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
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
  • C10G1/04—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by extraction
  • C10G1/045—Separation of insoluble materials
• • 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

Definitions

• the invention relates to a system for the registration of the passage of articles through a priorly determined field of the kind that comprises a transmitter and a receiver with a common aerial for alternately transmittance and receiving as well as a marker fastened to the articles for receiving and transmittance of signals by the passage of a transmitter- and receiver bracket or -brackets.
• a system which comprises a common aerial for the transmitter and the receiver as well as a marker, which consists of a tuned circuit.
• the transmitter transmits during each trans ⁇ mittance period a continuous, cyclically alternating fre ⁇ quency, and the registration of the marker passage takes place according to the grid-dip meter principle, as the resonant frequency of the marker is preferably in the middle of the frequency field of the transmitter.
• This system is rather complicated and vulnerable, because any energy absorb- tion will result in alarm.
• the aerial is also complicated, because it composed of three coils, which are placed round the passage that is to be controlled, and in such a way that they are at three planes, which are at right angles to each other.
• the purpose of the invention is to provide a system for the registration of unauthorized taking of articles and the like, which system is simply built up by few components and consequently cheap, which is easily set up by non-experts which is insensitive to electromagnetic distant fields a energy absorbing articles, and which is reliable so that false alarm can be excluded.
• This purpose is fulfilled b the fact that the transmittance and receiving function changes at a suitably high frequency, that the transmitt signals have a constant frequency during the complete transmittance period, that an analytical circuit monitor the number of received signals from the marker, and com ⁇ pares the frequency of these to that of the signals whic are transmitted by the transmitter, and that the marker consists of a tuned circuit, i.e. of an inductive and a capacitive component.
• the system can be charact zed in that the transmitter- and receiver aerial is shap like a figure eight or a double loop.
• Fig. 1 shows the system according to the invention in the shape of a block diagram
• Fig. 2 shows a way of use of the system accord ⁇ ing to the invention perspectively and schematically
• Fig. 3 shows another way of use with information of the construction of the aerial
• Fig. 4 shows a third way of use of the system according to the invention.
• Fig. 1 is shown how an aerial 1 is connected partly to a transmitter 2 and partly to a receiver 3, 4 through a switch 5.
• This switch is controlled by a synchronizing unit 6 with a suitably high frequency.
• a synchronizing unit 6 By transmitting a brief signal from the transmitter 2 with a suitable frequency an alternating current is induced in the LC-circuit of a marker 18, if this marker is in the rather limited elec- tromagnetic field that is made by the transmitter aerial 1.
• this signal transmittance stops i.e. when the aerial 1 is connected to the receiver 3, 4 by means of the switch 5
• the LC-circuit of the marker sends out a signal with the same frequency, until the oscillation in the LC- circuit dies out.
• This signal is received by the aerial 1 so that the signal is sent off via the receiver 3, ⁇ to a signal processing circuit 7.
• This circuit 7 receives at the same time impulses from the synchronizing circuit 6, so that it is able to count, how many signals are received from a marker in an uninterrupted succession. This can be achieved by zeroing the counter if no signal is received during the receiving period immediately after a transmitting periode. It has appeared that a claim for e.g. 100 received signals from a marker in an uninterrupted succession satis- factorily secures that it is a marker passage and not any electrical noise.
• the signal processing circuit 7 also moni ⁇ tors, whether the received signals have the same frequency
• O PI IPO as the signals which have been sent ' out. by the transmitte 2. This secures furthermore from false alarm. If the alar is to be given, i.e. if 100 signals have been, received in an uninterrupted succession with a correct frequency the signal processing circuit 7 sends an larm signal to an auditory or a visual alarm system.
• Fig. 2 is shown how several aerials 8 can. be placed in a way that a broad passage can be controlled.
• the system is built-in in a frame stand.
• the aerial that is shaped l figure eight is placed in the frame parts 9,. 10, 11, 12, 13, 14, 15, and l6, ⁇ whereas the transmitter 2, the receiv er 3, , and the monitoring ' unit 7 are built-in in a box 17.
• Fig. 3 the system is extended by an extra aerial.
• One aerial 19 is here placed in a door, the other aerial bein placed in the floor by the door opening.
• the marker l ⁇ being registered with what ever orientation it may have contrary to the placing in Figs. 2 and 4, where the marker may pass freely if it is oriented at right angles to the aerial as well as the flo
• the construction according to the invention can be ' used whereever you want to control the taking of articles.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Computer Security & Cryptography (AREA)
• Automation & Control Theory (AREA)
• Electromagnetism (AREA)
• Signal Processing (AREA)
• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Burglar Alarm Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8123744

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (6)

• 1978
  • 1978-08-09 DK DK351178A patent/DK145169C/da not_active IP Right Cessation
• 1979
  • 1979-08-09 DE DE792953405T patent/DE2953405T1/de active Granted
  • 1979-08-09 WO PCT/DK1979/000023 patent/WO1980000386A1/en unknown
• 1980
  • 1980-03-11 EP EP79900978A patent/EP0016809A1/en not_active Withdrawn
  • 1980-04-02 SE SE8002530A patent/SE424116B/sv not_active IP Right Cessation

Non-Patent Citations (1)

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