Coupling device for near-field communication between a smart card and a radio frequency transmitter.

Abstract

A coupling device (10) for near-field communication between a smart card (20) and a radio frequency transmitter (30), said device comprising: - A flat and flexible support (11), - a near-field communication antenna, disposed on the support (11), characterized in that said device comprises: - means for relative positioning said device with a smart card (20) or with a transmitter, said relative positioning means comprising at least one of the following: fastening means, and visual reference means, said relative positioning means being configured to dispose said antenna of said device in a relative position such that: when said antenna of said smart card (20) is powered by said transmitter, then said antenna (12) of said device is disposed in the field lines of the smart card (20) and in those of said transmitter. Figure for the abbreviation: Figure 1

Description

Title of the invention: Coupling device for near-field communication between a smart card and a radiofrequency transmitter.

[0001] The present invention relates to the field of near-field communication between a smart card and a radiofrequency transmitter.

[0002] This technology is well known in banking applications. Typically in this case, the smart card is a debit and / or credit card. The smart card is flat, it has two dimensions and includes four corners, in this case rounded. The format of smart cards is most often standardized.

[0003] The smart card includes a near field communication antenna.

[0004] In banking applications, the radiofrequency transmitter is, for example, a smart card reader, integrated into an Electronic Payment Terminal available in any type of business. However, with advances in technology, smartphones can also be transmitters. Unless specifically stated, the term "transmitter" here means indistinctly a smart card reader or a smartphone.

[0005] The radio frequency transmitter comprises a near field communication antenna.

[0006] Note that the operating principle for banking applications described below also exists for official identity documents, i.e. those issued by an authority (State, government, ministry, etc.), for example an identity card, a passport, a driving license, etc., or for unofficial identity documents, for example a subscription card, a transport card, etc., where the identity document comprises a chip and a near-field communication antenna, to enable communication between the chip and a radiofrequency transmitter.

[0007] By “smart card” we therefore indistinctly mean a smart card for banking or identity applications, in particular biometric.

[0008] Generally, the frequency of the RFID carrier between the radiofrequency transmitter and the smart card is between 13 MHz and 14 MHz, the antenna of the smart card and the antenna of the radiofrequency transmitter form two tuned resonant circuits, the resonance frequency of which is in the vicinity of the carrier frequency (11-19 MHz).

[0009] To communicate in the near field between the smart card and the radiofrequency transmitter, the radiofrequency transmitter emits a magnetic field. When the smart card is in the field lines of the radiofrequency transmitter, an electric current is created in it, it is then powered by the radiofrequency transmitter, and it also emits a magnetic field. There is then a coupling between the smart card and the radiofrequency transmitter.

[0010] However, there are more and more parasitic elements which can disturb the coupling. Even in a smart card reader such as an ATM in which the relative position of the smart card and the radiofrequency transmitter is mechanically controlled, there may be field disturbing elements, for example additional magnetic fields, metallic elements or electrically conductive elements which disturb the coupling. Likewise in a smart card reader such as a payment terminal, for example at a merchant's.

[0011] A fortiori when the radiofrequency transmitter is a smartphone, on the one hand the magnetic field emitted by it is generally less intense than that emitted by a smart card reader, and on the other hand, controlling the relative position of the smart card and the radiofrequency transmitter is more delicate since it is generally manual. In addition, the position of the near-field communication antenna of a smartphone is not standardized, and generally not known to its end user.

[0012] For example, the exchange of “large” data between a smart card and a reader, for example biometric data, may be compromised due to loss of connection during the exchange phase. The same applies to a banking transaction.

[0013] There is therefore a need to improve the coupling between a smart card and a radiofrequency transmitter, for mechanically controlled or non-mechanically controlled applications, i.e. in a constrained environment. Summary of the invention

[0014] More specifically, the invention relates, according to a first of its objects, to a coupling device for near-field communication between a chip card having two dimensions and comprising four corners, and a radiofrequency transmitter, the coupling device comprising:

[0015] - A flat and flexible support, and

[0016] - a near-field communication antenna, arranged on the support.

[0017] It is essentially characterized in that the coupling device comprises in besides :

[0018] - means for relative positioning of said coupling device with a card with chip or with a radiofrequency transmitter, said relative positioning means comprising at least one of:

[0019] * means of securing, and

[0020] * visual reference means,

[0021] said relative positioning means being configured to arrange the near-field communication antenna of said coupling device in a relative position such that: when the near-field communication antenna of said smart card is powered by said radiofrequency transmitter, then the near-field communication antenna of the coupling device is arranged in the field lines of the smart card and in the field lines of said radiofrequency transmitter.

[0022] It can be predicted that:

[0023] - the support comprises an upper face and a lower face,

[0024] - the relative positioning means comprise securing means which include a set of at least one stop, arranged on one or the other face of the support.

[0025] It can be predicted that:

[0026] the relative positioning means comprise securing means which comprise a set of at least one notch in the support, each notch being configured to be able to insert a corner of the smart card therein.

[0027] It can be predicted that:

[0028] the support has two dimensions, at least one of which is greater than the smallest dimension of the smart card

[0029] Alternatively, it can be provided that:

[0030] the support has two dimensions, each of which is smaller than the smallest dimension of the smart card,

[0031] And that the relative positioning means comprise securing means which comprise an adhesive layer.

[0032] According to another of its objects, the invention relates to a chip card having two faces and comprising a coupling device according to the invention, in which:

[0033] - the flat and flexible support is integrated into the smart card.

[0034] It can be provided that, the chip card having two faces and comprising a coupling device according to the invention:

[0035] - the relative positioning means comprise securing means which include an adhesive layer, and

[0036] - the flat and flexible support of the coupling device is glued to one side of the card chipped by said adhesive layer.

[0037] According to another of its objects, the invention relates to a near-field radiofrequency transmitter comprising a coupling device according to the invention, in which:

[0038] - said radiofrequency transmitter is a smart card reader, comprising a near-field communication antenna, and

[0039] - the coupling device is glued to the near-field communication antenna said smart card reader.

[0040] It can be provided that, the near-field radiofrequency transmitter comprising a coupling device according to the invention:

[0041] - said radiofrequency transmitter is a smartphone comprising a chassis, and

[0042] - the coupling device is integral with said smartphone or said chassis, or when the smartphone includes a protective case, the coupling device can optionally be attached to the protective case.

[0043] Finally, according to another of its objects, the invention also relates to a method for coupling near-field communication between a smart card and a radiofrequency transmitter using a coupling device according to the invention,

[0044] The method comprising steps of:

[0045] - secure the coupling device with the smartphone or with the smart card,

[0046] - emit a radiofrequency field through the smartphone,

[0047] - moving said smartphone and said smart card in parallel planes, at a distance such that said smart card is within the field lines of said smartphone,

[0048] - determine the coupling factor between said smartphone and said smart card for a set of relative positions, and

[0049] - identify the relative position for which the coupling factor is maximum.

[0050] Other characteristics and advantages of the present invention will appear more clearly on reading the following description given by way of illustrative and non-limiting example and made with reference to the appended figures. DESCRIPTION OF THE DRAWINGS

[0051] [Fig.l] illustrates an embodiment of a coupling device according to the invention,

[0052] [Fig.2] illustrates a mode of assembly of an embodiment of a device according to the invention with a smart card,

[0053] [Fig.3] illustrates another mode of assembly of an embodiment of a device according to the invention with a chip card,

[0054] [Fig.4] illustrates the relative positioning of a coupling device according to the invention when a smart card is in a smart card reader such as an ATM. DETAILED DESCRIPTION

[0055] [Fig.l] illustrates an embodiment of a coupling device 10 according to the invention.

[0056] The device according to the invention is a coupling device 10 for near-field communication between a smart card 20 and a radiofrequency transmitter 30, for example a smart card reader 20 or a smartphone, and hereinafter “transmitter” for brevity.

[0057] The transmitter comprises a near-field communication antenna 31, hereinafter referred to as “antenna” for brevity.

[0058] Typically, a smart card 20 is flat and has two dimensions. It includes four corners, most often rounded. The format of a smart card 20 is often standardized.

[0059] The coupling device 10 according to the invention comprises a flat and flexible support 11, and a near-field communication antenna, arranged on said support 11. The support 11 comprises an upper face and a lower face.

[0060] The coupling device 10 is a passive resonant circuit (without chip), tuned to a natural frequency, preferably between 11 MHz and 19 MHz.

[0061] The antenna 12 of the coupling device 10 is a series RLC circuit. Preferably the inductance is between 100 nH and 10 pH, and preferably 3 or 4 pH. The capacitance is between 5 pF and 300 pF, and preferably 30 pF.

[0062] In [Fig.l], the coupling device 10 has a shape similar to that of a smart card 20 meeting for example the ISO / IEC 7810 standards, called ID-1. And the antenna has an oval shape. This example is illustrative and not limiting. The support 11 and the antenna can each have any type of two-dimensional shape as long as the antenna is supported by the support 11.

[0063] It is provided that the coupling device 10 further comprises means for relative positioning of said coupling device 10 with a chip card 20 or with a transmitter.

[0064] These relative positioning means are configured to arrange the near-field communication antenna of said coupling device 10 in a clever relative position with respect to the antenna of the smart card 20 or the antenna of the transmitter.

[0065] Indeed, as seen previously, it happens that the near-field communication between a chip card 20 and a transmitter is disturbed, or even impossible.

[0066] To overcome this drawback, the coupling device 10 according to the invention acts as a waveguide between the waves from the transmitter and the smart card 20.

[0067] For this purpose, it is provided that when the antenna 12 of the smart card 20 is powered by said transmitter, then the near-field communication antenna 12 of the coupling device 10 is arranged in the field lines of the smart card 20 and in the field lines of said transmitter.

[0068] The coupling device 10 thus allows coupling between the transmitter and the chip card 20, more precisely between the transmitter and the coupling device 10 on the one hand, and between the coupling device 10 and the chip card 20 on the other hand.

[0069] A non-zero coupling coefficient is thus obtained between the coupling device 10 and the chip card 20 on the one hand, and a non-zero coupling coefficient between the coupling device 10 and the transmitter on the other hand.

[0070] To enable this, it is anticipated that the relative positioning means may comprise:

[0071] means of securing,

[0072] visual cue means, or

[0073] a combination of securing means and visual reference means.

[0074] The securing means comprise, for example, a set of at least one stop 15, arranged on one or the other face of the support 11. The stop 15 or the stops 15 may for example be embossments of the face of the support 11, for example as illustrated in [Fig.3].

[0075] Alternatively or in combination, the securing means may comprise a set of at least one notch 14 in the support 11, each notch 14 being configured to be able to insert a corner of the smart card 20 therein, as illustrated in [Fig.2].

[0076] In this case, two notches 14 are provided, allowing two adjacent corners of a smart card 20 to be inserted.

[0077] The position of the antenna 21 of a smart card 20 is generally known. The position of the antenna 12 of the coupling device 10 is known. It is therefore easy to position the securing means so that the antenna 12 of the coupling device 10 is in the field lines of the antenna 21 of a smart card 20, when the latter is powered.

[0078] The visual reference means comprise, for example, a drawing of all or part of the perimeter of a smart card 20, allowing a user to intuitively understand the positioning of the latter on the support 11.

[0079] Any other type of visual marker can be provided, for example a set of lines, crosses, graphic symbols (in particular arrows) etc. allowing the chip card 20 to be positioned on the support 11.

[0080] For example, the support 11 may be in the form of a letter accompanying the supply to a user of the smart card 20, for example an A4 sheet comprising an antenna 12, said sheet being equipped with notches 14 and / or a visual marker (not illustrated) making it possible to position the smart card 20 relative to the support 11 according to a predefined relative position.

[0081] In this case, the dimensions of the support 11 are greater than those of a smart card 20 but this characteristic is not obligatory. Provided that the relative positioning allows the coupling device 10 to be in the field lines of the card chip 20, then the support 11 can have any dimensions, including smaller than that of the chip card 20.

[0082] The support 11 has two dimensions, it can therefore be provided that at least one of them is greater than the smallest dimension of the chip card 20.

[0083] It can also be provided that each dimension of the support 11 is less than the smallest dimension of the chip card 20.

[0084] In this case, it is advantageous for the relative positioning means to comprise securing means which comprise an adhesive layer 13, preferably allowing temporary securing between the coupling device 10 and the smart card 20, so that the flat and flexible support 11 of the coupling device 10 is stuck to one face of the smart card 20 by said adhesive layer 13.

[0085] The coupling device 10 can thus be in the form of a self-adhesive label, arranged on one face of the chip card 20. Like the self-adhesive labels which protect the chip before its first use, the coupling device 10 in the form of a label can advantageously also be removed, for example once the enrollment phase is complete.

[0086] The position of the coupling device 10 on the smart card 20 is advantageously predetermined.

[0087] It may be provided that the coupling device 10 comprises visual reference means which make it possible to position the smart card 20 relative to these visual reference means. Alternatively or in combination, it may be provided that the smart card 20 comprises visual reference means which make it possible to position the coupling device 10 relative to these visual reference means, for example relative to at least one edge or at least one corner of the smart card 20; or, if the smart card 20 is personalized, relative to a personalization element. It may also be provided ad hoc visual references on at least one of the smart card 20 and the coupling device 10, for example lines or arrows on one face of the smart card 20 and on the coupling device 10, said arrows having to be positioned opposite each other to obtain an optimal coupling factor.

[0088] Preferably, the joining of the coupling device 10 and the chip card 20 is implemented during manufacturing or at the latest during personalization of the chip card 20, so that the end user, the holder of the chip card 20, receives a chip card 20 equipped with the coupling device 10 already positioned.

[0089] However, it is also possible to provide a definitive connection between the coupling device 10 and the smart card 20, in particular because the manufacturer of coupling devices is often different from the manufacturer of smart cards.

[0090] For this purpose, it can be provided that the flat and flexible support 11 is integrated into the chip card 20, with or without adhesive layer 13.

[0091] Thus, it is possible to temporarily or permanently secure a coupling device 10 according to the invention and a smart card 20.

[0092] Similarly, a coupling device 10 according to the invention and a radiofrequency transmitter 30 can be secured, temporarily or permanently.

[0093] In a first embodiment, illustrated in [Fig.4], the radiofrequency transmitter 30 is a smart card reader 20, comprising a near-field communication antenna 31, housed in a plastic support 33, and which comprises a chassis 32.

[0094] In this case, the coupling device 10 is preferably glued to the support 11 of the near-field communication antenna of said smart card reader 20, typically in a similar manner to the embodiment in which the coupling device 10 is glued to one face of a smart card 20.

[0095] In this embodiment, the coupling device 10 may have any dimensions, i.e. both dimensions are greater than those of a smart card 20, or both dimensions are less than those of a smart card 20, or only one of the two dimensions is greater than one of the dimensions of a smart card 20.

[0096] In a second embodiment, the radiofrequency transmitter 30 is a smartphone.

[0097] A smartphone comprises a chassis 32, and often a protective shell, which protects the chassis 32 and which is removable.

[0098] In this embodiment, it can be provided that the coupling device 10 is integral with said smartphone.

[0099] For example, it can be provided that the coupling device 10 is integrated into the smartphone, preferably with an adhesive layer 13.

[0100] It is also possible to provide that the coupling device 10 is integral with the chassis 32. For example, it is possible to provide that the coupling device 10 is glued to the internal face or to the external face of the chassis 32, using an adhesive layer 13.

[0101] Similar to the positioning of the coupling device 10 on a smart card 20, the position of the coupling device 10 on the chassis 32 or in the smartphone is preferably predetermined.

[0102] When the smartphone includes a protective shell, the coupling device 10 can also be secured to the protective shell, typically glued to the internal face or to the external face of the protective shell.

[0103] For example, the shell or chassis 32 comprises visual reference means for positioning the coupling device 10, as described previously.

[0104] For the near-field communication coupling between a smart card 20 and a transmitter using a coupling device 10 according to the invention, it is desirable that the near-field communication antenna of said coupling device 10 is in a relative position such that when the radiofrequency transmitter 30 emits a field, then the antenna of the smart card 20 and the antenna of the coupling device 10 are arranged in the field lines of the radiofrequency transmitter 30, the antenna of the coupling device 10 also being in the field lines of the smart card 20.

[0105] For this purpose, in particular when the transmitter is a smartphone, therefore manipulable, the following method can be provided, typically by the user of the smartphone.

[0106] First of all, provision is made to secure the coupling device 10 with the smartphone or with the smart card 20.

[0107] The smartphone can then emit a radiofrequency field such that the smart card and the smartphone will be able to have stable communication thanks to the coupling device 10 according to the invention which, like a waveguide, allows orientation of the electromagnetic field emitted by the smartphone.

[0108] To optimize the coupling factors, it is then planned to move said smartphone and said smart card 20 in parallel planes, at a distance such that said smart card 20 remains in the field lines of said smartphone, the coupling device 10 remaining integral with the smartphone or the smart card 20.

[0109] During this relative movement, the coupling factor between said smartphone and said smart card 20 can be determined for a set of relative positions, for example by a software application installed on the smartphone.

[0110] It is thus possible to identify the relative position for which the coupling factor is maximum.

[0111] For example, it is possible to provide for emitting a sound or displaying a graphic representation on the display screen of the smartphone, the sound or the graphic representation being representative of the value of the coupling factor.

[0112] The user of the smartphone can thus very easily position the smartphone relative to the smart card 20 thanks to the coupling device 10 which acts as a waveguide, so that the coupling factor between the smartphone and the smart card 20 is optimal, that is to say between two predetermined values ​​around the maximum.

[0113] The coupling device 10 is not an amplifier but a waveguide which orients the field lines. In the optimal position, the coupling device 10 receives both the radiofrequency field of the transmitter and the radiofrequency field of the smart card 20.

[0114] Nomenclature

[0115] 10 Coupling device

[0116] 11 flat and flexible support

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126] 12 near-field communication antenna of the coupling device 13 adhesive layer 14 notch 15 stopper 20 smart card 21 near-field communication antenna of the smart card 30 radio frequency transmitter 31 near-field communication antenna of the radio frequency transmitter 32 chassis of the radio frequency transmitter 33 plastic support

Claims

Claims

1. Coupling device (10) for near-field communication between a chip card (20) having two dimensions and comprising four corners and a near-field communication antenna (21), and a radiofrequency transmitter (30), the coupling device (10) comprising: - A flat and flexible support (11), - a near-field communication antenna, arranged on the support (11), characterized in that the coupling device (10) further comprises: - means for relative positioning of said coupling device (10) with a chip card (20) or with a radiofrequency transmitter (30), said relative positioning means comprising at least one of: securing means, and visual reference means,said relative positioning means being configured to arrange the near-field communication antenna (12) of said coupling device (10) in a relative position such that: when the near-field communication antenna (21) of said smart card (20) is powered by said radiofrequency transmitter (30), then the near-field communication antenna (12) of the coupling device (10) is arranged in the field lines of the smart card (20) and in the field lines of said radiofrequency transmitter (30) and the coupling device (10) acts as a waveguide so that the coupling factor between the radiofrequency transmitter (30) and the smart card (20) is optimal.,

2. Coupling device (10) according to claim 1, in which: - the support (11) comprises an upper face and a lower face, - the relative positioning means comprise securing means which comprise a set of at least one stop (15), arranged on one or the other face of the support (11).

3. Coupling device (10) according to any one of the preceding claims, in which the relative positioning means comprise securing means which comprise a set of at least one notch (14) in the support (11), each notch (14) being configured to be able to insert a corner of the smart card (20) therein.

4. Coupling device (10) according to any one of the preceding claims, in which the support (11) has two dimensions, at least one of which is greater than the smallest dimension of the smart card (20).

5. Coupling device (10) according to any one of claims 1 to 3, in which the support (11) has two dimensions, at least one of which is smaller than the smallest dimension of the smart card (20), and in which the relative positioning means comprise securing means which comprise an adhesive layer (13).

6. Smart card (20) having two faces and comprising a coupling device (10) according to claim 1, in which: - the flat and flexible support (11) is integrated into the smart card (20), with or without an adhesive layer (13).

7. Smart card (20) having two faces and comprising a coupling device (10) according to claim 1, in which: - the relative positioning means comprise securing means which comprise an adhesive layer (13), and - the flat and flexible support (11) of the coupling device (10) is stuck to one face of the smart card (20) by said adhesive layer (13).

8. Near-field radiofrequency transmitter comprising a coupling device (10) according to claim 1, wherein: - said radiofrequency transmitter (30) is a smart card reader (20), comprising a near-field communication antenna, and - the coupling device (10) is bonded to the near-field communication antenna of said smart card reader (20).

9. A near-field radiofrequency transmitter comprising a coupling device (10) according to claim 1, wherein: - said radiofrequency transmitter (30) is a smartphone comprising a chassis (32), and - the coupling device (10) is integral with said smartphone or said chassis (32), and when the smartphone comprises a protective shell, the coupling device (10) can optionally be integral with the protective shell.

10. Method for coupling near-field communication between a smart card (20) and a smartphone using a coupling device (10) according to any one of claims 1 to 5, comprising steps consisting of: - securing the coupling device (10) with the smartphone or with the smart card (20), - emitting a radiofrequency field by the smartphone, - moving in parallel planes said smartphone and said smart card (20), at a distance such that said smart card (20) is in the field lines of said smartphone, - determining the coupling factor between said smartphone and said smart card (20) for a set of relative positions, and - identifying the relative position for which the coupling factor is maximum.

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