Patent ID: 10354115

Abstract:
The present invention relates to a capacitive fingerprint sensor, and the capacitive fingerprint sensor includes: a fingerprint sensor electrode for sensing a fingerprint of a human body; a first transistor of which a current or an output voltage is changed according to a voltage change of capacitive coupling formed by fingerprint capacitance formed when a fingerprint contacts the fingerprint sensor electrode and coupling capacitance formed for capacitive coupling; a fifth transistor that resets a gate electrode of the first transistor and applies capacitive coupling to the gate electrode of the first transistor through a coupling pulse; a second transistor of which a current or an output voltage is changed due to a difference in the current flowing through the first transistor and a gate voltage is maintained by a capacitor; a third transistor that resets a gate electrode of the second transistor; and a fourth transistor that controls a current flowing through the second transistor or an output voltage of the second transistor and transmits the controlled current or output voltage to a readout circuit.