Synaptics Incorporated
Systems and methods for optical imaging based on diffraction gratings

Abstract:

Disclosed is a device comprising: a light guide configured to receive incident light from one or more light sources; a cover layer with a sensing surface configured to receive an input object to be sensed; and a set of photodetectors. The light guide includes diffraction gratings configured to diffract the incident light as diffracted light, wherein the diffracted light exits the light guide and travels towards the sensing surface. The diffracted light is reflected from the sensing surface as reflected light. The reflected light is sensed by the set of photodetectors to form an image of the input object.