Inspection Device for Moving Objects on Conveyor
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Solution Overview
Problem
Existing inspection solutions using laser profilometers face challenges in detecting and characterizing black and dark objects on black or dark conveyor belts, due to issues with laser beam containment and safety concerns.
Innovation Solution
A device comprising a lighting means that generates an illuminated strip with a width greater than 10 mm, delimited by clear parallel edges, and a detection means with a parallax angle between its optical axis and the lighting beam axis, allowing for effective detection and mapping of moving objects regardless of their color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser profilometer is used to detect objects on a conveyor belt, then measurement precision is improved, but device complexity and safety requirements increase due to laser beam containment needs
Solution Approach 1:
The patent extracts the illumination function from the measurement system by using a separate lighting means (LED bar) to create an illuminated strip on the conveyor belt, while the camera only performs detection. This separation eliminates the need for complex laser beam containment structures while maintaining height mapping precision through the parallax effect between the lighting and detection axes.
Solution Approach 2:
The patent introduces an intermediary illuminated strip on the conveyor belt surface as a reference plane. This strip serves as a mediator between the lighting source and the objects being measured, providing a consistent reference background that enhances detection precision without requiring complex laser containment mechanisms.
2Measurement precision
If a laser profilometer is used for inspection, then measurement precision is improved, but safety concerns and operational restrictions worsen due to laser exposure risks
Solution Approach 1:
The patent replaces the expensive and potentially hazardous laser source with an inexpensive LED-based lighting means. The LED bar creates sufficient illumination for precise detection without the safety risks associated with laser exposure, eliminating the need for protective measures while maintaining measurement precision.
Solution Approach 2:
The patent converts the potential harm of direct laser exposure into a beneficial diffuse illumination pattern. By using an LED bar that creates an extended illuminated strip rather than a concentrated laser beam, the system achieves precise measurement capability while the light is safely diffused across the conveyor surface, eliminating exposure risks.
3Measurement precision
If the illuminated strip width is reduced to increase resolution, then measurement precision is improved, but detection reliability worsens for dark objects on dark backgrounds
Solution Approach 1:
The patent applies local quality by creating an illuminated strip with specific width characteristics - narrow enough to provide resolution but wide enough to ensure reliable detection. The strip width is optimized locally on the conveyor surface to balance resolution and reliability, with the illumination concentrated in a controlled pattern that enhances contrast for dark objects while maintaining spatial precision.
4Device complexity
If incoherent light source is used instead of laser, then device complexity is reduced, but measurement precision may worsen due to beam focusing limitations
Solution Approach 1:
The patent substitutes the complex laser scanning mechanism with a simpler LED bar lighting means. The incoherent light from the LED bar is shaped into a focused illuminated strip pattern using optical elements, replacing the need for complex laser scanning electronics and moving parts while maintaining measurement precision through the geometric parallax relationship.
Solution Approach 2:
The patent transitions from the temporal scanning approach of lasers to a spatial illumination approach using an LED bar. Instead of scanning a narrow beam over time, the system illuminates an extended strip spatially, creating a continuous reference plane that simplifies the electronics while maintaining precision through the parallax geometry between the lighting and detection axes.
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 enables reliable detection and height mapping of dark or black objects, overcoming the limitations of laser profilometers while ensuring safety and reducing costs.
Implementation Method 1
at least one lighting means (4) providing a lighting beam (5) with a median plane or axis
Implementation Method 2
at least one detection means (7) having an optical axis or plane (AO) and an acquisition field (7')
Implementation Method 3
means (8) for processing and evaluating the signals or data provided by said at least one detection means (7)
Data Source
AI summary
The present invention relates to a device (1) for inspecting objects (2) moving in a flow (F) on a surface (3) moving in a direction (D), this device (1) comprising a lighting means (4) providing an illuminated strip (6) at the surface (3), a detection means (7) having an optical axis (AO) and, finally, a means (8) for processing and evaluating the signals supplied by the detection means (7) in order to detect the presence of the moving objects (2), map their height and/or determine their volume. This device (1) is characterised in that the median plane (PM) of the light beam (5) and the optical axis (AO) of the detection means (7) have an angle (AP) between them, in that the image of the illuminated strip (6) acquired by the detection means (7) has a width equal to at least three times the resolution of the means (7), and in that the lighting means (4) is configured in such a way that the illuminated strip (6) generated at the support surface (3) is delimited by two opposing straight parallel edges and has a sufficient contrast with respect to the non-illuminated zones (6′), regardless of the colour of the object (2).