X-Ray Inspection Geometry for Minute Metal Foreign Matter Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional X-ray inspection methods struggle to accurately detect minute metal foreign matters due to blurring caused by the finite width of X-ray radiation, especially when inspecting objects being conveyed, leading to reduced detection sensitivity and stability.
Innovation Solution
The X-ray inspection device and method involve setting specific distances and focal diameters to minimize blur, using a scintillator and imaging device configuration that reduces the influence of the X-ray radiation's focal diameter, and employing shielding to enhance imaging resolution and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance from the inspected object to the imaging device is increased to geometrically enlarge the shadow of minute metal foreign matter, then detection stability is improved, but detection sensitivity is lowered due to blur (penumbra)
Solution Approach 1:
The patent changes the geometric parameters of the X-ray inspection system by setting specific relationships between the focal diameter R, distance L1 from X-ray radiation device to inspected object, and distance L2 from inspected object to scintillator. By controlling these parameters to satisfy the formula (L1+L2)/L1 × R ≤ 1/6 × minimum diameter of defect, the system achieves both adequate shadow enlargement for stability and minimal blur for sensitivity.
2Measurement precision
If the scintillator is brought close to the inspected object to reduce blur width, then imaging resolution is improved, but it becomes difficult to maintain stable inspection due to conveyance requirements and operational constraints
Solution Approach 1:
The patent establishes specific parameter relationships that allow the scintillator to be positioned at an optimized distance from the inspected object. By controlling L2 (distance from inspected object to scintillator) and L1 (distance from X-ray radiation device to inspected object) to satisfy the formula, the system achieves minimal blur while maintaining operational stability for conveyed objects.
3Measurement precision
If the focal diameter of the X-ray radiation device is reduced to minimize blur, then detection precision is improved, but the X-ray radiation intensity decreases affecting inspection reliability
Solution Approach 1:
The patent optimizes the focal diameter R of the X-ray radiation device by establishing a specific relationship with the inspection distances L1 and L2. The formula (L1+L2)/L1 × R ≤ 1/6 × minimum diameter of defect allows selection of an appropriate focal diameter that minimizes blur while maintaining sufficient X-ray intensity for reliable inspection of conveyed objects.
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 approach allows for stable detection of minute metal foreign matters by reducing blur, achieving high imaging resolution and accurate inspection of conveyed objects.
Implementation Method 1
The imaging device 3 includes a scintillator 31 that emits fluorescence based on the incident X-ray dose and emits visible light
Implementation Method 2
An X-ray is radiated from the X-ray radiation device 2 to the inspected object 10, and the X-ray transmitted through the inspected object 10 is received by the imaging device 3. At this time, if a metal foreign matter 11 is mixed in the inspected object 10, the X-ray is absorbed and becomes a shadow at the portion
Data Source
AI summary
An X-ray inspection device includes: an X-ray radiation device configured to emit an X-ray toward an inspected object; a scintillator configured to convert an X-ray emitted from the X-ray radiation device and incident through the inspected object into visible light; and an imaging device including an optical unit configured to collect the visible light emitted from the scintillator, the imaging device being configured to receive the visible light. The X-ray radiation device and the scintillator are installed such that the following formula (1) is 30 μm or less, where L1 [mm] represents a distance from a radiation position of the X-ray radiation device to an installation position or a conveyance position of the inspected object, L2 [mm] represents a distance from the radiation position to the scintillator, and R [μm] represents a focal diameter of the X-ray radiation device: Formula (1): (L2−L1)×R/L1