Thin, multi-lens, optical fingerprint sensor adapted to image through cell phone displays and with multiple photodiode groups each having separate fields of view for each microlens

Abstract

An image sensor for imaging fingerprints has multiple photodiode groups each with field of view through a microlens determined by optical characteristics of the microlens and locations of the microlens and openings of upper and lower mask layers. Many photodiode groups have fields of view outwardly splayed from a center-direct field of view. A diameter of openings of the upper mask layer distant from the group having a center-direct field of view is larger than openings of a photodiode group having a center-direct field of view. A method of matching illumination of a group of photodiodes with center-direct field of view to illumination of photodiode groups having outwardly splayed fields of view includes sizing openings in the upper mask layer of photodiode groups with outwardly splayed fields of view larger than openings in the upper mask layer associated with photodiode groups having center-direct field of view.