Biometric image sensing

An impedance sensor, comprising:na plurality of substantially parallel drive lines configured to transmit a signal to a proximally located object; anda plurality of substantially parallel pickup lines configured to receive a resultant signal and oriented substantially perpendicular to the drive lines and separated from the drive lines on a different layer by a dielectric to form a two dimensional array of intrinsic electrode pairs that are impedance sensitive to a proximally located finger about each drive line and pickup crossover location;wherein the dielectric is a single flexible substrate having both the drive and pickup lines located thereon.

An impedance sensor, comprising:na plurality of substantially parallel drive lines configured to transmit a signal to a proximally located object;a plurality of substantially parallel pickup lines configured to receive a resultant signal and oriented substantially perpendicular to the drive lines and separated from the drive lines on a different layer by a dielectric to form a two dimensional array of intrinsic electrode pairs that are impedance sensitive to a proximally located finger about each drive line and pickup crossover location;a signal generator configured to generate an AC signal at and AC driving frequency communicated to a drive line, and a signal processor configured to process a resultant signal from a pickup line, wherein said drive and pickup crossover locations form individual pixels configured to capture a plurality of pixels of image information; anda signal processor including a narrow band receiver tuned to the AC driving frequency.

An impedance sensor, comprising:na plurality of substantially parallel drive lines configured to transmit a signal to a proximally located object;a plurality of substantially parallel pickup lines configured to receive a resultant signal and oriented substantially perpendicular to the drive lines and separated from the drive lines on a different layer by a dielectric to form a two dimensional array of intrinsic electrode pairs that are impedance sensitive to a proximally located finger about each drive line and pickup crossover location; anda detection system configured to subtract the signal on a pickup plate in contact with the object being sensed from the signal on a pickup plate that is isolated from the object being sensed prior to further processing.