Fingerprint sensing system and method
AssigneeNXP B.V.
InventorThomas Suwald
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Abstract
According to a first aspect of the present disclosure, a fingerprint sensing system is provided, comprising: a sensing unit configured to measure a physical property of a sensing cell and to produce a voltage in dependence on said physical property; and an analog-to-digital converter configured to convert said voltage into a digital signal, wherein said analog-to-digital converter implements a non-linear conversion function. According to a second aspect of the present disclosure, a corresponding fingerprint sensing method is conceived. According to a third aspect of the present disclosure, a corresponding computer program product is provided.
Claims18
A fingerprint sensing system, comprising:
- a capacitance-to-voltage converter configured to measure a capacitance from a fingerprint sensing cell and to produce a voltage in dependence on said capacitance from the fingerprint;
- an analog-to-digital converter configured to convert said voltage into a digital signal, wherein said analog-to-digital converter implements a non-linear conversion function;
- and
- a look-up table used to convert the digital signal to a value representing a measured valley depth of the fingerprint.
A fingerprint sensing method, comprising:
- using a capacitance-to-voltage converter to measure a capacitance from the fingerprint sensing cell to produce a voltage in dependence on said physical property;
- providing an analog-to-digital converter that implements a logarithmic conversion function to convert said voltage into a digital signal;
- and
- using a look-up table to convert the digital signal to a value representing a linearization of the logarithmic conversion function to provide a measurement of a valley depth of the fingerprint.
Dependencies are inferred from the claim text.