144299A (en) * | 1996-07-05 | 2000-11-07 | Integrated Silicon Design Pty. Ltd. | Presence and data labels |
WO2000075038A1 (de) * | 1999-06-02 | 2000-12-14 | Cascades Arnsberg Gmbh | Verkaufsverpackung |
US6208062B1 (en) | 1997-08-18 | 2001-03-27 | X-Cyte, Inc. | Surface acoustic wave transponder configuration |
US6229442B1 (en) * | 2000-03-14 | 2001-05-08 | Motorola, Inc, | Radio frequency identification device having displacement current control and method thereof |
US6259991B1 (en) | 1999-02-10 | 2001-07-10 | X-Cyte Inc. | Environmental location system |
US20020075152A1 (en) * | 2000-12-15 | 2002-06-20 | Paul Nysen | Apparatus and method for locating a tagged item |
US6535108B1 (en) | 1995-08-14 | 2003-03-18 | Intermec Ip Corp. | Modulation of the resonant frequency of a circuit using an energy field |
US6633226B1 (en) | 1997-08-18 | 2003-10-14 | X-Cyte, Inc. | Frequency hopping spread spectrum passive acoustic wave identification device |
US20040069847A1 (en) * | 2002-10-15 | 2004-04-15 | Chester Kolton | Electronic article surveillance marker assembly |
US6724311B1 (en) | 2001-11-09 | 2004-04-20 | B&G Plastics, Inc. | Anti-theft hang tag |
US6775616B1 (en) | 1999-02-10 | 2004-08-10 | X-Cyte, Inc. | Environmental location system |
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US20050270159A1 (en) * | 1995-08-14 | 2005-12-08 | Brady Michael J | Combination radio frequency identification transponder (RFID Tag) and magnetic electronic article surveillance (EAS) tag |
US7123129B1 (en) | 1995-08-14 | 2006-10-17 | Intermec Ip Corp. | Modulation of the resonant frequency of a circuit using an energy field |
US20070115137A1 (en) * | 2005-11-21 | 2007-05-24 | Lyon Geoff M | Method and apparatus for localization of RFID tags |
US20090109005A1 (en) * | 2007-10-19 | 2009-04-30 | Usa As Represented By The Administrator Of The National Aeronautics & Space Administration | Wireless Damage Location Sensing System |
US20120169500A1 (en) * | 2010-12-29 | 2012-07-05 | Symbol Technologies, Inc. | Radio frequency identification system and method used to perform electronic article surveillance |
US8692562B2 (en) | 2011-08-01 | 2014-04-08 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Wireless open-circuit in-plane strain and displacement sensor requiring no electrical connections |
US9329153B2 (en) | 2013-01-02 | 2016-05-03 | United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Method of mapping anomalies in homogenous material |
Families Citing this family (4)
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---|---|---|---|---|
US4321586A (en) | 1980-08-21 | 1982-03-23 | Knogo Corporation | Article theft detection |
US4481428A (en) * | 1981-05-19 | 1984-11-06 | Security Tag Systems, Inc. | Batteryless, portable, frequency divider useful as a transponder of electromagnetic radiation |
DE10221484B4 (de) * | 2002-05-15 | 2012-10-11 | Hans-Joachim Laue | Vorrichtung zur Energieversorgung einer Datenerfassungs- und Datenübertragungseinheit sowie Datenerfassungs- und Übertragungseinheit |
CN107708410A (zh) * | 2015-05-06 | 2018-02-16 | 亚历斯有限公司 | 天线设备 |
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- 1970-03-31 BR BR217852/70A patent/BR7017852D0/pt unknown
- 1970-03-31 DE DE2015295A patent/DE2015295C2/de not_active Expired
- 1970-03-31 SE SE7004418A patent/SE394042B/xx unknown
- 1970-04-01 CH CH481270A patent/CH516853A/fr not_active IP Right Cessation
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DE3438052A1 (de) * | 1984-10-09 | 1986-04-24 | X-Cyte, Inc., Mountain View, Calif. | System zum abfragen eines passiven, phasenkodierte informationen aufweisenden transponders |
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EP0341828A1 (de) * | 1988-04-08 | 1989-11-15 | Esselte Meto International GmbH | Antidiebstahletiketten und ihre Verwendung |
EP0340015A3 (de) * | 1988-04-29 | 1991-06-05 | Esselte Meto International GmbH | Sicherungsetikett und Diebstahlschutzsystem |
EP0340015A2 (de) * | 1988-04-29 | 1989-11-02 | Esselte Meto International GmbH | Sicherungsetikett und Diebstahlschutzsystem |
EP0431343A3 (en) * | 1989-12-05 | 1992-04-08 | Sensormatic Electronics Corporation | Audible tag for magnetic electronic article surveillance systems |
EP0431343A2 (de) * | 1989-12-05 | 1991-06-12 | Sensormatic Electronics Corporation | Härtbares Etikett für magnetische elektronische Artikel-Überwachungssysteme |
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Also Published As
Publication number | Publication date |
---|---|
BR7017852D0 (pt) | 1973-04-17 |
FR2038184A1 (de) | 1971-01-08 |
NL7004748A (de) | 1970-10-06 |
LU60653A1 (de) | 1971-06-14 |
DE2015295C2 (de) | 1983-10-27 |
SE394042B (sv) | 1977-05-31 |
IL34185A0 (en) | 1970-05-21 |
DE2015295A1 (de) | 1970-10-15 |
GB1292380A (en) | 1972-10-11 |
CH516853A (fr) | 1971-12-15 |
BE748054A (fr) | 1970-09-28 |
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