Fingerprint sensing and body area network communication system

1. Combined fingerprint sensing and body area network communication system for communication with an electronic unit using the body of a user as communication medium, comprising:

a sensing arrangement comprising:

an array of sensing structures, each being covered by a dielectric structure; and

read out circuitry connected to each of said sensing structures for providing sensing signals indicative of a capacitive coupling between each sensing structure and the user's finger in response to a change in potential difference between a sensing structure potential of said sensing structure and a finger potential of said finger;

a connection electrode arranged adjacent to said sensing structures for making electrical contact with said finger when said finger is placed for sensing the fingerprint pattern of the finger;

a switch; and

a body area network communication circuitry,

wherein the system is controllable between:

a fingerprint sensing state, in which a first signal for controlling the finger potential is provided to the finger via the connection electrode, and the readout circuitry is controlled to provide said sensing signals indicative of the capacitive coupling between each sensing structure and the user's finger; and

a body area network communication state in which a second signal is provided to the connection electrode by one of the electronic unit and the body area network communication circuitry, the signal is to be sent from said one of the electronic device and the body area network communication circuitry via the user's body to the other one of the electronic unit and the body area network communication circuitry, and

wherein the switch is arranged to alternatively, in said fingerprint sensing state, connect said sensing arrangement with said connection electrode, and, in said body area network communication state, connect said body area network communication circuitry with said connection electrode.

2. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein, said body area network circuitry is in an at least partly inactive mode in said fingerprint sensing state.

3. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said sensing arrangement further comprises control circuitry, wherein a transition between said states is controlled by said control circuitry.

4. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said sensing arrangement is configured to provide an instruction signal to said body area network communication circuitry for allowing the body area network communication circuitry to send said second signal to the electronic unit via the user's body and the connection electrode or to receive said second signal from said electronic unit.

5. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said sensing arrangement is configured to instruct the body area network communication circuitry to be in an at least partly inactive mode during a time slot in which said system is in said fingerprint sensing state.

6. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said body area network communication circuitry comprises a transceiver for sending information obtained from said electronic unit to an external electronic device.

7. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said body area network communication circuitry comprises a transceiver for sending signals to said electronic unit.

8. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said connection electrode is arranged for providing a finger drive signal to said finger for driving the potential of said finger relative the sensing structure potential between a relatively high potential and a relatively low potential.

9. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein

in said a fingerprint sensing state, the sensing arrangement is connected to the connection electrode and the communication unit is not connected to the connection electrode, and

in said body area network communication state the body area network communication circuitry is connected to the connection electrode, and the sensing arrangement is not connected to the connection electrode.

10. Combined fingerprint sensing and body area network communication system according to claim 1 , further comprising a switch arranged to, in said fingerprint sensing state, connect said sensing arrangement with said connection electrode, and, in said body area network communication state, connect said body area network communication circuitry with said connection electrode.

11. Combined fingerprint sensing and body area network communication system according to claim 1 , configured to:

perform, in said a fingerprint sensing state, a user authentication procedure to authenticate the user,

when the result of the authentication procedure indicates a successful authentication of the user, read, using the body area network communication circuitry, information from said electronic device.

12. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said connection electrode is a bezel for said sensing arrangement.

13. Combined fingerprint sensing and body area network communication system according to claim 1 , wherein said connection electrode is a metallic housing for said sensing arrangement.

14. An electronic device comprising:

a control unit; and

a combined fingerprint sensing and body area network system according to claim 1 .

15. The electronic device according to claim 14 , wherein the fingerprint sensor is a capacitive fingerprint sensor.

16. The electronic device according to claim 14 , wherein the electronic device is a mobile phone.