Patent ID: 11902494
Assignee: NLIGHT, INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A method of reducing glint from a returned electromagnetic radiation signal in an active illumination 3D imaging system so as to avoid saturation effects that introduce errors in distance calculation, comprising:
illuminating a scene with an electromagnetic radiation signal having a predetermined first polarization, the electromagnetic radiation signal configured for providing illumination distributed uniformly across a field of view representing the scene, in which an object in the field of view produces specular reflection that would introduce the saturation effects;
receiving, at a receiver, the returned electromagnetic radiation signal that is scattered or reflected from the scene as a result of illuminating the scene with the electromagnetic radiation signal;
passing the returned electromagnetic radiation signal through a polarizer included in the receiver to establish a filtered portion of the returned electromagnetic radiation signal, the polarizer having a second polarization that differs from the predetermined first polarization of the electromagnetic radiation signal so that the specular reflection produced from the object is reduced to be within a dynamic range of the active illumination 3D imaging system;
modulating the filtered portion of the returned electromagnetic radiation signal as a function of time and thereby generate a modulated returned portion having its intensity vary as a function of distance in the field of view;
converting into one or more electrical signals the modulated returned portion of the electromagnetic radiation signal; and
determining 3D information regarding the scene based on the electrical signals, in which the determining includes calculating a distance to the object according to its corresponding electrical signals representing the intensity that varies while falling within the dynamic range of the active illumination 3D imaging system.