Nlight, Incorporated

Other

Tetravue, Inc.

Bodo Schmidt

Paul S Banks

Charles Stewart Tuvey

Lorenzo N Venneri

C Stewart Tuvey

Steve Herman

Christopher Allen Ebbers

Systems and methods for reducing the deleterious effects of specular reflections (e.g., glint) on active illumination systems are disclosed. An example system includes an illuminator or light source configured to illuminate a scene with electromagnetic radiation having a defined polarization orientation. The system also includes a receiver for receiving portions of the electromagnetic radiation reflected or scatter from the scene. Included in the receiver is a polarizer having a polarization axis crossed with the polarization orientation of the emitted electromagnetic radiation. By crossing the polarizer with the polarization of the emitted electromagnetic radiation, the polarizer may filter out glint or specular reflections in the electromagnetic radiation returned from the scene.

System and method for glint reduction

Systems and methods for reducing or eliminating undesired effects of retro-reflections in imaging are disclosed. A system for reducing the undesired effects of retro-reflections may include an illuminator and an optical receiver. The illuminator is configured to emit an illumination signal for illuminating a scene. The optical receiver is configured to receive returned portions of the illumination signal scattered or reflected from the scene. Return signals from retroreflectors present in the scene may oversaturate or otherwise negatively affect sensors in the optical receiver. To limit return signals from retroreflectors that may be present in the scene, the illuminator and optical receiver are physically separated from each other by an offset distance that limits or prevents retro-reflections from the retroreflectors from being received by the optical receiver.

Method and system for reducing returns from retro-reflections in active illumination system

Apparatuses, systems and methods are disclosed for reducing interference between an active illumination device and external radiation sources, for example, other active illumination devices operating within the vicinity. A disclosed system includes one or more active illumination devices, each configured to emit an illumination signal and also to receive a returned portion of its respective illumination signal with at least one sensor. At least one of the active illumination devices is capable of detecting interference caused by an external source, for example, an illumination signal emitted from another active illumination device. As a result of detecting the interference, the receiving active illumination device changes the timing of its subsequent illumination signals and sensor operation. By detecting collisions between illumination signals and consequently altering the timing of it operation, the active illumination device may reduce interference in congested environments where multiple active illumination devices are operating within range of each other.

Reducing interference in an active illumination environment

The methods and systems disclosed herein improve upon previous 3D imaging techniques by making use of a longer illumination pulse to obtain the same or nearly the same range resolution as can be achieved by using a much shorter, conventional laser pulse. For example, a longer illumination pulse can be produced by one or more Q-switched lasers that produce, for example, 5, 10, 20 ns or longer pulses. In some instances, the laser pulse can be longer than the modulation waveform of a MIS-type imaging system and still produce a repeatable response function. The light pulse generation technologies required to achieve longer pulse lengths can be significantly less expensive and less complex than known technologies presently used to generate shorter illumination pulse lengths. Lower-cost, lower-complexity light pulse sources may facilitate lower-cost, commercial 3D camera products.

Method and system for robust and extended illumination waveforms for depth sensing in 3D imaging

A system and method for reducing background light in an image are disclosed. The system includes a sensor and a processor. An illuminator may illuminate a scene with emitted light. The sensor outputs one or more images in response to received light. The processor processes images from the sensor to reduce or eliminate ambient light in a captured image. The processor may do this by causing the sensor to capture a first image of the scene, where the first image includes background light and portions of the emitted light reflected or scattered from the scene. The processor also causes the sensor to capture a second image of the scene, where the second image includes background light with no contribution from the emitted light. The processor subtracts the second image from the first image to produce a third image of the scene predominately illuminated by the emitted light.

System and method of reducing ambient background light in a pulse-illuminated image

A 3D imaging system includes an optical modulator for modulating a returned portion of a light pulse as a function of time. The returned light pulse portion is reflected or scattered from a scene for which a 3D image or video is desired. The 3D imaging system also includes an element array receiving the modulated light pulse portion and a sensor array of pixels, corresponding to the element array. The pixel array is positioned to receive light output from the element array. The element array may include an array of polarizing elements, each corresponding to one or more pixels. The polarization states of the polarizing elements can be configured so that time-of-flight information of the returned light pulse can be measured from signals produced by the pixel array, in response to the returned modulated portion of the light pulse.

3D imaging system and method

Imaging systems and methods are disclosed that use multiple illumination pulses to irradiate a scene of interest. An example system includes optics to receive a sequence of returned light pulse portions scattered or reflected from the scene. A modulator is configured to modulate the intensity of the returned light pulse portions to form a sequence of modulated light pulse portions. A means of selectively exposing a sensor during a sequence of exposure periods is also included, so that each modulated light pulse portion is received by the sensor during one of the exposure periods, respectively. The sensor is configured to generate a sequence of sensor signals as a result of receiving the modulated light pulse portions and to accumulate the sensor signals to form a sensor output signal. A processor may read the sensor output signal and process the image based on that signal.

System and method of imaging using multiple illumination pulses

An electro-optic modulator (EOM) includes a first electro-optic (EO) material configured to receive light. The first EO material has an optic axis that is not parallel to the optical axis of the EOM. The optic axis indicates the direction through the first EO material along which a ray of light passing through the first EO material experiences no birefringence. The EOM also includes a polarization rotator that receives light output from the first EO material. The rotated light passes through a second EO material. The second EO material is positioned in the EOM such that its optic axis is not parallel to the optical axis of the EOM. The second EO material compensates for the birefringence and/or higher-order optical effects of the first material, thus reducing optical transmission errors of the EOM. The EOM may provide a wider field of view for imaging systems.

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Carlsbad, CA, United States of America

Bodo Schmidt