AN ELECTRO-MAGNETIC SECURITY/SURVEILLANCE EQUIPMENT

Abstract: An electro-magnetic security/surveillance equipment comprising transmitting means (1, 3) encircling and defining at least one area (1) in which at least one security device (7) is contained. Said security device (7) may be supplied with energy from a capacitor or other EMF accumulating means (9a) being sustained or charged by aforesaid transmitting means (1, 3) via "pick-up"/antenna means (8) and rectifying means (9a). Aforesaid security device (7) may be releasably attached to the secured objects by attachment means (10). If aforesaid security device (7) is removed, across the boundary of aforesaid secured area (1), or if the attachment means (10) are tempered with, a reaction from said security device (7) is caused, said reaction being registered by detecting means (4, 5) making it possible to register the state of said security device and thus establish a desired reaction (6) e.g. an alarm.

Description: An Electro-magneticSecurity/Surveillance Equipment. The invention relates to an electromagnetic equipment for secur- ing/surveilling objects including the prevention of unauthorised removal or theft of displayed or stored merchandise e.g. in a shop or warehouse. The equipment comprises a device to be releasably attached to an object said device having transmitting means, if a removal of said device from said object is attempted the device emits a signal which may be registered by detection means. A known equipment for said purpose is described in WO 9009648. In said equipment a releasably attached device emits a radio frequency signal if removed from the object to which it is attached. The emitted signal is detected by a receiver said receiver causing an alarm. Said de¬ vice may further comprise a rebroadcast antenna and thus function as the traditional "tag"-systems on which the above mentioned patent is based. Said device does not comprise receiving means. Said device is primarily supplied from a battery. The function of the herein described equipment is significantly differ¬ ent from the function of the above mentioned, thus: At least one security device being releasably attached to the secured object is situated within at least one secured area said area being encir- cled and defined by at least one transmitting means generating a field said field may be continuous or not be continuous. (A continuous field is herein regarded as a not modulated field, likewise a not continuous field may herein be a modulated field). Said security device is equipped with at least one transmitting means and at least one receiving/detecting means. When the security device is removed from said area, at the boundaries of which the field strength is significantly changed, said change in field strength is registered by the receiving/detecting means of the security device causing the transmitting means of said security device to emit a signal, alternatively to cease emitting a signal. Likewise the security device may emit a signal, alternatively cease emitting a signal, if the attachment means is tampered with during an attempt to remove the security device from the secured object. Said signal, alternatively, the lack of said signal, is detected by detect¬ ing means thus making it possible to register the status of said security device and to establish a desired reaction e.g. an alarm. A capacitor or other EMF accumulating means may be charged and/or sus¬ tained via rectifying means from the receiving means of the security de¬ vice. Compared to the known technology the following advantages are obtained: The secured objects can not be moved beyond the boundary of at least one sharply defined area without causing a reaction. On the other hand the secured objects may freely be moved, handled, tried out, and inspected inside said area; contrary to devices of the known technology, the boundaries of which, due to the nature of the equip¬ ment, are indefinable and to a certain extend based on random local condi¬ tions. The system is highly insensitive to local conditions causing reflection, screening or phasing of the emitted signal. If the security device is wilfully screened e.g. by wrapping it in alu¬ minium foil this will cause an alarm; contrary to devices of the known technology in which such an action will inhibit an alarm, both from the enclosed transmitter and an additional rebroadcast antenna. If the security device is supplied from an internal EMF store instead of a battery the device is maintenance free with regard to battery change. The fact that both the mobile security device and the stationary control system may be equipped with transmitters and receivers makes a very "tight" relation possible, giving raise to advantages with regard to con¬ trol, communication and operation including operation by means of e.g. pocket-sized remote controls. Utilising EDB processor control in said systems makes controlled cover¬ age of e.g. large buildings with several floors possible, the individual secured objects may be tracked, and by assigning codes (that may be iden¬ tical to the objects "bar-codes") to the individual security devices a high degree of invoice- storage- and identity-control may be obtained. According to the invention said effects are obtained by at least one ad¬ ditional transmitting means encircling the area in which aforesaid releas- ably attached security device is located and emitting a field in a defined area said field being detected by a receiver in said security device in a way that said security device emi ts a signal upon removal from said de¬ fined area due to the reduced strength of the field from said additional transmitting means; the signal being emitted from said security device is detected by detecting means said detecting means causing a reaction e.g. an alarm. Thus the earlier described aim and advantages of the invention is achieved. In a further embodiment, aforesaid security device ceases to emit a sig¬ nal if removed from aforesaid defined area. Said emitted signal may be pe¬ riodic and contain a code which may be specific to the individual security device. Thus the system may employ a polling protocol so that the individual se¬ curity devices may be addressed one by one and thus verify their presence, if they are still within the defined area, if a security device is moved outside the defined area said security device ceases to emi t its identifi¬ cation which is detected by detecting means said detecting means causing a reaction e.g. an alarm. In a further embodiment aforesaid additional transmitting means, encir¬ cling and defining the secured area, emits a continuous field (A continu¬ ous field is herein regarded as a not modulated field). Thus the equipment may be adapted to environments and applications in which it is not desirable or possible to utilise a not continuous field (A not continuous field may herein be a modulated field). In a further embodiment aforesaid additional transmitting means and the supplementing receiving/detecting means and aforesaid security device, utilises primarily the magnetic component or primarily the electric compo¬ nent or both said components of the emitted fields. Thus the equipment may be adapted to environments and applications call¬ ing for said arrangements. In a further embodiment aforesaid security device is supplied with en¬ ergy from a capacitor or other EMF accumulating means, sustained and/or charged via "pick-up"/antenna means and rectifying means, contained in said security device, by means of the field generated by aforesaid addi¬ tional transmitting means. Thus for all practical purposes the energy supply of said security de¬ vices is battery-less and cord-less. In a further embodiment aforesaid security device comprises means which deactivates circuits not in use as long as said security device is within a field strength larger than that required to activate its transmitting means; above said means activating the formerly deactivated circuits as the field strength approaches the value necessary to activate the trans¬ mitting means of said security device. Thus a reduced current consumption from battery or EMF storing means is achieved. In a further embodiment each of aforesaid security devices and/or each of aforesaid transmitting/receiving/detecting means comprises at least one LSI (Large Scale Integrated) circuit and/or at least one micro-processor, both of which may be a standard circuit or may be realised for the appli¬ cation. Thus marked advantages with regard to space saving, system complexity and cost efficiency is achieved. In a further embodiment at least one of aforesaid security devices is contained within at least one of aforesaid areas, encircled and defined by aforesaid additional transmitting means, said area/areas being monitored by at least one receiving/detecting means thus making it possible to reg¬ ister the status of said security device and to establish a desired reac¬ tion e.g. an alarm. It is thus achieved that a plurality of areas, each secured by its own additional transmitting means, may be served by at least one separate re¬ ceiving/detecting means. In a further embodiment the above mentioned receiving/detecting means is combined with aforesaid additional transmitting means in a way that the "pick-up"/antenna means of said receiving/detecting means is a physical part of the radiating/antenna means of aforesaid additional transmitting means, whether said "pick-up"/antenna means and said radiating/antenna means are electrically isolated or utilises at least one common electrical conductor. Thus the transmitting/receiving/detecting means are simplified and a number of areas, each being secured by its individual additional transmit- ting means, may be served by at least one receiving/detecting means com¬ bined with at least one additional transmitting means in a way that fur¬ ther secured areas may be established in a hierarchical order if so de¬ sired. In a further embodiment of the equipment, radiating/"pick-up"/antenna means are loops/coils having at least one turn, whether said loops/coils are electrically or magnetically screened or not or whether they are tuned or not. Thus a "tight", well defined coupling between the security device and the transmitting/receiving/detecting means is achieved In a further embodiment of the equipment, radiating/"pick-up"/antenna means are field-plates/grids, whether they are tuned or not. Thus the equipment may be adapted to environments and applications call- ing for said arrangements. Fig. 1 Shows the secured area represented by a transmitting device (1, 3) together with the associated receiving/detecting device (4, 5, 6, 1, (12)) and a security device (7) inside said area. Fig. 2 Shows, by way of example, three secured areas represented by transmitting devices (1, 3) containing security devices (7). The three se¬ cured areas are served, by way of example, by one receiving/detecting de¬ vice (4, 5, 6, 11, (12)). Fig. 3 Shows, by way of example, three secured areas represented by transmitting devices (1, 3) containing security devices (7). The three se¬ cured areas are served by a receiving/detecting device (4, 5, 6, 11, (12)) combined with an additional transmitting device (la, 3a) containing fur¬ ther security devices (7). The equipment in Fig. 1-3 comprises: transmitting means (1, 3 & la, 3a), receiving/detecting means (4, 5, 1, 11 and/or 12), indicating/alarm means (6) and a plurality of security devices (7). At least one radiating/antenna device (1, la) being a loop, utilising the magnetic component or the electric component or both said components of the emitted field, encircle and defines an area said area being the se¬ cured/surveyed area. The radiating/antenna device is connected, e.g. via a transmit/receive filter (2), to a transmitter (3, 3a) generating a continuous or a not con¬ tinuous output in a suitable band, e.g. in one of the internationally rec¬ ognised ISM (Industrial Scientific Medical) bands, or in another interna¬ tionally or locally suitable band. At least one receiving/detecting device (4, 5), connected to said radi¬ ating/antenna device (1, la, 11), e.g. via a transmit/receive filter (2), or/and to another "pick-up"/antenna device (12), connects to an indicat¬ ing/alarm device (6) giving the desired indication and/or alarm. Said in¬ dicating/alarm device (6) may comprise data in/out means, e.g. for regis- tration, control and statistics, being utilised either locally or to/from a remote location. A plurality of security devices (7), is found within the boundaries of aforesaid secured area/areas (1, la), each comprising at least one trans¬ mitting device and at least one receiving/detecting device (8, 9). The security devices may be releasably attached to the secured/surveilled objects by attachment means (10). If aforesaid security devices (7) are removed from a secured area or if the attachment means (10) are tampered with said security devices emits (9b) e.g. a coded signal (9c), alternatively ceases to emit a signal, by means of one or more coils/loops (8) or other radiating means. Said signal is generated by means of energy stored in the security devices in either a battery, or in a capacitor or other EMF accumulating means sustained and/or charged via "pick-up"/antenna means (8) and rectify- ing/limiting means (9a) from the field of aforesaid transmitting means (1, 3 & la, 3a) encircling and defining the secured area. Said signal, generated by the security device (7), or the lack of said signal, is detected by receiving/detecting means (4, 5) utilising either the radiating/antenna device (1, la) and or a separate "pick-up"/antenna device (11 and/or 12), making it possible to register the state of said security device and thus establish a desired reaction e.g. an alarm.

Claims: Claims: CLAIM 1: (Fig. 1) Equipment for securing/surveying objects, including the prevention of unauthorised removal or theft of displayed or stored articles, e.g. in a shop or a warehouse, said equipment comprising a releasably attached secu¬ rity device (7) to be attached to an object said security device compris¬ ing a transmitter emitting a signal if said security device is removed from the object. The security device may be supplemented by a rebroadcast antenna. CHARACTERISED by comprising at least one additional transmitting means (1, 3) encircling the area in which aforesaid releasably attached security de¬ vice is located and emitting a field in a defined area said field being detected (9) by said security device, comprising at least one receiving means, in a way that said security device emi ts a signal upon removal from said defined area due to the reduced strength of the field from said addi¬ tional transmitting means; the signal being emitted from said security de¬ vice is detected by detecting means (4, 5, 1 and/or 12) said detecting eans causing a reaction e.g. an alarm (6). CLAIM 2: (Fig. 1) Equipment for securing/surveying objects, including the prevention of unauthorised removal or theft of displayed or stored articles, e.g. in a shop or a warehouse, said equipment comprising a releasably attached secu¬ rity device (7) to be attached to an object said security device compris¬ ing a transmitter emitting a signal if said security device is removed from the object. The security device may be supplemented by a rebroadcast antenna. CHARACTERISED by comprising at least one additional transmitting means (1, 3) encircling the area in which aforesaid releasably attached security de¬ vice is located and emitting a field in a defined area said field being detected (9) by said security device, comprising at least one receiving means, in a way that said security device ceases to emit a signal upon re- moval from said defined area due to the reduced strength of the field from said additional transmitting means; the signal being emitted from said se¬ curity device is detected by detecting means (4, 5, 1 and/or 12) said de¬ tecting means causing a reaction e.g. an alarm (6). CLAIM 3: (Fig. 1 - 3) An equipment as in claim 1 & 2, CHARACTERISED in that aforesaid addi¬ tional transmitting means (1, 3 & la, 3a), encircling and defining the se- cured area, emits: A: a continuous field (a continuous field is herein regarded as a not modulated field) . B: a not continuous field (a not continuous field may herein be a modu¬ lated field). CLAIM 4: (Fig. 1 - 3) An equipment as in claim 1 & 2, CHARACTERISED in that aforesaid addi¬ tional transmitting means (1, 3 & la, 3a) and aforesaid security device (7), utilises primarily the magnetic component or primarily the electric component or both said components of the emitted fields CLAIM 5: (Fig. 1 - 3) An equipment as in claim 1 & 2, CHARACTERISED in that aforesaid security device (7) is supplied with energy from a capacitor or other EMF accumu- lating means, sustained and/or charged via "pick-up"/antenna means (8) and rectifying means (9a), contained in said security device (7), by means of the field generated by aforesaid additional transmitting means (1, 3 & la, 3a). CLAIM 6: (Fig. 1) An equipment as in claim 1 & 2, CHARACTERISED in that aforesaid security device (7) comprises means (9d) which deactivates circuits not in use as long as said security device is within a field strength larger than that required to activate its transmitting means; abovesaid means (9d) activat- ing the formerly deactivated circuits as the field strength approaches the value necessary to activate the transmitting means of said security de¬ vice. CLAIM 7: (Fig. 1) An equipment as in claim 1 & 2, CHARACTERISED in that each of aforesaid security devices (7) and/or each of aforesaid transmit- ting/receiving/detecting means (2-6) comprises at least one LSI (Large Scale Integrated) circuit and/or at least one micro-processor, both of which may be a standard circuit or may be realised for the application. CLAIM 8: (Fig. 2) An equipment as in claim 1 & 2, CHARACTERISED in that at least one of aforesaid security devices (7) is contained within at least one of afore¬ said areas (1) , encircled and defined by aforesaid additional transmit¬ ting means (1, 3), said area/areas being monitored by at least one receiv¬ ing/detecting means (4, 5, 11 and/or 12) thus making it possible to reg- ister the status of said security device and to establish a desired reac¬ tion (6) e.g. an alarm. CLAIM 9: (Fig. 3) An equipment as in claim 1, 2 & 8 CHARACTERISED in that the in claim 8 mentioned receiving/detecting means (4, 5, 11 and/or 12) is combined with aforesaid additional transmitting means (la, 3a) in a way that the "pick- up"/antenna means (11) of said receiving/detecting means is a physical part of the radiating/antenna means (la) of aforesaid additional transmit¬ ting means (la, 3a), whether said "pick-up"/antenna means and said radi- ating/antenna means are electrically isolated or utilises at least one common electrical conductor. CLAIM 10: (Fig. 1 - 3) An equipment as in claim 1, 2, 3, 4, 5, 8 & 9 CHARACTERISED in that ra- diating/"pick-up"/antenna means (1, la, 11, 12, 8) are: A: loops/coils having at least one turn, whether said loops/coils are electrically or magnetically screened or not or whether they are tuned or not. B: field-plates/grids, whether they are tuned or not.

Inventors: FORCHHAMMER JEPPE, FORCHHAMMER, JEPPE
Applicants: FORCHHAMMER JEPPE, FORCHHAMMER, JEPPE
Application year: 1992
Main classification: G08B13
IPC codes: G08B13