2-D Planar VCSEL Array for 3D Imaging
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Solution Overview
Problem
Current 3-D proximity sensing and imaging technologies are complex and costly, limiting their application to only a few areas due to the need for sophisticated optical sources, detectors, and processors, and they often require careful calibration, making them unsuitable for everyday use.
Innovation Solution
A lightfield optical source using a 2-D planar array of Vertical Cavity Surface Emitting Lasers (VCSELs) is developed, which generates a lightfield illumination pattern with low divergence and high intensity, allowing for accurate distance measurement and imaging by varying the diameter and intensity of scanning beams, and can be operated in programmable modes to adapt to different applications and ambient light levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sophisticated optical sources and detectors are used for 3-D imaging, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The optical source is segmented into a 2-D planar array of individual VCSELs, where each VCSEL can be independently controlled. This segmentation allows the system to achieve high measurement precision through selective illumination of specific regions while maintaining manageable device complexity by activating only necessary VCSEL elements for each measurement task.
Solution Approach 2:
The VCSEL array operates in programmable modes where individual VCSELs can be dynamically activated or deactivated based on measurement requirements. This dynamic control enables the system to adapt illumination patterns for different measurement scenarios, achieving high precision without requiring all VCSELs to operate simultaneously, thus managing complexity.
2Measurement precision
If high intensity light pulse is used for time of flight measurement, then measurement precision is improved, but use of energy increases
Solution Approach 1:
Instead of illuminating the entire field with high intensity, the system applies local quality by directing high intensity light pulses only to specific regions of interest using selectively activated VCSELs. This localized high-intensity illumination maintains measurement precision for target areas while reducing overall energy consumption by leaving other VCSELs inactive or operating at lower power.
Solution Approach 2:
The system uses partial action by activating only the necessary subset of VCSELs required for the current measurement task rather than operating the entire array at full intensity. This partial activation achieves sufficient measurement precision for the region of interest while significantly reducing total energy consumption compared to full-array operation.
3Adaptability or versatility
If VCSEL array operates in programmable modes with selective activation, then adaptability is improved, but device complexity increases
Solution Approach 1:
The VCSEL array is designed with universal programmable control that enables a single device to perform multiple functions across different applications. The same hardware infrastructure supports various illumination patterns and measurement modes, achieving high adaptability without requiring separate specialized systems for each application, thus managing complexity through multi-functionality.
Solution Approach 2:
The system achieves adaptability through parameter changes by modifying activation patterns, pulse timing, and intensity levels of the VCSEL array rather than changing physical hardware. These programmable parameter adjustments allow the same device to adapt to different measurement scenarios, maintaining versatility while avoiding the complexity of multiple specialized components.
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
The solution provides a cost-effective and versatile 3-D sensing, imaging, and scanning apparatus capable of accurate distance measurement and high-resolution imaging over a wide range, suitable for various applications without the need for complex calibration, by using a VCSEL array chip with programmable VCSELs and additional optical components for beam shaping.
Implementation Method 1
A plurality of Vertical Cavity Surface Emitting Laser (VCSEL) devices are configured in a 2-D planar array and emit radiation in a direction perpendicular to the substrate plane
Implementation Method 2
The radiation emitted from a VCSEL is a substantially symmetric circular beam having a very low divergence (narrow beam emission)
Data Source
AI summary
An apparatus and a method are provided for 3-D imaging and scanning using a 2-D planar VCSELs source configured as a lightfiled optical source. VCSELs are configured in different 2-D spatial arrangements including single VCSEL, or preferably a group, cluster, or array each to be operated effectively as an independent VCSEL array source. A set of microlens and an imaging lens positioned at a pre-determined distance collimates radiation from each VCSEL array source to a set of parallel beams. The parallel beams from different VCSEL array sources generated in a rapid pre-determined timing sequence provide scanning beams to illuminate an object. The radiation reflected from the object is analyzed for arrival time, pulse shape, and intensity to determine a comprehensive set of distance and intensity profile of the object to compute a 3-D image.