GB1440398A - Reuduction of false alarms in electronic theft-detection systems - Google Patents

Reuduction of false alarms in electronic theft-detection systems

Info

Publication number
GB1440398A
GB1440398A GB1430274A GB1430274A GB1440398A GB 1440398 A GB1440398 A GB 1440398A GB 1430274 A GB1430274 A GB 1430274A GB 1430274 A GB1430274 A GB 1430274A GB 1440398 A GB1440398 A GB 1440398A
Authority
GB
United Kingdom
Prior art keywords
frequency
transmitter
alarm
range
gate
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
GB1430274A
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.)
Knogo Corp
Original Assignee
Knogo Corp
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 Knogo Corp filed Critical Knogo Corp
Publication of GB1440398A publication Critical patent/GB1440398A/en
Expired legal-status Critical Current

Links

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
    • G08B13/2414—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 inductive 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
    • 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
    • G08B13/2474—Antenna or antenna activator geometry, arrangement or layout

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Computer Security & Cryptography (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Burglar Alarm Systems (AREA)
  • Geophysics And Detection Of Objects (AREA)

Abstract

1440398 Theft alarms KNOGO CORP 1 April 1974 [13 April 1973] 14302/74 Heading G4N [Also in Division H4] In a theft alarm of the type in which a responder on an article to be protected responds to the field of a transmitter in the protected area by modifying the field or reradiating at a different frequency, false operation due to spurious signals is reduced by inhibiting the receiver detecting the response when it receives signals differing in frequency from that from the responder. In Fig. 3 the frequency of the transmitter is periodically swept over a range and the responders are resonant within part of the range to produce a dip in the radiated field. At the receiver the signal picked up on the antenna is passed through a filter 70 tuned to the sweep repetition frequency and a gate 76 to the alarm 80. A monostable circuit 88 triggered at each sweep, opens the gate while the frequency sweeps through the frequency range of the responders and outside that range opens a "noise" gate 74 so that any signal above a threshold level triggers a device 94 which holds gate closed during the next sweep. In Fig. 2 (not shown) the responder responds to the field of a fixed frequency transmitter by radiating signal of different frequency and this operates an alarm at the receiver if the alarm channel is not blocked by the concurrent receipt of a signal of a frequency different from the transmitter and reradiation.
GB1430274A 1973-04-13 1974-04-01 Reuduction of false alarms in electronic theft-detection systems Expired GB1440398A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US351019A US3868669A (en) 1973-04-13 1973-04-13 Reduction of false alarms in electronic theft detection systems

Publications (1)

Publication Number Publication Date
GB1440398A true GB1440398A (en) 1976-06-23

Family

ID=23379246

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1430274A Expired GB1440398A (en) 1973-04-13 1974-04-01 Reuduction of false alarms in electronic theft-detection systems

Country Status (12)

Country Link
US (1) US3868669A (en)
JP (1) JPS5752637B2 (en)
AU (1) AU474729B2 (en)
BE (1) BE813708A (en)
CA (1) CA1023034A (en)
DE (1) DE2417928C3 (en)
FR (1) FR2228258B1 (en)
GB (1) GB1440398A (en)
IT (1) IT1018645B (en)
NL (2) NL161904B (en)
SE (1) SE397145B (en)
ZA (1) ZA742089B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2489001A1 (en) * 1980-08-21 1982-02-26 Knogo Corp METHOD AND DEVICE FOR ELECTRONIC DETECTION OF ARTICLE FLIGHTS
US5459451A (en) * 1993-03-12 1995-10-17 Esselte Meto International Gmbh Electronic article surveillance system with enhanced geometric arrangement

Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4063230A (en) * 1975-06-12 1977-12-13 The Magnavox Company Balanced field theft detection system
US4016553A (en) * 1975-06-27 1977-04-05 Knogo Corporation Article detection system with near field electromagnetic wave control
US4045778A (en) * 1976-02-23 1977-08-30 Wagner Electric Corporation Dual channel wide-band frequency modulated keyable control circuit and keying circuit therefor
US4095214A (en) * 1976-06-17 1978-06-13 Knogo Corporation Electronic monitoring system and responder device
US4117466A (en) * 1977-03-14 1978-09-26 Lichtblau G J Beat frequency interference rejection circuit
NL7708012A (en) * 1977-07-19 1979-01-23 Nedap Nv DETECTION SYSTEM.
US4135184A (en) * 1977-08-31 1979-01-16 Knogo Corporation Electronic theft detection system for monitoring wide passageways
ZA7994B (en) * 1978-01-11 1980-01-30 Tag Radionics Ltd Presence sensing system
DK145169C (en) * 1978-08-09 1983-02-21 Security Prod Int PLANT FOR REGISTERING A PASSAGE OF AN OBJECT THROUGH A PRESERVED AREA
DE3066810D1 (en) * 1979-05-18 1984-04-12 Parmeko Ltd Method and surveillance system for detecting the presence of an e.m. wave receptor reradiator
US4532511A (en) * 1979-10-12 1985-07-30 Lemelson Jerome H Automatic vehicle identification system and method
US4281321A (en) * 1980-06-09 1981-07-28 Sensormatic Electronics Corporation Surveillance system employing a floor mat radiator
US4481428A (en) * 1981-05-19 1984-11-06 Security Tag Systems, Inc. Batteryless, portable, frequency divider useful as a transponder of electromagnetic radiation
USRE32627E (en) * 1981-09-10 1988-03-22 Sensormatic Electronics Corporation Electrical surveillance apparatus with moveable antenna elements
NL8202951A (en) * 1982-07-21 1984-02-16 Nedap Nv ABSORPTION DETECTION SYSTEM.
US4623877A (en) 1983-06-30 1986-11-18 Knogo Corporation Method and apparatus for detection of targets in an interrogation zone
NL8600738A (en) * 1986-03-24 1987-10-16 Nedap Nv Suppression of false alarms due to touch.
US4794470A (en) * 1986-06-25 1988-12-27 Media Security Incorporated And Associates Security system for protecting information
US4812822A (en) * 1987-08-31 1989-03-14 Monarch Marking Systems, Inc. Electronic article surveillance system utilizing synchronous integration
NL9100026A (en) * 1991-01-09 1992-08-03 Texas Instruments Holland INTERESTING STATION FOR IDENTIFYING OBJECTS PROCESSED OVER A TRANSPORTATION TRACK.
NL9100111A (en) * 1991-01-23 1992-08-17 Texas Instruments Holland ANTENNA SYSTEM FOR AN INQUIRY STATION FOR IDENTIFYING OBJECTS.
NL9100110A (en) * 1991-01-23 1992-08-17 Texas Instruments Holland INTERESTING STATION FOR IDENTIFICATION PURPOSES WITH SEPARATE TRANSMITTER AND RECEIVER ANTENNAS.
US5349332A (en) * 1992-10-13 1994-09-20 Sensormatic Electronics Corportion EAS system with requency hopping
AU8073194A (en) * 1993-10-05 1995-05-01 Pac/Scan, Inc. Retail theft prevention and information device
US5661470A (en) * 1994-03-04 1997-08-26 Karr; Gerald S. Object recognition system
DE19514601A1 (en) * 1995-04-20 1996-10-24 Esselte Meto Int Gmbh System for electronic article monitoring, especially for the detection of resonant circuits with very different resonance frequencies
AU2546597A (en) * 1996-04-10 1997-10-29 Sentry Technology Corporation Electronic article surveillance system
US5790031A (en) * 1997-01-13 1998-08-04 Trw Inc. Apparatus and method for sensing a rearward facing child seat with error detection
US5990791A (en) * 1997-10-22 1999-11-23 William B. Spargur Anti-theft detection system
FR2828016B1 (en) * 2001-07-30 2005-03-25 Pygmalyon ANTENNAS OF THE TYPE LOOP
WO2018204020A1 (en) 2017-05-01 2018-11-08 Johnson Controls Technology Company Building security system with false alarm reduction

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2794974A (en) * 1955-01-24 1957-06-04 Kidde & Co Walter Compensation for turbulence and other efects in intruder detection systems
US3218556A (en) * 1963-03-29 1965-11-16 Sierra Research Corp Spectrum centered receiver
US3577136A (en) * 1967-08-04 1971-05-04 Security Systems Inc Short-range signaling system
US3465336A (en) * 1968-05-09 1969-09-02 Us Army Doppler radar with clutter controlled filter channel
US3696379A (en) * 1970-12-02 1972-10-03 Knogo Corp Apparatus for article theft detection
US3711848A (en) * 1971-02-10 1973-01-16 I D Eng Inc Method of and apparatus for the detection of stolen articles
US3801977A (en) * 1971-12-07 1974-04-02 Gulf & Western Mfg Co Ultrasonic alarm circuit
US3781860A (en) * 1972-02-14 1973-12-25 Williamson W Method and apparatus for inhibiting article theft

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2489001A1 (en) * 1980-08-21 1982-02-26 Knogo Corp METHOD AND DEVICE FOR ELECTRONIC DETECTION OF ARTICLE FLIGHTS
US5459451A (en) * 1993-03-12 1995-10-17 Esselte Meto International Gmbh Electronic article surveillance system with enhanced geometric arrangement

Also Published As

Publication number Publication date
JPS5752637B2 (en) 1982-11-09
FR2228258A1 (en) 1974-11-29
SE397145B (en) 1977-10-17
JPS5010600A (en) 1975-02-03
DE2417928A1 (en) 1974-10-24
NL161904B (en) 1979-10-15
BE813708A (en) 1974-10-14
NL161904C (en)
DE2417928B2 (en) 1977-10-27
IT1018645B (en) 1977-10-20
FR2228258B1 (en) 1981-05-22
CA1023034A (en) 1977-12-20
DE2417928C3 (en) 1978-06-15
AU6740774A (en) 1975-10-02
ZA742089B (en) 1975-04-30
AU474729B2 (en) 1976-07-29
NL7404466A (en) 1974-10-15
US3868669A (en) 1975-02-25

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee