Fingerprint sensing signal correction method and device thereof
AssigneeNovatek Microelectronics Corp.
InventorMin Huang
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Abstract
A fingerprint sensing signal correction method for a fingerprint sensing signal correction device including a plurality of fingerprint sensors integrated inside of a display panel of an electronic device is disclosed. The method includes obtaining a plurality of environmental voltages of the display panel during a pre-scanning mode; generating a plurality of correction voltages associated with the plurality of environmental voltages during a signal processing mode; and canceling the plurality of environmental voltages from a plurality of amplified sensing voltages to generate a plurality of corrected sensing voltages during a normal mode.
Claims13
A fingerprint sensing signal correction method for a fingerprint sensing signal correction device including a plurality of fingerprint sensors integrated inside of a display panel of an electronic device, comprising:
- obtaining a plurality of environmental voltages corresponding to a polarity distribution of the display panel during a pre-scanning mode, wherein the plurality of environmental voltages are induced by voltages applied to the display panel;
- generating a plurality of correction voltages associated with the plurality of environmental voltages during a signal processing mode;
- and
- canceling the plurality of environmental voltages from a plurality of amplified sensing voltages to generate a plurality of corrected sensing voltages during a normal mode,
- wherein the fingerprint sensing signal correction device comprises an analog-to-digital converter having a conversion range from a maximum voltage to a minimum voltage, and an offset range between the plurality of correction voltages and the plurality of environmental voltages is either from the maximum voltage to a middle voltage of the conversion range or from the middle voltage to the minimum voltage.
A fingerprint sensing signal correction device for an electronic device including a display panel and a fingerprint sensor integrated inside of the display panel, the fingerprint sensor being configured to generate a sensing voltage, the fingerprint sensing signal correction device comprising:
- an AFE (analog front-end) amplifier configured to amplify the sensing voltage by a gain to generate an environmental voltage of the display panel during a pre-scanning mode;
- an A/D (analog-to-digital) converter coupled to the AFE amplifier, and configured to convert the environmental voltage into an environmental code during the pre-scanning mode;
- a digital processor coupled to the A/D converter, and configured to calculate an offset code according to the environmental code and data including a display zone and a column location corresponding to the environmental code during a signal processing mode;
- a D/A (digital-to-analog) converter coupled to the digital processor, and configured to convert the offset code into a correction voltage associated with the environmental voltage during a normal mode;
- and
- a subtractor coupled to the AFE amplifier, the A/D converter and the D/A converter, and configured to subtract the environmental voltage from the amplified sensing voltage, so as to generate a corrected sensing voltage during the normal mode.
Dependencies are inferred from the claim text.