Time-of-Flight Depth Camera Low Resolution Detector
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-resolution depth imaging requires high-resolution detectors, which are complex and costly, whereas existing time-of-flight depth cameras struggle to achieve high resolution with low-resolution detectors.
Innovation Solution
A time-of-flight depth camera using a VCSEL array and optical arrangement to provide a limited number of distinct illumination patterns, which are detected by a low-resolution light detector, allowing for reconstruction of high-resolution depth images through a computer algorithm, leveraging compressible signal principles to reduce the number of required patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high-resolution detector is used to achieve high-resolution depth imaging, then the imaging resolution is improved, but the device complexity and cost increase
Solution Approach 1:
The illumination is segmented into multiple distinct patterns projected onto the target scene. Each pattern provides different spatial information that, when combined through computational algorithms, reconstructs high-resolution depth images. This segmentation of illumination patterns replaces the need for a high-resolution detector array.
Solution Approach 2:
Computational algorithms serve as an intermediary between the low-resolution detector and the final high-resolution depth image. The evaluator processes the limited detector measurements through reconstruction algorithms to generate high-resolution depth information, effectively mediating the resolution gap.
2Device complexity
If a low-resolution detector is used to reduce complexity and cost, then the device complexity is reduced, but the depth imaging resolution deteriorates
Solution Approach 1:
The system transitions from spatial resolution dimension (detector pixel count) to temporal dimension (number of illumination patterns over time). Instead of achieving resolution through multiple spatial detector elements, the system uses multiple temporal measurements with different illumination patterns, effectively trading spatial dimension for temporal dimension.
Solution Approach 2:
The system changes the illumination parameter (pattern type) across multiple measurements rather than changing the detector parameter (pixel resolution). By varying the illumination pattern parameter and collecting multiple measurements, the system recovers high-resolution information that would otherwise require a high-resolution detector.
3Measurement precision
If multiple distinct illumination patterns are projected to improve depth image quality, then the measurement precision is improved, but the measurement time increases
Solution Approach 1:
The system employs periodic projection of distinct illumination patterns in a structured sequence. Multiple patterns are projected in rapid succession, with each pattern providing complementary information. This periodic action allows the system to collect sufficient data for high-resolution reconstruction while maintaining efficient timing.
Solution Approach 2:
Multiple illumination patterns are projected in advance to collect all necessary measurement data before the final image reconstruction. This preliminary data collection ensures that all information needed for high-resolution depth imaging is gathered upfront, allowing for efficient post-processing without iterative measurements.
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
Enables high-resolution depth imaging with a low-resolution detector, reducing complexity and cost while maintaining high temporal resolution, by using a VCSEL array and optical arrangement to generate orthogonal projection patterns and reconstruct multipixel images from a small set of detected patterns.
Implementation Method 1
The time-of-flight depth camera comprises a VCSEL array, an optical arrangement, an evaluator and a light detector having at least one detector pixel. The VCSEL array or the optical arrangement are arranged to provide different illumination patterns
Implementation Method 2
The VCSEL array or the optical arrangement are arranged to provide different illumination patterns in a reference plane in a defined field-of-view of the time-of-flight depth camera
Implementation Method 3
The light detector is arranged to detect the different illumination patterns
Implementation Method 4
The evaluator is arranged to reconstruct a depth image of the field of view with a resolution of a predefined number of pixels P based on the detected different illumination patterns
Data Source
AI summary
A time-of-flight depth camera includes a VCSEL array, an optical arrangement, an evaluator and a light detector having at least one detector pixel. The VCSEL array or the optical arrangement are arranged to provide different illumination patterns in a reference plane in a defined field-of-view of the time-of-flight depth camera. The light detector is arranged to detect the different illumination patterns and the evaluator is arranged to reconstruct a depth image of the field of view with a resolution of a predefined number of pixels P based on the detected different illumination patterns. A number of the detected different illumination patterns N is at least 5% of the predefined number of pixels P, preferably at least 10% of the predefined number of pixels P and most preferred at least 20% of the predefined number of pixels P.