Lidar Imager Using Spatial Light Modulator for Flexible Scanning
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Solution Overview
Problem
Current lidar imaging systems are inflexible, requiring mechanical adjustments for field of view changes and having fixed frame rates, with complex and costly automatic zooming capabilities, and numerous moving components.
Innovation Solution
A lidar imager utilizing a spatial light modulator (SLM) to scan a light beam across the scene without mechanical parts, allowing for reconfiguration and flexible operation by programming holograms for beam direction and field of view, enabling variable frame rates and resolutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mechanical scanning devices (rotating mirrors) are used to sweep the light beam across the scene, then the field of view can be adjusted, but the system becomes mechanically complex and expensive
Solution Approach 1:
The patent replaces mechanical scanning devices (rotating mirrors) with a spatial light modulator that uses programmable holograms to deflect the light beam. This substitution eliminates moving mechanical parts while maintaining the ability to adjust the field of view and scanning patterns through software control of the SLM device.
Solution Approach 2:
The patent changes the operational parameters of the light beam deflection by programming different holograms on the spatial light modulator. By modifying the holographic patterns, the system can dynamically adjust the field of view, scanning speed, and illumination patterns without any mechanical movement, resolving the contradiction between adaptability and mechanical complexity.
2Adaptability or versatility
If automatic zooming capabilities are added to change the field of view, then the system becomes more versatile, but the complexity and cost increase significantly
Solution Approach 1:
The patent replaces mechanical zooming mechanisms with a spatial light modulator that achieves field of view changes through programmable holographic diffraction. Different zoom levels are obtained by loading different holographic patterns onto the SLM, eliminating the need for mechanical zoom lenses or moving optical components.
Solution Approach 2:
The patent makes the field of view dynamically adjustable through software control of the spatial light modulator. The system can switch between different field of view configurations instantly by changing the programmed holograms, providing dynamic adaptability without mechanical movement or complex optical assemblies.
3Speed
If mechanical scanning components are used, then the light beam can be swept across the scene, but the frame rate is limited by the scanning frequency
Solution Approach 1:
The patent replaces the mechanical scanning mirror with a spatial light modulator that can change beam deflection angles instantaneously through electrical control. This allows the system to achieve much higher effective frame rates since the SLM can update holographic patterns at frequencies far beyond mechanical scanning capabilities.
Solution Approach 2:
The patent uses periodic updating of holographic patterns on the spatial light modulator to achieve high-speed scanning. By rapidly cycling through different holographic configurations, the system can sweep the light beam across the scene at very high frequencies, limited only by the SLM's response time rather than mechanical inertia.
4Measurement precision
If the system is configured for high resolution imaging, then the image quality improves, but the frame rate decreases due to mechanical scanning limitations
Solution Approach 1:
The patent replaces mechanical scanning with a spatial light modulator that can independently control the light beam position for each pixel location. This allows the system to achieve high resolution by programming precise beam deflection patterns while maintaining high frame rates through rapid holographic updates, breaking the trade-off between resolution and frame rate that plagues mechanical systems.
Solution Approach 2:
The patent segments the scanning process into independently controllable beam deflection steps controlled by individual holographic patterns. Each hologram can be optimized for specific resolution requirements while the rapid switching between holograms maintains high frame rates, allowing flexible trade-offs between resolution and speed without mechanical constraints.
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 SLM-based system simplifies mechanics, allows for easy reconfiguration, and flexible operation modes, enabling high-resolution, high-frame-rate imaging where needed, while reducing complexity and cost by eliminating the need for mechanical scanners.
Implementation Method 1
the scanning device comprises a spatial light modulator (SLM) configured to display holograms that deflect the light beam into different directions within the scene to be imaged
Implementation Method 2
the scanning device comprises a spatial light modulator (SLM) configured to display holograms that deflect the light beam
Implementation Method 3
a light sensor for receiving light reflected from the scene
Implementation Method 4
The range (distance) from the imaging apparatus to a point in the scene is measured by timing of the return of a pulse of light projected onto that point
Data Source
AI summary
A lidar imager for acquiring a range image of a scene comprises a light source for emitting a light beam, a scanning device for scanning the light beam across the scene and a light sensor for receiving light reflected from the scene. The scanning device comprises a spatial light modulator (SLM) configured to display holograms that deflect the light beam into different directions within the scene to be imaged.