Diffuser Plate Measurement for Specular Curved Surface Inspection
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Solution Overview
Problem
Existing inspection devices face challenges in achieving high accuracy when measuring vehicle body surfaces with varying normal directions and curvatures due to the specular reflection of light from regions with different orientations.
Innovation Solution
A measuring apparatus with an illuminator and a diffuser plate that diffuses light beams to illuminate the surface, combined with a light receiver to capture specular reflections, adhering to specific distance and angle conditions to ensure accurate measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple light sources are used to illuminate all regions of the object surface, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by using a single light source with a diffuser plate that creates directionally controlled diffused light. Instead of uniformly illuminating all surfaces, the light is directed to specifically illuminate regions with normal directions within a predetermined angle range relative to the light receiver's optical axis. This localized illumination strategy ensures measurement precision for relevant regions while avoiding the complexity of multiple light sources.
Solution Approach 2:
The patent changes the illumination parameters by controlling the diffuser plate's properties and its distance from the light source. By adjusting the diffuser plate diameter, material, and position, the light distribution is optimized to illuminate only the necessary surface regions. This parameter control allows a single light source to replace multiple sources, reducing device complexity while maintaining measurement precision.
2Adaptability or versatility
If the light source is positioned to illuminate tilted surface regions, then measurement coverage is improved, but light reception accuracy deteriorates due to specular reflection
Solution Approach 1:
The diffuser plate serves as an intermediary between the light source and the object surface. It transforms the direct light into diffused light with controlled directionality. This intermediary element allows the light to reach tilted surfaces indirectly, maintaining the relationship between the light receiver and reflected light while expanding coverage to regions with normal directions within the predetermined angle range.
Solution Approach 2:
The patent introduces a spatial dimension constraint by defining a predetermined angle range relative to the optical axis of the light receiver. By controlling the illumination angle through the diffuser plate geometry and position, the system expands measurement coverage to tilted surfaces while maintaining light reception accuracy. The angle range acts as an additional dimensional parameter that reconciles coverage and precision requirements.
3Measurement precision
If a diffuser plate is introduced to control light direction, then light reception consistency is improved, but device complexity increases
Solution Approach 1:
The diffuser plate performs multiple functions simultaneously: it diffuses light to control directionality, defines the illumination angle range, and determines the measurement coverage area. This single component replaces what would otherwise require multiple light sources and complex positioning mechanisms, improving light reception consistency while actually reducing overall device complexity through functional integration.
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 highly accurate measurement of vehicle body surfaces by ensuring consistent light reception regardless of surface tilting, reducing the number of light sources needed and enhancing measurement precision.
Implementation Method 1
a diffuser plate to diffuse the light beam emitted from the light source to illuminate a surface of the object with a diffused light beam
Implementation Method 2
The light receiver receives reflection light specularly reflected from the surface of the object illuminated by the illuminator
Data Source
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AI summary
A measuring apparatus (1) includes an illuminator (11) and a light receiver (12). The illuminator (11) includes a light source (13) to emit a light beam to an object conveyed in a conveyance direction; and a diffuser plate (14) to diffuse the light beam emitted from the light source (13) to illuminate a surface of the object with a diffused light beam. The light receiver (12) receives reflection light specularly reflected from the surface of the object illuminated by the illuminator (11). A conditional expression below is satisfied: L1>L2 where L1 denotes a distance between the light source (13) and the diffuser plate (14), and L2 denotes a distance between the diffuser plate (14) and the surface of the object.