VCSEL Light-Source Device Uniform Illuminance Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LIDAR systems using LEDs or LDs suffer from non-uniform illuminance across the irradiated surface due to aberrations in the projection optical system, leading to reduced accuracy in distance measurements.
Innovation Solution
A light-source device with a surface-emitting laser array and a projection optical system that includes a condenser lens and a projector lens, along with a microlens array, which adjusts divergence angles to achieve uniform illuminance across the surface, using VCSELs and microlenses with varying curvatures and refractive indices to correct for distortion aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a projection optical system is used to emit laser beams from an LED or LD, then the light can be directed toward the target object, but distortion aberrations occur causing non-uniform illuminance across the irradiated surface
Solution Approach 1:
The patent applies local quality by assigning different divergence angles to different regions of the light emitter. Specifically, the light emitter is divided into a first region and a second region, where the first region emits light with a first divergence angle and the second region emits light with a second divergence angle that is smaller than the first. This regional differentiation corrects the non-uniform illuminance caused by distortion aberrations in the projection optical system, as different regions compensate for the varying magnification rates across the optical field.
Solution Approach 2:
The patent employs parameter changes by varying the divergence angle of emitted light across different regions. The light emitter is designed to change the divergence angle parameter spatially - the first region has a larger divergence angle while the second region has a smaller divergence angle. This parameter variation compensates for the distortion aberrations in the projection optical system, achieving uniform illuminance distribution across the irradiated surface despite the optical aberrations.
2Area of stationary object
If multiple light emitters are used to improve coverage, then the irradiated area increases, but the complexity of the optical system increases
Solution Approach 1:
The patent applies merging by integrating multiple light-emitting regions with different divergence angles into a single light emitter component. Instead of using separate light emitters or complex optical correction elements for each region, the invention combines the first region and second region within one light emitter, allowing them to work together through the shared projection optical system. This reduces overall system complexity while achieving both wide coverage and uniform illuminance.
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 uniformity of illuminance, improving the accuracy of distance measurements by ensuring consistent light intensity across the irradiated area, thereby enhancing the performance of LIDAR systems.
Implementation Method 1
A light-source device with a surface-emitting laser array and a projection optical system that includes a condenser lens and a projector lens, along with a microlens array
Implementation Method 2
using VCSELs and microlenses with varying curvatures and refractive indices to correct for distortion aberrations
Implementation Method 3
a projection optical system that includes a condenser lens and a projector lens
Data Source
AI summary
A light-source device includes a plurality of light emitters; and a plurality of optical elements through which laser beams emitted from the plurality of light emitters pass. The plurality of optical elements includes: a first optical element configured to emit a laser beam of a first divergence angle; and a second optical element configured to emit a laser beam of a second divergence angle smaller than the first divergence angle.