SECURITY SYSTEM

Abstract: A security system to detect unauthorised removal of articles e.g. from a retail store, each article carrying a read/write tag, the security system comprising at least one point-of-sale apparatus (30) arranged to write specific data into (or erase specific data from) the tag to indicate that the article has been paid for, and a detector apparatus (40) for the or each exit of the store and arranged to read each tag to determine if the specific data has been written into (or erased from) the tag, and otherwise to initiate an alarm. The system also includes a refunds/returns detector apparatus (50) to read the tag of each article presented to it, to determine if the specific data has been written into (or erased from) the tag, and to erase (or write in) that data so that the article can be returned to stock.

Description: Security System This invention relates to a security system to detect unauthorised removal of articles from a restricted area, such as a retail store. Various systems have been adopted in retail outlets to combat fraud. In one type of system, a tag is attached to each article of clothing or other merchandise, and must be removed before the article is taken out of the store, otherwise a detector at the exit door senses the tag and sets off a general audible alarm. However, another form of fraud which is developing consists of the fraudster removing an article from one part of the store, then taking it to the "returns" desk and claiming a cash refund. We have now devised a security system of improved effectiveness and which is able to counter the above-described form of fraud. In accordance with this invention, there is provided a security system to detect unauthorised removal of articles from a restricted area such as a retail store, in which each article carries a read/write tag, the security system comprising at least one-point-of-sale or point-of-authorisation apparatus arranged to write specific data into (or erase specific data from) the tag to indicate that the article has been paid or its removal has otherwise been authorised, and a detector apparatus for the or each exit of said restricted area, said detector apparatus being arranged to read each tag to determine if said specific data has been written into (or erased from) the tag and otherwise to initiate an alarm. The security system preferably further comprises a refunds/returns detector apparatus arranged to read the tag of each article presented to it and to determine if said specific data has been written into (or erased from) the tag, and to erase (or write in) said data so that the article can be returned to stock. For example the point-of-sale apparatus may write into the tag data representing the date of sale and the actual price paid for the article. Then the refunds/returns detector erases the data and price-paid data. Preferably the security system also includes detector equipment for installing internally of the store (for example at passageways between departments or at stairways or escalators between floors) , this detector equipment being arranged to read the tags of articles passing them to determine whether any of those articles has not yet been paid for: preferably each such detector equipment is arranged to initiate a low level or discrete alarm, which is available to staff but not to customers. Such a detector may also be arranged as a personal detector to be worn or carried by a member of staff, e.g. providing a discrete audible alarm to an ear piece worn by that member of staff. Preferably also the detector equipment at each exit location, or at each internal fixed location, comprises at least one ferrite core aerial used in scanning mode. For example, a plurality of such ferrite core aerials may be spaced apart along one transverse dimension of the exit or other passageway (e.g. across its width) and directed generally perpendicular to that dimension (e.g. vertically) . The aerials are then switched on one-by-one in succession to scan across the exit or other passageway. Alternatively, a ferrite core aerial may be mounted to a drive apparatus which moves the aerial to scan back-and-forth across the exit or other passageway. Embodiments of this invention will now be described by way of examples only and with reference to the accompanying drawings, in which: FIGURE 1 is a block diagram schematically showing the individual elements of a security system in accordance with this invention; FIGURE 2 is a front view of an exit doorway from a retail store, showing diagrammatically a scanning-mode detector aerial array; FIGURE 3 is a similar view of an exit doorway, showing diagrammatically an alternative form of scanning mode detector aerial array; and FIGURE 4 is a similar view of an exit doorway, showing diagrammatically another from of scanning-mode aerial. In accordance with this invention, each article of merchandise to be sold in a store carries a tag to which data can be written and from which data can be read. The tag generally comprises a small flat semiconductor chip: in the case of garments, the chip is preferably bonded to the usual label of the garment. The chip may include an air-core aerial or a ferrite core aerial for inductive coupling with read/write equipment both for powering the chip and for data transfer, Preferably the manufacturer or wholesaler of the merchandise uses data-write equipment which inductively couples to the tag of each article to write into the tag data such as a code identifying the article, the identity of the manufacturer and/or wholesaler and the date of manufacture. As shown in Figure 1 of the drawings, each store has read-write equipment 10 at its goods-entry. This equipment 10 is linked to a stock control computer 20 of the store, and via an inductively-coupling read head 11 reads the tag of each article newly-received into the store to identify the article and add it to the data held by the computer 20. Also via an inductively-coupling write head 12 the equipment 10 writes data to the tag of each article, this data including the identity of the store and the date of receipt of the article. The equipment 10 preferably includes a visual display 13 for showing the data read from each tag and for verifying the data written into each tag. The equipment 10 may also have a keyboard 14 for manually entering any other desired data into the tag memory. Each store also has at least one point-of-sale, having read/write equipment 30. This equipment is linked to the store's stock control computer 20 which, in addition to maintaining a record of the numbers of the different articles or items of merchandise within the store, also maintains a record of the current price applicable to each different article. The equipment 30 is used to read, via an inductively- coupling read head 31, the tag of each article being purchased: the identity code is read from the tag and the current price of the article is obtained by referring this code to the computer 20. The equipment 30 includes a visual display 32 arranged to display the identity of the article and its current price. The equipment 30 further includes a printer 33 to print a bill or receipt for the customer, the data for this being derived from that read from the tag of each article being purchased. The equipment 30 also includes an inductively- coupling write head 34 which writes data into the tag of each article being purchased, to indicate that the article has been paid for: this data preferably includes the date of the sale and the actual price paid. As each article is purchased, the stock control computer 20 debits its stock control records accordingly. At the or each exit of the store, a fixed detector 40 is installed to check that every article being taken out of the store has been paid for. Thus, the detector 40 includes an inductively-coupling read head 41 to read data from the tag of each article being taken out of the store, to determine whether the tag carries data indicating that it has been paid for (i.e. the data that should have been written in at the point of sale) . If the detector 40 fails to read such data, it initiates an alarm. In an alternative, the point-of-sale equipment 30 may erase a special indicator from the tag memory: then if the exit detector 40 detects the presence of such an indicator (indicating that the customer is carrying an article that has not been paid for) , the detector 40 initiates its alarm. Preferably the store also has detector equipment installed internally of the store, for example at passageways between departments or at stairways or escalators between floors. Normally customers would pay for the goods from one department or floor before moving to another department or floor: these detectors can therefore monitor movements of merchandise within the store, being arranged (similar to the exit-detectors) to read the tags of articles passing them to determine whether those articles have been paid for at one of the store's points-of-sale. Preferably these in-store detectors are arranged to initiate a low level or discrete alarm enabling staff to discretely monitor customers: for example the alarm may consist of a light positioned to be visible only by members of staff, e.g. a security guard. Such a detector may also be carried or worn by an in-store security guard, who can then discretely screen any customer within the store: in this case the alarm may be an audible alarm e.g transmitted to an ear plug. The store also has a refunds or returns department, which includes read/write equipment 50. When a customer returns an article to this department, the equipment 50 is used via its inductively-coupling read head 51 to read the tag to check that the article had been paid for and to determine the date of purchase and the price paid. This information is erased from the tag memory via an inductively-coupling write head 52 of the equipment 50: also the identity of the store and date of receipt is written into the tag, and the store's stock control records are updated, so that the article can be placed back on sale within the store. It will be appreciated that although separate read and write heads are shown in each of the items of equipment 10, 30 and 50, each pair of read and write heads (e.g. 11 and 12) may comprise a single aerial. Referring to Figure 2, the detector equipment at each exit or internal fixed location of the store preferably comprise an array of ferrite core aerials 60 spaced apart across the width of the exit and directed vertically: for example as shown the aerials may be positioned above the exit and directed downwardly. The effective field of each aerial is shown by dotted lines, and is generally in the shape of an elongated pear which extends the height of the exit but is relatively narrow. In use, the aerials 60 are switched one-by- one to effect a scan across the width of the exit. As shown in Figure 3, alternate aerials 60, 61 may be positioned above and below the exit. Instead, the array(s) may be spaced apart up the vertical side(s) of the exit and directed across its width. As shown in Figure 4, there may be a single aerial 62 which is continuously energised and mounted to a drive apparatus which moves (e.g. pivots or linearly displaces) the aerial 62 back-and-forth across the exit, effectively in a scanning mode.

Claims: CLAIMS 1) A security system to detect unauthorised removal of articles from a restricted area such as a retail store, in which each article carries a read/write tag, the security system comprising at least one point-of-sale or point-of- authorisation apparatus arranged to write specific data into (or erase specific data from) the tag to indicate that the article has been paid for, or its removal has otherwise been authorised, and a detector apparatus for the or each exit of said restricted area, said detector apparatus being arranged to read each tag to determine if said specific data has been written into (or erased from) the tag and otherwise to initiate an alarm. 2) A security system as claimed in claim 1, further comprising a refunds/returns detector apparatus arranged to read the tag of each article presented to it and to determine if said specific data has been written into (or erased from) the tag, and to erase (or write in) said data so that the article can be returned to stock. 3) A security system as claimed in claim 1 or 2, in which the point-of-sale apparatus is arranged to write into each tag data representing the date of sale and the actual price paid. 4) A security system as claimed in claim 3, in which the refunds/returns detector apparatus is arranged to erase the date of sale and price-paid data from each tag. 5) A security system as claimed in any preceding claim, comprising at least one detector apparatus for installing internally of the restricted area and arranged to read each tag passing it to determine if said specific data has been written into (or erased from) the tag and otherwise to initiate a discrete alarm. 6) A security system as claimed in any preceding claim, comprising at least one detector apparatus arranged to be carried or worn by a number of staff and to read each nearby tag to determine if said specific data has been written into (or erased from) the tag and otherwise to initiate a discrete alarm. 7) A security system as claimed in any preceding claim, in which the or each exit or internal fixed detector apparatus comprises at least one ferrite core aerial arranged to act in a scanning mode. 8) A security system as claimed in claim 7, in which each said fixed-location detector comprises a plurality of ferrite core aerials for spacing apart along one transverse dimension of an exit or other passageway, and means for switching the aerials one-by-one in scanning mode. 9) A security system as claimed in claim 7, in which each fixed-location detector comprises a ferrite core aerial mounted to a drive apparatus which is arranged to displace the aerial in scanning mode across an exit or other passageway. 10) A detector apparatus comprising at least one ferrite core aerial arranged to act in a scanning mode relative to an exit or other passageway, to inductively couple with a tag passing through the exit or other passageway and read data from the tag.

Inventors: CLEMENT MARC, DAVIES STEPHEN, CLEMENT, MARC, DAVIES, STEPHEN
Applicants: SLS WALES LTD, SLS (WALES) LIMITED
Application year: 1993
Main classification: G08B13
IPC codes: G07G1, G07G3, G08B13