METHOD AND SYSTEM FOR CALIBRATION OF A FINGERPRINT SENSING DEVICE

1 - 18 . (canceled)

19 . A fingerprint sensing device comprising an array of sensing elements for sensing a fingerprint pattern, said device comprising a calibration control unit configured to:

acquire information indicative of a change of an environmental parameter influencing the operating of said fingerprint sensing device;

if said change is larger than a predetermined threshold value, perform a calibration operation of said fingerprint sensing device;

receive information indicative of an event in a device in which said fingerprint sensing device is arranged; and

if said event is one of a group of predetermined events, perform a calibration operation of said fingerprint sensing device.

20 . The fingerprint sensing device according to claim 19 , further comprising a temperature sensor, a humidity sensor, and/or an electromagnetic field sensor.

21 . The device according to claim 19 , wherein said control unit is further configured to:

determine a present value of an environmental parameter;

determine a difference between said present value of said environmental parameter and a predetermined value of said environmental parameter; and

if said difference is larger than said predetermined threshold value, perform said calibration operation of said fingerprint sensor.

22 . The device according to claim 21 , wherein said predetermined value of said environmental parameter is a value determined at the last performed calibration operation.

23 . The device according to claim 21 , wherein said environmental parameter is selected from the group comprising humidity, temperature and electrical field strength.

24 . The device according to claim 21 , wherein determining a present value of an environmental parameter comprises acquiring information from a sensor integrated in said fingerprint sensing device.

25 . The device according to claim 21 , wherein determining a present value of an environmental parameter comprises acquiring information from a sensor external to said fingerprint sensing device.

26 . The device according to claim 21 , wherein determining a present value of an environmental parameter comprises acquiring information via a network connection.

27 . The device according to claim 19 , wherein said control unit is further configured to initiate a second calibration operation of said fingerprint sensing device a predetermined time after a first operation has been performed resulting from said change in environmental parameter.

28 . The device according to claim 19 , wherein said group of predetermined events comprises events requiring a user interaction with said user device in which said fingerprint sensing device is arranged.

29 . The device according to claim 19 , wherein said group of predetermined events comprises an incoming call, an alarm, an incoming message and an incoming notification.

30 . The device according to claim 19 , wherein said event comprises a change in a network connection.

31 . The device according to claim 30 , wherein said change in network connection comprises a change in cell ID in a cellular network.

32 . The device according to claim 30 , wherein said change in network connection comprises a change of strength in a wireless network connection.

33 . The device according to claim 19 , wherein said event comprises a change in location of said user device in which said fingerprint sensing device is arranged.

34 . The device according to claim 19 , wherein said event comprises connecting a charger to said user device in which said fingerprint sensing device is arranged.

35 . The device according to claim 19 , wherein said control unit is further configured to wait for a minimum period of time between consecutive calibration operations.

36 . The method according to claim 19 , wherein said control unit is further configured initiate a second calibration operation of said fingerprint sensing device a predetermined time after a first operation has been performed resulting from said indication of said event.