HK1051591B - Contact-free portable object comprising one or several contact-free peripheral devices - Google Patents

Description

Contactless portable object with one or more contactless peripheral devices

Technical Field

The present invention relates to portable objects, and more particularly to contactless portable objects having at least one peripheral device that is not in ohmic contact with a host chip.

Background

Portable objects, such as contactless smart cards, are in widespread use today in a number of ways. Generally, an ISO type card is involved, which is coupled to a reader, and which is supplied with energy in a contactless manner by the reader. That is, it obtains magnetic energy from the reader and communicates with the reader. In public transport, contactless portable objects are implemented in the form of ISO cards or in a more narrow way, such as a debit card. The user places the user card in front of the reader to enable public transportation. Communication between the card and the reader enables the user to query and make payments for travel on the user's account.

Such devices have further evolved into payment devices, such as in the case of electronic purses. Electronic purses, used to pay small amounts in accordance with transactions, are composed of smart cards. The card can be paid before a special payment machine, the user can pay for a purchase with the card by placing the card in front of a reader, and the communication between the card and the reader leads to payment of an amount corresponding to the purchase.

Many companies have also developed contactless smart cards as identification devices for their employees. Sliding the card in front of the reader identifies whether the card holder is able to enter the controlled area. The same card may also be used by employees as a "attendance record".

The increasing system of smart card technology has created new needs.

The first of these needs is the possibility to directly know the information on the contactless portable object. In fact, the user wishes to be able to know the information stored in the chip of the card without having to place the card in the field of a reader to read it directly on the display screen of the reader. In fact, this constraint is felt in the use of electronic purses. When the user is depositing money into the card or conducting a transaction, that is, placing the card in a magnetic field generated by a reader for consumption, the user cannot know the balance in the card.

There is a device on the market that eliminates this drawback. This is a case for an electronic purse which has a display screen to allow the balance in the card to be looked up at any time. When the card is inserted into the case, contact is made between the chip of the card and the chip of the case, and communication by the contact displays the balance on the display screen of the case. However, this technique has various disadvantages. The first disadvantage is that the box requires an internal power source to operate the box and to communicate between the cards and the box. This energy source is typically a battery. The batteries need to be replaced periodically when the cartridge is used. A second drawback is that the box only receives cards with a shape matching the box. Thus, a variety of different cards cannot be used.

A second need is that the same card can be applied in a number of different aspects. In fact, it is conceivable that a card may communicate with different readers, such that a card may be perceived by the operation of different systems. In fact, a credit card running on a ticket vending machine can be used as an electronic wallet, and likewise a contactless transport card can be used to pay small payments. The same card can be accessed on a number of different applications each day.

A third need is to have a keypad on the contactless card to learn the data when the card and terminal are engaged in a transaction. Such a keypad is mounted on a smart card.

The various cards on the market today have only one main chip, which can communicate with only one type of system.

In addition, the attached functions require energy when the card is placed in a magnetic field emitted by a reader to communicate with the reader.

Finally, the use of peripheral devices to perform these functions may cause interference with the operation of the master chip, particularly when communication is performed between the master chip and the corresponding reader.

Disclosure of Invention

The object of the present invention is to eliminate the aforementioned drawbacks and to provide a portable object with multiple independent functions, which can communicate with a plurality of different systems by means of one or more independent peripheral devices. These peripheral devices require little power consumption in their operation and have little impact on the operation of the host chip.

The invention consists in a contactless portable object comprising a main chip and a main antenna connected to the main chip for communication between said main chip and a reader associated with said contactless portable object, said contactless portable object being characterized in that it further comprises at least one contactless peripheral device, which is not in ohmic contact with the main chip, for receiving data from the main chip or a dedicated reader by means of a coupling.

According to the invention, among the peripheral devices there is a device for receiving energy and data.

According to the invention, the means for receiving energy and data is a planar coil.

According to the invention, the planar coil functions as the secondary coil of a transformer whose primary is formed by said main antenna, when this antenna receives data and energy from the portable object reader by electromagnetic coupling.

According to the invention, wherein both the energy and the data transmitted by the main antenna are generated by the reader of the portable object.

According to the invention, both the energy and the data transmitted by the main antenna are generated by the main chip of said portable object.

According to the invention, the peripheral device has a tuning capacitor for coupling the peripheral device to the reader.

According to the invention, the coupling between the peripheral device and the reader is achieved by the combination of the tuning capacitors of the peripheral device and the main chip.

According to the invention, the contactless peripheral device is an additional chip.

According to the invention, the peripheral device is a keyboard.

According to a particular embodiment, the invention relates to a contactless smart card comprising an additional chip, which is independent of the main chip and communicates with a reader different from that of the main chip.

Drawings

The objects, objects and features of the present invention will be further clarified by reading the following description with reference to the accompanying drawings, in which:

fig. 1 shows a contactless portable object with a plurality of peripheral devices.

Fig. 2 shows a contactless portable object with an additional chip and a display peripheral.

Fig. 3 shows a circuit diagram of a contactless smart card.

Fig. 4 shows a circuit diagram of a peripheral device.

Detailed Description

Fig. 1 shows a contactless smart card of the ISO type. The smart card 10 has a main chip 12 which is interfaced to the reader via a main antenna 14. In fact, when the card is placed in a magnetic field generated by the reader, there is an electromagnetic coupling between the chip 12 and the reader, and data and energy are transmitted between the chip and the reader through their antennas. The main antenna 14 is formed by a gradually increasing perimeter coil, each end of which is connected to the chip 12. Also in this smart card 10 are two peripheral devices 16 and 18. The two peripheral devices may be of the same nature or of different nature. They are not electrically connected to the main chip and are independent of each other. According to other embodiments, such a smart card may have only one peripheral device, or more than two peripheral devices, as desired.

Figure 2 shows an example of an ISO smart card in which there are two peripheral devices of different nature. The smart card 20 has a main chip 22 connected to a main antenna 24. The smart card also has an additional chip 26, which is connected to a planar coil 28. The smart card also has a display peripheral device comprising a chip (not shown), a display 30 and a planar coil 32, the planar coil 32 enabling the display peripheral device to receive data and power from the reader or the main chip.

The size of this planar coil varies with the peripheral device with which it is associated. The size of the planar coil 28 is then seen to be smaller than the size of the planar coil 32. In addition, its size is related to the characteristics of the card on which the peripheral device operates. It can be seen that there is no direct wire connection to the main chip 22 and to its antenna 24, whatever the peripheral device.

Fig. 3 shows a circuit diagram of a contactless smart card 34. The circuit forming the card comprises a main or coupling antenna 36, at least one capacitor 38 and a plurality of resistors, at least one of which 40 and a circuit switch 42. The function of the capacitor 40 is to provide a tuning capacitance for resonating the contactless smart card with the reader when the smart card is placed in a magnetic field generated by the reader. The frequency at which resonance occurs, that is, the rate at which the smart card circuit and the reader circuit resonate, is 13.56 megahertz (MHz) according to current standards. The resistor 40 may communicate with the chip internally through a circuit converter 42 to form a demodulation subcarrier frequency between the smart card and the reader. According to a particular embodiment corresponding to the present standard, the demodulation subcarrier has a frequency of 847 kilohertz (KHz). Demodulating the subcarrier frequency causes the smart card to send information to the reader.

Fig. 4 shows a circuit diagram of one peripheral device 44. In this circuit there is a planar coil 46, a plurality of resistors forming a load comprising a resistor 48 and a circuit switch 50. There is no tuning capacitor in the circuitry 44 of this peripheral device, which can only operate in a self-powered manner according to the available efficiency of the energy transmitted by the reader. This circuit then uses the overvoltage associated with the tuning between the contactless smart card and its reader by coupling with the main antenna. The principle is to use the tuned main circuit of the contactless smart card as the primary of a transformer, the planar coil 46 of the peripheral device constituting the secondary of this transformer and receiving power and data by electromagnetic coupling. Resistor 48 changes the impedance of the circuit by switching 50 to generate the demodulated subcarrier. In fact, according to a particular mode of operation, the impedance of the peripheral device can be varied to transmit the response to the reader by demodulation.

As in all transformers, the peripheral circuit has an impedance in parallel relationship with the impedance of the chip on the main antenna of the contactless smart card, which is related to the mutual coupling coefficient m and the ratio n1/n2 between said main antenna and said planar coil, where n1 is the number of turns of the main antenna of the contactless smart card and n2 is the number of turns of the peripheral antenna.

If the impedance of the peripheral device is large and the parasitic capacitance before rectification is small, the peripheral device can be energized when the contactless smart card is placed in the magnetic field of the reader without significantly impairing the operation of the contactless smart card.

According to one mode of operation of the peripheral device, the latter uses the contactless smart card chip to provide data in the form of specific commands sent by the main antenna. This instruction is generated as soon as a transaction between the contactless smart card and the reader is made.

According to another operating mode of the peripheral device, the peripheral device can transmit to the contactless smart card, by means of amplitude modulation, using energy simultaneously with the data transmitted by the reader, and then by means of the main antenna of the contactless smart card.

According to a particular embodiment, the circuitry of the peripheral device has an integral tuning capacitor that is summed with the tuning capacitance of the main chip to provide integral coupling of the main chip circuitry, the peripheral device circuitry, and the reader circuitry at the operating frequency of the reader. If multiple peripheral devices are placed on this contactless smart card, the capacitance of these peripheral devices and the capacitance of the main chip accumulate to provide an overall tuning capacitance. The tuning capacitance of the peripheral device is typically smaller than the tuning capacitance of the main chip, so that 75% of the total capacitance is the capacitance of the main chip and 25% is the capacitance of the peripheral device. The overall tuning capacitance is also related to mutual coupling, which is related to the number of turns of the main antenna and the number of turns of the peripheral device antenna.

The peripheral device can be operated by the same reader as the main chip, and the operating frequency of the peripheral device is the same as that of the main chip.

The peripheral device may be operated with a dedicated reader operating at the same frequency as the main chip.

To obtain a total coupling frequency of 13.56MHz, the eigen-resonance frequency of the individual circuits on the card needs to be higher than the operating frequency.

According to another embodiment, the peripheral device has a tuning capacitor that enables it to be directly coupled to a dedicated reader. In this case, the coupling frequency is different from and higher than the frequency of the main chip.

The individual peripheral devices may be of different types. According to a first embodiment, this peripheral device is an additional chip with its own instructions. The chip can talk to the master chip by using the same reader or talk to a dedicated reader.

According to a second embodiment, the peripheral device may be a display device as shown in fig. 2. This device displays information generated by the dialogue between the master chip and the reader. If the smart card is an electronic wallet, the amount of money remaining in the contactless smart card is displayed on the display device. This display device can also display information associated with the operation of the card as well. According to a particular embodiment, the display is persistent so that the user is aware of various information at any time between transactions.

According to a third embodiment, the peripheral device is a keyboard, preferably a numeric keypad. This function is particularly useful when the smart card is used as an electronic wallet. In fact, such means can be used to know the amount of money that is desired to be exchanged by the vending machine's electronic purse, and such a keypad can also be used to know the access code. The operation of the peripheral device requires that the contactless portable object remain in the field of the reader when it is aware of the information.

Peripheral devices that operate without ohmic contacts may be integrated on the contactless portable object at the time of manufacture. The planar coil of the peripheral device is then in the same plane as the main antenna.

According to another embodiment, the peripheral device may be associated with the portable object at the time of manufacture of the portable object. In this case, the peripheral device can be removed from the portable object.

In the case where the peripheral device is removable, the portable can only receive data and power when in proximity to the portable and the portable is in the magnetic field emitted by the reader. And in order to be able to transmit the demodulated response the peripheral device should be placed in the vicinity of the contactless portable object.

In general, each of the peripheral devices is independent and not connected to the main contactless portable chip and therefore is not associated with the operation of the main chip, nor with other peripheral devices of the contactless portable object, nor with transactions between the main chip, other peripheral devices and their readers. Thus, in the case where the peripheral device is physically separate from the contactless portable object, the faulty operation of the contactless portable object does not affect the function of another element of the contactless portable object, whether it is the main chip or another peripheral device. The user can then always use the functions of the main chip and the peripheral devices on the smart card. For a malfunctioning peripheral device, such as one that has established a relationship with the contactless portable object, it can be replaced with a new peripheral device.

Claims (10)

1. A contactless portable object comprising a main chip and a main antenna connected to the main chip for communication between the main chip and a reader associated with the contactless portable object,

said contactless portable object is characterized in that it further comprises at least one contactless peripheral device, which is not in ohmic contact with the main chip and receives data from the main chip or a dedicated reader via a coupling.

2. The portable object of claim 1, wherein the peripheral device has a means for receiving power and data.

3. The portable object of claim 2, wherein the means for receiving energy and data is a planar coil.

4. The portable object according to claim 3, wherein the planar coil functions as a secondary coil of a transformer, the primary of which is formed by said main antenna, when the main antenna receives data and energy from the portable object reader through electromagnetic coupling.

5. The portable object of claim 4, wherein the energy and data transmitted by the main antenna are both generated by a reader of the portable object.

6. The portable object of claim 4, wherein the energy and data transmitted by the main antenna are generated by a main chip of the portable object.

7. The portable object of any one of claims 1-6, wherein the peripheral device has a tuning capacitor for coupling the peripheral device to the reader.

8. The portable object of any of the preceding claims, wherein the coupling of the peripheral device to the reader is accomplished by a combination of tuning capacitors of the peripheral device and the main chip.

9. Portable object according to one of claims 1 to 6, characterized in that the contactless peripheral device is an add-on chip.

10. Portable object according to any one of claims 1 to 6, characterized in that the peripheral device is a keyboard.