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GB1292380A - Electronic surveillance systems - Google Patents

Electronic surveillance systems

Info

Publication number
GB1292380A
GB1292380A GB04101/70A GB1410170A GB1292380A GB 1292380 A GB1292380 A GB 1292380A GB 04101/70 A GB04101/70 A GB 04101/70A GB 1410170 A GB1410170 A GB 1410170A GB 1292380 A GB1292380 A GB 1292380A
Authority
GB
United Kingdom
Prior art keywords
label
resonator
acoustic
energy
transmitter
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
Application number
GB04101/70A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Unisearch Ltd
Original Assignee
Unisearch Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Unisearch Ltd filed Critical Unisearch Ltd
Publication of GB1292380A publication Critical patent/GB1292380A/en
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/22Electrical actuation
    • G08B13/24Electrical actuation by interference with electromagnetic field distribution
    • G08B13/2402Electronic 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
    • G08B13/2405Electronic 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
    • G08B13/2422Electronic 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
    • GPHYSICS
    • G06COMPUTING OR CALCULATING; COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06Record 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
    • G06K19/067Record 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
    • G06K19/0672Record 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
    • GPHYSICS
    • G06COMPUTING OR CALCULATING; COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0008General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
    • GPHYSICS
    • G06COMPUTING OR CALCULATING; COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/02Methods 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
    • GPHYSICS
    • G06COMPUTING OR CALCULATING; COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/08Methods 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
    • G06K7/082Methods 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
    • G06K7/083Methods 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
    • G06K7/086Methods 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
    • GPHYSICS
    • G06COMPUTING OR CALCULATING; COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009Methods 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
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/22Electrical actuation
    • G08B13/24Electrical actuation by interference with electromagnetic field distribution
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/22Electrical actuation
    • G08B13/24Electrical actuation by interference with electromagnetic field distribution
    • G08B13/2402Electronic 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
    • G08B13/2428Tag details
    • G08B13/2437Tag layered structure, processes for making layered tags
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/22Electrical actuation
    • G08B13/24Electrical actuation by interference with electromagnetic field distribution
    • G08B13/2402Electronic 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
    • G08B13/2465Aspects related to the EAS system, e.g. system components other than tags
    • G08B13/2468Antenna in system and the related signal processing
    • G08B13/2471Antenna signal processing by receiver or emitter

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Electromagnetism (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Computer Security & Cryptography (AREA)
  • Automation & Control Theory (AREA)
  • Toxicology (AREA)
  • Health & Medical Sciences (AREA)
  • Signal Processing (AREA)
  • General Health & Medical Sciences (AREA)
  • Acoustics & Sound (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

1292380 Ultrasonic locating systems UNISEARCH Ltd 24 March 1970 [2 April 1969] 14101/70 Heading H4D [Also in Division G4] A theft-detection system, e.g. for preventing shop-lifting, comprises a pulse transmitter 1 of acoustic or electromagnetic energy, a passive label 3 for attachment to an article to be protected, means on the label to receive the acoustic or electromagnetic energy and to transmit a reply in energy of the other form, and a gated receiver 5 turned on at a predetermined time after each transmitter pulse whereby replies from labels outside the region are eliminated. The transmitter 1 may be a 100w., 100kHz pulsed oscillator feeding a barium titanate resonator and horn 2, the acoustic energy of which is received by flexural-mode quartz resonator 9 mounted between cardboard covers, forming the label 3 attached to the article being protected. Electrodes 10 and 11 plated on the resonator 9 are connected to a printed circuit coil 12 radiation from which is picked up by Helmholtz coil-pair 4 and detected by a gated receiver 5 (Fig. 6, not shown) which operates an alarm. Modifications.-The label may alternatively employ a magnetostrictive resonator which converts acoustic energy to electromagnetic energy.
GB04101/70A 1969-04-02 1970-03-24 Electronic surveillance systems Expired GB1292380A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU5296869 1969-04-02

Publications (1)

Publication Number Publication Date
GB1292380A true GB1292380A (en) 1972-10-11

Family

ID=3739076

Family Applications (1)

Application Number Title Priority Date Filing Date
GB04101/70A Expired GB1292380A (en) 1969-04-02 1970-03-24 Electronic surveillance systems

Country Status (11)

Country Link
US (1) US3755803A (en)
BE (1) BE748054A (en)
BR (1) BR7017852D0 (en)
CH (1) CH516853A (en)
DE (1) DE2015295C2 (en)
FR (1) FR2038184A1 (en)
GB (1) GB1292380A (en)
IL (1) IL34185A0 (en)
LU (1) LU60653A1 (en)
NL (1) NL7004748A (en)
SE (1) SE394042B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
WO2016176728A1 (en) 2015-05-06 2016-11-10 Aleis Pty Ltd Antenna apparatus

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US3849633A (en) * 1972-01-04 1974-11-19 Westinghouse Electric Corp Object identifying apparatus
US3838409A (en) * 1973-04-13 1974-09-24 Knogo Corp Field strength uniformity control system for article theft detection system
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
US4134538A (en) * 1976-03-18 1979-01-16 La Societe Metalimphy Process and apparatus for identification of objects
JPS534410A (en) * 1976-07-02 1978-01-17 Masakiyo Negishi Device for transmitting information wave using resonator
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
US4725841A (en) * 1983-06-30 1988-02-16 X-Cyte, Inc. System for interrogating a passive transponder carrying phase-encoded information
US4625207A (en) * 1983-06-30 1986-11-25 X-Cyte Inc. Surface acoustic wave passive transponder having amplitude and phase-modifying surface pads
US4605929A (en) * 1983-06-30 1986-08-12 X-Cyte Inc. Surface acoustic wave passive transponder having optimally-sized transducers
US4625208A (en) * 1983-06-30 1986-11-25 X-Cyte Inc. Surface acoustic wave passive transponder having acoustic wave reflectors
US4604623A (en) * 1983-06-30 1986-08-05 X-Cyte Inc. Surface acoustic wave passive transponder having non-reflective transducers and pads
US4620191A (en) * 1983-06-30 1986-10-28 Halvor Skeie Surface acoustic wave passive transponder having parallel acoustic wave paths
US4600829A (en) * 1984-04-02 1986-07-15 Walton Charles A Electronic proximity identification and recognition system with isolated two-way coupling
AU564509B2 (en) * 1984-10-09 1987-08-13 X-Cyte Inc. Phase-encoded transponder interrogation
AU565454B2 (en) * 1984-10-09 1987-09-17 X-Cyte Inc. Saw transponder
US4818855A (en) * 1985-01-11 1989-04-04 Indala Corporation Identification system
US4798175A (en) * 1986-10-09 1989-01-17 Alfa-Laval Agri, Inc. Electronic identification system
NL8702426A (en) * 1987-10-12 1989-05-01 Nedap Nv METHOD AND APPARATUS FOR IDENTIFYING METAL PALLETS AND CONTAINERS.
DE68907125T2 (en) * 1988-04-08 1994-03-17 Esselte Meto Int Gmbh Anti-theft labels and their use.
GB8810178D0 (en) * 1988-04-29 1988-06-02 Scient Generics Ltd Antipilferage systems
CA2020952A1 (en) * 1989-12-05 1991-06-06 Frank Drucker Audible tag for magnetic electronic article surveillance systems
US5012224A (en) * 1989-12-05 1991-04-30 Sensormatic Electronics Corporation Audible tag for magnetic electronic article surveillance systems
ATE313134T1 (en) * 1991-04-03 2005-12-15 Tagsys Sa ITEM SORTING SYSTEM
US5367289A (en) * 1991-11-27 1994-11-22 Sensormatic Electronics Corporation Alarm tag for an electronic article surveillance system
IL107636A (en) * 1992-11-18 1998-02-08 Csir Detection of multiple articles
ZA941671B (en) * 1993-03-11 1994-10-12 Csir Attaching an electronic circuit to a substrate.
CA2147746A1 (en) * 1993-08-31 1995-03-09 Hiroyuki Fujiuchi Theft preventive apparatus having alarm output
CA2196158A1 (en) * 1994-07-29 1996-02-15 Hiroyuki Fujiuchi Burglar alarm apparatus and radio receiver
US5959532A (en) * 1994-07-29 1999-09-28 Kubota Corporation Theft preventive apparatus and radio wave receiving signaling device
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
FR2727549B1 (en) * 1994-11-29 1997-03-28 Verardi Giorgio Adriano GLOBAL AND UNCONDITIONAL SECURITY PROCESS IN THE MONITORING OF ARTICLES (EAS) ON A PREDETERMINED PLACE BY MESH OF PSEUDO-SATELLITES AND ACQUISITION UNITS
US7002475B2 (en) * 1997-12-31 2006-02-21 Intermec Ip Corp. 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
US5812065A (en) 1995-08-14 1998-09-22 International Business Machines Corporation Modulation of the resonant frequency of a circuit using an energy field
AUPO085596A0 (en) * 1996-07-05 1996-07-25 Integrated Silicon Design Pty Ltd Presence and data labels
US6107910A (en) * 1996-11-29 2000-08-22 X-Cyte, Inc. Dual mode transmitter/receiver and decoder for RF transponder tags
US5883575A (en) * 1997-08-12 1999-03-16 Hewlett-Packard Company RF-tags utilizing thin film bulk wave acoustic resonators
US6208062B1 (en) 1997-08-18 2001-03-27 X-Cyte, Inc. Surface acoustic wave transponder configuration
US6633226B1 (en) 1997-08-18 2003-10-14 X-Cyte, Inc. Frequency hopping spread spectrum passive acoustic wave identification device
US5986382A (en) 1997-08-18 1999-11-16 X-Cyte, Inc. Surface acoustic wave transponder configuration
US6114971A (en) * 1997-08-18 2000-09-05 X-Cyte, Inc. Frequency hopping spread spectrum passive acoustic wave identification device
US6060815A (en) * 1997-08-18 2000-05-09 X-Cyte, Inc. Frequency mixing passive transponder
US6775616B1 (en) 1999-02-10 2004-08-10 X-Cyte, Inc. Environmental location system
US6259991B1 (en) 1999-02-10 2001-07-10 X-Cyte Inc. Environmental location system
DE29909681U1 (en) * 1999-06-02 1999-08-26 Cascades Arnsberg GmbH, 59821 Arnsberg Sales packaging
US6229442B1 (en) * 2000-03-14 2001-05-08 Motorola, Inc, Radio frequency identification device having displacement current control and method thereof
US6995654B2 (en) * 2000-12-15 2006-02-07 X-Cyte, Inc. Apparatus and method for locating a tagged item
US6724311B1 (en) 2001-11-09 2004-04-20 B&G Plastics, Inc. Anti-theft hang tag
DE10221484B4 (en) * 2002-05-15 2012-10-11 Hans-Joachim Laue Device for powering a data acquisition and data transfer unit and data acquisition and transfer unit
US20040069847A1 (en) * 2002-10-15 2004-04-15 Chester Kolton Electronic article surveillance marker assembly
US7086593B2 (en) * 2003-04-30 2006-08-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Magnetic field response measurement acquisition system
US9285471B2 (en) * 2005-11-21 2016-03-15 Hewlett-Packard Development Company, L.P. Method and apparatus for localization of RFID tags
WO2009051783A1 (en) * 2007-10-19 2009-04-23 United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Wireless damage location sensing system
US8497776B2 (en) * 2010-12-29 2013-07-30 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

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4321586A (en) 1980-08-21 1982-03-23 Knogo Corporation Article theft detection
DE3128980A1 (en) * 1980-08-21 1982-04-08 Knogo Corp., 11801 Hicksville, N.Y. METHOD AND DEVICE FOR PROTECTING OBJECTS AGAINST THEFT
US4481428A (en) * 1981-05-19 1984-11-06 Security Tag Systems, Inc. Batteryless, portable, frequency divider useful as a transponder of electromagnetic radiation
WO2016176728A1 (en) 2015-05-06 2016-11-10 Aleis Pty Ltd Antenna apparatus
EP3291669A4 (en) * 2015-05-06 2018-05-30 Aleis Pty Ltd Antenna apparatus
US10333196B2 (en) 2015-05-06 2019-06-25 Aleis Pty Ltd Antenna apparatus
AU2020202460B2 (en) * 2015-05-06 2022-02-03 Allflex Australia Pty Limited Antenna apparatus

Also Published As

Publication number Publication date
DE2015295A1 (en) 1970-10-15
BR7017852D0 (en) 1973-04-17
DE2015295C2 (en) 1983-10-27
NL7004748A (en) 1970-10-06
CH516853A (en) 1971-12-15
IL34185A0 (en) 1970-05-21
LU60653A1 (en) 1971-06-14
US3755803A (en) 1973-08-28
FR2038184A1 (en) 1971-01-08
SE394042B (en) 1977-05-31
BE748054A (en) 1970-09-28

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Legal Events

Date Code Title Description
414F Notice of opposition given (sect. 14/1949)
414B Case decided by the comptroller ** grants allowed (sect. 14/1949)
PS Patent sealed [section 19, patents act 1949]
PE20 Patent expired after termination of 20 years