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

Claim 7:
8. An active illumination 3D imaging system configured to reduce glint from a returned electromagnetic radiation signal to avoid saturation effects that introduce errors in distance calculation, comprising:
an illuminator configured to illuminate a scene with electromagnetic radiation 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;
a sensor subsystem including:
a polarizer having a second polarization that differs from the predetermined first polarization of the electromagnetic radiation, the polarizer configured to receive the returned portion of the electromagnetic radiation returned from the scene so as to establish a filtered portion with the specular reflection produced from the object reduced to be within a dynamic range of the active illumination 3D imaging system;
a modulator configured to modulate the filtered portion of the electromagnetic radiation 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; and
a sensor configured to receive the filtered portion of the electromagnetic radiation and generate one or more electrical signals; and

a processor, operatively coupled to the modulator and sensor, configured to compute 3D information regarding the scene based on the one or more electrical signals from the sensor by calculating a distance to the object according to its corresponding electrical signals representing the intensity that vanes while falling within the dynamic range of the active illumination 3D imaging system.