CH719752A2 - Pair of transponders in resonance and electronic device, in particular a timepiece, comprising such a pair of transponders. - Google Patents

Abstract

The invention relates to a pair of transponders (1) comprising a first transponder (10) provided with a first electronic system (3) for managing the sending and reception of data and a first antenna, the first electronic system (3) being connected to the first antenna, the pair of transponders (1) comprising a second transponder (12) provided with a second electronic system (9) for managing the sending and reception of data and of a second antenna, the second electronic system (9) being connected to the second antenna, characterized in that the second antenna is configured and arranged so that the second transponder (12) forms a resonator circuit of the first antenna. The invention also relates to an electronic device, in particular a timepiece comprising such a pair of transponders.

Description

Technical field of the invention

[0001] The invention relates to the field of information transmission and telecommunications, and in particular to transponders comprising a transmitting and/or receiving antenna.

Technology background

[0002] Transponders are electronic devices configured to transmit and/or receive data. There are passive RFID type transponders (for Radio Frequency Identification in English), which are often intended to encode and record consumer products.

[0003] Other passive transponders are for example used in terminals and bank cards, for example for contactless payment. These transponders are generally of the NFC type (for Near Field Communication in English), and allow data transfer over a short distance.

[0004] Communication is established between two terminals, each terminal comprising an electronic system for managing and recording data, as well as an antenna for transmitting and receiving data from the other terminal.

[0005] The antenna is of great importance in determining the operating distance of the transmission/reception between the terminals, but its dimensions must be very small to limit the bulk of the terminals. To this end, there are antennas in the shape of a spiral portion, which allow a sufficient antenna length to be had in a minimum of space. The number of turns determines the inductance of the antenna. The connection points of the electronic system are arranged at both ends of the spiral portion, that is to say at the external end and the internal end of the spiral portion to have sufficient inductance and to achieve maximum communication distance.

[0006] When this is not sufficient, a second antenna is arranged in parallel with the first antenna, in order to increase the communication distance. The second antenna functions as a resonator circuit, so that the nominal frequency of the two antennas together does not change compared to the nominal frequency of the spiral portion alone. Thanks to the second antenna, an increase in the communication distance is achieved.

However, the second antenna occupies a volume which is used only for this purpose. Thus, it has this unique function of forming a resonator circuit.

[0008] Furthermore, a transponder is generally configured to perform a single function. For example, a transponder has the function of either enabling payments, registering or passing through a barrier on public transport.

[0009] Thus, to obtain several functions, it is necessary to associate several transponders.

Summary of the invention

[0010] The invention aims to remedy the aforementioned drawbacks, and aims to provide a pair of transponders making it possible to associate two different functions while keeping antennas of reduced dimensions but ensuring the adequate communication distance.

[0011] The pair of transponders comprises a first transponder provided with a first electronic system for managing the sending and reception of data and a first antenna, the first electronic system being connected to the first antenna, the pair transponders comprising a second transponder provided with a second electronic system for managing the sending and reception of data and a second antenna, the second electronic system being connected to the second antenna.

The pair of transponders is remarkable in that the second antenna is arranged and configured so that the second transponder forms a resonator circuit of the first antenna.

[0013] Thus, the two transponders make it possible, on the one hand, to associate two different functions in the same electronic device, and on the other hand, each transponder forms a resonator circuit for the other transponder in order to improve the distance Communication.

[0014] Indeed, the resonator circuit formed by the second transponder, and in particular by its antenna, makes it possible to improve the communication distance of the spiral antenna by 10 to 20%. Thus, transponders can meet specific operating standards while maintaining a reduced footprint.

[0015] Thanks to the invention, it is possible to use particular electronic devices, for example a watch-type timepiece, for NFC-type data transfer uses, and which have two functions. In particular, this watch may be provided with a payment system usable as a short distance payment bank card, and with another function.

According to a particular embodiment of the invention, the first antenna is configured and arranged so that the first transponder forms a resonator circuit of the second antenna.

[0017] According to a particular embodiment of the invention, the first and the second antenna are arranged in continuity with each other.

According to a particular embodiment of the invention, the first antenna comprises a first set of turns, and the second antenna comprises a second set of turns.

[0019] According to a particular embodiment of the invention, the first set of turns and the second set of turns form at least partly a spiral.

[0020] According to a particular embodiment of the invention, the first set of turns and the second set of turns are disjointed, so that the spiral is discontinuous, a caesura being arranged at the border of the first set of turns and the second set of turns.

According to a particular embodiment of the invention, the spiral comprises a third set of turns beyond the second set of turns and the first set of turns.

[0022] According to a particular embodiment of the invention, the third set of internal turns is free from connection

According to a particular embodiment of the invention, the second transponder is inactive when the first transponder is active, and the first transponder is inactive when the second transponder is active.

[0024] According to a particular embodiment of the invention, the first electronic system and the second electronic system each comprise a capacitance, so that each resonator circuit comprises a capacitance arranged in parallel with the first or the second set of turns

[0025] According to a particular embodiment of the invention, the first transponder has a first function, for example payment, and the second transponder has a second function different from the first function, for example access control.

[0026] According to a particular embodiment of the invention, the transponders are of the NFC type, in particular to serve as a means of payment.

According to a particular embodiment of the invention, the first set of turns, and the second set of turns, and the third set of turns extend in the same plane.

The invention also relates to an electronic device comprising such a pair of transponders.

[0029] According to a particular embodiment of the invention, the electronic device is a timepiece, such as a watch.

[0030] According to a particular embodiment of the invention, the spiral forms a dial of the timepiece.

Brief description of the figures

[0031] The aims, advantages and characteristics of the present invention will appear on reading several embodiments given solely by way of non-limiting examples, with reference to the appended drawings in which: - Figure 1 shows a schematic representation of a top view of a first embodiment of a pair of transponders according to the invention, and – Figure 2 shows a schematic representation of a top view of a watch comprising a pair of transponders according to the invention .

Detailed description of the invention

In Figure 1, there is shown an embodiment of a pair of transponders 1 comprising a first transponder 10 and a second transponder 12.

The communication protocol is for example of the NFC type (for Near Field Communication in English), or CCP in French (for Near Field Communication). This technology is used in particular for means of payment, for example for payment cards, which can pay remotely using so-called “contactless” terminals.

The first transponder 10 comprises a first electronic system 3 for managing the sending and reception of data and the second transponder 12 comprises a second electronic system 9 for managing the sending and reception of data. The pair of transponders 1 further comprises a spiral-shaped antenna 2.

The spiral 2 comprises a wound ribbon forming a plurality of concentric turns 11, which extends substantially in the same plane in order to minimize the thickness of the antenna. Thus, all the turns 11 of the spiral 2 are wound in the same plane.

The first electronic system 3 and the second electronic system 9 are for example integrated circuits equipped with a chip configured to manage NFC type communications.

Each electronic system 3, 9 is connected to the spiral 2 by two connection points 6, 7, 18, 19 arranged on the ribbon.

A first pair of wires 25 connects the two first connection points 6, 7 to the first electronic system 3. A second pair of wires 26 connects the two second connection points 18, 19 to the second electronic system 3. The wires 25 , 26 are for example welded, or glued with a conductive glue, to the connection points 6, 7, 18, 19 and to the integrated circuit.

The turns 11 included between the two connection points 6, 7 of the first transponder 10 form a first set of turns 4, and therefore a first antenna of the first transponder 10. The first set of turns 4 comprises several adjacent turns the most eccentric from spiral 2, and whose radius of curvature is the highest. In Figure 1, the first set of turns 4 comprises two complete turns. The first set of turns 4 can of course include more, for example three, four, five or more, or a single turn or part of a turn.

The turns 11 included between the two connection points 18, 19 of the second transponder 12 form a second set of turns 5, and therefore a second antenna of the second transponder 12. The second set of turns 5 comprises several adjacent turns, which follow the turns 11 of the first set of turns 4. The turns 11 of the second set of turns 5 are more concentric than those of the first set of turns 4. They have a radius of curvature smaller than that of the turns of the first set of turns 4 .

The first two connection points 6, 7 are preferably arranged at the two ends of the first set of external turns 4. In other words, the two connection points 6, 7 are respectively arranged at the most eccentric point and at the most concentric point of the first set of turns 4.

The two second connection points 18, 19 are preferably arranged at the two ends of the second set of turns 5. Thus, the two second connection points 18, 19 are respectively arranged at the most eccentric point and at the most concentric of the second set of turns 5.

[0043] In the embodiment shown in Figure 1, the first set of turns 4 and the second set of turns 5 are disjoint, so that the spiral 2 is discontinuous. In other words, the spiral 2 comprises two distinct parts separated by a caesura 8 arranged at the border of the first set of turns 4 and the second set of turns 5. Thus, the two sets of turns 4, 5 are not directly connected. one to the other.

The caesura 8 is preferably arranged after the most concentric connection point 6 of the two connection points 6, 7. Thus, the two connection points 6, 7 are not connected to the second set of turns 5.

[0045] In this embodiment, the spiral 2 comprises a third set of turns 23 extending outside the connection points 6, 7 of the first 10 and the second transponder 12. In addition, the third set of turns 23 is free to connect. In other words, there is no connection on the third set of turns 23, whether with the first electronic system 3 or the second electronic system 9. The most concentric turns 11 of the spiral 2 form the third set of turns 23.

[0046] In Figure 1, the third set of turns 23 comprises all the internal turns 11 from the most concentric connection point 18 of the spiral 2. Thus, the third set of turns 23 here comprises at least twenty-five turns . It can of course include fewer or more, for example ten, twenty, thirty turns or more.

The third set of turns 23 makes it possible to improve the range of remote data transmission between these transponders 10, 12 and another transponder or a terminal. Indeed, the third set of turns 23 makes it possible to accumulate more energy than the first set of turns 4 or the second set of turns 5 alone. This additional energy thus makes it possible to increase the transmission distance.

The first set of turns 4, the second set of turns 5 and the third set of turns 23 extend in the same plane.

[0049] In this embodiment, the first transponder 10 forms a resonator circuit of the second transponder 12, and the second transponder 12 forms a resonator circuit of the first transponder 10. A resonator circuit makes it possible to improve the communication range of a transponder antenna.

Preferably, the second transponder 12 is inactive when the first transponder 10 is active, and the first transponder 10 is inactive when the second transponder 12 is active, to avoid possible interference in the communications of each transponder 10, 12 .

Preferably, the first 3 and the second electronic system 9 each include a capacity. Thus, each capacitor is connected in parallel to the corresponding set of turns 11. Thanks to a resonator circuit equipped with a capacitor, each transponder 10, 12 further increases the range of data transfer by 30 to 40%.

[0052] Furthermore, this pair of transponders 1 makes it possible to associate two different functions. Thus, the first transponder 10 has a first function, and the second transponder 12 has a second function. The second function is preferably different from the first function.

[0053] For example, the first function is a payment function, similar to a bank card, and the second function is an access control function, or “ticketing”.

Such a pair of transponders 1 can be used in an electronic product. For example, a timepiece configured to make payments like a bank card. The NFC type transponder allows, for example, short distance payment, called “contactless”.

[0055] Preferably, the transponder having the most efficient antenna is associated with the most demanding function concerning the standards required for the communication distance, for example for the payment function.

The first antenna having the best range, the first transponder 10 is chosen for this more demanding function. This way, we can meet the standards more easily.

[0057] In Figure 2, a watch 30 is shown comprising a pair of transponders according to the invention. The watch 30 comprises a case 31, in which is housed a clock movement, preferably an electronic movement, and hands 32 to indicate the time. The pair of transponders 1 is also arranged in the housing 31. In this embodiment, the spiral 22 of the pair of transponders is used as the dial of the watch 30. The spiral 22 is arranged under the crystal 33 of the watch 30. The needles 32 move above the spiral 22, the spiral 22 being visible through the glass of 33 by a user. The electronic systems 3 and the contact points are arranged under the spiral 22 to be hidden.

[0058] Optionally, the upper surface of the spiral 22 includes a pattern, for decorative purposes or to indicate hour indices for example.

Naturally, the invention is not limited to the embodiments of transponder and electronic device described with reference to the figures and variants could be considered without departing from the scope of the invention. For example, the shapes of the antennas and their arrangements may be different in other embodiments.

Claims (15)

1. Pair of transponders (1, 20) comprising a first transponder (10) provided with a first electronic system (3) for managing the sending and reception of data and a first antenna, the first electronic system (3) being connected to the first antenna, the pair of transponders (1) comprising a second transponder (12) provided with a second electronic system (9) for managing the sending and reception of data and a second antenna, the second electronic system (9) being connected to the second antenna, characterized in that the second antenna is configured and arranged so that the second transponder (12) forms a resonator circuit of the first antenna. 2. Pair of transponders according to claim 1, characterized in that the first antenna is configured and arranged so that the first transponder (10) forms a resonator circuit of the second antenna. 3. Pair of transponders according to any one of the preceding claims, characterized in that the first and the second antenna are arranged in continuity with one another. 4. Pair of transponders according to any one of the preceding claims, characterized in that the first antenna comprises a first set of turns (4), and the second antenna comprises a second set of turns (5). 5. Pair of transponders according to claim 4, characterized in that the first set of turns (4) and the second set of turns (5) form at least partly a spiral (2, 22). 6. Pair of transponders according to claim 5, characterized in that the first set of turns (4) and the second set of turns (5) are disjoint, so that the spiral (2) is discontinuous, a caesura ( 8) being arranged at the border of the first set of turns (4) and the second set of turns (5). 7. Pair of transponders according to any one of the preceding claims, characterized in that the spiral (2) comprises a third set of turns (23) beyond the second set of turns (5). 8. Pair of transponders according to claim 7, characterized in that the third set of internal turns (23) is free from connection. 9. Pair of transponders according to any one of the preceding claims, characterized in that the second transponder (12) is inactive, when the first transponder (10) is active, and the first transponder (10) is inactive when the second transponder (12) is active. 10. Pair of transponders according to any one of the preceding claims, characterized in that the first electronic system (3) and the second electronic system (9) each comprise a capacitance, so that each resonator circuit comprises an arranged capacitance in parallel with the first (4) or the second set of turns (5). 11. Pair of transponders according to any one of the preceding claims, characterized in that the first transponder (10) has a first function, for example payment, and the second transponder (12) has a second function different from the first function, for example access control. 12. Pair of transponders according to any one of the preceding claims, characterized in that they are of the NFC type, in particular to serve as a means of payment. 13. Electronic device comprising a pair of transponders (20) according to any one of the preceding claims. 14. Electronic device according to claim 13, characterized in that it is a timepiece, such as a watch (30), 15. Electronic device according to claim 14, characterized in that the spiral (22) forms a dial of the timepiece.