Defect outflow preventionProductivity improvementWorkload reductionYield improvementLead time improvementEfficiency improvementTwin IlluminationSurface defectsDefect detectionHigh accuracyOn-lineHigh speed

Detection of Minute Defects

Twin Illumination Surface Defect Detection Technique for High-Speed Lines

Enables on-line detection of minute defects (φ1 mm) that tend to be hidden by scale pattern, etc.

Solution Point

Possible to detect minute defects with high accuracy at high-speed lines such as pickling lines, cold-rolling lines, etc.,where detection had been difficult with conventional detection techniques.
Enables detection of defects even where scale pattern exists, hindering detection.
Enables on-line detection at high-speed (500 mpm) lines.
Reduces missed defects by achieving detection performance exceeding visual inspection.

Features 01

Expected Problems

・Are missed defects/over-detection a problem due to the difficulty of distinguishing defects and surface pattern a problem?

・Doesn't visual inspection place a high workload on operators?

・Doesn't visual inspection reduce efficiency?

・Isn't management/sharing of defect position information tedious and time-consuming?

Features 02

Technology highlight

・Uses the fact that pattern areas are flat, whereas dents and other surface defects have concave/convex shapes.

・Alternating illumination by 2 oblique light sources enables detection irrespective of the defect direction.

・Detection is possible by emphasizing only convex/concave defects with large differences in shadows by image difference processing.

・Defect information is digitalized by on-line automatic detection.

Features 03

Proposed Solutions (Examples)

JFE Steel supplies the detection mechanism and an integrated system capable of identifying the position of detects at a 1 meter interval for existing production lines (steel sheet, etc.) where surface inspection is necessary.

Links 01

Information related to this technology

Twin-Illumination Type High Accuracy Surface Inspection System for Flaw Detection

JFE Steel Introduces Industry’s first Image-based Technique for Detecting Surface Defects in Mill Scale Steel
—Achieves more accurate detection than visual inspection process—

Links 02