Apple Inc.
UNDER-DISPLAY FINGERPRINT SENSING BASED ON OFF-AXIS ANGULAR LIGHT

Abstract:

An apparatus for touch-sensing includes a light-emitting layer covered by a transparent layer and configured to illuminate a surface touching the transparent layer and to allow transmission of reflected light rays from the surface to underlying layers. The underlying layers include an optical coupling layer, a collimator layer and a pixelated image sensor. The optical coupling layer bends the reflected light rays to create oblique light rays. The collimator layer includes a number of apertures to collimate the received light rays. The pixelated image sensor senses the collimated oblique light rays.