Magnetooptic Electron Gun Abnormality Detection

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Solution Overview

Problem

In the magnetic domain refining process for electrical steel sheets, the existing inspection techniques are unable to immediately detect abnormalities in electron guns, leading to reduced yield due to nonconforming products being continuously manufactured, as the detection process is time-consuming and requires offline sampling.

Innovation Solution

An electron gun abnormality detecting device and method that uses a magnetooptic element to inspect the magnetic domain structure of steel sheets and detect abnormalities in the electron guns, allowing for real-time inspection at points fewer than the number of installed electron guns, thereby controlling and adjusting the electron guns as necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional inspection techniques are used to detect magnetic domain structure, then inspection can be performed, but detection cannot be done immediately and requires time-consuming offline sampling

Engineering Contradiction:
Improvedetection accuracyVSAvoidinspection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical/offline inspection methods with a magnetooptic detection system that uses light interaction with magnetic domains. The magnetooptic element optically detects magnetic domain structure in real-time without requiring offline sampling, thus maintaining detection accuracy while eliminating time loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetooptic element as an intermediary between the magnetic domain structure and the detection system. This element converts magnetic domain information into optical signals that can be detected immediately, enabling real-time inspection without the time-consuming offline sampling required by conventional techniques.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If multiple electron guns are installed for magnetic domain refining, then processing capability is improved, but inspection points must equal the number of electron guns increasing complexity

Engineering Contradiction:
Improveprocessing capabilityVSAvoidinspection system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent makes the inspection system universal by using a single magnetooptic inspection point that can detect abnormalities from multiple electron guns simultaneously. The magnetooptic element detects the combined magnetic domain structure effect, allowing one inspection point to monitor multiple electron guns, thus improving productivity without increasing inspection system complexity.

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

Solution Approach 2:

The patent merges the inspection function for multiple electron guns into a single inspection point. By detecting the overall magnetic domain structure resulting from multiple electron gun operations, the system combines multiple inspection requirements into one unified detection process, maintaining high processing capability while simplifying the inspection system.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If offline sampling is used for inspection, then detection can be performed, but nonconforming products continue to be manufactured during detection delay

Engineering Contradiction:
Improvedetection capabilityVSAvoidyield
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent enables continuous real-time detection during the magnetic domain refining process. The magnetooptic element continuously monitors the magnetic domain structure as it forms, allowing immediate detection of abnormalities without stopping production. This continuous detection prevents nonconforming products from being manufactured during the detection delay inherent in offline sampling methods.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent performs detection immediately as the magnetic domain structure is being formed, before defective products complete the manufacturing process. The magnetooptic element detects abnormalities in real-time, allowing preliminary identification of issues before they result in nonconforming products, thus protecting yield without sacrificing detection precision.

Inventive Principle:
Principle #10Preliminary action

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 immediate detection of electron gun abnormalities, reducing the production of nonconforming products and increasing yield by allowing for timely intervention and adjustment of the electron guns, thus improving the efficiency of the magnetic domain refining process.

Implementation Method 1

a magnetooptic element that contacts with and separates from the inspection regions set to include boundaries of magnetic domain discontinuities generated by the plurality of electron guns irradiating the surface of an electrical steel sheet with electron beams, and that is capable of detecting the magnetic domain structure of the electrical steel sheet in the inspection regions as an optical property

Methodology Applied
Scientific EffectMagneto-optical effect: Magneto-Optic Effects

Data Source

PatentEP2902777B1Electron gun abnormality detector and electron gun abnormality detection method
Publication Date: 2021.08.25 JFE STEEL CORP
  • EP2902777B1 patent drawingFigure 1~2
  • EP2902777B1 patent drawingFigure 3
  • EP2902777B1 patent drawingFigure 4

AI summary

An electron gun abnormality detecting device 1 according to the present invention is the electron gun abnormality detecting device 1 that detects an abnormality in electron guns 3 of a magnetic domain refining device 2 for an electrical steel sheet, the magnetic domain refining device including a plurality of electron guns 3a, 3b, 3c, and 3d, and the electron gun abnormality detecting device 1 includes: a magnetooptic element 5 that contacts with and separates from inspection regions R1, R2, and R3 set to include boundaries of magnetic domain discontinuities "L" generated by irradiation of a surface of the electrical steel sheet with electron beams by the plurality of electron guns 3a, 3b, 3c, and 3d, and that is able to detect a magnetic domain structure of a steel sheet "S" in the inspection regions R1, R2, and R3; a light source 7 that irradiates the magnetooptic element with linearly polarized light; and a detector 12 that detects polarized light rotated by the magnetic domain structure of the steel sheet "S" transferred to the magnetooptic element 5.