Sorting Machine Illumination Assembly Mirror Box Radiance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current light guides and illumination assemblies for sorting machines suffer from non-uniform radiance and insufficient maximum radiance, which hinders effective imaging of commodities with varying reflectance.
Innovation Solution
The proposed solution involves a mirror box with elongate main mirror sections, a transmissive diffuser, and a shutter mechanism, which provides multiple reflections and controlled radiance, ensuring uniform and enhanced illumination by constraining light within the mirror box and using a diffuser for Lambertian-type diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a fluorescent tube is enclosed in a box with diffusing coating, then illumination is delivered through an aperture, but the radiance is not uniform across the viewable area
Solution Approach 1:
The mirror box is divided into multiple reflective surfaces (first mirror, second mirror, third mirror) that segment the light path and create multiple virtual images of the light source, distributing light more uniformly across the aperture
Solution Approach 2:
The mirrors create virtual copies of the light source through reflection, generating multiple images of the fluorescent tube that appear to originate from different positions, thereby uniforming the radiance distribution across the viewable area
2Illumination intensity
If a fluorescent tube is enclosed in a box with diffusing coating, then illumination is delivered through an aperture, but the maximum radiance is not large enough to accommodate all commodities to be sorted
Solution Approach 1:
Multiple reflected light paths from different mirror surfaces are merged and combined to converge at the aperture, accumulating light energy and increasing the maximum radiance output
Solution Approach 2:
The mirrors create multiple virtual images of the light source, effectively multiplying the light output without requiring additional physical light sources, thereby increasing maximum radiance
3Illumination intensity
If the internal surfaces of the box are coated with a diffusing white coating, then light is diffusely reflected from the aperture, but the radiance is not uniform and maximum radiance is insufficient
Solution Approach 1:
The diffusing white coating is replaced with a system of mirrors that use reflection instead of diffusion to control light distribution, achieving both uniformity and high radiance through optical geometry rather than material properties
Solution Approach 2:
The optical parameters of the illumination system are changed by introducing mirrors with specific reflective properties and geometric arrangements, transforming the light distribution characteristics without relying on diffusing materials
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
This configuration achieves more uniform and increased radiance across the field of view, accommodating commodities with different reflectance levels and ensuring clear signal distinction, thereby improving the sorting machine's imaging capabilities.
Implementation Method 1
a mirror box which defines a mirror cavity, which receives the light source therein, and includes an illumination aperture, in this embodiment an elongate aperture, from which illumination is delivered
Implementation Method 2
a transmissive diffuser which is located in the illumination aperture to render the illumination diffuse
Data Source
Figure 1~2
Figure 3~4
AI summary
A light guide (15) for delivering an illumination, in particular a reference or background illumination, the light guide comprising : a mirror box (21) which defines a mirror cavity (23), which receives a light source (19) therein, and includes an illumination aperture (25) from which an illumination is delivered; a transmissive diffuser (27) which is located at the illumination aperture to render the illumination diffuse; and a shutter member (41) which is movable into the cavity to obstruct the light source and provide for control of the radiance of the delivered illumination, whereby control of the radiance of the delivered illumination is determined by a position of the shutter member in the cavity.