Coded Pattern Projection Using VCSEL Arrays for Gap-Free 3D Imaging
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Solution Overview
Problem
Existing structured light illumination systems for 3D imaging and gesture recognition lack efficiency, brightness, and flexibility, and are limited by gaps between pattern features, which affect resolution and coverage.
Innovation Solution
The use of surface-emitting array technology, specifically VCSEL and RC-LED arrays, to generate coded sequences of structured illumination patterns, including stripe and spot patterns, with integrated microlens arrays and DOE masks to achieve full coverage and high resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional structured light illumination systems are used, then the system structure is simple, but the illumination efficiency and brightness are insufficient
Solution Approach 1:
The patent divides the illumination system into multiple independent VCSEL elements arranged in arrays, where each element can be independently controlled to emit structured light patterns. This segmentation enables higher illumination efficiency and brightness while maintaining manageable system complexity through modular design
Solution Approach 2:
The patent replaces traditional mechanical illumination systems with semiconductor-based VCSEL arrays, transitioning from mechanical to optical/electronic control. This substitution significantly improves illumination efficiency and brightness while reducing moving parts and mechanical complexity
2Reliability
If traditional illumination systems are used, then the system is easy to manufacture, but the reliability at high temperatures is poor
Solution Approach 1:
The patent utilizes the inherent properties of VCSELs and RC-LEDs that allow operation at elevated temperatures, changing the operational parameters of the illumination source. These semiconductor devices are specifically designed to maintain reliability at high temperatures, and while their integration adds manufacturing complexity, it enables superior thermal performance
3Speed
If conventional light sources are used, then the system is simple to operate, but the modulation speed is limited
Solution Approach 1:
The patent employs VCSELs and RC-LEDs that can be rapidly modulated at high frequencies to generate coded sequences of structured illumination patterns. This periodic switching capability enables high-speed modulation for applications like 3D imaging and gesture recognition, with the added benefit of being able to selectively activate different array elements to maintain operational simplicity
4Area of stationary object
If standard illumination patterns are used, then the pattern generation is simple, but the coverage has gaps between features
Solution Approach 1:
The patent uses arrays of individually addressable VCSEL elements to generate structured light patterns without gaps. By segmenting the illumination source into multiple controllable elements, the system achieves complete area coverage while maintaining the ability to create complex coded patterns through selective activation of array elements
Solution Approach 2:
The patent transitions from one-dimensional or simple two-dimensional patterns to fully populated two-dimensional arrays of light elements. This dimensional expansion allows complete coverage of the illumination area with the ability to create complex coded patterns by controlling individual elements across both spatial dimensions
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 approach enables the creation of efficient, bright, and flexible structured light illumination systems with high reliability, capable of operating at high temperatures and modulating at high rates, resulting in improved 3D imaging and gesture recognition capabilities.
Implementation Method 1
The light from an array of vertical-cavity surface-emitting laser (VCSEL) elements or resonant cavity light emitting diode (RC-LED) elements
Implementation Method 2
The light from an array of vertical-cavity surface-emitting laser (VCSEL) elements or resonant cavity light emitting diode (RC-LED) elements
Implementation Method 3
The array of light sources is configured with a microlens array or asymmetric optics to form patterns without gaps between pattern features
Implementation Method 4
A diffractive optical element (DOE) or mask is used to further define the structured pattern
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3
AI summary
A coded pattern projector apparatus comprises a surface-emitting array of emitters comprising a plurality of emitters where each of the plurality of emitters generates one of a plurality of optical beams in response to an electrical drive signal applied to a respective electrical input of each of the plurality of emitters. A first optical element projects each the plurality of optical beams generated by the surface-emitting array of emitters. A second optical element collimates the optical beams in a first dimension and diverges the optical beams in a second dimension such that the optical beams form at least one stripe patterns. A controller has a plurality of electrical outputs, each of the plurality of electrical outputs is connected to a respective electrical inputs of each of the plurality of emitters. The controller generating desired electrical drive signals that produce a desired coded stripe pattern.