Patent ID: 9298967
Filing Date: 2016-03-29
CPC Classification: G06F,G06K,H03G

Claim Text:
1. A finger biometric sensing device comprising: drive circuitry capable of generating a drive signal and comprising a finger coupling electrode to couple a drive signal to a finger and a voltage generator coupled to said finger coupling electrode; an array of finger biometric sensing pixel electrodes adjacent said finger coupling electrode, cooperating with said drive circuitry, and capable of generating a detected signal based upon placement of the finger adjacent said array of finger biometric sensing pixel electrodes, the detected signal including a relatively large drive signal component based upon the drive signal and a relatively small sense signal component superimposed thereon, the relatively small sense signal component comprising finger biometric characteristic data for performing an authentication function; at least one gain stage coupled to said array of finger biometric sensing pixel electrodes; and drive signal nulling circuitry coupled to said at least one gain stage capable of reducing the relatively large drive signal component from the detected signal.