Abstract
An RFID tag comprising a lower housing, an upper housing and an antenna unit. The lower housing is configured to be attached to the an object. The upper housing is placed on the lower housing and comprises a peripheral portion laterally surrounding the lower housing and configured to be attached to the object. The antenna unit is positioned between the lower housing and the upper housing. A first portion of the antenna unit is attached to the lower housing and a second portion of the antenna unit is attached to the upper housing. When the distance between the upper housing and the lower housing changes in case someone attempts to remove the RFID tag from the object, the at least one first portion of the antenna unit remains attached to the lower housing and the at least one second portion of the antenna unit remains attached to the upper housing.
Claims
1. An RFID tag for a tamper proof attachment to an object, the RFID tag comprising: a lower housing configured to be attached to the object; an upper housing placed on the lower housing and comprising a peripheral portion, the peripheral portion laterally surrounding the lower housing and configured to be attached to the object; and an antenna unit positioned between the lower housing and the upper housing; wherein at least one first portion of the antenna unit is attached to the lower housing and at least one second portion of the antenna unit is attached to the upper housing such that the antenna unit is damaged when the a distance between the upper housing and the lower housing changes because the at least one first portion of the antenna unit remains attached to the lower housing and the at least one second portion of the antenna unit remains attached to the upper housing.
2. The RFID tag according to claim 1, wherein the antenna unit is an RFID inlay, the RFID inlay comprising a substrate and an antenna.
3. The RFID tag according to claim 2, wherein the antenna is etched on the substrate.
4. The RFID tag according to claim 2, further comprising an adhesion reducing layer between the antenna and the substrate.
5. The RFID tag according to claim 1, further comprising a first adhesive layer positioned between the upper housing and the lower housing and attaching the upper housing to the lower housing.
6. The RFID tag according to claim 5, further comprising a second adhesive layer configured to attach the lower housing to the object.
7. The RFID tag according to claim 6, wherein the first adhesive layer and the second adhesive layer are configured such that, when the RFID tag is attached to the object, the a peel strength between the lower housing and the object is larger than the a peel strength between the upper housing and the lower housing.
8. The RFID tag according to claim 7, wherein the a ratio of the peel strength between the lower housing and the object to the peel strength between the upper housing and the lower housing is in the a range of 2 to 8, preferably in the range of 4 to 6.
9. The RFID tag according to claim 1, wherein each of the a peel strength between the at least one first portion of the antenna unit and the lower housing and the a peel strength between the at least one second portion of the antenna unit and the upper housing are greater than the a breaking strength of the antenna unit such that the antenna unit breaks when the distance between the upper housing and the lower housing is increased.
10. The RFID tag according to claim 1, wherein the lower housing comprises a protrusion and the a top of the protrusion is attached to the at least one first portion of the antenna unit.
11. The RFID tag according to claim 1, wherein the lower housing comprises multiple protrusions and the a top of each protrusion is attached to the at least one first portion of the antenna unit.
12. The RFID tag according to claim 10, wherein the protrusion have has a conic shape.
13. The RFID tag according to any one of claim 10, wherein the antenna unit comprises an antenna which in a top view enters and exits the area which is positioned above the top of the protrusion at least one time and not more than two times.
14. The RFID tag according claim 1, further comprising an RFID inlay holder, wherein: the at least one second portion of the antenna unit is attached to the RFID inlay holder; and the RFID inlay holder is attached to the upper housing.
15. The RFID according to claim 14, wherein the RFID inlay holder is attached to the upper housing by means of a clip mechanism.
16. The RFID tag according to claim 14, wherein the antenna unit is positioned on a top side of the RFID inlay holder, is folded at an outer edge of the RFID inlay holder, and protrudes on a lower side of the RFID inlay holder.
17. The RFID tag according to any one of claim 14, wherein the lower housing comprises a protrusion and a top of the protrusion is attached to the at least one first portion of the antenna unit, and wherein the RFID inlay holder comprises a through hole through which the protrusion of the lower housing extends.
18. The RFID tag according to claim 17, wherein the antenna unit is attached to the RFID inlay holder and to the top of the protrusion, the top of the protrusion extending through the through hole of the RFID inlay holder.
19. The RFID tag according to claim 1, wherein the peripheral portion comprises a bottom surface with a width not smaller than 2 mm.
20. A method for providing a tamper proof attachment of an RFID tag to an object such as a license plate, the method comprising: providing a lower housing configured to be attached to the object; providing an upper housing configured to be attached to the object and to be mated with the lower housing, wherein in a mated state, the lower housing and the upper housing form an inner chamber and the upper housing laterally surrounds the lower housing; mating the upper housing with the lower housing while positioning an antenna unit in the inner chamber between the upper housing and the lower housing and attaching at least one first portion of the antenna unit to the lower housing and at least one second portion of the antenna unit to the upper housing; attaching the lower housing and the upper housing, between which the antenna unit is positioned, to the object such that: when someone tries to remove the RFID tag from the object, the upper housing has to be removed before the lower housing can be removed; and when the upper housing is removed from the object, a distance between the upper housing and the lower housing changes and the antenna unit breaks because the at least one first portion of the antenna unit remains attached to the lower housing and the at least one second portion of the antenna unit remains attached to the upper housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 shows an RFID tag 1 which is attached to an object 100 in a simplified sectional view in closed state (I) and in open state (II).
[0054] FIG. 2 shows an RFID tag 1 according to an exemplary embodiment in top view which is attached to a licence plate 100.
[0055] FIG. 3 shows the RFID tag 1 of FIG. 2 in an exploded view. FIG. 4 shows the RFID tag 1 of FIG. 2 in bottom view.
[0056] FIG. 5 shows the RFID tag 1 of FIG. 2 in top view.
[0057] FIG. 6 is a cross-sectional view of the RFID tag 1 of FIG. 5 along line A-A.
[0058] FIG. 7 is a detailed view of section D of the RFID tag 1 as marked in FIG. 6.
[0059] FIG. 8 is a detailed view of section B of the RFID tag 1 as marked in FIG. 6.
[0060] FIG. 9 is a cross-sectional view along line C-C of the RFID tag 1 of FIG. 5.
[0061] FIG. 10 is a detailed view of section E of the RFID tag 1 as marked in FIG. 9.
[0062] FIG. 11 is a perspective view from below on the upper housing 20 and the RFID inlay holder 120, the other components of the RFID tag 1 not being displayed.
[0063] FIG. 12 is a bottom view on the top housing as illustrated in FIG. 11.
[0064] FIG. 13 schematically illustrates three different exemplary embodiments for the form and number of protrusions 150 of the lower housing 10 in top view.
[0065] FIG. 14 is a perspective view of a damaged RFID tag 1 from which the upper housing 20 has been removed.
[0066] FIG. 15 schematically illustrates three different exemplary embodiments for the form of the antenna 32 and its positioning in relation to the top of the one or more protrusions 150, 151, 152 of the lower housing 10 in top view.
DETAILED DESCRIPTION
[0067] The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.
[0068] FIG. 1 shows an RFID tag 1 which is attached to an object 100 in a simplified sectional view in closed state (I) and in open state (II).
[0069] FIG. 1 illustrates in I a state in which the upper housing 20 is placed on the lower housing 10. The lower housing 10 is attached to the object 100. The lower housing 10 may for example be attached to the object 100 by means of an adhesive layer (not shown in FIG. 1). The upper housing is attached to the object 100. The upper housing may for example be attached to the object 100 by means of rivets (not shown in FIG. 1). The upper housing 20 has a peripheral portion 22 which laterally surrounds the lower housing 10. An antenna unit 30 is positioned between the lower housing 10 and the upper housing 20. The antenna unit 30 has a first portion 35 and a second portion 36 (dotted line in FIG. 1 marks separation point of first portion 35 and second portion 36). The first portion of the antenna unit 35 is attached to the lower housing 20 by using a connecting means 38 such as an adhesive layer. The second portion of the antenna unit 36 is attached to the upper housing 10 by using a connecting means 37 such as an adhesive layer. The upper housing 20 and the lower housing 10 form an inner chamber 300 in which the antenna unit 30 is positioned.
[0070] FIG. 1 illustrates in II a state in which the upper housing 20 is moved away (lifted) from the lower housing 10 by means of a screwdriver 52. In that case, the attachment means of the upper housing 20 to the object 100 such as rivets have already been removed. Due to the upward movement of the upper housing 20, the distance D between the upper housing 20 and the lower housing 10 is increased. The distance D is the distance from an upper surface of the lower housing 10 to a lower surface of the upper housing 20 in up-down direction in the area where the antenna unit 30 is positioned. The first portion of the antenna unit 35 remains attached to the lower housing 10 and the second portion of the antenna unit 36 remains attached to the upper housing 20. The antenna unit 30 is broken.
[0071] FIG. 2 shows an RFID tag 1 according to an exemplary embodiment in top view which is attached to a licence plate 100. The RFID tag 1 is attached to a licence plate 100 by means of two rivets 110 positioned in the peripheral portion 22 of the upper housing 20.
[0072] FIG. 3 shows the RFID tag 1 of FIG. 2 in an exploded view. Listed from the bottom to the top in the up-down direction, the RFID tag has an adhesive tape 130, a lower housing 10, an RFID inlay holder 120, an antenna unit 30 and an upper housing 20. The adhesive tape 130 is configured to attach the lower housing 10 to the licence plate 100 (the licence plate is not shown). The adhesive tape 130 is an optional component which might be omitted in other exemplary embodiments of the RFID tag. The lower housing 10 comprises a protrusion 150 extending in upward direction. The RFID inlay holder 120 has an RFID inlay holder through hole 160 which is positioned in the RFID inlay holder 120 such that in a assembled state, the protrusion 150 of the lower housing 10 extends through the RFID inlay holder through hole 160.
[0073] The antenna unit 30 has an integrated circuit 31, an antenna 32 and a substrate 33, the substrate holding the integrated circuit 31 and the antenna 32. The upper housing 20 is the outermost component of the RFID tag 1 and covers the other before mentioned components in an assembled state. In an assembled state, when the RFID tag 1 is attached to an object such as a licence plate 100, only the upper housing 20 is visible. The other components are covered from the upper housing 20 from the top and the side and from the licence plate 100 from the bottom.
[0074] FIG. 4 shows the RFID tag 1 of FIG. 2 in bottom view. The adhesive tape 130 is not shown. The upper housing 20 has a peripheral portion 22 which surrounds the lower housing 10. The peripheral portion 22 has two through holes 111 configured to receive an attachment means such as a rivet for attachment of the upper housing 20 to an object such as a licence plate 100. The peripheral portion 22 has a minimal width W, the minimal width W being measured at the lower side of the upper housing 20.
[0075] FIG. 5 shows the RFID tag 1 of FIG. 2 in top view. The upper housing 20 has a central portion 21 which is positioned on top of the lower housing 10 in the area where the antenna unit 30 is positioned. The upper housing 20 has a peripheral portion 22 which surrounds the lower housing 10. The lower housing 10 is illustrated with a dashed line as it is covered by the upper housing 20. The peripheral portion 22 has two through holes 111 configured to receive an attachment means such as a rivet for attachment of the upper housing 20 to an object such as a licence plate 100.
[0076] FIG. 6 is a cross-sectional view of the RFID tag 1 of FIG. 5 along line A-A. The lower housing 10 has a protrusion 150. At the bottom of the lower housing 10 an adhesive tape 130 is attached. The upper housing 20 is positioned on top of the lower housing 10 and has a peripheral portion which surrounds the lower housing 10. The peripheral portion has two through holes 111.
[0077] An antenna unit 30 is positioned between the lower housing 10 and the upper housing 20. The antenna unit 30 has a first portion 35 and a second portion 36. The first portion 35 is attached to the top of the protrusion 150. The antenna unit 30 is an RFID inlay.
[0078] An RFID inlay holder 120 is positioned between the lower housing 10 and the upper housing 20. The RFID inlay holder 120 has an RFID inlay holder through hole 160 through which the protrusion 150 extends. The top of the protrusion 150 is attached to the first portion of the antenna unit 35. The second portion of the antenna unit 36 is attached to the RFID inlay holder 120. The antenna unit 30 is positioned on the top side of the RFID inlay holder 120, is folded at outer edges of the RFID inlay holder 120 and protrudes on the lower side of the RFID inlay holder towards the centre of the RFID tag 1. The antenna unit 30 is folded at outer edges of the RFID inlay holder 120 and extends on the upper side and the lower side of the RFID inlay holder 120. In other embodiments the antenna unit 30 may extend only on the upper side of the RFID inlay holder.
[0079] FIG. 7 is a detailed view of section D of the RFID tag 1 as marked in FIG. 6. The antenna unit 30 is an RFID inlay includes a substrate 33 and an antenna 32 which is edged on the substrate 33. The antenna 32 and the substrate 33 are illustrated schematically. The RFID inlay 30 is positioned between the lower housing 10 and the upper housing 20. The first portion 35 of the RFID inlay 30 is positioned above the protrusion 150 of the lower housing 10. In the area of the protrusion 150 of the lower housing 10, the antenna 32 is positioned on an upper side S1 of the RFID inlay 30 and the substrate 33 is positioned on a lower side S2 of the RFID inlay 30. The top of the protrusion 150 is attached to the first portion 35 of the RFID inlay 30. More specifically, the top of the protrusion 150 is attached to the substrate 33 of the RFID inlay 30 in the area of the first portion 35. At the bottom of the lower housing 10 an adhesive tape 130 is attached. The second portion 36 of the RFID inlay 30 is attached to the RFID inlay holder 120. More specifically, the RFID inlay 30 is attached to the substrate 33 of the RFID inlay 30 in the area of the second portion 36.
[0080] FIG. 8 is a detailed view of section B of the RFID tag 1 as marked in FIG. 6. The top housing 20 is positioned on top of the lower housing 10. A projection 115 of the lower housing 10 extends in a groove 116 of the upper housing 20. In the groove 116 silicone 200 is provided between the upper housing 20 and the lower housing 10. At the bottom of the lower housing 10 an adhesive tape 130 is attached. An RFID inlay 30 and an RFID inlay holder 120 are positioned between the lower housing 10 and the upper housing 20. The RFID inlay 30 is folded around the RFID inlay holder 120.
[0081] FIG. 9 is a cross-sectional view of the RFID tag 1 of FIG. 5 along line C-C. The top housing 20 is positioned on top of the lower housing 10. Between the top housing 20 and the lower housing 10 silicone 200 is provided. At the bottom of the lower housing 10 an adhesive tape 130 is attached. An RFID inlay 30 and an RFID inlay holder 120 are positioned between the lower housing 10 and the upper housing 20.
[0082] FIG. 10 is a detailed view of section E of the RFID tag 1 as marked in FIG. 9. The top housing 20 is positioned on top of the lower housing 10. Between the top housing 20 and the lower housing 10 silicone 200 is provided. At the bottom of the lower housing 10 an adhesive tape 130 is attached. An RFID inlay 30 and an RFID inlay holder 120 are positioned between the lower housing 10 and the upper housing 20. The RFID inlay holder 120 has a groove 161 for a clip 160 of the upper housing 20. The clip 160 extends in the groove 161 such that the RFID inlay holder 120 is fixed in the upper housing 20. The clip 160 and the groove 161 form a clip mechanism. The clip mechanism 160 prevents an up- down movement of the RFID inlay holder 120 in relation to the upper housing 20.
[0083] FIG. 11 is a perspective view from below on the upper housing 20 and the RFID inlay holder 120, the other components of the RFID tag 1 not being displayed. The RFID inlay holder 120 has two grooves 161 on outer side edge surfaces. The upper housing 20 has two clips 160 on inner side edge surfaces. The grooves 161 and the clips 160 are positioned such that in the assembled state, the clips 160 and the grooves 161 form a clip mechanism wherein the clips 160 extend in the grooves 161.
[0084] FIG. 12 is a bottom view on the top housing as illustrated in FIG. 11. The two clips 160 of the upper housing 20 are positioned on inner side edge surfaces of the upper housing 20 and are arranged offset to each other in a width direction X of the upper housing 20.
[0085] FIG. 13 illustrates three different exemplary embodiments for the form and number of protrusions 150 of the lower housing 10 in top view.
[0086] In FIG. 13 a), the lower housing 10 has one protrusion 150 and the top of the protrusion has a cylindrical surface.
[0087] In FIG. 13 b), the lower housing 10 has two protrusions 150 and the top of the protrusion have a cylindrical surface.
[0088] In FIG. 13 c), the lower housing 10 has two protrusions 150 and the top of the protrusions has a rectangular surface.
[0089] FIG. 14 is a perspective view on a damaged RFID tag 1. FIG. 12 shows a licence plate 100 on which a lower housing 10 is attached. The upper housing 20 has been removed and is not illustrated. On the protrusion 150 of the lower housing 10 sticks a part of an antenna 32. The part of the antenna 32 has a meander form.
[0090] FIG. 15 illustrates three different exemplary embodiments for the form of the antenna 32 and its positioning in relation to the top of the protrusion 150 of the lower housing 10 in top view.
[0091] In FIG. 15 a), the antenna 32 enters and exits the area in which the top of the protrusion 150 is positioned three times. If the antenna enters and exits the area which is positioned above the top of the protrusion three time, this means that the antenna both enters this area three times and exits this area three times. Therefore, when viewed in top view, six bridging antenna sections 201 (marked with dots) between the antenna 32 and the area above the top of the protrusion exist.
[0092] In FIG. 15 b), the antenna 32 enters and exits the area in which the top of the protrusion 150 is positioned two times. Therefore, when viewed in top view, four bridging antenna sections 201 between the antenna 32 and the area above the top of the protrusion exist.
[0093] In FIG. 15 c), the lower housing has a first protrusion 151 and a second protrusion 152. The antenna 32 enters and exits the area in which the top of the first protrusion 151 is positioned two times. The antenna 32 enters and exits the area in which the top of the second protrusion 152 is positioned two times. Therefore, when viewed in top view, in total eight bridging antenna sections 201 between the antenna 32 and the area above the top of the first protrusion and the second protrusion exist.
[0094] It will be appreciated that the foregoing description provides examples of the disclosed systems and methods. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the general disclosure.
[0095] Recitation of ranges of values herein are merely intended to serve as a shorthand method for referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All method steps described herein can be performed in any suitable order, unless otherwise indicated or clearly contradicted by the context.
[0096] Although the preferred embodiments of the present disclosure have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.
