NEAR FIELD COMMUNICATION RING

Abstract

A near field communication ring that can be read by nearby NFC-enabled devices. The ring comprises an annular shell and a near field communication transponder mounted on the annular shell. The near field communication transponder has a coil antenna that has a plurality of turns that each extend around the entire circumference of the annular shell. The rings has various potential applications including, for example, contactless payment, ticketing on mass transit systems, operation of NFC door locks or other access systems, identity authentication, venue or event entry/ticketing and the sharing of information with NFC-enabled smartphones.

Claims

1. A ring for wearing on a user's finger, the ring comprising: an annular shell; and a near field communication transponder mounted on the annular shell; the near field communication transponder having a coil antenna that has a plurality of turns that each extend around the entire circumference of the annular shell.

2. The ring of claim 1, wherein the coil antenna includes at least 5 turns.

3. The ring of claim 1, wherein the coil antenna includes at least 8 turns.

4. The ring of claim 1, wherein the plurality of turns of the coil antenna are spaced from one another across a width of the ring.

5. The ring of claim 1, wherein a surface of the annular shell has an annular recess extending around its entire circumference, the coil antenna being mounted in the annular recess.

6. The ring of claim 5, wherein the annular recess is in a centre portion of the annular shell and edge portions of the annular shell extend radially inwards or outwards either side of the annular recess.

7. The ring of claim 1, further comprising an annular cover, wherein the near field communication transponder is encapsulated between the annular shell and the annular cover.

8. The ring of claim 7, wherein the annular cover is a resin seal.

9. The ring of claim 1, wherein the annular shell is formed from a ceramic.

10. The ring of claim 1, wherein the coil antenna is a wound metal wire coil.

11. The ring of claim 1, wherein the coil antenna is formed by a conductive track carried on a flexible substrate.

12. The ring of claim 11, wherein the near field communication transponder comprises an NFC chip and the NFC chip is also carried on the flexible substrate.

13. The ring of claim 1, wherein the coil antenna is directly applied to an inner surface of the annular shell.

14. The ring of claim 13, wherein the coil antenna is directly applied to the inner surface of the annular shell by electroplating.

15. The ring of claim 13, wherein the coil antenna is directly applied to the inner surface of the annular shell by laser direct structuring.

16. The ring of claim 1, wherein the coil antenna includes a series of parallel track sections that extend circumferentially around the annular shell, with a tail end of one track section being joined to the leading end of an adjacent track section by a track step section that extends in a width direction across the annular shell.

17. A method of manufacturing a wearable ring according to claim 1, the method comprising: providing an annular shell; mounting a near field communication transponder within the shell, so that a coil antenna of the transponder extends all of the way around the inner circumference of the shell; and applying a cover over the transponder to encapsulate the transponder between the annular shell and the cover.

18. The ring of claim 17, wherein the near field communication transponder comprises a flexible substrate on which the coil antenna is formed, the step of mounting the transponder in the shell comprising positioning the flexible substrate within the annular shell.

19. The ring of claim 17, wherein the step of mounting the transponder in the shell comprises directly forming the coil antenna on the inner surface of the shell.

20. The method of claim 17, wherein the annular shell is ceramic.

21. The method of claim 17, wherein the cover is a resin seal and the step of applying the cover comprises applying the resin seal in liquid form over the transponder after the transponder is mounted within the annular shell and curing the resin seal to solidify it.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0027] An embodiment of the invention is described below, by way of example, with reference to the accompanying figures, in which:

[0028] FIG. 1 shows an exterior view of a contactless payment ring in accordance with an embodiment of the present invention;

[0029] FIG. 2 shows an outer shell component of the ring of FIG. 1 in a pre-machining state (1) and in a post-machining state (2);

[0030] FIG. 3 shows a dimensioned cross section of the shell component of the ring of FIG. 1;

[0031] FIGS. 4(a), (b) and (c) show three alternative forms of coil antenna that could be used with rings in accordance with embodiments of the present invention; and

[0032] FIG. 5 illustrates the manner in which the contactless payment ring of FIG. 1 can be used to complete a transaction.

DETAILED DESCRIPTION

[0033] The invention is exemplified in the following discussion with reference to a contactless payment ring. It will be appreciated, however, the rings in accordance with embodiments of the invention can be used for other near field communication (NFC) applications, such as ticketing on mass transit systems, operation of NFC door locks or other access systems (e.g. automotive entry systems such as for car doors), identity authentication, event/venue ticketing and the sharing of information with NFC-enabled smartphones for example.

[0034] Referring to FIG. 1, the contactless payment ring includes an outer shell, which in this example is formed from a Zirconia ceramic, and an inner, shaped resin seal. An NFC transponder (not visible in FIG. 1) is encapsulated between the outer shell and the resin seal.

[0035] As best seen in FIG. 2, the outer shell is ring-shape and has a recess or annular channel extending circumferentially around its inner surface defined between lips at opposite edges of the ring. This recess/annular channel is configured to receive the NFC transponder, as discussed further below.

[0036] FIG. 3 shows a cross-section through the outer shell. The recess/channel and the lips at either side of the recess/channel can be clearly seen. The shaded area depicts the ceramic body of the outer shell. The dimensions on this figure are in mm. Rings can be offered in a number of different sizes without changing the cross-sectional dimensions; only the ring diameter need change.

[0037] The main components of the NFC transponder are an NFC chip and an antenna. In accordance with the present invention, the antenna is a coil (or solenoid) form antenna with multiple turns that extend around the entire internal circumference of the ring. Opposite ends of the coil antenna are connected to the chip.

[0038] One exemplary transponder construction is illustrated in FIG. 4(a). The transponder shown in this figure is formed as a flexible PCB. The turns of the coil antenna are printed or etched onto a flexible substrate in a known manner, with opposite ends of the coil being connected to the chip (see in the front view).

[0039] The flexible substrate is itself formed as a cylinder, having a diameter that closely corresponds to the inner diameter of the outer shell of the ring so that it can be assembled into the recess/channel on the inside of the outer shell. Preferably the flexible substrate is pre-formed as a cylinder and the antenna track and other components of the NFC transponder are applied to the cylindrical substrate. Alternatively, the antenna track and other components of the transponder could be applied to the substrate in a flat state and the substrate could subsequently be rolled to form the cylinder, whilst ensuring that the sections of track on the substrate are appropriately aligned and joined to one another to create the continuous coil of the antenna. Especially in the latter case, the coil antenna can include a series of parallel track sections that extend circumferentially around the annular shell, with a tail end of one track section being joined to the leading end of an adjacent track section by a track step section that extends in a width direction across the annular shell (as seen in FIG. 4(a)). This makes it easier to precisely align and join the track sections when the flexible substrate is rolled into a cylinder.

[0040] Once the flexible substrate, having the antenna formed thereon and NFC chip mounted thereon, has been seated in the recess/channel of the outer shell, the resin seal can be applied over the top to encapsulate the flexible substrate, thus protecting the components of the NFC transponder from water, dirt, damage and tampering.

[0041] FIGS. 4(b) and 4(c) illustrate alternative approaches to forming the coil antenna. Specifically, FIG. 4(b) illustrates a simple copper wire coil. Whilst this form of coil is simple and inexpensive, it is likely to result in a bulkier ring.

[0042] FIG. 4(c) illustrates an approach in which the coil antenna is fabricated directly on the inner surface of the outer shell. The track of the antenna may, for example, be laid down on the inner surface of the shell by electroplating to selectively metalise the surface of the shell, with a laser being used, if necessary, to remove unwanted metal material. Another approach is to use laser direct structuring to metalise specific areas of a reactive plastic on the inner surface of the shell.

[0043] By using a coil antenna wound in the manner proposed here, the contactless payment ring can be optimally coupled to an NFC-reader (e.g. a regular contactless payment card reader) when the axis of the ring is perpendicular to the surface of the reader. This orientation is best achieved, as shown in FIG. 5, by the person wearing the ring uses a knocking-type action.

[0044] The contactless payment ring described above is one exemplary implementation of a ring in accordance with an embodiment of the invention. The skilled person will appreciate that many modifications can be made to the specifically described features within the scope of the present invention. For example, in other embodiments the ring may be large in diameter so that it can be worn as a bracelet rather than a finger ring.