Multi-Energy X-Ray Inspection for High-Speed Foreign Material Detection

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Solution Overview

Problem

As the transport speed of articles increases, the X-ray inspection accuracy decreases due to reduced X-ray irradiation time, leading to insufficient inspection accuracy.

Innovation Solution

An X-ray inspection apparatus and method that uses a control unit to generate and process transmission images using electromagnetic waves in different energy bands, applying a subtraction process based on luminance distribution of the background to correct image brightness and generate a difference image, thereby enhancing inspection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transport speed of the article is increased, then the productivity is improved, but the inspection accuracy is reduced due to shorter X-ray irradiation time

Engineering Contradiction:
Improvetransport speedVSAvoidinspection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the energy band parameter of X-rays by using multiple sensors sensitive to different energy bands (first energy band and second energy band). This allows the system to perform multi-energy analysis that is insensitive to irradiation time, thereby maintaining inspection accuracy even when transport speed increases and irradiation time decreases.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a new dimension of energy band analysis by comparing X-ray transmission in multiple energy bands. Instead of relying solely on transmission intensity (single dimension), the system analyzes the spectral characteristics across different energy bands (multiple dimensions), enabling accurate foreign object detection even with reduced irradiation time.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the transport speed of the article is increased, then the productivity is improved, but the X-ray irradiation time becomes shorter leading to insufficient inspection accuracy

Engineering Contradiction:
Improvetransport speedVSAvoidX-ray irradiation time
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The system changes from single-energy to multi-energy X-ray analysis by using sensors with different energy band sensitivities. This parameter change enables the inspection to be completed accurately in shorter time because the multi-energy comparison method is more efficient at identifying foreign objects than traditional single-energy transmission imaging.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multi-energy band X-ray analysis is performed, then the inspection accuracy is improved, but the device complexity increases due to multiple sensors and image processing

Engineering Contradiction:
Improveinspection accuracyVSAvoidsensor unit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor unit is designed with multi-functionality by incorporating sensors that can detect X-rays in multiple energy bands. Each sensor serves dual purposes: detecting transmission intensity for basic imaging and detecting energy-specific characteristics for foreign object identification. This universal design reduces the need for separate dedicated sensors for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of multiple sensors with different energy band sensitivities into a single integrated sensor unit. The control unit combines the detection results from both sensors to generate transmission images and perform foreign object detection, reducing overall system complexity compared to using completely separate inspection systems for each energy band.

Inventive Principle:
Principle #5Merging (Combining)

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 method prevents a reduction in inspection accuracy by ensuring high-accuracy energy analysis even at increased transport speeds through image processing that corrects luminance distribution and generates appropriate difference images.

Implementation Method 1

an electromagnetic wave sensor configured to detect the first electromagnetic wave and the second electromagnetic wave emitted to the article

Methodology Applied
Scientific EffectX-ray detection: X-Ray

Implementation Method 2

an electromagnetic wave irradiation unit configured to irradiate the article with a first electromagnetic wave in a first energy band and a second electromagnetic wave in a second energy band higher than the first energy band

Methodology Applied
Scientific EffectX-ray irradiation: X-Ray

Data Source

PatentEP4191237B1X-ray inspection apparatus, x-ray inspection system, and x-ray inspection method
Publication Date: 2025.08.20 ISHIDA CO LTD
  • EP4191237B1 patent drawingFigure 1
  • EP4191237B1 patent drawingFigure 2
  • EP4191237B1 patent drawingFigure 3A~3B

AI summary

An X-ray inspection apparatus includes a transport unit configured to transport an article, an electromagnetic wave irradiation unit configured to irradiate the article with a first electromagnetic wave in a first energy band and a second electromagnetic wave in a second energy band, an electromagnetic wave sensor configured to detect the first electromagnetic wave and the second electromagnetic wave, and a control unit configured to receive an input of a detection result. The control unit is configured to generate a first transmission image based on a detection result of the first electromagnetic wave and a second transmission image based on a detection result of the second electromagnetic wave, to perform image processing including a subtraction process on the first transmission image and the second transmission image, and to determine whether or not a foreign material is included in the article on the basis of a difference image.