CONTACTLESS COMMUNICATION WITH AUTHORIZATION BY HUMAN CONTACT AND VISUAL INDICATOR

• US 20120149335A1
• Filed: 12/09/2011
• Published: 06/14/2012
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Inventors: Wuidart, Luc
• Granted Patent: US 8,676,163 B2
• Time in Patent Office: Days
• US Class Current: 455/411
• CPC Class Codes: G06K 19/07345 by activating or deactivating at least a part of the circuit on the record carrier, e.g. ON/OFF switches

Abstract

Transponder comprising a resonant circuit, comprising an antenna and a capacitor, and at least one memory, wherein it comprises at least one contact zone for receiving a portion of human body, so that the positioning of a portion of human body on a contact zone modifies the electric circuit of the transponder, capable of switching from a first state in which it does not allow the memory to be read and/or written to a second state in which it allows the memory to be read and/or written when the resonant circuit of the transponder is contactlessly powered by a reader and in that it comprises an indicator which makes it possible to indicate that the positioning of a portion of human body on the contact zone of the transponder is or has been recognized.

Claims

1. A transponder comprising:

a resonant circuit that includes an antenna and a capacitor;

a memory;

a contact zone configured to be contacted by a portion of human body;

an enable/disable circuit configured to switch from a first state, in which the enable/disable circuit does not allow the memory to be accessed, to a second state in which the enable/disable circuit allows the memory to be accessed when the resonant circuit of the transponder is contactlessly powered by a reader; and

a first indicator configured to indicate that a portion of human body has contacted the contact zone of the transponder.

2. A transponder according to claim 1, comprising a second indicator configured to indicate that the transponder is contactlessly powered by a reader.

3. A transponder according to claim 1, wherein the first indicator is also configured to indicate that the transponder is contactlessly powered by a reader.

4. A transponder according to claim 1, wherein the first indicator is a visual indicator that includes a light-emitting diode.

5. A transponder according to claim 1, comprising:

first and second supply terminals;

a first switch coupled in series with the first indicator in a first branch between the supply terminals;

first and second resistors coupled to each other in a second branch, parallel to the first branch, between the supply terminals, the resistors being coupled to each other by an intermediate node that is also coupled to a control terminal of the first switch; and

a second switch coupled between the intermediate terminal and the second terminal of the transponder.

6. A transponder according to claim 1, wherein the indicator is electrically coupled to the contact zone.

7. A transponder according to claim 1, wherein the resonant circuit it is configured to be powered contactlessly around a resonance frequency that remains the same in both states of the transponder.

8. A transponder according to claim 7, wherein the resonant circuit is configured to resonate and induce a voltage difference between the first terminal and the second terminal when the transponder is contactlessly powered by a reader, in both states of the transponder.

9. A transponder according to claim 1, wherein the enable/disable circuit and contact zone are part of an intermediate circuit coupled between the resonant circuit and the memory.

10. A transponder according to claim 1, the contact zone includes a contact pad on which the positioning of a portion of human body has a capacitive effect, or includes two adjacent contact pads on which the positioning of a portion of human body has a resistive effect.

11. A transponder according to claim 1, wherein the enable/disable circuit is configured to switch from the first state to the second state in response to a portion of human body being placed on the contact zone and is configured to remain in the second state after the portion of human body is removed from the contact zone.

12. A transponder according to claim 1, wherein the transponder is a contactless or dual integrated circuit card.

13. A telephone, comprising:

a transponder that includes;

a resonant circuit that includes an antenna and a capacitor;

a memory;

a contact zone configured to be contacted by a portion of human body;

an enable/disable circuit configured to switch from a first state, in which the enable/disable circuit does not allow the memory to be accessed, to a second state in which the enable/disable circuit allows the memory to be accessed when the resonant circuit of the transponder is contactlessly powered by a reader; and

an indicator configured to indicate that a portion of human body has contacted the contact zone of the transponder.

14. A telephone according to claim 13, wherein the indicator is also configured to indicate that the transponder is contactlessly powered by a reader.

15. A telephone according to claim 13, wherein the indicator is a visual indicator.

16. A telephone according to claim 13, comprising:

first and second supply terminals;

a first switch coupled in series with the first indicator in a first branch between the supply terminals;

first and second resistors coupled to each other in a second branch, parallel to the first branch, between the supply terminals, the resistors being coupled to each other by an intermediate node that is also coupled to a control terminal of the first switch; and

a second switch coupled between the intermediate terminal and the second terminal of the transponder.

17. A telephone according to claim 13, wherein the enable/disable circuit is configured to switch from the first state to the second state in response to a portion of human body being placed on the contact zone and is configured to remain in the second state after the portion of human body is removed from the contact zone.

18. A system comprising:

a reader configured to oscillate at a resonance frequency; and

a transponder that includes;

a resonant circuit having a resonance frequency substantially equal to the resonance frequency of the reader;

a memory;

a contact zone configured to be contacted by a portion of human body;

an enable/disable circuit configured to switch from a first state, in which the enable/disable circuit does not allow the memory to be accessed, to a second state in which the enable/disable circuit allows the memory to be accessed when the resonant circuit of the transponder is contactlessly powered by a reader; and

an indicator configured to indicate that a portion of human body has contacted the contact zone of the transponder.

19. A system according to claim 18, wherein the indicator is also configured to indicate that the transponder is contactlessly powered by a reader.

20. A system according to claim 18, wherein the indicator is a visual indicator.

21. A system according to claim 18, comprising:

first and second supply terminals;

a first switch coupled in series with the first indicator in a first branch between the supply terminals;

first and second resistors coupled to each other in a second branch, parallel to the first branch, between the supply terminals, the resistors being coupled to each other by an intermediate node that is also coupled to a control terminal of the first switch; and

a second switch coupled between the intermediate terminal and the second terminal of the transponder.

22. A system according to claim 18, wherein the enable/disable circuit is configured to switch from the first state to the second state in response to a portion of human body being placed on the contact zone and is configured to remain in the second state after the portion of human body is removed from the contact zone.

23. A method of contactless communication between a reader and a transponder, the method comprising:

transmitting an electromagnetic field by the reader;

contactlessly powering the transponder using the electromagnetic field, based on a resonance of the resonant circuit of the transponder, the transponder having a first state in which a memory is inaccessible to the reader;

switching to the second state in response to a conductive object being positioned on a contact zone of the transponder;

visually indicating a recognition of the positioning of the conductive object on the contact zone of the transponder;

interchanging data between the memory of the transponder and the reader while the transponder is in the second state.

24. A method of contactless communication according to claim 23, wherein interchanging data comprises sending data relating to a payment and/or an authentication, and/or a digital signature to the reader, and/or the sending of other secure data.