Sensors using overlapping grid lines and conductive probes to extend the sensing surface from the grid lines

摘要

An electronic sensor forms a grid to detect surface features of a proximally located object, such as a fingerprint. The grid includes a plurality of parallel drive lines connectable to a drive source and a plurality of parallel pickup lines oriented substantially perpendicular to the drive lines and overlapping the drive lines. The drive lines are separated from the pickup lines by an insulating dielectric layer. The overlaps where the drive lines and pickup lines cross define impedance-sensitive electrode pairs which act as pixels at which surface features of the proximally located object are detected. One or more conductive probes extend from one or more corresponding impedance-sensitive electrode pairs, through an overlay layer of insulating material, to the sensing surface.