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US 10,762,325 B2Granted
Pressure detection and measurement with a fingerprint sensor
AssigneeCypress Semiconductor Corporation
InventorsAndriy Ryshtun, Viktor Kremin
Life of this patent
Estimating the term…
Abstract
A circuit, system, and method for measuring or detecting pressure or force of a fingerprint on an array of electrodes is described. Pressure or force may be measured or detected using a processed image of the fingerprint, or by measurement of capacitance of deformed variable capacitors.
Claims20
A method comprising:
- converting a mutual capacitance on each of a plurality of nodes of a sensing array disposed beneath a surface to a digital value;
- comparing digital values for at least one of the plurality of nodes with the highest digital value to at least one of the plurality of nodes with the lowest digital value;
- and
- based on the comparison, calculating a pressure value, the pressure value representative of an amount of force applied to the surface by a conductive object.
1 more element
A fingerprint sensing device comprising:
- a scan engine configured to convert a plurality of capacitances coupled to a plurality of inputs of the fingerprint sensing device to a plurality of digital values;
- an imaging module to configured convert the plurality of digital values into a representation of a fingerprint;
- a pressure detection module configured to convert the representation of the fingerprint into a pressure value, the pressure detection module configured to compare maximum capacitance values to minimum capacitance values and, based on the comparison determining a measure of force applied to a surface by a conductive object.
A system comprising:
- a first plurality of electrodes disposed along a first axis;
- a second plurality of electrodes disposed along a second axis, each of the first and second pluralities of electrodes forming a mutual capacitance between them;
- a measurement circuit coupled to the first plurality of electrodes, the measurement circuit configured to convert the mutual capacitance into a digital value;
- an imaging module configured to convert the mutual capacitance formed between the first and second pluralities of electrodes into an image representative of a fingerprint on a surface above the first and second pluralities of electrodes;
- and
- a pressure detection module configured to convert the representation of the fingerprint into a pressure value, the pressure detection module configured to compare maximum capacitance values to minimum capacitance values and, based on the comparison determining a measure of force applied to a surface by a conductive object.
3 more elements
Dependencies are inferred from the claim text.