Range Imaging Apparatus Using Segmented Optical Beam Stripes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current range imaging apparatuses face inefficiencies due to low irradiance resulting in poor signal-to-noise ratio, primarily caused by flood or diffuse illumination methods.
Innovation Solution
The apparatus employs a semiconductor laser transmitter generating optical pulses with multiple parallel stripes, which are directed to specific single photon avalanche detector elements, improving irradiance and signal-to-noise ratio by concentrating optical power on a minimum number of detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If flood or diffuse illumination methods are used, then the field of view is fully illuminated, but the irradiance is low resulting in poor signal-to-noise ratio
Solution Approach 1:
The patent segments the optical beam into multiple parallel stripes and directs each stripe to specific detector elements, rather than using uniform flood illumination. This segmentation concentrates optical power into discrete regions, increasing irradiance at targeted locations while maintaining comprehensive field coverage through multiple stripes.
Solution Approach 2:
The patent applies local quality by directing optical stripes selectively to specific detector elements based on spatial correspondence. Each stripe illuminates a corresponding region on the detector array, creating localized high-irradiance zones that improve signal-to-noise ratio at specific measurement locations rather than distributing power uniformly across all detectors.
2Measurement precision
If optical power is distributed across all detector elements, then the entire field of view is covered, but the signal-to-noise ratio deteriorates due to low irradiance per detector
Solution Approach 1:
The detector array is segmented into groups corresponding to different spatial regions, with each group receiving optical stripes from specific transmitter elements. This segmentation allows concentrated illumination of active detector regions while leaving other regions inactive or minimally illuminated, improving signal-to-noise ratio without sacrificing overall field coverage.
Solution Approach 2:
The patent introduces a spatial correspondence dimension between transmitter stripes and detector elements. By mapping specific stripe patterns to specific detector regions in a two-dimensional correspondence, the system achieves both localized high irradiance and comprehensive field coverage through coordinated activation of transmitter and detector subsets.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the signal-to-noise ratio and improves the accuracy of time-of-flight measurements, leading to more precise distance determination and 3D imaging.
Implementation Method 1
a semiconductor laser transmitter generating optical pulses with a plurality of parallel stripes of optical beams
Implementation Method 2
directed to specific single photon avalanche detector elements, improving irradiance and signal-to-noise ratio
Data Source
AI summary
A range imaging apparatus comprises a semiconductor laser transmitter, a receiver, and a data processing unit, a field-of-illumination of the semiconductor transmitter and a field-of-view of the receiver being overlapping. The receiver comprises single photon avalanche detector elements arranged two-dimensionally and operate in a Geiger mode. The semiconductor laser transmitter generates optical pulses repeatedly, a single optical pulse of the optical pulses being output as an optical beam with one or more stripes, which are parallel, one above another, and separate from each other. Each of the stripes of optical beams, which are reflected from objects within the field-of-view, illuminates a detector element configuration of the single photon avalanche detector elements. The data processing unit performs, synchronously with the optical pulses repeatedly generated, a selection of single photon avalanche detector elements of the detector element configurations in response to a generation of an optical pulse that illuminates one or more detector element configurations with the one or more stripes, and determines values corresponding to time-of-flights of said optical pulse based on electrical signals from the single photon avalanche detector elements of the selection for performing range imaging.