SURFACE INSPECTION METHOD OF METAL BAND

• Main Author: TAKADA HIDEKI
• Format: Patent
• Language: English; Japanese
• Published: 22.02.2018
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a surface inspection method of a metal band capable of accurately and stably inspecting the presence or absence of a surface defect of a metal band by setting an efficiently appropriate inspection threshold value in the line for manufacturing multiple type or short length metal band (for example, a manufacturing line of a plated steel band)and even in the line for manufacturing the metal band significantly different particularly in properties of the surface.SOLUTION: An inspection method for performing a surface inspection of a metal band automatically collects an inspection image photographed by a predetermined pitch, and includes: a step of finding a gray value for each image with the inspection image as a gray image, a step of calculating and storing an average value and a standard deviation of the gray value for each metal band, finding the gray value for a plurality of metal bands so as to be compressed into a section of a predetermined range with respect to the standard deviation of the gray value and a step of setting a waveform amplitude threshold value (inspection threshold value) of the gray value of the inspection image for each section of the predetermined range of the standard deviation.SELECTED DRAWING: Figure 4 【課題】多品種または短尺の金属帯を製造するライン、特に表面の性状が大きく異なる金属帯を製造するライン（例えば、鍍金鋼帯の製造ライン）においても、効率的に適切な検査しきい値を設定して、金属帯の表面欠陥の有無を精度良く安定して検査することができる金属帯の表面検査方法を提供する。【解決手段】金属帯の表面検査を行う表面検査方法であって、所定のピッチで撮像した検査画像を自動的に収集し、前記検査画像をグレイ画像として当該画像ごとのグレイ値を求めるステップと、前記金属帯ごとに、前記グレイ値の平均値、標準偏差を算出し記憶するステップと、複数の金属帯についてグレイ値を求めて、前記グレイ値の標準偏差について、所定範囲の区分にまとめて、当該標準偏差の所定範囲の区分ごとに検査画像のグレイ値の波形振幅しきい値（検査しきい値）を設定するステップとを備える。【選択図】図４