Changsik Woo

Hello, I am a Senior Engineer with 9 years of experience in the WOLED Manufacture Inspection Process at LG Display Co., Ltd.

As an inspection process engineer, my goal is to achieve Full Automation of the Inspection Process through AI.

I am deeply interested in various research fields essential for making inspection process automated by using diverse types of images.

My key areas of focus include: (1) Image / Video Understanding, (2) Data-efficient Learning, (3) Neural Architecture Search.


Education
  • SungKyunKwan University
    SungKyunKwan University
    B.S. in Electronic and Electric Engineering
    Mar. 2010 - Aug. 2016
Work Experience
  • LG Display Co.,Ltd
    LG Display Co.,Ltd
    Senior Engineer of WOLED Manufacture Inspection Process
    Jul. 2016 - Present
Honors & Awards
  • Selected as Degree Dispatcher (@LG Display)
    2024
  • Selected as Core Employee (@LG Display)
    2023 - Present
Projects
Mura Defect Detection Automation via Anomaly Detection (PaDiM)
Mura Defect Detection Automation via Anomaly Detection (PaDiM)

Completed (setup in 2025)   Jul. 2023 - Jun. 2024

To detect Mura defect automatically, PaDiM, that is a type of Anomaly Detection, was tested.
1. [Feasibility Test] at now, Mura defect is currently only detected under manual inspection. But in previous process,
there is process of making screen images by camera. By using these images, test involved Image Download, Image Processing, Training & Modeling,
and Performance Verification. It is concluded that PaDiM will be good solution for automating to detect.
2. [Optimizing Image Processing] When taking an image in the previous process, images may be rotated or curved due to many reasons.
If these images are cut into same size and pattern without image processing, not only miss-detect will occur in the cut location,
but also over-detect will occur due to Black data. To improve this problem, a Python module for image processing was developed.
that module find edges through contour approximation, and rotation and curve are improved through perspective transform.
In conclusion, PaDiM Accuracy is improved. (OK Accuracy : 11% → 69% / NG Accuracy : 29% → 93%)

Mura Defect Detection Automation via Anomaly Detection (PaDiM)

Completed (setup in 2025)   Jul. 2023 - Jun. 2024

To detect Mura defect automatically, PaDiM, that is a type of Anomaly Detection, was tested.
1. [Feasibility Test] at now, Mura defect is currently only detected under manual inspection. But in previous process,
there is process of making screen images by camera. By using these images, test involved Image Download, Image Processing, Training & Modeling,
and Performance Verification. It is concluded that PaDiM will be good solution for automating to detect.
2. [Optimizing Image Processing] When taking an image in the previous process, images may be rotated or curved due to many reasons.
If these images are cut into same size and pattern without image processing, not only miss-detect will occur in the cut location,
but also over-detect will occur due to Black data. To improve this problem, a Python module for image processing was developed.
that module find edges through contour approximation, and rotation and curve are improved through perspective transform.
In conclusion, PaDiM Accuracy is improved. (OK Accuracy : 11% → 69% / NG Accuracy : 29% → 93%)

Defect Classification Automation through Trained Classification Model
Defect Classification Automation through Trained Classification Model

Completed   Jul. 2022 - Dec. 2022

There is camera inspection process in which pixel defects can be detected.
By using thumbnail images, classfication model was trained and applied at this process to classify different types of defects label including over-defect.
In conclusion, This model can be classified with 95% accuracy and over-detect can be improved by more than 70%.

Defect Classification Automation through Trained Classification Model

Completed   Jul. 2022 - Dec. 2022

There is camera inspection process in which pixel defects can be detected.
By using thumbnail images, classfication model was trained and applied at this process to classify different types of defects label including over-defect.
In conclusion, This model can be classified with 95% accuracy and over-detect can be improved by more than 70%.