GB2197565A - Tags for use in electronic article surveillance systems and methods of making them - Google Patents

Description

1 GB2197565A 1

SPECIFICATION

Tags for use in electronic article surveillance systems and methods of making them This invention relates to tags for use in electronic article surveillance systems, and to methods 5 of making tags.

The prior art includes the following documents: U.S. Patents 3,240,647; 3, 624,631;

3,810,147; 3,913,219; 4,482,874; 4,555,291 and 4,567,473; and French patent 2,412,923.

The invention in its various aspects is defined in the appended claims to which reference should now be made.

One particular problem that has been found is that a deactivatable tag can be accidentally deactivated prematurely before the tag is ready to be willfully deactivated. Such deactivation can occur during manufacture or even after manufacture such as during storage or when a web of the tags is being printed upon in a marking machine. The deactivation can occur due to static electricity which builds up and can arc in a longitudinal direction along the web between adjacent 15 resonant circuits if the resonant circuits touch each other or are too close to each other and additionally if a normally non-conductive breakdown deactivator extends longitudinally from reso nant circuits-to-resonant circuits.

In a preferred embodiment of this inventibn this problem is overcome by spacing the resonant circuits from each other in the longitudinal direction of - the web and by separating the web of 20 deactivation material into separate spaced strips so that there is one deactivator strip for each resonant circuits. The premature deactivation of adjacent resonant circuits is then prevented, even though both the conductive material of which the resonant circuits are formed and the deactivator material is originally in web form.

Brief Description of the Drawings

The invention will now be described in detail by way of example, with reference being made to the drawings, in which:

Figure 1 is an exploded perspective view of a tag in accordance with an embodiment of the invention; Figure 2 is a fragmentary sectional view of the tag in Fig. 1; Figure 3 is a diagrammatic perspective view illustrating method of making a tag in accordance with the invention; Figure 4 is a diagrammatic top plan view showing a mask having been applied to a first 35. adhesive coated web and showing an electrically conductive web being laminated to the masked 35 first adhesive coated web; Figure 5 is a diagrammatic top plan view showing the conductive web having been cut to provide first and second pairs of conductors and showing a masked second adhesive coated web being laminated to the conductive web; 40 Figure 6 is a diagrammatic top plan view showing the first coated web with the first conduc- 40 tors adhered thereto being separated relative to the second coated web with the second conductors adhered thereto, and showing further the first coated web having been recoated with adhesive and two webs of dielectric being laminated to the recoated first coated web, and showing the dialectric webs having been coated with adhesive; 45 Figure 7 is a diagrammatic top plan view showing the second coated web with the second conductors adhered thereto having been shifted and laminated over and to the dialectric webs and to the first coated web with the first conductors to provide a composite tag web, showing the staking of the first and second conductors of each tag to provide resonant circuits for each tag, and showing slitting of the composite tag web to provide a plural series of composite tag webs; Figure 8 is a vertically exploded view showing the first and second coated webs with the first and second conductors that result from cutting the electrically conductive web spirally; Figure 9 is a top plan view showing the first and second coated webs shifted by a distance equal to the width of one conductor spiral plus the width of one conductor; Figure 10 is a top plan view of two tags with the dielectric web shown in phantom lines; 55 Figure 11 is a fragmentary perspective view which, when taken together with the preceding figures of the drawings, illustrates an improved method of making deactivatable tags; Figure 12 is a fragmentary top plan view taken along line 12-12 of Fig. 11; Figure 13 is a sectional view taken along line 13-13 of Fig. 12; Figure 14 is a fragmentary perspective view similar to Fig. 1, but showing one embodiment of 60 structure for deactivating the tag; Figure 15 is a fragmentary top plan view of the tag shown in Fig. 14; Figure 16 is a fragmentary perspective view which, taken together with Figs. 1 through 10, illustrated an alternative improved method of making deactivatable tags; Figure 17 is a fragmentary top plan view taken along line 17-17 of Fig. 16; 2 GB2197565A 2 Figure 18 is a sectional view taken along line 18-18 of Fig. 17; Figure 19 is a fragmentary perspective view similar to Fig. 14 but showing another embodiment of structure for deactivating the tag; Figure 20 is a fragmentary top plan view of the tag shown in Fig. 19; Figure 21 is a sectional view similar view similar to Fig. 18 but showing an alternative structure for deactivating the tag; Figure 22 is a top plan view of an alternative cut pattern for the web of conductive material corresponding generally to D in Fig. 5; Figure 23 is a top plan view of the alternative cut pattern with one-half of the conductive 10 material removed and corresponding generally to G in Fig. 6; Figure 24 is a diagrammatic perspective view showing the manner in which the webs of deactivating material are cut into stripes or strips; and Figure 25 is a top plan view of a pair of longitudinally spaced resonant circuits with separate respective deactivator strips.

Description of the Preferred Embodiments

Referring initially to Fig. 1, there is shown an exploded view of a tag generally indicated at 19.

The tag 19 is shown to include a sheet 20T having pressure sensitive adhesive 21 and 22 on opposite faces thereof. A mask 23 in a spiral pattern covers a portion of the adhesive 21 and a release sheet 24T is releasably adhered to the adhesive 22. The mask 23 renders the adhesive 20 21 which it covers non-tacky or substantially so. A conductor spiral indicated generally at 25 includes a spiral conductor 26 having a number of turns. The conductor 26 is of substantially the same width throughout its length except for a connector bar 27 at the outer end portion of the conductor spiral 26. There is a sheet of dielectric 28T over and adhered to the conductor spiral 25 and the underlying sheet 20T by means of adhesive 29. A conductor spiral generally 25 indicated at 30 includes a spiral conductor 31 having a number of turns. The conductor 31 is adhered to adhesive 29' on the dielectric 28T. The conductor 31 is substantially the same width throughout its length except for a connector bar 32 at the outer end portion of the conductor spiral 30. The conductor spirals 25 and 30 are generally aligned in face- to-face relationship except for portions 3 which are not face-to-face with the conductor 26 and except for portions 30 which are not face-to-face with the conductor 31. A sheet 37T has a coating of a pressure sensitive adhesive 38 masked off in a spiral pattern 39. The exposed adhesive 38' is aligned with the conductor spiral 30. Adhesive is shown in Fig. 1 by heavy stippling and the masking is shown in Fig. 1 by light stippling with cross-hatching. The connector bars 27 and 32 are electrically connected, as for example by staking 90. It should be noted that the staking 90 35 occurs where connector bars 27 and 32 are separated only by adhesive 29. There is no paper, film or the like between the connector bars 27 and 32. Accordingly, the staking disclosed in the present application is reliable.

With reference to Fig. 3, there is shown diagrammatically a method for making the tag 19 shown in Figs. 1 and 2. A roll 40 is shown to be comprised of a composite web 41 having a 40 web 20 with a full-gum or continuous coatings of pressure sensitive adhesive 21 and 22 on opposite faces thereof. The web 20 is "double-faced" with adhesive. A release liner or web 42 is releasably adhered to the upper side of the web 20 by the pressure sensitive adhesive 21, and the underside of the web 20 has a release liner or web 24 releasably adhered to the pressure sensitive adhesive 22. As shown, the release liner 42 is delaminated from the web 20 to expose the adhesive 21. The adhesive coated web 20 together with the release liner 24 pass partially about a sandpaper roll 43 and between a pattern roll 44 and a back-up roll 45 where mask patterns 23 are applied onto the adhesive 21 to provide longitudinally recurring adhesive patterns 21'. Masking material from a fountain 46 is applied to the pattern roll 44. With reference to Fig. 4, the portion marked A represents the portion of the web 20 immediately upstream of the pattern roll 44. The portion marked B shows the mask patterns 23 printed by the roll 44. The patterns 23 are represented by cross-hatching in Fig. 4. With reference to Fig. 3, the web 20 now passes through a dryer 47 where the mask patterns 23 are dried or cured.

The adhesive 21 is rendered non-tacky at the mast patterns 23. A web 49 of planar, electrically conductive material such as copper or aluminum from a roll 48 is laminated onto the coated 55 web 20 as they pass between laminating rolls 50 and 50'. Reference character C in Fig. 4 denotes the line where lamination of the webs 20 and 49 occurs. With reference to Fig. 3, the laminated webs 20 and 49 now pass between a cutting roll 51 having cutting blades 52 and a back-up roll 53. The blades 52 cut completely through the conductive material web 49 but preferably do not cut into the web 20. The blades 52 cut the web 49 into a plurality of series 60 of patterns 25 and 30 best shown in the portion marked D in Fig. 5. With reference again to Fig. 3, there is shown a roll 54 comprised of a composite web 55 having a web 37 with a full gum or continuous coating of pressure sensitive adhesive 38 and a release liner 56 releasably adhered to the adhesive 38 on the web 37. The release liner 56 is separated from the web 37 and the web 37 passes about a sandpaper roll 57. From there the web 37 passes between a 65 3 GB2197565A 3 pattern roll 58 and a back-up roll 59 where mask patterns 39 are applied onto the adhesive 38 to render the adhesive 38-non-tacky at the mask patterns 39 to provide longitudinally recurring adhesive patterns 38' (Fig. 1). Masking material from a fountain 60 is applied to the pattern roll 58. The masking material of which the patterns 23 and 39 are comprised is a commercially available printable adhesive deadener such as sold under the name "Aqua Superadhesive Dead- 5 ener" by Environmental Inks and Coating Corp, Morganton, North Carolina. From there the web 37 passes partially about a roll 61 and through a dryer 62 where the mask patterns 39 are dried or cured. The adhesive 38 is rendered non-tacky at the mask patterns 39. From there the webs 20, 49 and 37 pass between laminating rolls 63 and 64. Fig. 5 shows that lamination occurs along line E where the web 37 meets the web 49. When thus laminated, each adhesive 10 pattern 21' registers only with an overlying conductor spiral 25 and each adhesive pattern 38' registers only with an underlying conductor spiral 30.

The webs 20, 37 and 49 pass successively partially about rolls 65 and 66 and from there the web 37 delaminates from the web 20 and passes partially about a roll 67. At the place of delamination, the web 49 separates into two webs of conductor spirals 25 and 30. As shown 15 in Fig. 6, delamination occurs along the line marked F. When delamination occurs, the conductor spirals 30 adhere to the adhesive patterns 38' on the web 37, and the conductor spirals 25 adhere to the adhesive patterns 21' on the web 20. Thus, the conductor spirals 30 extend in one web and the spirals 25 extend in another web. The web 20 passes partially about rolls 68, 69 and 70 and from pass between an adhesive coating roll 71 and a back-up roll 72. Adhesive 20 29 from a fountain 73 is applied to the roll 71 which in turn applies a uniform or continuous coating of adhesive 29 to the web 20 and over conductive spirals 25. The portion marked G in Fig. 6 shows the portion of the web 20 and conductor spirals 25 between the spaced rolls 66 and 72. The portion marked H shows the portion of the web 20 between the spaced rolls 72 and 74. With reference to Fig. 3, the web 20 passes through a dryer 75 where the adhesive 29 is dried. A plurality,. specifically two laterally spaced dielectric webs 28a and 28b wound in rolls 76 and 77 are laminated to the web 20 as the webs 20, 28a and 28b pass between the rolls 74 and 74'. This laminating occurs along reference line I indicated in Fig. 6. With reference to Fig. 3, the web 20 with the conductor spirals 25 and the dielectric webs 28a and 28b pass about rolls 78 and 79 and pass between an adhesive applicator roll 80 and a back-up roll 81. 30 The roll 80 applies adhesive 29' received from a fountain 83 to the webs 28a and to the portions of the web 20 not covered thereby. From there, the webs 20, 28a and 28b pass through a dryer 84 and partially about a roll 85.

The web 37 which had been separated from the web 20 is laminated at the nip of laminating rolls 86 and 87 along a line marked J in Fig. 7 to provide a composite tag web generally indicated at 88. The webs 20, 28a, 28b and 37 are laminated between rolls 86 and 87 after the conductor spirals 30 have been shifted longitudinally with respect to the conductor spirals so that each conductor spiral 30 is aligned or registered with an underlying conductor spiral 25. The shifting can be equal to the pitch of one conductor spiral pattern as indicated at p (Fig.

9) plus the width w of one conductor, -or by odd multiples of the pitch p plus the width w of 40 one conductor. Thus, each pair of conductor spirals 25 and 30 is capable of making a resonant circuit detectable by an appropriate article surveillance circuit.

Fig. 8 shows the web 20 and the web 37 rotated apart by 180'. Fig. 9 shows the web 20 and the web 37 rotated apart by 180' and as javing been shifted with respect to each other so that the conductor spirals 25 and 30 are aligned. As best shown in Fig. 10, the dielectric 28a 45 terminates short of stakes 90 resulting from the staking operation. By this arrangement the stakes 90 do not pass through the dielectric 28a (or 28b). Fig. 10 shows the conductor spirals and 30 substantially entirely overlapped or aligned with each other, except as indicated at 35 for the conductor spiral 25 and as indicated at 33 for the conductor spiral 30. Each circuit is completed by staking the conductor bars 27 and 32 to each other as indicated at 90 or by other suitable means. The staking 90 is performed by four-spiked wheels 89 which make four stake lines 90 in the composite web 88. The spiked wheels 89 pierce through the conductor bars 27 and 32 and thus bring the conductor bars 27 and 32 into electrically coupled relation ship. The web composite 88 is slit into a plurality of narrow webs 91 and 92 by slitter knife 93 and excess material 94 is trimmed by slitter knives 95. The webs 91 and 92 are next cut through up to but not into the release liner 24 by knives on a cutter roll 96, unless it is desired to cut the tags T into separated tags in which event the web 88 is completely severed transversely. As shown, the webs 91 and 92 continue on an pass about respectiv6 rolls 97 and 98 and are would into rolls 99 and 100. As shown in Fig. 7, the stacking 90 takes place along a line marked K and the slitting takes place along a line marked L.

The sheet 37T, the dielectric 28T, the sheet 20T and the sheet 24T are respectively provided by cutting the web 37, the web 28a (or 28b), the web 20 and the web 24.

Fig. 11 is essentially a duplicate of a portion of Fig. 3, but a pair of coating and drying stations generally indicated at 111 and 112. where respective coatings 113 and 114 in the form of continuous stripes are printed and dried. The coating 113 is conductive and is applied directly65 4 GB2197565A 4 onto the pressure sensitive adhesive 38 on the web 37. The coatings 114 are wider than the respective coatings 113 which they cover to assure electrical isolation, as best shown in Figs. 12 and 13. The coatings 114 are composed of a normally non-conductive activatable material. The remainder of the process is the same as the process taught in connection with Figs. 1 5 through 10.

With reference to Figs. 14 and 15, there is shown a fragment of the finished tag 37T' with the coatings 113 and 114 having been severed as the tag 37T' is severed from the tag web as indicated at 113T and 114T respectively. As shown the coating 113T is of constant width and thickness throughout its length and the coating 114T is of constant width and thickness but is wider than the coating 113T. The coating 113T which is conductive is thus electrically isolated 10 from the conductor spiral 30. The coatings 113T and 114T comprise an activatable connection AC which can be activated by subjecting the tag to a high level of energy above that for causing the resonant circuit to be detected at an interrogation zone.

Fig. 16 is essentially a duplicate of a portion of Fig. 3, but a pair of webs 118 and 119 are adhered to the adhesive 38 on the web 37. The webs 118 and 119 are wound onto spaced reels 120 and 12 1. The webs 118 and 119 pass from the reels 120 and 121 partially about a roll 122. The webs 118 and 119 are spaced apart from each other and from the side edges of the web 37. The webs 118 and 119 are identical in construction, and each includes a thin layer of conductive material 123 such as copper or aluminum on a layer of paper 123', a high temperature, normally non-conductive, activatable, conductor-containing layer 124, and a low temperature, normally non-conductive, activatable, conductor-containing layer 125. The layers 124 and 125 contain conductors such as metal particles or encapsulated carbon. The layer 125 bonds readily when heated, so a drum heater 115 is positioned downstream of the roll 67 (Figs.

3 and 16) and upstream of the rolls 86 and 87 (Fig. 3). The heated circuits 30, heat the layer 125 and a bond is formed between the circuits 30 and the layer 125. Rolls 116 and 117 (Fig. 25 16) guide the web 37 about the drum heater 115. The heating of the layer 125 has some tendency to break down the normally non-conductive nature of the layer 125, but this is not serious because the layer 124 is not broken down or activated by heat from the drum heater 115.

With reference to Figs. 19 and 20, there is shown a fragment of a finished tag 37T" with the 30 webs 118 and 119 having been severed so as to be coextensive with the tag 37T" and is indicated at 118T. The web strip or stripe 118T includes the paper layer 123', the conductive layer or conductor 123 and the normally 123 and the normally non- conductive layers 124 and 125. The layers 123, 124 and 125 are shown to be of the same width and comprise an activatable connection AC. Both coatings 124 and 125 electrically isolate the conductor 123 form the conductor spiral 30. In other respects the tag 37T" is identical to the tag 37T and is made by the same process as depicted for example in Fig. 3.

The embodiment of Fig. 21 is identical to the embodiment of Figs. 16 through 20 except that instead of the webs 118 and 119 there are a pair of webs comprised of flat bands, one of which is shown in Fig. 21 and is depicted at 118'. The band 118' is comprised of a web or band conductor 126 of a conductive material such as copper enclosed in a thin coating of a non-conductive material 127. The band 118' comprises an activatable connection AC. As seen in Fig. 21, the upper surface of the coating 127 electrically isolates the conductor 126 from the conductor spiral 30. The band 118' is processed according to one specific embodiment, by starting with coated motor winding wire, Specification No. 8046 obtained from the Belden

Company, Geneva, Illinois 60134 U.S.A. and having a diameter of about 0. 004 inch (O.1mm) with an insulating coating of about 0.0005 (0.013), flattening the wire between a pair of rolls into a thin band hand having a thickness of 0.0006 inch (0.015mm). Thus processed the insulating coating is weakened to a degree which breaks down when the resulting tag is subjected to a sufficiently high energy level signal.-The coating 118' is thus termed a "break down coating" because it acts as an insulator when the tag is subjected to an interrogation signal at a first energy level but no longer acts as an electrical insulator when subjected to a sufficently higher energy level signal. The conductor 126 accordingly acts to short out the inductor 30 at the higher energy level signal.

The embodiments depicted in Figs. 11 through 20 and described in connection therewith enable the tag 377 or 377' to be detected in an interrogation zone when subjected to a radio frequency signal at or near the resonant frequency of the resonant circuit. By sufficiently increas ing the energy level of the signal, the normally non-conductive coating 114 (or 114T), or 124 and 125 becomes conductive to alter the response of the resonant circuit. This is accomplised in a specific embodiment by using a normally non-conductive coating to provide an open shortcircuit between different portions of the conductor spiral 30.

When the tag is subjected to a high level of energy, in the embodiments of Figs. 11 through 15, and 16 through 20 the normally non-conductive coating becomes conductive and shorts out the inductor. Thus, the resonant circuit is no longer able to resonate at the proper frequency and is unable to be detected by the receiver in the interrogation zone.

1 ' GB2197565A 5 While the illustrated embodiments disclose the activatable connection AC provided by an additional conductor as extending across all the turns of the conductor spiral 30 and by a normally non-conductive material or breakdown insulation electrically isolating the conductor from the conductor spiral 30 and also extending across all of the turns of the conductor spiral 30, the invention is not to be considered limited thereby.

By way of example, not limitation, examples of the various coatings are stated below:

1. For the embodiment of FIGURES 11 through 15 A. Examples of the normally non-conductive 10 coating 114 are: Example 1 cellulose acetate (C.A.) powder (E-398-3) acetone Parts by Weight 300 Mixing procedure: Solvate C.A. powder in acetone with stirring. C.A. /copper dispersion above C.A. solution (16%T.S.) copper 8620 powder 2.5 Mixing procedure: Add copper powder to C.A. solution with adequate stirring to effect a smooth metallic dispersion. Example 2 acrylvid B-48N (45% in toluene) acetone isopropanol above solution (25%T.S.) copper 8620 powder Mixing procedure: disperse copper powder into B-48N solution (Percent copper powder is 60- 70% on dry weight basis.) 20 3 5 B. Examples of the conductive coating 113 are: Example 1 acryloid B-67 arylic 35 (45% in naptha) naptha silflake #237 metal powder Parts by weight 16 42 Mixing procedure: add metal powder to solvent and wet out. Add solvated acrylic and stir well to disperse. Mix or shake well prior to use. (75% to 85% conductive metal on dry weight 40 basis.) Example 2 acryloid NAD-10 (40% in naptha) silflake #237 metal powder 45 Mixing procedure: Add metal powder to acrylic dispersion with stirring. Example 3 S & V aqueous foil ink OFG 11525 (37%T.S.) silflake #237 metal powder 1 8 Mixing procedure: Add metal powder to aqueous dispersion slowly with adequate agitation to 50 effect a smooth metallic dispersion.

i 6 1. For the embodiment of FIGURES 16 through 20 A. Examples of the low temperature coating 125 are:

Example I Parts by Weight acryloid NAD-10 dispersion (30% T. Solids) 10 naptha 2 copper 8620 copper powder 5 Mixing procedure: wet copper powder with Naptha and disperse completely. Add NAD-10 dispersion slowly with stirring. Mix well or shake before use. Example 2 polyester resin (K1979) ethanol isopropanol ethyl acetate above polyester solution copper 8620 powder Mixing procedure: add copper powder to polyester solution while stirring to effect a smooth metallic dispersion. (48% copper powder on dry basis) 28 10 10 20 10 2.5 B. Examples of the high temperature coating 124 are:

Example 1 cellulose acetate butvrate GB2197565A 6 (C.A.B.)(551-0.2) 40 toluene 115 Ethyl Alcohol 21 Above C.A.B. solution 30 (22.7%) toluene copper 8620 copper powder Mixing procedure: wet copper powder with solvent and add C.A.B. solution with stirring.

2 5 Example 2 35 acryloid B-48N (45% in toluene) 30 acetone 20 isopropanol 3 Above solution (25%T.S.) 10 40 copper 8620 copper powder 5 (Dry weight basis-copper is 60-70%) Mixing procedure: add copper powder to above solution with proper agitation to effect a smooth metallic dispersion.

The materials used in the above examples are obtainable from the following suppliers in the U. S. A; Acryloid NAD-10, Acryloid B-48N and Acryloid B-67, Rohm & Hass, Philadelphia, Pennsylvania; Cellulose Acetate (E-398-3) and Cellulose Acetate Butyrate (551-0.2), Eastman Chemical Products, Inc., Kingsport, Tennessee; Copper 8620, U.S. Bronze, Flemington, New Jersey; Silflake #237, Handy & Harmon, Fairfield, Connecticut;

Krumbhaar K-1979, Lawter International, Inc., Northbrook, Illinois; Aqeuous foil ink Figs. 22 through 25 depict an improved method over the embodiment of Figs. 11 through 15, over the embodiment of Figs. 16 through 20, and over the embodiment of Fig. 21. The method of the embodiment of Figs. 22 through 25 relates to the formation of longitudinally spaced cleactivatable resonant circuits arranged in a web. The longitudinal spacing of the resonant circuits assures that electrostatic charge that can prematurely deactivate one resonant circuit i the web cannot arc longitudinally to the other resonant circuits in the web to cause their premature deactivation. Where possible, the same reference character will be used in the embodiment of Figs. 22 through 25 as in the embodiment of Figs. 16 through 20 to designate components having the same general construction and function, but increased by 200. It will OFG 11525, Sinclair & Valentine, St. Paul, Minnesota.

be 65 7 p GB2197565A appreciated that reference is also made to Figs. 3, 5 and 6.

With reference initially to Fig. 22, web 249 of planar, electrically conductive material is cut in patterns of conductor spirals 400 and 401. The cut patterns include lateral or transverse lines of complete severing 402. The conductor spirals 400 and 401 are generally similar to the conduc tor spirals 25 and 30, however, inspection of Fig. 5 will indicate that all conductor spirals 25 5 and 30 are in very close proximity to each other in the longitudinal direction, being spaced only by knife cuts themselves. In addition, spirals 25 are connected to each other and spirals 30 are connected to each other. In contrast, in the embodiment of Figs. 22 through 25, only the conductor spirals 400 and 401 between adjacent lines of complete severing 402 are connected to each other. In the method of Figs. 22 through 25, reference may be had to Fig. 3 which shows that the conductor spiral webs 20 and 37 are separated as they pass partly about roll 66, thereafter dielectric material webs 28a and 28b are applied, the webs 20 and 37 are shifted longitudinally by the pitch of one conductor spiral 400 (or 401) plus the width of one conductor, and thereafter the webs 20 and 37 are re-laminated as they pass between rolls 86 and 87.

As is evident from Fig. 23, once the web of resonant circuits 401 is stripped away, the resultant web 220 has pairs of resonant circuits 401 that are longitudinally spaced apart. In like manner, the pairs of resonant circuits 400 in the stripped away web (corresponding to the web 37 in Fig. 3), are also spaced apart longitudinally.

The method of the embodiment of Figs. 22 through 25, relates to production of deactivatable tags. The illustrated arrangement for deactivating the tags utilizes the arrangement taught in the 20 embodiment of Figs. 16 through 20 with the exception that the deactivator webs 318 and 319 (corresponding to the deactivator webs 118 and 119 in Fig. 16 forexample), are separated into longitudinally spaced deactivator strips or stripes 318' and 319'. The separation is accomplished in accordance with the specific embodiment shown in Fig. 24, by punching out portions or holes 407 of the web 238 and the deactivator webs 318 and 319. For this purpose, a diagrammati- cally illustrated rotary punch 403 and a rotary die 404 are used. The rotary punch 403 has punches 405 and the rotary die 404 has cooperating die holes 406. The resultant holes 407 are wider than the spacing between the resonant circuits. The holes 407 are thus registered with the margins of the longitudinally spaced resonant circuits are shown in Fig. 25. Thus, static electricity cannot arc between resonant circuits in a longitudinal direction and static electricity 30 cannot arc between deactivator strips 318' (or 319').

Other embodiments and modifications of the invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.

Claims (38)

1. Method of making tags for use in an electric article surveillance system, comprising the steps of: providing a first web having a series of longitudinally recurring first patterns of adhesive, providing a second web having a series of longitudinally recurring second patterns of adhesive, cutting a web of conductive material to form longitudinally recurring pairs of first and 40 second contiguous, coplanar, spiral conductors wrapped about each other, the first and second webs being positioned on opposite sides of the conductive material web with the first adhesive patterns in contact with only the first conductors and with the second adhesive patterns in contact with only the second conductors, separating the first web with the first conductors adhered thereto and the second web with the second conductors adhered thereto from each 45 other, thereto from each other, thereafter positioning the first and second conductors into a related arrangement for capacitive and inductive coupling, and connecting the related first and second conductors to provide a composite tag web of a series of tags each having a resonant cricuit.

2. Method as defined in claim 1, wherein the step of providing a first web having the 50 recurring first adhesive patterns includes the step of applying to an adhesive-coated first carrier web a series of longitudinally recurring patterns of masking material which prevent the second conductors from adhering to the first carrier web, and wherein the step of providing a second web having the recurring second adhesive patterns includes the step of applying to an adhesive- coated second carrier web a 'series of longitudinally recurring second patterns of masking material which prevent the first conductors form adhering to the second carrier web.

3. Method as defined in claim 1, wherein the step of positioning the first and second webs includes the step of bringing a web of dielectric material between the first conductors on the first web and the second conductors on the second web.

4. Method as defined in claim 2, including the step of bringing a web of dielectric material 60 between. the first conductors on the first web and the second conductors on the second web.

5. Method as defined in claim 1, wherein there are a plurality of said resonant circuits formed laterally across the composite web, and slitting the composite tag web longitudinally to provide a plurality of series of tags.

6. Method of making tags for use in an electric article surveillance system, comprising the 65 8 GB2197565A steps of: providing a longitudinally extending web of conductive material, cutting the web of conductive material to form a plurality of sets of conductors with each set having contiguous, coplanar, first and second spiral conductors wrapped about each other, supporting the first spiral conductors in a first longitudinally extending conductor web, supporting the second spiral con ductor in a second longitudinally extending conductor web, separating the first spiral conductor 5 web and the second spiral conductor web from each other, shifting the first spiral conductor web and the second spiral conductor web longitudinaly relative to each other to bring the first spiral conductors and the second spiral conductors into related arrangement for capacitive and inductive coupling, and connecting the related first and second conductors to provide a series of tags each having a resonant circuit.

7. Method as defined in claim 6, wherein the shifting step includes shifting the first spiral conductor web and the second spiral conductor web relative to each other by a distance equal to the longitudinal pitch of the first conductors plus the width of the first conductors or to any multiple thereof.

8. Method of making tags for use in an electronic article surveillance system, comprising the steps of: providing a first composite web including a first web having a full-gum coating of pressure-sensitive-adhesive and a release-coated first backing web, stripping the first backing web from the first coated web, applying a first masking pattern to the adhesive on the first coated web, drying the first masking pattern, laminating a web of conductive material onto the first coated web and against the unmasked adhesive on the first coated web, cutting the conductive material web to form longitudinally recurring pairs of first and second contiguous, coplanar, spiral conductors wrapped about each other and so that the first conductors are adhered to the unmasked adhesive on the first coated web, providing a second composite web including a second coated web having a full-gum coating of pressure- sensitive adhesive and a release coated second backing web, stripping the second backing web from the second coated 25 web, applying a second masking pattern to the second coated web, drying the second masking pattern, laminating the second coated web to the conductive material web, with the unmasked adhesive on the second coated web registered with the second conductors, delaminating the first coated web with the first conductors adhered thereto and the second coated web with the second conductors adhered thereto from each other, applying adhesive to the first coated web, 30 drying the adhesive applied to the recoated first coated web, laminating a web of dielectric material onto the recoated first coated web, applying adhesive to the dielectric material web, drying the adhesive on the dielectric material web, laminating the first and second coated webs to each other with the web of dielectric material therebetween to provide a composite tag web, wherein the laminating step includes shifting the first and second coated webs longitudinally to 35 bring the first and second conductors into a related arrangement for capacitive and inductive coupling, and staking the related first and second conductors to provide a series of connected tags each having a resonant circuit.

9. Method as defined in claim 8, wherein there are a plurality of said resonant corcuits found laterally across the composite tag web, and slitting the composite tag web longitudinally to 40 provide a plurality of series of tags.

10. A tag for use in an electronic article surveillance system, comprising: a generally planar dielectric inverse first and second spiral conductors positioned in capacitive and inductively coupled relationship on opposite sides of the dielectric, means for electrically connecting the first and second conductors to provide a resonant circuit, and wherein the first and second conduc- 45 tors are inverse patterns formed by cutting conductive planar material spirally to provide pairs of contiguous first and second inverse conductors and positioning a pair of first and second conductors in said relationship.

11. Method of making a cleactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level 50 signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the circuit including an inductor having a spiral conductor, providing an additional conduc tor, and positioning the additional conductor adjacent the spiral conductor while electrically isolating the additional conductor from the spiral conductor by a normally non-conductive ma terial which can be rendered conductive to deactivate the tag in response to a second energy 55 level signal at an energy level higher than the first energy level signal.

12. Method of deactivating a tag made by the method defined in claim 11, further including the steps of applying the second energy level signal to the tag to render the non-conductive material conductive so that the additional conductor alters the characteristics of the inductor and hence the circuit to prevent the emission of the alarm signal.

13. Method of making a cleactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the circuit including an inductor having a spiral conductor, applying a first coating across at least a portion of the spiral conductor with the first coating being normally non-conductive but 65 9 GB2197565A 9 which can be rendered conductive in response to a second energy level signal at an energy level higher than the first energy level signal, and applying a conductive second coating over the first coating in electrically isolated relationship to the spiral conductor so that upon receipt of the second energy level signal the first coating becomes conductive and the second coating thereby becomes electrically coupled to the conductor to alter the characteristics of the inductor to 5 prevent emission of the alarm signal.

14. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the circuit in an interrogation zone, the circuit including an inductor having a spiral conductor with a plurality of turns, providing an open 10 short-circuit between two turns of the spiral conductor, the step of providing the open short circuit including the step of isolating the two turns from each other by a normally non-conductive material which can be rendered conductive to short circuit the inductor in response to receipt of a second energy level signal at an energy level higher than the first energy level signal.

15. Method of making a deactivatable tag for use in an electronic article surveillance system, 15 comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the circuit including an inductor having a spiral conductor with a plurality of turns, providing an open short-circuit between two turns of the spiral conductor, the step of providing the open short-circuit including the step of applying a first coating across at least a portion of 20 one of the turns with the first coating being normally non-conductive but which can be rendered conductive in response to a second energy level signal at an energy level higher than the first energy level signal, and applying a conductive second coating between the two turns and over the first coating so that receipt of the second energy level signal of the inductor is short circuited and consequently the characteristics of the inductor are altered to prevent emission of 25 the alarm signal.

16. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the circuit in an interrogation zone, the circuit including an inductor having a spiral conductor with a plurality of turns, and positioning a 30 web of conductive material adjacent one of the spiral conductors, with the conductive material web having a layer of a normally non-conductive material electrically isolating the conductive material web from the spiral conductor but wherein the normally non- conductive material can be rendered conductive in response to a second energy level signal at an energy level higher than the first energy level signal to alter the characteristics of the inductor to prevent emission of the 35 alarm signal.

17. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a first web with a first series of first spiral conductors and a second web with a series of second spiral conductors, providing a web of conductive material having a layer of normally non-conductive material, positioning the conductive material web with 40 the normally non-conductive layer adjacent either the first or the second series of conductors, adhering the first and second webs to each other, connecting the conductors of the first and second webs to each other to provide a series of resonant circuits in a composite web, separating the composite web into tags each having a first conductor and a second conductor coupled to each other, and wherein the normally non-conductive layer can be rendered conduc- 45 tive in response to an energy level higher than that level necessary to activate the tag.

18. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a first web, printing conductive material on the first web, printing non-conductive material on the first web over the conductive material, providing a second web, first and second spiral conductors positioned between the first and second webs, 50 adhering the webs to each other with pairs of the first and second spiral conductors connected to provide resonant circuits, wherein the normally non-conductove material can be rendered conductive in response to an energy level higher than that level necessary to activate the tag, and separating the webs to provide tags each having a deactivatable circuit.

19. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the circuit including an inductor having a spiral conductor, and providing an activatable connection to the spiral conductor including normally non-conductive, conductor-containing ma- terial which can be rendered conductive in response to a second energy level signal at an energy 60 level higher than the first energy level signal.

20. Method as defined in claim 19, wherein the step of providing an activatable connection includes the step of applying the normally nonconductive material between spaced but connected portions of the spiral conductor.

21. Method as defined in claim 19, wherein the step of providing an activatable connection 65 GB2197565A 10 includes the step of connecting spaced portions of the spiral conductor with an additional conductor electrically isolated from the spaced portions by the normally non-conductive material.

22. A deactivatable tag for use in an electronic article surveillance system, the tag compris ing: a support, the resonant circuit being responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the 5 resonant circuit including a spiral conductor, a deactivating conductor adapted to connect spaced portions of the spiral conductor to each other, normally non-conductive material electrically isolating the deactivating conductor from at least one portion of the spiral conductor, and wherein the normally non-conductive material can be rendered conductive to deactivate the resonant circuit in response to a second energy level signal higher than the first energy level signal.

23. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a resonant circuit responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, and positioning an insulated conductor having a breakdown coating in contact with the circuit for deactivating the tag in response to a second energy level signal at an energy level higher than the first energy level signal.

24. Method as defined in claim 23, wherein the insulated conductor is made by flattening an insulated conductive metal wire.

25. A deactivatable tag for use in an electronic article surveillance system, the tag compris- 20 ing: a support, a resonant circuit on the support, the resonant circuit being responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the resonant circuit including a spiral conductor having turns, a stripe of normally non-conductive material across at least two turns, a stripe of conductive material isolated from the two turns by the normally non-conductive material, and wherein the normally non-conductive material can be rendered conductive to deactivate the resonant circuit in response to a second energy level signal higher than the first energy level signal.

26. A deactivatable tag as defined in claim 25, wherein the stripe extends across all the turns of the spiral conductor.

27. A deactivatable tag for use in an electronic article surveillance system, the tag compris- 30 ing: a support, a resonant circuit on the support, the resonant circuit being responsive to receipt of a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, the resonant circuit including a spiral conductor, means for altering the signal emitted by the resonant circuit to prevent detection of the presence of the circuit in the interrogation zone, the signal altering means including normally non-conductive material connected to the spiral conductor, and wherein the normally non- conductive conductor containing material can be rendered conductive in response to a second energy level signal at an energy level higher than the first energy level signal.

28. A cleactivatable tag as defined in claim 27, wherein the signal altering means further includes conductive material electrically isolated from the spiral conductor by the normally non- 40 conductive material.

29. A deactivatable tag as defined in claim 27, wherein the spiral conductor includes a plurality of turns, the normally non-conductive material constituting a stripe across at least two of the turns, a strip of conductive material on the normally non- conductive material stripe and across the same two turns, and wherein the stripe of conductive material is electrically isolated 45 from those two turns by the normally non-conductive material stripe.

30. A deactivatable tag as defined in claim 29, wherein both the normally non-conductive material stripes and the conductive material stripe extend across all the turns of the spiral conductor.

31. A deactivatable tag for use in an electronic article surveillance system, the tag compris- 50 ing: a support, a resonant circuit on the support, the resonant circuit being responsive to a first energy level signal to emit an alarm signal to indicate the presence of the resonant circuit in an interrogation zone, and an insulated conductor having a breakdown coating and being in contact with the circuit for deactivating the tag in response to a second energy level signal at an energy level higher than the first energy level signal.

32. Method of making tags for use in an electronic article surveillance system, comprising the steps of: providing a first web having a series of longitudinally recurring first patterns of adhesive, providing a second web having a series of longitudinally recurring second patterns of adhesive, cutting a web of conductive material to form longitudinally recurring pairs of first and second contiguous, coplanar, spiral conductors wrapped about each other, wherein the cutting step includes the step of completely severing each pair from the longitudinally adjacent pair, the first and second webs being positioned on opposite sides of the conductive material web with the first adhesive patterns in contact with only the first conductors and with the second adhesive patterns in contact with only the second conductors, separating the first web with the first conductors adhered thereto and the second web with the second conductors adhered 65 1 11 11 GB2197565A 11 thereto from each other, thereafter positioning the first and second conductors into a related arrangement for capacitive and inductive coupling, wherein each arrangement of first and second conductors is spaced from each adjacent arrangement of first and second conductors, providing a separate deactivator for each said arrangement with the deactivators being longiduinally spaced and with each deactivator including electrically conductive material, connecting the related first and second conductors to provide a composite tag web of a series of tags each having a resonant circuit, and whereby accidental deactivation of one resonant circuit in the composite tag web does not effect deactivation of any other resonant circuit spaced longitudinally thereform in the composite tag web.

33. Method of making tags for use in an electronic article surveillance system, comprising the 10 steps of: providing a longitudinally extending web of conductive material, cutting the web of conductive material to form a plurality of sets of conductors with each set having continuous, coplanar, first and second spiral conductors wrapped about each other, wherein the cutting step includes the step of completely severing each set from the longitudinally adjacent set, supporting the first spiral conductors in a first longitudinal extending conductor web, supporting the second 15 spiral conductor in a second longitudinally extending conductor web, separating the first spiral conductor web and the second spiral conductor web from each other, shifting the first spiral conductor web and the second spiral conductor web longitudinally relative to each other to bring the first spiral conductors and the second spiral conductors into related arrangement for capaci tive and inductive coupling, wherein each arrangement of first and second conductors is spaced 20 from each adjacent arrangement of first and second conductors, providing a separate deactivator for each said arrangement with the deactivators being longitudinally spaced and with each deactivator including electrically conductive material, connecting the related first and second conductors to provide a series of tags each having a resonant circuit, and wherein accidental deactivation of one resonant circuit in the composite tag web does not effect deactivation of 25 any other resonant circuit spaced longitudinally therefrom in the composite tag web.

34. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a first web with a first series of longitudinally spaced first spiral conductors and a second web with a series of longitudinally spaced second spiral conduc tors, providing spaced strips of conductive material having a layer of normally non-conductive 30 material, positioning the strips with the normally non-conductive layer adjacent either the first or the second series of conductors, adhering the first and second webs to each other, connecting the conductors of the first and second webs to each other to provide a series of spaced resonant circuits in a composite web and there being one of said strips for each resonant circuit, separating the composite web into tags each having a first conductor and a second conductor 35 coupled to each other, and wherein the normally non-conductive layer can be rendered conduc tive in response to an energy level higher than that level necessary to activate the tag.

35. Method of making a deactivatable tag for use in an electronic article surveillance system, comprising the steps of: providing a first longitudinally extending web, printing conductive ma terial on the first web, printing non-conductive material on the first web over the conductive material, providing discontinuities in the conductive material and the non-conductive material printed thereover to provide longitudinally spaced strips, providing a second web, providing longitudinally spaced pairs of first and second spiral conductors positioned between the first and second webs, adhering the webs to each other with pairs of the first and second spiral conductors connected to provide spaced resonant circuits with a strip in contact with each 45 circuit but without contacting any other circuit, wherein the normally non-conductive material can be rendered conductive in response to an energy level higher than that level necessary to activate the tag, and separating the webs to provide tags each having a deactivatable circuit.

36. Method of making deactivatable tags for use in an electronic article surveillance system, comprising the steps of: providing a longitudinally extending web of longitudinally spaced reso- 50 nant circuits, providing a continuous longitudinally extending web of a deactivator, and separating the deactivator web into a series of longitudinally spaced strips with each strip being registered with one resonant circuits and out of contact with any other resonant circuit.

37. A method of making tags for use in an electronic article surveillance system, substantially as herein described with ref4ence to the drawings.

38. A tag for use in an electronic article surveillance system, substantially as herein described with reference to the drawings.

Published 1988 at The Patent Office, State House, 66/71 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

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