公开(公告)号：US20210326567A1

公开(公告)日：2021-10-21

申请号：US17273945

申请日：2018-09-12

Applicant: Fingerprint Cards AB

Inventor： Jun LIU ,  René NILSSON ,  Hans MARTINSSON ,  Ehsan HASHEMI

IPC: G06K9/00 ,  G06K9/42

Abstract: The invention relates to a method of reconstructing a fingerprint image from a plurality of fingerprint subimages captured by an optical microlens array fingerprint sensor, and a sensor system performing the method. In an aspect, a method of reconstructing a fingerprint image from a plurality of fingerprint subimages captured by an optical microlens array fingerprint sensor arranged under a touch-display of a device is provided. The method comprises capturing an image of a fingerprint with the fingerprint sensor, extracting, from the captured fingerprint image, a fingerprint subimage for each microlens in the array, normalizing the corrected fingerprint subimages with corresponding subimages of a uniformity calibration image with known uniformity properties, rotating the normalized fingerprint subimages 180 degrees while maintaining their relative position with respect to the captured fingerprint image from which the fingerprint subimages are extracted, and combining the rotated and normalized fingerprint subimages into a fingerprint image.

公开(公告)号：US20210312157A1

公开(公告)日：2021-10-07

申请号：US17272577

申请日：2018-09-05

Applicant: Fingerprint Cards AB

Inventor： Jun LIU ,  Ehsan HASHEMI ,  Hans MARTINSSON ,  René NILSSON ,  Farzan GHAVANINI

IPC: G06K9/00 ,  H03K17/96

Abstract: There is an optical biometric imaging device configured to capture an image of an object in contact with an outer surface of the biometric imaging device, the biometric imaging device comprising: an image sensor comprising a photodetector pixel array and image sensor circuitry configured to capture an image of the object in contact with the outer surface of the imaging device; the image sensor comprising a first electrically conductive structure arranged adjacent to an active sensing area of the photodetector pixel array; a display panel arranged on top of and at a distance from the image sensor, the display panel comprising a second electrically conductive structure on a bottom side of the display panel and arranged to face the first electrically conductive structure of the image sensor; and capacitive readout circuitry arranged and configured to detect a capacitance between the first electrically conductive structure and the second electrically conductive structure.