Display Defect Detection via Feature Amount Analysis
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Solution Overview
Problem
Current display device manufacturing technologies face challenges in detecting defects during the process, particularly in large-sized liquid crystal display elements, where defects may require line stops or repairs, and existing methods do not effectively determine whether defects can be repaired or if the manufacturing line needs to be stopped.
Innovation Solution
A defect detection method and apparatus that measure feature amounts in partial regions of display devices, calculate differences with peripheral regions, and determine defect density to decide whether to stop the manufacturing line based on threshold values, allowing for identification of defective areas and determination of repair feasibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a roll-shaped flexible substrate is used to reduce apparatus cost and running cost, then manufacturing cost is reduced, but the manufacturing line must be stopped when fatal defects are generated
Solution Approach 1:
The patent applies preliminary action by performing defect detection during the manufacturing process rather than after completion. The detection apparatus identifies defects in real-time on the roll-shaped substrate, allowing for early intervention before defects propagate or require complete line shutdowns for repair.
Solution Approach 2:
The patent introduces an intermediary defect detection apparatus as a mediator between the manufacturing process and quality control. This apparatus continuously monitors the substrate during production, enabling distinction between repairable and non-repairable defects without stopping the manufacturing line.
2Measurement precision
If defect detection is performed with high accuracy using line sensor, then detection precision is improved, but it cannot determine whether defects require line stop or repair
Solution Approach 1:
The patent applies local quality by performing defect detection at multiple locations across the substrate surface. The detection apparatus measures feature amounts in different partial regions and compares them to determine both presence and severity of defects, providing localized quality assessment rather than uniform detection.
Solution Approach 2:
The patent uses parameter changes by measuring multiple feature amounts (such as luminance, color, or other optical properties) and comparing variations in these parameters across different regions. By analyzing changes in these parameters, the system can distinguish between repairable defects and those requiring line shutdown.
Data Source
AI summary
A defect detecting method of a display device includes a defect counting process that measuring a feature amount for each partial region of a display device (P32), and counting regions which is determined as a defective portion based on the measured feature amount of the region (P36), a process that stopping a manufacturing line of the display device when a number of defects counted at the defect counting process is greater than a first threshold value (P38, P42), a defect density calculating process that calculating a defect density in a predetermined area when the number of defects counted at the defect counting process is smaller than the first threshold value (P38), and a process that stopping the manufacturing line of the display device when the defect density calculated at the defect density calculating process is higher than a second threshold value (P40, P42).