A time of flight based depth detection system is disclosed that includes a projector configured to sequentially emit multiple complementary illumination patterns. A sensor of the depth detection system is configured to capture the light from the illumination patterns reflecting off objects within the sensor's field of view. The data captured by the sensor can be used to filter out erroneous readings caused by light reflecting off multiple surfaces prior to returning to the sensor.

The disclosure discloses a Gm-APD array lidar imaging method under strong background noise, comprising following steps: respectively acquiring two sets of cumulative detection data of the Gm-APD array lidar at two different opening times of a range gate of the Gm-APD array lidar under strong background noise; respectively performing a statistic operation on the two sets of cumulative detection data of the Gm-APD array lidar with respect to all pixels, to obtain two cumulative detection result histograms of the Gm-APD array lidar; determining a range interval of the imaging target according to the two cumulative detection result histograms; and acquiring a lidar image by a peak discrimination method in the range interval of the imaging target. The Gm-APD array lidar imaging method according to the present disclosure is capable of improving the laser image quality by eliminating the interference of strong background noise in other range intervals.

Methods and systems for generating illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter control signals in a three-dimensional image-capturing system with one or more frequency synthesizers is disclosed. The illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter signal are all coherent with one another, being derived from a common clock source. The use of frequency synthesizer concepts allow for the use of rapid modulation phase changes for homodyne operation, and further allow the use of rapid modulation frequency changes to mitigate the effects of inter-camera interference.

Methods and systems for generating illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter control signals in a three-dimensional image-capturing system with one or more frequency synthesizers is disclosed. The illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter signal are all coherent with one another, being derived from a common clock source. The use of frequency synthesizer concepts allow for the use of rapid modulation phase changes for homodyne operation, and further allow the use of rapid modulation frequency changes to mitigate the effects of inter-camera interference.

A method and device for determining distances to a scene determines a laser light pulse width PW that is smaller than a maximum time of flight TOFmax corresponding to a maximum distance Dmax by using a pulse width reduction factor N such that PW=(TOFmax−TDL)/N wherein TDL is a predefined delay window, determines a pulse frequency FP such that FP≤1/((N+1)×PW+TDL), illuminates the scene with an illuminating pattern comprising a plurality of spatially separated pulsed laser beams having the determined pulse width and frequency, performs the detection as function of time during a detection time period TD divided in M=α×(N+1) consecutive detection time windows, with α≥1, such that TD=M×(PW/α), identifies in what detection time windows reflected laser light is detected, and calculates a distance to the scene based on this identification.

A method and device for determining distances to a scene determines a laser light pulse width PW that is smaller than a maximum time of flight TOFmax corresponding to a maximum distance Dmax by using a pulse width reduction factor N such that PW=(TOFmax−TDL)/N wherein TDL is a predefined delay window, determines a pulse frequency FP such that FP≤1/((N+1)×PW+TDL), illuminates the scene with an illuminating pattern comprising a plurality of spatially separated pulsed laser beams having the determined pulse width and frequency, performs the detection as function of time during a detection time period TD divided in M=α×(N+1) consecutive detection time windows, with α≥1, such that TD=M×(PW/α), identifies in what detection time windows reflected laser light is detected, and calculates a distance to the scene based on this identification.

A movable device includes a light deflector including a movable part rotatable about a predetermined axis; a mount including a pair of stationary parts to which the light deflector is secured; and a substrate attached to an opposite side of a light-deflector side of the mount. The substrate has a through hole between the pair of the stationary parts.

A movable device includes a light deflector including a movable part rotatable about a predetermined axis; a mount including a pair of stationary parts to which the light deflector is secured; and a substrate attached to an opposite side of a light-deflector side of the mount. The substrate has a through hole between the pair of the stationary parts.

An image recognition device includes a light source that emits lighting pulses to a measurement space, a image generator that generates a distance image based on reflected light acquired by a light receiving element, a reflectivity calculator that calculates a correction coefficient corresponding to a reflectivity for each measurement section, and a lighting pulse controller that controls a number of lighting pulses emitted from the light source according to the correction coefficient for each measurement section.

Techniques for adaptive scanning with a laser scanner include obtaining range measurements at a coarse angular resolution and determining a range gate subset and a characteristic range. A fine angular resolution is based on the characteristic range and a target spatial resolution. If the fine angular resolution is finer than the coarse angular resolution, then a minimum vertical angle and maximum vertical angle is determined for a horizontal slice of the subset of angular width based on the first angular resolution. The scanning laser ranging system is then operated to obtain second range measurements at the second angular resolution in the slice between the minimum vertical angle and the maximum vertical angle. In some embodiments, the scanning is repeated for each horizontal slice in the range gate subset using a minimum vertical angle and maximum vertical angle for that slice.