Image Generator Comparison for Abnormality Inspection Without Defect Data

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Solution Overview

Problem

Existing inspection methods for determining the normality or abnormality of products require significant time, labor, and cost due to the variability of abnormal modes and the difficulty in obtaining diverse teaching data for machine learning discriminators.

Innovation Solution

An inspection method and device utilizing an image generator prepared by machine learning to fill missing regions in images with complementary images, followed by a difference analysis to determine normality or abnormality, eliminating the need for extensive training data on abnormalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a trained model built by machine learning is used as a discriminator for quality check, then inspection speed and automation are improved, but the accuracy depends on the availability of diverse teaching data showing various abnormal modes which are difficult and costly to obtain

Engineering Contradiction:
Improveinspection speedVSAvoidinspection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Instead of using a discriminator to directly identify abnormalities, the invention inverts the approach by using a generator to create normal images and comparing them with actual inspection images. The generator creates images of normal products, and the discriminator then identifies abnormalities by detecting differences between generated normal images and actual inspection images, eliminating the need for extensive abnormal teaching data.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention performs preliminary action by pre-training a generator model on normal product images before actual inspection. The generator is trained in advance to create realistic normal product images, which are then used during inspection to compare against actual images. This preliminary training on normal data alone enables the system to detect abnormalities without requiring pre-collected abnormal images.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If images of products with various modes of abnormalities are collected for machine learning training, then the discrimination accuracy is improved, but the time, labor and cost for preparing teaching data increase significantly

Engineering Contradiction:
Improveabnormality detection accuracyVSAvoiddata preparation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The invention inverts the traditional approach by training the generator only on normal product images rather than collecting diverse abnormal images. The generator learns to create normal images, and abnormalities are detected by comparing actual images against these generated normal images, eliminating the time-consuming process of collecting and preparing abnormal teaching data.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The generator creates synthetic copies of normal product images that can be used for comparison during inspection. These generated images serve as reference copies of what normal products should look like, enabling accurate abnormality detection without needing physical samples of every possible defect type.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If a discriminator is trained to recognize various abnormal modes, then the versatility of the inspection system is improved, but the device complexity and training data requirements increase

Engineering Contradiction:
Improveability to detect various abnormal modesVSAvoidtraining data preparation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention simplifies the system by inverting the training approach: instead of training a discriminator to recognize multiple abnormal modes directly, a generator is trained only on normal modes. This single training process provides universal adaptability because the generator learns the fundamental characteristics of normal products, enabling detection of any deviation from normality regardless of the specific abnormal mode.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The generator trained on normal images serves a universal function for detecting all types of abnormalities. Rather than requiring separate training for each abnormal mode, the single generator model provides multi-functional capability to detect any deviation from normal product appearance, simplifying the inspection system while maintaining versatility.

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

Data Source

PatentUS20250224349A1Inspection Method and Inspection Device
Publication Date: 2025.07.10 SHIMADZU CORP
  • US20250224349A1 patent drawing
  • US20250224349A1 patent drawing
  • US20250224349A1 patent drawing

AI summary

An image generator built by machine learning is stored in an image-generator storage section (31). The image generator receives an image having a missing region and fills that region with a complementary image. An inspection target image is stored in an image storage section (32). A missing-image generator (44) generates, from the inspection target image, a missing image (63) in which a region is missing, a window (62) having a specified shape and size being applied on the region. A complemented-image generator (45) generates a complemented image (65) having the region filled with a complementary image by inputting the missing image into the image generator. A difference acquirer (46) determines a difference (66) between the inspection target image and the complemented image. A determiner (47) determines whether the region is normal or abnormal by comparing the difference with a predetermined criterion.