PROCESSING METHOD AND SYSTEM FOR FINGERPRINT SENSING SIGNAL AND FINGERPRINT RECOGNITION TERMINAL
First Claim
1. A method for processing fingerprint sensing signals, the method comprising:
- mixing a collected high frequency fingerprint sensing signal with a first high frequency signal to obtain a low frequency signal; and
amplifying the low frequency signal.
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Abstract
The present invention relates to the field of fingerprint identification technologies, and provides a method and a system for processing fingerprint sensing signals, and a fingerprint identification terminal. The method includes a frequency mixing step by mixing a collected high frequency fingerprint sensing signal with a first high frequency signal to obtain a low frequency signal; and an amplification step by amplifying the low frequency signal. By using the character that capacitance impedance is inversely proportional to signal frequency, the present invention shifts a fingerprint sensing signal with a high frequency into a signal with a low frequency through frequency spectrum shifting and performs signal amplification on the signal with a low frequency, which can overcome the difficulty in amplifying the high frequency fingerprint sensing signal and thus improves the signal-to-noise ratio SNR.
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Citations
14 Claims
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1. A method for processing fingerprint sensing signals, the method comprising:
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mixing a collected high frequency fingerprint sensing signal with a first high frequency signal to obtain a low frequency signal; and amplifying the low frequency signal. - View Dependent Claims (2)
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3. A system for processing fingerprint sensing signals, the system comprising:
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a frequency mixer configured to mix a collected high frequency fingerprint sensing signal with a first high frequency signal to obtain a low frequency signal; and a capacitive feedback amplifier configured to perform amplification of the low frequency signal, wherein an inverting input end of the capacitive feedback amplifier is connected to an output end of the frequency mixer, a feedback capacitor is connected between the inverting input end and an output end of the capacitive feedback amplifier, and a non-inverting input end of the capacitive feedback amplifier is connected to a bias voltage. - View Dependent Claims (4, 5, 6, 11, 12, 14)
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7. A fingerprint identification terminal, comprising a plurality of fingerprint sensing pixels distributed in an array manner, wherein each fingerprint sensing pixel is connected to a processing system for fingerprint sensing signals, and the processing system comprises:
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a frequency mixer configured to mix a collected high frequency fingerprint sensing signal with a first high frequency signal to obtain a low frequency signal; and a capacitive feedback amplifier configured to perform amplification of the low frequency signal, wherein an inverting input end of the capacitive feedback amplifier is connected to an output end of the frequency mixer, a feedback capacitor is connected between the inverting input end and the output end of the capacitive feedback amplifier, and a non-inverting input end of the capacitive feedback amplifier is connected to a bias voltage. - View Dependent Claims (8, 9, 10, 13)
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Specification