LiDAR Lens Assembly for External Light Noise Filtering
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Solution Overview
Problem
Existing LiDAR devices face challenges in reducing noise caused by external light, which affects the accuracy and distance measurement capabilities.
Innovation Solution
A lens assembly is designed with multiple lens and gap layers, along with a filter layer, to distribute lasers to different detectors while minimizing noise from external light, utilizing specific central wavelengths and bandwidths to separate light signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a lens assembly with multiple lens layers and gap layers is used to distribute lasers to different detectors, then the measurement precision and accuracy are improved, but the device complexity increases
Solution Approach 1:
The lens assembly is divided into multiple lens layers (first lens layer, second lens layer, third lens layer, fourth lens layer) separated by gap layers. Each lens layer focuses light at different positions, enabling spatial separation of laser wavelengths and distribution to different detectors. This segmentation allows the system to achieve high measurement precision by resolving multiple wavelengths simultaneously while managing complexity through modular layering.
2Measurement precision
If a filter layer is added to reduce noise from external light, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
A filter layer is extracted and positioned within the first gap layer of the lens assembly. This filter layer selectively transmits laser wavelengths while blocking external light noise, thereby improving the signal-to-noise ratio. By integrating the filter function into a separate layer rather than attempting to achieve wavelength separation through lens geometry alone, the system enhances measurement precision while maintaining a manageable structural complexity.
3Adaptability or versatility
If the bandwidth of the filter layer is increased to cover more wavelengths, then the adaptability is improved, but the measurement precision may deteriorate due to reduced wavelength discrimination
Solution Approach 1:
The system uses multiple lens layers with different focal positions to spatially separate different laser wavelengths before they reach the filter layer. This preliminary segmentation by the lens layers enables the filter layer to maintain a broader bandwidth for wavelength coverage while still achieving precise wavelength discrimination through the combined effect of spatial separation and spectral filtering. Each lens layer contributes to directing specific wavelength ranges to appropriate detection zones.
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 enhances the accuracy and measurement distance of LiDAR devices by effectively filtering out noise from external light, improving the precision of distance and location detection.
Implementation Method 1
a filter layer located in the first gap layer... the filter layer is designed to have a first central wavelength for a light incident on the filter layer at the (0) degree, a second central wavelength for a light incident on the filter layer at the (a) degree, and a third central wavelength for a light incident on the filter layer at the (b) degree
Implementation Method 2
the second lens assembly is configured to distribute the plurality of lasers to the at least two detectors... at least four lens layers including a first lens layer, a second lens layer, a third lens layer and a fourth lens layer
Data Source
AI summary
Proposed is a light detection and ranging (LiDAR) device. The device may include i) a transmission module including a laser emitting array configured to emit a plurality of lasers at a first wavelength, and ii) a first lens assembly configured to steer the plurality of lasers at different angles within a first angle range. The device may also include a reception module including i) a laser detecting array that includes at least two detectors for detecting at least a portion of the plurality of lasers, and ii) a second lens assembly configured to distribute the plurality of lasers to the at least two detectors. The second lens assembly may include i) at least four lens layers including first to fourth lens layers, ii) at least two gap layers including first and second gap layers, and iii) a filter layer located in the first gap layer.