The present invention relates to a capacitive fingerprint sensing system comprising an excitation signal supply circuit configuration and a plurality of sensing elements. Each sensing element is a protective dielectric top layer and a conductive sensing structure connected to the excitation signal that exhibits a change in charge on the sensing structure due to a change in potential difference between the finger and the sensing structure. A conductive sensing structure for supplying a sensing signal and a demodulating circuit configuration connected to the sensing circuit configuration, wherein the sensing structure combines the sensing signal and a demodulated signal related in timing to the excitation signal. And a demodulating circuit configuration for supplying a combined signal including a DC signal component indicating a change in charge. The fingerprint sensing system further comprises readout circuitry connected to each of the sensing elements to provide a display of a fingerprint pattern based on the DC signal component from each of the sensing elements.本発明は、励起信号供給回路構成と複数の感知素子とを備える容量性指紋感知システムに関する。各感知素子は、保護誘電最上層と、該励起信号に接続された導電性感知構造であって、指と感知構造との間の電位差の変化に起因して感知構造が帯びる電荷の変化を示す感知信号を供給する導電性感知構造と、感知回路構成に接続された復調回路構成であって、該感知信号と該励起信号にタイミング的に関係する復調信号とを結合して、該感知構造が帯びる電荷の変化を示すＤＣ信号成分を含む結合信号を供給する復調回路構成と、を含む。指紋感知システムは、該感知素子の各々に接続されて、該感知素子の各々からの該ＤＣ信号成分に基づいて指紋パターンの表示を提供する読み出し回路構成を更に備える。
