PIXEL SENSING CIRCUIT FOR FINGERPRINT IDENTIFICATION, FINGERPRINT IDENTIFICATION SYSTEM AND ELECTRONIC DEVICE THEREOF

摘要

Disclosed is a pixel sensing circuit, which is in a fingerprint identification mode or a noise detection mode, and includes: a plurality of shielding layers, including a first-type shielding layer and a second-type shielding layer, the second shielding layer being coupled to a ground terminal; and a charging circuit, coupled to the capacitance sensing layer and the first-type shielding layer, and comprising a positive voltage generator configured to providing a positive voltage; wherein when the pixel sensing circuit is in a fingerprint identification mode, the charging circuit periodically provides the positive voltage for the capacitance sensing layer and the first-type shielding layer; or when the pixel sensing circuit is in the noise detection mode, the charging circuit cuts off connections between the positive voltage generator and the capacitance sensing layer and the first-type shielding layer, and periodically outputs a voltage of the capacitance sensing layer to a first output terminal.