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US 2022/0100984 A1Published application
Capacitive fingerprint sensing device
AssigneeEgis Technology Inc.
InventorsYu-Hsuan Lin, Chung-Yi Wang, Zhe-Wei Kuo
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Abstract
A capacitive fingerprint sensing device is provided. A sensing pixel unit includes a capacitor, a reset circuit, and a sensing capacitor. The reset circuit provides a reset voltage during a reset period to reset a voltage on the capacitor and provides an adjustment current during a sensing period to adjust a sense voltage generated on a common junction of the capacitor and the reset circuit.
Claims10
A capacitive fingerprint sensing device, comprising:
- a sensing pixel unit, comprising:
- a capacitor, wherein a first terminal of which is coupled to a bias voltage;
- a reset circuit coupled to a second terminal of the capacitor;
- and
- a sensing capacitor formed between a common junction of the capacitor and the reset circuit and the finger in response to a fingerprint sensing operation of a finger, wherein the reset circuit provides a reset voltage to reset a voltage on the capacitor during a reset period and provides an adjustment current during a sensing period to adjust a sensing voltage generated on the common junction of the capacitor and the reset circuit;
- and
- a buffer amplifier circuit coupled to the sensing pixel unit and amplifying the sensing voltage to generate an output voltage.
4 more elements
Dependencies are inferred from the claim text.