Spatial Light Modulator Lidar Camera for Adaptive Illumination

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Active imaging systems, such as lidar, face inefficiencies due to wastage of laser power in illumination, particularly in applications like foliage penetration and bathymetry, where light is scattered by intermediate clouds or saturated by water reflections, leading to noise and reduced signal returns.

Innovation Solution

A lidar camera system utilizing a spatial light modulator to selectively concentrate laser illumination on specific targets or mask out undesirable areas, optimizing power distribution and reducing noise by using a spatial light modulator to shape the laser beam and redirect power to areas of interest.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If laser illumination is distributed uniformly across the entire field of view, then complete scene coverage is achieved, but laser power is wasted on undesirable features such as foliage, clouds, and water surfaces

Engineering Contradiction:

Improvelaser power efficiencyVSAvoidillumination pattern adaptability

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent employs a spatial light modulator that can dynamically reconfigure the illumination pattern in real-time based on scene requirements. The SLM allows the system to adapt the laser beam shape from uniform distribution to focused patterns, enabling dynamic optimization of power distribution across different field of view regions during operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention applies local quality by concentrating laser illumination specifically on regions of interest (such as ground targets through foliage gaps) while reducing or eliminating illumination on undesirable features. This selective illumination approach optimizes energy utilization by directing power only where needed rather than uniformly across the entire scene

Inventive Principle:

Principle #3Local quality

2Measurement precision

If laser power is increased to penetrate foliage and reach ground targets, then signal return from ground targets improves, but noise from intermediate foliage increases

Engineering Contradiction:

Improveground target detection accuracyVSAvoidfoliage scattering noise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the field of view into multiple regions with different illumination requirements. By using the spatial light modulator to create distinct illumination zones, the system can selectively illuminate gaps in foliage while leaving dense foliage regions dark, thereby reducing scattering noise from intermediate foliage while maintaining detection capability for ground targets

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention converts the natural gaps in foliage structure from obstacles into beneficial pathways for laser penetration. By analyzing the scene and identifying gaps through which light can reach ground targets, the system directs illumination through these natural openings, transforming the foliage structure from a noise-generating obstacle into a transmission channel

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If laser illumination is directed at water surfaces for bathymetry measurement, then water depth information is obtained, but intense reflections saturate the camera sensor

Engineering Contradiction:

Improvewater depth measurement accuracyVSAvoidsurface reflection saturation

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating spatially varying illumination patterns that adapt to different surface types. For water surfaces, the system reduces direct illumination angles that cause specular reflections while maintaining illumination on adjacent non-reflective regions, thereby preventing sensor saturation while preserving bathymetry measurement capability

Inventive Principle:

Principle #3Local quality

4Illumination intensity

If conventional optics are used to reshape beam profiles, then beam shaping is achieved, but system size, weight and power increase

Engineering Contradiction:

Improvebeam profile controlVSAvoidsystem weight

Core Design Contradiction:

Illumination intensityVSWeight of moving object

Solution Approach 1:

The patent replaces conventional mechanical/optical beam shaping components with a spatial light modulator that uses electro-optic or acousto-optic effects to reshape the laser beam. This substitution eliminates the need for heavy conventional optics while achieving the same or superior beam profile control, thereby reducing system weight, size, and power consumption

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS10557923B2Real-time processing and adaptable illumination lidar camera using a spatial light modulator

Publication Date: 2020.02.11 THE GOVERNMENT OF THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY DEPARTMENT OF HEALTH & HUMAN SERVICES

AI summary

An apparatus for illuminating or masking an object and a method of using same. The apparatus includes a spatial light modulator transmitting, a structured pulsed laser beam from a pupil plane to at least one image plane in a field of view. The apparatus further includes a lidar detector receiving reflected laser beam reflected from the at least one image plane. For example, the lidar detector detects range, position, and/or time data for at least one object of interest or at least one object of disinterest. Using the detected data, the spatial light modulator illuminates object of interest or masks an object of disinterest, depending on a user's application.