Dual-LED Illumination System with Adaptive Field Angles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging systems face challenges in providing adequate illumination with a wide field of view for close targets and sufficient illumination for distant targets, often requiring complex and costly optics, and suffer from cross-talk between illumination sources and inefficient illumination profiles.
Innovation Solution
A compact optical assembly with a dual-LED illumination system that includes a first and second illumination source, aperture, collimator, and microlens array, configured to provide different illumination fields of view, allowing for adaptive illumination with a wide FOV for close targets and a narrow FOV for distant targets, reducing size and cost while preventing cross-talk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a wide FOV illumination system is used for reading barcodes at short distances, then the field of view is improved, but the illumination is insufficient for targets at farther distances
Solution Approach 1:
The illumination system is divided into multiple independent illumination sources, each with its own collimating lens and microlens array. This segmentation allows each source to be optimized for specific illumination angles, enabling the system to provide both wide FOV for close targets and narrow FOV for distant targets simultaneously without compromise
Solution Approach 2:
Different regions of the illumination system are assigned different optical properties. Specifically, different microlens arrays with varying focal lengths are positioned at different locations to generate illumination beams with different divergence angles, matching the local illumination requirements of different target distances
2Adaptability or versatility
If multiple illumination sources are used to provide different illumination fields of view, then the adaptability is improved, but cross-talk between closely spaced collimating lenses creates parasitic illumination and reduces useful illumination power
Solution Approach 1:
The harmful cross-talk between illumination sources is extracted and eliminated by positioning each illumination source and its associated collimating lens in spatially separated optical paths. This physical separation prevents parasitic illumination while maintaining the ability to provide multiple illumination fields of view
Solution Approach 2:
Individual collimating lenses and microlens arrays serve as intermediary optical elements for each illumination source. These intermediaries precisely control the illumination beams, ensuring that light from each source follows its intended optical path without interfering with other sources, thereby preventing cross-talk and energy loss
3Volume of moving object
If compact imaging systems are implemented with internal illumination sources, then the size is reduced, but the power requirements and illumination performance become difficult to implement
Solution Approach 1:
Multiple illumination sources and their associated optical elements (collimating lenses, microlens arrays) are merged into a single integrated compact assembly. This consolidation achieves the desired compact size while maintaining the power efficiency and illumination performance of individual components through optimized spatial arrangement and shared structural support
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 efficient reading of targets at various distances with improved illumination efficiency and reduced system complexity, supporting high-performance machine vision applications with adaptable illumination profiles.
Implementation Method 1
a collimator element having a first collimating lens disposed along the first optical axis and a second collimating lens disposed along the second optical axes, the collimator element configured to receive the first illumination and the second illumination from the aperture element and further configured to collimate the first illumination and the second illumination
Implementation Method 2
a microlens array element having a first microlens array disposed along the first optical axis and a second microlens array disposed along the second optical axes, the microlens array element being configured to receive, at the first surface, the first illumination and the second illumination from the collimator element and further configured to provide, from the second surface, a first output illumination field and a second output illumination field
Data Source
AI summary
An optical assembly for illuminating at least one object appearing in a field of view (FOV). The optical assembly includes first and second illumination sources configured to provide first and second illumination to illuminate a target of the object. An aperture configured to collimate the first and second illumination and to provide the illumination to a dual collimator. The dual collimator is disposed to collimate the first and second illumination and to provide the first and second illumination to a dual microlens lens array (MLA). The dual MLA has microlens arrays configured to receive the collimated first and second radiation, to provide two illumination output fields, each output field having a different output illumination field angle.