Fingerprint detection circuit and fingerprint recognition system
First Claim
1. A fingerprint detecting circuit, applied in a fingerprint identification system transmitting a first signal to a finger, the fingerprint detecting circuit comprising:
- a conductive layer, configured to couple a touch from the finger; and
an amplifier, comprising;
a negative input terminal, coupled to the conductive layer;
a positive input terminal, configured to receive a second signal; and
an output terminal, wherein a first capacitance is formed between the output terminal and the negative input terminal;
wherein a first phase of the first signal is inverse to a second phase of the second signal.
1 Assignment
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Accused Products
Abstract
The present invention provides a fingerprint detecting circuit applied in a fingerprint identification system, wherein the fingerprint identification system transmits a first signal to finger. The fingerprint detecting circuit includes a conductive layer to couple a touch from the finger; and an amplifier including a first input terminal coupled to the conductive layer; a second input terminal to receive a second signal; and an output terminal, wherein a first capacitance is between the output terminal and the first input terminal; wherein a phase of the first signal is inverse to a phase of the second signal. The present invention utilizes the two signals with the inverse phases to drive the fingerprint detecting circuit, so as to enhance strength of the output signal and lower hardness of fingerprint detecting. Power consumption and production cost are reduced, and the requirement of conventional voltage for the portable electronic device is satisfied.
6 Citations
16 Claims
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1. A fingerprint detecting circuit, applied in a fingerprint identification system transmitting a first signal to a finger, the fingerprint detecting circuit comprising:
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a conductive layer, configured to couple a touch from the finger; and an amplifier, comprising; a negative input terminal, coupled to the conductive layer; a positive input terminal, configured to receive a second signal; and an output terminal, wherein a first capacitance is formed between the output terminal and the negative input terminal; wherein a first phase of the first signal is inverse to a second phase of the second signal. - View Dependent Claims (2, 3, 4)
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5. A fingerprint identification system, which transmits a first signal to a finger, the fingerprint identification system comprising:
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a plurality of fingerprint detecting circuits, each fingerprint detecting circuit comprising; a conductive layer, configured to couple a touch from the finger; and an amplifier, comprising; a negative input terminal, coupled to the conductive layer; a positive input terminal, configured to receive a second signal; and an output terminal, wherein a first capacitance is formed between the output terminal and the negative input terminal; wherein a first phase of the first signal is inverse to a second phase of the second signal; a fingerprint determining module, coupled to the plurality of fingerprint detecting circuits, configured to determine whether each fingerprint detecting circuit corresponds to a finger ridge or a finger valley. - View Dependent Claims (6, 7, 8)
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9. A fingerprint detecting circuit, comprising:
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a conductive layer; and an amplifier, comprising a negative input terminal, a positive input terminal and an output terminal; wherein the negative input terminal is coupled to the conductive layer, and a first capacitance is formed between the negative input terminal and the output terminal; the conductive layer is configured for forming a second capacitance with a finger, and the second capacitance is configured to couple a first signal transmitted to the finger to the negative input terminal; the positive input terminal is configured to receiving a second signal which has a phase inverse to that of the first signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification